Success in Africa: the Onchocerciasis Control Programme in West Africa, 1974-2002

WH0 l-ibrary (ataloguing-in-Publication Data Success in Africa: the Onchocerciasis Control Programme in West Africa, 1974-2002. 1. 0nchocerciasis - prevention and control 2. Regional medical programs - history 3. Program evaluation 4. Alrica, Western l. 0nchocerciasis Control Programme in West Alrica. lsBN 92 4 156227 7 (NLM classilication: WC 885) o World Health organization 2002 All rights reserved. Publi(ations 0f the World Health 0rganization (an be obtained trom Marketing ônd Disseminatron, World Health organization, 20 Avenue Appia, 1211 Geneva 27, Switzerland (tel: +41 22 791 2476; tax: +41 22 791 4857; email: bookorders@who.int). Requests for permis- sion to reproduce or translate WH0 publa(ations whether for sale or for noncommercial distribution - should be addressed to Publications, at the above address (lax: +41 22 791 4806; email: permissions@who.int). 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Pictures: All property of 0CP/AP0( Coordination: Abdulai 0aribi/0le Christensen Written by: Helen Syoum Design: l-isa Schwarb Printed in tranre tor any inquiries, please (onta(t: World Health 0rganization 20, Avenue Appia 12'l'l Geneva 27 §witzerland Tel.: +41 - 22 791 2111 in Africa: aa O CC [CIAS IS Suc The Cont in CCSS 0nch rol Programme West Africa, 197 4-2002 Abbleviations and acronyms AFRO WHO Regional Office for Africa AIDS Acquired Immune Deficienry Syndrome AP0C African Programme for Onchocerciasis Control IIS Biostatistics and Information Systems B.t Bacillus thuingiensis CDII Communi§-directed Treatment with Ivermectin CSA Committee of Sponsoring Agencies DDT Dichl.orodiphenyttrich[oroethane DEC Diethytcarbamazine (drug - kil.ts microfitariae) DNA Deoxyribonucleic acid EAC Expert Adüsory Committee EDAP Economic Development Adüsory Panel EDF European Development Fund EG Ecological Group EPI EpidemiotogicaI Evaluation Unit FAO Food and Agricutture Organization FED Fonds Européen de Développement HIV Human Immunodeficiency Virus HQ Headquarters IBRD International Bank for Reconstruction and Development JCC Joint Coordinating Committee JPC Joint Programme Committee I{acrofit (See 0CT) Macrofilaria AduLt 0nchocerca volvulus worm MDP Mectizan Donation Program }IDSC Multidisease Survei[ance Centre ltlectlzano Trade name for ivermectin liticrofi taria offspring of macrofi laria NGD0 Non-governmentaI Development 0rganization OCP Onchocerciasis Control Programme in the Volta River Basin area: Later renamed 0nchocerciasis Control Programme in ltlest Africa 0CCGE 0rganisation de Coordination et de Coopéntion pour [a Lutte contre les Grandes Endêmies OCT 0nchocerciasis Chemotherapy Project (renamed Macrofit) OI{CHOBIB OCP database 0NCHOSIii 0nchocerciasis simutation model OPEC Organization of Petroleum Exporting Countries ORSIOi| 0ffice de recherche scientific et technigue Outre-Mer (tater renamed Institut français de recherche scientifique pour [e développement) PAG Preparatory Assistance Mission to the Governments (of the initiat seven countries) PEI Planning, Evaluation and Tnnsfer Unit SAP Scientific Adüsory Pane[ STAC Scientific and Technical Adüsory Committee Suramin Drug with toxic side effects - kitts rnacrofitariae TDR UNDP/1rt/ortd Bank/ûlH0 Special Programme for Research and Training in Tropical Diseases UNDP United Nations Devetopment Programme UNICEF United Nations Chitdren's Fund U§ÂID United States Agency for International Development t{HO Wortd Heatth Organization I I) i I l I I Contents v Foreword vn Preface t lmagine s Onchocerciasis and Afilca, before the OcP z Knowing the enemy: Sickness, flies and worms 8 Pre-0CP time line s the disease 10 The parasite: 1nchocerca volvulus 12 The 'damned' black fly, Simuliun damnosum 13 Control: Larviciding and drugs 14 Ïhe effects of onchocerciasis 17 Science becomes practice: Planning control on a large-scale 21 Concentric circles: How the OCP worked 22 At the Core l: 0uagadougou Headquarters 25 At the Core ll: The Vector Control Unit - Aerial Operations and the Entomological Evaluation Network 25 Getting ready to spray 27 Aerial 1perations are go! 29 Larvicides 31 Are we getting it right? Entonological Evaluation 37 At the Core lll: The Epidemiological Evaluation Unit, later renamed Planning, Evaluation and Transfer Unit 41 The 1NCH1Sllrl model 42 Beyond the Core 4s Meeting the challenges: Conceptualising 0CPt history 46 Reinvasion 48 Resistance 50 lvermectin 53 0ver to you: Ihe process of Iransfer s7 looking back: Success in Africa 57 Achieving the objectives or'the hard facts file' 59 Some less tangible benefits: 59 A new dignity 60 'Afro-optimism' 62 Research and training 63 Flexibility in health care approaches 6s The future 66 Appendix 1 Donors to the Programme 67 Appendix 2 NGDOs associated with OCP 67 Appendix 3 Directors of the OCP 68 Appendix 4 ' Contributors to this history 6s Appendix 5 Lancet extract 71 Appendix 6 Geographic distribution of onchocerciasis 72 Appendix 7 Projected operational development: The Strategy Foreword The Onchocerciasis Control Programme in West Africa (OCP) has in many respects been a unique undertaking. OCP started off as a verttcal programme for the control o[ a single disease at a time when WHO Member Srar.es were eagerly embracing the concept of integrated primary health care. As could be expected, there was a greaL deal of hesitation, in certain quarters, to accepting such a deviation lrom the horizontal, integrated health development approach. Much credit is therefore due to those who, imbued with empathy for the sufferers of river blindness and its devastating manifestations, saw the potential for eliminating the disease as a public health problem through aerial larviciding, the only means o[ Iarge-scale control then available. Another aspect o[ the planned control operations was their potential for opening-up the previously deserted oncho-infested zones for socioeconomic development. OCP was one of the first disease conrrol programmes whose stated objective included promoting socioeconomic development. This broad vision ensured close collaboration with, and supporr [rom, such development agencies as UNDB the world Bank and FAo. OCP is one o[ the largest intercountry field operations ever undertaken by WHO and its close partners wirhin the United Nations family. The Programme stretched over I 200 000 km, ro prorecr 30 million people in eleven countries from the debilitating effects of river blindness. The operations in such a large aT ea tan smoothly with practi- caliy no problems of overflight across borders even in times o[ localized armed disputes. In the late 1980s control operations changed from exclusive vector control to larviciding combined with ivermectin treatment or, in some areas, to ivermectin treatment alone. This development increased substantially the involvement o[ the Participating Countries which today carry our on their own epidemioiogical surveillance/evaluation and organ- ize community-directed treatment with ivermectin (CDTI). OCP can be proud of haüng conducted with Merck 6c Co., Inc. the field trials that led to the approval o[ ivermectin as a means o[ onchocerciasis control and of haüng introduced the CDTI approach, which is increasingly found appiicable to the delivery of other health development activities. At the end o[ its operations, OCP leaves behind by far the largest part o[ its area freed from the threat of river blindness and the knowledge that the Participating Countries will be capable of coping with onchocerciasis recrudescence should it ever occur. Furthermore, detailed plans and financial means are available for time-limited continua- tion of control in a few foci where the entomologicaVepidemiological situation, although improving, srill requires special intervention to bring it to the same level as other parts of the Programme. I \Mas foflunate to be Director of oCP from 1980 to 1994. During this period, the Programme was faced with operational problems such as blackfly re-invasion and larvi- cide resistance which could have wrecked it. However, through joint efforts with the scienrific and research communities, solutions were found and control operations con- tinued unhindered. I continued to lollow closely the progress of the Programme since I became WHO Regional Director for Africa. On behalf of the Programme, I would therefore like to thank the Participating Countries for their close collaboration and the Donors for their unfailing financial assistance over more than a quârter of a century Merck Âz Co., Inc. deserve special thanks for their un- precedented gift of free ivermectin. The technical and scientific contributions from the Expert Advisory commirree and the Ecological Group have been of particular impor- tance to the success of the Programme, as has the collaboration with several Non- govemmental Development Organizations in the field of ivermectin treatment. Of course, without the devoted and hardworking OCP staff, river blindness would still be a major public health problem in West Africa. And to finish on an encouraging and highly satisfactory note, rhe conversion of OCp facilities into a Multidisease Surveillance Centre clearly demonstrates how a mono- disease control programme can gradually develop into a comprehensive public health institurion. Dr Ebrahim M. Samba Regional Director WHO Regional Office for Preface This publication brings together the experience of working with, and for, the Onchocerciasis Control Programme in West Africa (OCP), as recorded by many of those who, as staff members in Ouagadougou and in the field, contributed to the success o[ the Programme. Contributions v/ere also made by several others who came in contact with OCB members of the scientific and donor communities and representatives of the rural population who have benefited from the Programme. Bringing such disparate contribu- tions together in one coherent story presents to the reader a lively account of what can be achieved in the field of public health development when all concerned work togeth- er towards a common goal. The publication provides the reader with an understanding of riverblindness as a dis- ease and its impact not only in the field of health but also as an impediment to socioe- conomic development. lt describes how the Programme came about, how it implanted its structure and how it developed its activities over time. lt depicts its gradually increas- ing success in bringing the disease under control to the extent that onchocerciasis today is no longer a disease of public health importance or an impediment to socioeconomic development in West Africa. During this travel through the history of OCP with its tri umphs and problem-solving, the views and experience of those who contributed to the book attach a personal Ilavour to the factual account. The readership of this publication will first and foremost include those who are con- cemed with, or simply take an interest in, health development and the increasing under- standing of the important role of partnership, so clearly demonstrated by OCP I would like to take this opportunity to express my personal gratification in haüng been given the opportunity to serve OCP The Programme is coming to an end and all of us who have been involved with supporting OCP to rid West Africa of a debilitating public heaith and socioeconomic problem cannot but feel proud of having made a contribution to this African success. Dr Boa§e A. Boati Director, OCP :-FT+; ''iË..;r' 'kË-#r &§ffiW ètrIi;§w4ffi ilf

,",irr.IrynlFr, i; 'îî ,n ...there is something you (an do about It will be expensive, require dedication over a sustained period of time, necessitate intercountry cooperation on an unprecedented scale and fly in the face of current public health programmes for the developing world. ln 1974 the World Health Organization Iaunched the Onchocerciasis Control Programme in the River Voita basin area, (renamed the Onchocerciasis Control Programme in West Africa in 1986), designed to tackle just such a set o[ bio- logical, sociai and economic problems, and facilitate development. In 2002 the OCP comes to an end, hav- ing achieved its stated goal: to eliminate onchocerciasis as a signlficant public health and socioeconomic problem and ensure that the participating countries are capable of maintaining thls achieve- ment. Now, in large tracts of the sub- region of West Africa, children are no longer born facing the risk of blindness from onchocerciasls. Previously aban- doned land can be re-cultivated by com- munities able to support, among other things, schools and medical services on a new scale: looking to the future with bright eyes. it... Over the years, the OCP has created its own dynamic identity. It leaves a legacy, which, like the direct freeing of the land from a former scourge, will be increas- ingly appreciated, in the coming years. This book looks at the history of the programme and its legacles. It is based upon the experiences of the diverse people who have worked for and con- tributed to the programme, and those who have benefited from its implemen- tation. As you turn these pages, lemembel the impoilance of sight.

0mchorerciasis and Africôu before the OCP The numbers affected by the disease were once quite smail because of the relatively stable ecosystem in Africa and its sparse human population. This environmental harmony was subject to increasing dise- quilibrium from the second ha1[ o[ 19th century onwards. Sustained contact with Europeans and the demands of colonialism on the local people-forced population movements and unfamiliar agricultural pursuits-caused rapid changes in the bal- ance between pathogens and humans. Onchocerciasis did not figure among the diseases that the colonlal authorities sought to control. Unlike maiaria it failed to take hold of the European's bodies and imagination during their conquest of Africa. It missed the second wave of med- ical interest, i.e. diseases affecting indige- nous labour forces such as schistosomiasis and sleeping sickness, perceived to hinder productlvity. Colonial governments and private companies usually concentrated on economic growth, recruiting the healthy and isolating or ignoring the sick. Economic infrastructure generally came before healthy human resources. Medical aid. often delivered by missionaries. was essentially humanitarian. It might present an interesting medical puzzle but oncho- cerciasis did not figure on colonial health agendas because it affected the poorest of the poor, those at the end o[ the road, and beyond, in remote rural areas. In 1946, a spirlt of post-war international- ism created the United Nations. The spe- cialized agencies quickly followed and ushered in a new era determined to improve health and sponsor development, on the global sca1e. The World Health Organization and UNICEF were involved in iaunching large-scale disease control and eradication programmes. Vaccination against smallpox was ultimately successful although anti-tuberculosis and anti-malar- 'ia efforts were thwarted to some extent by technical, funding and administrative problems, but the dream of controlling pathogens remained potent. Alongside these global events, independent nation states gradually replaced European colonial rule in Africa. These major cultur- al shifts brought new aspirations and hetped alter the agendas and priorities of health and development. Countries could now seek technical support from the WHO and its sister agencies to control disease and prime social and economic development. The Onchocerciasis Control Programme in West Africa must rate among the most successful progenies of this changing world picture. Against this dynamlc and sometimes tur- bulent backdrop, what was the scientilic background to the OCP? How was a topic of scientific research transformed into a disease control programme? Life cycle of 0nchocerca volvulus Knowing the enemy: Sickness, flies and worms Put simply onchocerciasis means infection with a parasitic w0rm of the genus lnchocerca. Such a stark sentence does little to convey the human suffering caused by 0nchocerca volvulus, the species responsi- ble for the skin and eye lesions that have such devastating conse- quences. Other 1nchocerca parasites cause disease in animals often with significant economic consequences if not controlled (a situation that would eventually help with the human disease). L)nchocerciasis ts a cumulativc concli- tion. Unlike uralaria, lvhere a single bite [rom an inlèctir.'e mosqui.ttl can lead [o the discasc. onchoterciasis rcclt-tircs con- stant exposLrre over a long peritlcl. As shor,vrr het'e schematically', adr-rlt Onchoccrca volvtrlus worlns lit,e out their long livcs in hunrans ancl their oflspring, thc nricrofilariae, are transrnitted by black flies, ivl'rere tl-rey r.rndcrgo a ptrrt oI thcir li{c-cycle bcl'orc inlecting or incrcasir-rg the parasrte lrrad ol the next rrrrchrlccrciasis victim. Black flies nced trr hrced in lilst [l()\\ittg rintcr. in rivcrs ancl streams. to clrsLtre su[['rcie nt oxygcrl reaches thc larvae. This qaver rise to the Iarlrliirr narle 'river blincl- ness'. lt also provicled one ol two means of breaking the trzrnsmission c1'cle o[ the parasite irnd controlling the disease. One o[ the benefits o[ the OCP has been thc g,rcat increase in knowledge abc.rutt all aspects o[ onchoccrciasis. However, the iclea for control ar-rd tlie means tll i,rchieving it built Llpon â slou' accumlt- lation o[ knowledge frr.rrn 1875 rvhen the [irst report ol'micro[ilariae appearecl. Pre-OCP time line 1875 O'Nelll describes microfilariae taken from the skin 1893 tvtanson reporrs Leuckart's dis- covery o[ an adult worm, which he names Filaria volyulus 1899 t-aUaaie-Lagrave 6u Daguy describe an adult worrn as Filaria yolyulus 1901 Prout describes both adulr worrns and microfilariae in detail 1910 naiUiet Âr Henry re-classify worm from the genus Filana rc Onchocerca 1916 Robles connecrs adult worms with the parhology o[ oncho- cerciasis 1920 Uontpellier links onchocercal microfiiariae in the skin with skin lesions I926 Slacklock pror.es black flies transmit onchocerciasis 1932 Htsette links eye lesions with microfilariae 1935 Sandground proves African and Central American parasites are the same 1938 Strong, Hiseue, Sandground 6r Bequaert suggesr black fly control 1942 r.nzer lesrs Suramin as a micro/macro filaricide 1944 narter 6r Burch resr neosribosan as a micro/macrofilaricide 1945 nialey describes posterior eye lesions, the Hissette-Ridley fundus 1945 Wanson arremprs experimental use ol DDT ro conrrol black llies 1945 nalrchild 6zBan'eda destroy black fiy larvae over a I0 km stretch of river 1946 Stewart gains 100o/o mortaliry o[ larvae with DDT in the laborar.ory 1947 van Hoo[ shows Suramin lethal for adult worrns - a macrofilari- cide 1947 Carnham 6c McMahon use DDT against S. neavei in streams in Kenya 1948 llazzoui shows DEC kills micro- filariae but nor the adult \Morms 1949 uctvtahon 6r Garnham eradicate S. neavei and stop üansmission 1949 wanson, Courrois 6r Lebied try aerial larviciding (DDT) around Léopoldville The disease It was the skin lesions which first attract- ed attention. ln 1875, John O'Neill an Irish surgeon in the British Nary was working at Addah Fort (Ada Foa) Hospital in the Gold Coast (Ghana). His patients were suffer- ing from 'craw craw', a skin condition characterized by chronic lesions and an unbearable itching and often confused with scabies. O'Neill described 'craw craw' and the microscopic 'threadlike worms' he had found in the skin of his patients in the Lancet, but his work made little impact. An extract of his arti- cle is attached as Appendix 5. By coincidence, in the same year but on the other side of the world in Brazil, Dr da Silva Araujo made what was probably the same discovery. His patients were the descendants of African slaves. With increasing knowledge, countries in Central America and West and Central Africa would come to be identified as the endemic foci of onchocerciasis (please see the geographical distribution maps in Appendix 6). In Guatemala in 1917 Rodolfo Robles connected the presence of onchocercal nodules with eye lesions and loss of sight. He mistakenly believed the symp- toms were caused by toxins produced by adult worms and failed to appreciate the significance of the microfilariae. ln Africa there was a considerable lag in realizing that blindness also resulted from inlection with this worm, particu- larly among those working in the coun- tries of British West Africa. Ouzilleau mentioned in l92i that eye lesions were found in onchocerclasis patients, but it was not until ten years later that the par- asite was incriminated as a cause o[ blindness. Hisette's 1931 study in the Belgian Congo (DRC) prompted others to explore the extent and nature ol eye disease among those carryring the para- site of onchocerciasis. Ophthalmological studies in the Sudan (1935), the Gold Coast (Ghana) (1945) and Mexico (l-945) lent support to the idea that blindness was commonly associated with onchocerciasis. Slit lamp examinations revealed the presence of both anterior and posterior lesions in the eyes and Rldley suggested that tissue reactions to dead microfilariae caused the lesions and not the living worms. By the 1960s, a well-established sequence of pathologi- cal changes had been documented and scientists increasingly accepted that onchocerciasis was a blinding disease. Ihe Parasite: ùnchocerca volvulus After 1875, scientists in Africa and Latin America came across examples of the parasitic 'vr/orrn, as the general interest in tropical diseases and parasitology con- tinued to expand. They found both the microfilariae in the skin and the adult male and female coiled together in the skin nodules. In 1899, two French doctors Labadie- l-agrave and Deguy reported findlng a young female worrn in a nodule taken from a soldier who returned home after serving in Dahomey (Benin). lwo years later William Prout, an officer of the British West African Medical Service, also investigating skin nodules, described the adult male and female worms and the microfilariae in some detail, but he did not relate his findings to rhe micro- filariae of O'Neill. However, rhese early reports prompted other colonial doc- tors-British, French and German - to look for Onchocerca yolvulus (as it was renamed in 1910) in skin nodules. It became apparent from observations in central Africa and Guatemala during the l9l0s that although Onchocerca microfi- lariae were difficult to detect in the blood, they were easily found in the ly-ph nodes. In 1920, J. Montpellier and A. Lacroix suggested that these tiny worms were responsible for a particular itching condition common among Africans serving as native troops and linked it, correctly, with O'Neill's microfilariae. Emile Brumpt disputed this aetiology but he was fighting a losing battle, by the mid 1920s it was accepted that microfi lariae of Onchocerca were the cause. He also believed the African and Central American parasites belonged to two dif- ferent species. Again he was proved wrong, this time byJack Sandgrove, who in 1935 confirmed there was only one species. Putting together the clinical and para- sitologlr work provided the human half of the parasite's life cycle. Larval forms of the Onchocerca parasite introduced by the bite of the black fly penetrate and take up residence in the subcutaneous tissues just beneath the skin. From the outside it looks as if little happens. However, the worms develop and grow. After about three years the characteristic onchocercal nodules appear under the I I I I I { I : I I I : I (oiled male and female worms. skin. The body creates the nodules ln response to the presence of the parasite. Inside their fibrous capsule, coiled together, adult male and female worms live by taking their nourishment from the host's blood supply. And they repro- duce. Onchocerca worms are very effi- cient reproducers. Over the course of her reproductive life, lasting between nine and fourteen years the female worm produces a staggering 500 thousand to I million live embryos per year-the microfilariae-which cause the clinical symptoms o[ the disease. It is not surprising, glven these figures that heavily infected patients have between 50 and 200 million microfilariae Microlilarrae. in their skin, eyes and elsewhere in the body Each of the mlcrofilariae can live for about two years. With such para- site loads, the cumulative eflects o[ the parasitism begin to be appreciated. The 'damned' black lly z Simulium damnosum While the doctors and parasitologists lvorked towards elucidating the complex aetiology o[ onchocerciasis in humans, those with an interest in entomology sought the vector responsible for carry- ing the parasite from one person to the next. A range of possibie arthropods were incriminated and rejected when feeding experiments and subsequent dissections failed to find eüdence ol in[ection. ln 1923, Donald B. Blacklock rvorking at the Liverpool School o[ Tropical Medicine's laboratory in Sierra Leone, turned his attention to Simulium clamno- surn (the d.amned black lly). He reasoned that the absence o[ microfi- lariae in the bloodstream would mean the vector must sufficiently damage the skin to release and ingest mrcrofilariae during the search for a blood meal. By 1926 a series of dissections at appropri- ate intervals following controlled feeding experiments revealed larva ol Onchocerca yolvulus in the stomach, tho- rax and, after several moults, in the head of these flies. Here they waited coiled up in the proboscis, ready to be injected into the next victim. Others confirmed Blacklock's work elsewhere in Africa. Further research revealed that other species ol Simulium could also carry the parasite [or instance Simulium neqvei was identified as the vector in Kenya in 1940. ln what would become the OCP area of operations Simulium damnosum was identified as the vector, but it was also d.iscovered that there are severai different forms (cyto- tlpes) of this species, nine o[ which, in particular groupings, were significant in control operalions. l[ differentiation of the species was important., so too was understanding their behaviour and longevity. It is only the lemale black fly that transmits onchocerciasis. While the male flies leed exclusively on plant juices, the lemale needs a blood meal to feecl her eggs, which are laid in batches of 200 to 800 at a time in fast-flowing water, 80 to 150 cm per seconcl. I I I I I i I I t ( I i ( The eggs. coatccl u,lth ir stick) substauce, cling to irce brirnches, ltlarnt stcrns attcl rocks rn thc u,iite r pre lèrably abottL 5 cm bclou, the snrface and hatch alter' :lboul- trvo clal's and the lari'ae feecl by catcl-ring particles susl>cnciecl in thc rvaler. lt is this constilnt âllpel"itc that makes thent vr.rlnerablc to clisstrlvecl larvicicles spraved r)nLo thc \vater, up stream lront the breecling sites. mosquitoes ancl tn:,rlartzr the rnain thrust of tropical pr-rblic health campzrigns hacl been directed agarnst vectors. Various experiments mosil)' using DDT against the nclr-rlt flics n,ere attcl-npiecl ivithout too nruch sLlcccss. Attention the n tr-rrne d to the more vultterab[e ltin'ae. Li.tborirtory stuclics in I9+6 Control: larviciding and drugs Tcr control a parasitic disease such as onchocerciasis, u''ith its crtr.nplicated lile cy'cle invoh'rng 2 hosts-hltnrans ;rncl blach llies-the key thing is to break the c1,clc. Strong ct al. sr-rggestccl vcctor control in I938. Since the establishmettt ol'the vcc- tor/parnsite paracligr.n o[ tropical medi- cine in 1898 aftcr Ronald Rtrss'work ol-t confirmed that DDT had a 1007o morral- ity rate against larvae. Ground larviciding with DDT either from riverbanks or boars was tried in Kenya and aerial larviciding in the Belgium Congo (DRC) in the 1940s. These trials had promising resuhs but because DDT is a residual chemical that remains in the enüronment for some time it can build up in the food chain and affect non-target organisms. Aside from effecrively killing the larvae, the other attributes of DDT are undesirable and so although this work was significant it could not provide the complete solution. However, follow-up studies in Kenya, aflter about sixteen years, provided excei- Ient markers for the long-term benefits of larviciding among rhe human population. Preventing the breeding of black flies and halting transmission of the parasite unfor- tunately could nor help those who already had a sufficient parasite load to cause s)rmptoms of the disease. The best sorr of drug to help patienrs would be a macrofi- laricide, which killed all the adult rvorïns in the human body and their offspring, the micro[i]ariae. Before the OCP began, the only drugs available to treat onchocerciasis were suramin and diethylcarbamazine (DEC). Suramin had been used to treat sleeping sicl«ress or human try?anosomiasis. It was effective against the adult worms but had todc side effects especially on rhe kidneys and certainly could nor be given outside ol a medical cenrre by fully quali- fied staff. This made irs use highly impractical at besr, and not viable at all as part of a public health programme. DEC kills the microfilariae. However, ir does so in such huge numbers that it can accelerate the body's immune reaction against the dead microfilariae and quickly cause blindness. Known as the Mazzotti reaction, the intense response after taking DEC made this drug essenrially unusable, although very small doses could proüde a diagnostic test. taken in various countries in Africa, that the health and socio-economic effects of the disease were realized. When people began to attempt to evalu- ate the prevalence o[ onchocerciasis, often in very remote parts of West Africa, they found hyperendemic regions. This meant that 60 % or more of rhe population in the savannah carried the parasite. Blindness The effects of onchocerciasis Onchocerciasis - a disease o[ rural popu- lations- affects those at the furthest reaches from urbanised medical research. Those most at risk were often the most isolated and impoverished, traditionally the groups least iikely to beneflir from medical seryices. Gven the limited a\r/are- ness o[ the extent o[ onchocerciasis it was not until the mid-2Oth cenrury when larg- er epidemiological surveys were under- ran at 10o/o in the adult population (5006 of males over 40 years of age). Visual impairment affected up to a further 30olo and early signs of onchocerciasis were all too eüdent among the children. Lines of the blind, each holding a stick to link to the person in front and led by a child was a familiar sight, becoming an icon o[ the disease and ultimately the programme designed to control it. ln the forest areas similar rates of infection did not thank- fully lead to such high levels of blindness because of differences in the parasite and vector complexes. The now familiar pattern of desertion of the valleys, for the less fertile uplands, provided further grim images. For approximately 10 km from the river on either side empty roofless huts and untilled fields represented hunger and despair. If pressure on the poorer land became too great there might be some- thing of a reverce migration, bringing people into even greater contact with the flies and increasing the blindness rates. From the early days o[ the programme staff carry poignant memories of those blinded by onchocerciasis but striving to remain useful members of their commu- nities. On the river Koni, in the Bani basin, an OCP staff member spent the moming with a blind man and woman. They had been brought to a field by a child and spent the long day slowly pick- lng out the unwanted grass from between the millet, differentiating the rwo by the feel of their leaves. He stayed to help them and asked rhetorically what these people had done to deserve their fate. A similar experience occurred in the ü1- lage of Wayen in Burkina Faso. Here the blind men moüng forward on their hands and knees, or inching along on their buttocks, continually picked out the 'witchweed'a parasitic plant that attaches itself to the roots o[ crops such as maize, sorghum, millet and rice. When the area of the field was complete, it would be time to begin again. Blind women, unable to assist in the domestic running of the household, would scramble beneath the shea butter trees collecting the precious flruits used for cooking fas, lamp [uel, soap and cosmetics. These images, multiplied by the hundred thousand, \rÿere the human face of oncho- cerciasis. nooo'. lo Ml o o'50'E Pattern of populôti0n retreat in the Iebila area of North-[artern Ghana, between 1940 and 1960. .ù+s; Science becomes practice: 0na By the early 1960s, a few interested people amongst the small community of tropical medicine specialists had recognized that oncho- cerciasis was endemic across the savannah regions of West Africa. Planning control It blinded and caused severe skin problems at distressingly high levels, but research papers and monographs, though they represent elegant science and add to the accumulated sum of knowledge, are only part of the means of helping the afflicted. Bringing onchocerciasis to the attention of the world would take something out of the ordinary but help was on the way From the 1950s onwards, in Cameroon, a British Medical Research Council team studied various aspects of the epidemiol- ogy of onchocerciasis. The team developed the skin snip into a reliable quantitative tool for epidemiological investigations. It determined a means to measure the Annual Tiansmission Potential, the maxi- mum theoretical exposure of an individual to infection with the parasite. From its research it also became apparent that both the parasite and the fly existed in what could be broadly classed as '[orest' and 'savannah' complexes. Relatively speaking large-scale the savannah forms of the parasite caused greater levels of blindness in less heavily infected patients. Disease control ought therefore to prioritize the savannah form the team concluded. These results and methods would uitimately be fed into the vector control programme emerging t.o the west of Cameroon under the auspices of the French Government. In 1960, scientists attached to the French group ORSTOM (Office for Scientific and Technical Research Overseas) working with the OCCGE (Organization for Coordination and Cooperation in the Control of Major Endemic Diseases) decided to attempt to transform science into practice. Over a five- year period (1960-I965) their entomolo- gists conducted a series of pilot studies. They first tackled black fly breeding sites on one river: the Bougouriba in Burkina Faso. These experimental operations were then extended to the upper basin of the Black Volta River also in Burkina Faso and the Farako River in Mali. In 1966, with EDF (European Development Fund) sponsor- ship, a sti1l larger operation began, covering 60,000 km2 and involving three countries, Burkina Faso, Côte d'Ivoire and Malj. ln its increasing size. intercountry involvement and use ol donor aid, this bold project presaged the future. The ORSTOM, and OCCGE scientists were quickly turning into world authorities on the practical control of Simulium flies by larvi- ciding. Their demonslration of vector control did not go unnoticed. The lnitiatlve of Dr N. Ansari, Chief of Parasitic Diseases at the WHO, and probably the most well informed WHO staff member on onchocerciasis at that time, and Médecln Général Richet of OCCGE led to a meeting rn July 1968 in Tunis. The USAID, OCCGE and the WHO cosponsored event considered the feasibility of controlling onchocerciasis in the savannah reglon of West Africa using the best methods of the pilot project on a grand scale. The key conclusion of the conference was that yes, it was possible, from a technical point of r,rew, to attempt to deal wrth onchocerciasis by vector control. The method would be aerial spraying of a suitable non-residual larvicide targeted with the maximum possible preci- sion against known breeding sites of the Simulium flies. The most severely affected areas of Africa, found along the Volta river basin in Dahomey (Benin), Ghana, Côte d'Ivoire, Mali, Niger, Togo and Upper Volta (Burkina Faso) would receive priority Not least because the governments of these coun- tries recognized the need to improve the health o[ the population along these fertile riverine valleys before sustainable develop- ment could be contemplated. Things moved quickly In April 1969, a fur- ther meeting in Brazzaville under the aus- pices of the WHO Regional Office refined the like1y needs of such a programme. The interested governments sent out requests for financial assistance and technical support to bilateral and internatlonal agencies. In response to these requests, the World Bank, WHO and UNDP (already involved with a small WHO onchocerciasis project, similar to that of OCCGUORSTOM) held a plan- ning meeting in Geneva in July 1970. As a result the UNDP sponsored Preparatory Assistance Mrssion (PAG), designed to set out in fine detail, for the governments con- cerned, the strategy for an onchocerciasis control operation. WHO would act as the executive agerrcy, it was a health programme after a1l, but the FAO (Food and Agriculture Organization) would also be intimately involved. So severe was onchocerciasis in the region under review, the local people were unable to grow enough food to feed them- selves alter belng driven to the higher, less fertile plateaus by the spectre of onchocerci- asis. The Government of Upper Volta (Burkina Faso) agreed to host the PAG mission and a Headquarters was established at Ouaga- dougou in the centre of that country and in effect in the centre of the target savannah area. Already the cooperation so characterls- tic of the future OCP was in place. In addi- tion to crossing the national boundaries of the six other countries with the full co- operation of the relevant government authorities, the PAG mission scientists liased with other independent studies. Thus the entomological work being done in northern Ghana, the on-going work sponsored by FED (Fonds Européen de Développement) t ( I iI in the Comoé-Léraba reglon, OCCGE's onchocerciasis section at Bobo-Dioulasso and hydro-biologlcal work on Lake Volta were all incorporated into the findings of the PAG report. Moreover, the close advisory and monitonng role of WHO, FAO, IBRD and UNDP was strengthened when the lead- ing officers of these organizations decided to form a Steering Committee in April 1972 to oversee the complex role of their agencies in the proposed multl-partner project. This Committee met regularly during the dura- tion of the mission and contlnued its role, overseeing the prqect and devising an effec- tive and efflcient division of labour among the four sponsoring agencies for the life of the programme. The PAG was originally scheduled to last for twelve months but at the first sesslon o[ the Steering Committee in )t\y 1972, lt was agreed to extend the preparatory phase through to the end of 1973. This allowed a pilot prqect during the whole of 1973 to conduct operational research, lmproving aerial spraying tech- niques and producing reliable estimates of the funds needed to run the proposed pro- gramme. During these intense months potential routes for spraying were drawn up. Drug trials, using the limited range of filari- cides were also undertaken to determine what role chemotherapy might play in the programme. Epidemioiogists and entomolo- gists also collected baseline data, essential if proper assessment of the progress of the pro- gramme was to be made. If the 1966 prqect had been bold, the PAG mission was audacious. With hindsight, the report handed to the seven governments in November 1973 has proven to be a blueprint for success in Africa. It would be impossible to recount this success without mentioning the story of the chance üsit of the President of the World Bank, Mr Robert McNamara, to Bobo-Dioulasso in 1972. Afnca is famous for its stories, told with charm and wit by its sons and daugh- ters. Myths and legends are of course, part of all story telling. McNamara's emotional expe- rience flpng over the deserted nllages of Burkina Faso and Maii; meeting the exuber- ant French scientist René Le Berre, leader of the ORSTOM team; and seeing the human and economic devastation caused by onchocerciasis has taken on a mythical qual- ity in the history of the OCP Certarnly, he came to West Africa and, sufficrently con- vinced of the practicality of the programme being researched, pledged, for the first time, direct sponsorship by the Bank. McNamara saw, as the donors continued to, that the pro- gramme had real potential to change the lives of the poorest o[ the poor. The World Bank went on to open a Tiust Fund and set up an Onchocerclasis unit, with an officer responsl- ble for raising the money for the duration of the project. With the World Bank on board health and development were cleariy united. Ultimately the OCP would provide inspira- tion to the world. Followrng signature by the seven participat- ing countries of the operational agreement late in I973, the lour sponsonng agencies. WHO, UNDB IBRD and FAO, (each with clearÿ defined tasks and a voice on the Steering Committee) launched the Oncho- cerciasis Control Programme in the Volta River Basin Area in January 1974. Later, rn 1986 as the programme expanded, the name would be changed to the Onchocerciasis Control Programme in West Africa.

Concentric circles: The basic strategy of the 0CP, the blueprint for controlllng onchocerci- asis, called for a programme of aerial larviciding to kill the vulnerable larvae of the black fly. Done often enough-weekly, so that none of the larva develops to the pupal stage when they are no longer so vulnerable-transmission of the parasite to the human population would be interrupted. How the OCP worked If this interruption of transmission lasted longer than the Onchocerca worm lived in people, the disease would no longer be a problem of public health and socio- economic development. The best con- temporary estimate of the parasite's lifespan was between 11 and 18 years: the OCP would therefore last for 20 years pending review and further research. And, the OCP worked. Taken over the long term, as a health and development programme it has achieved its goals. But from day to day, or week to week, or year to year, the OCP func- tioned extremely well. Following a set routine, it also proved able to adapt to weekly changes in rainfall, logistical dif- ficulties caused by political disturbances or major technical problems such as re- invasion of black flies or their resistance to larvicides. In this section we look at how the OCP functiomd. Ir is like taking a horizontal slice through the history of the pro- gramme. The diagram beside provides an overview. Here the OCP is represented as a series of concentric circles, like radio waves, reaching out from the central Core - the programme area - across West Africa to the rest of the world. At the (ore l: Ouagadougou Headquailers At the Core of the OCP there were two overlapping circles - the first contained the activlties of the Headquarters in Ouagadougou and the second, the whole programme area. Initlally this covered the river basins of the seven participating countries (later expanded to eleven when the extension zones were added). This vast swath of West Africa was divid- ed into a series of sectors and sub-sectors where larviclding, entomological evalua- tion and epidemlological evaluation actually took place. As onchocerciasis is a rural disease, action against the disease must be in the field. As had been the case for the PAG mis- sion, the town of Ouagadougou, Burkina Faso, was chosen to be the location of the headquarters. Although a compound with purposely built offices would take shape during the 1970s, the programme began life in four rented villas. Life was hectic ln the flrst few months in Ouagadougou. If the programme's activ- ities were modified over time, the pace always remained the same. Not so fast that mistakes and carelessness crept in, but quick enough to ensure the maxi- mum amount of work was carried out, giving the donors value for money and the people of the riverine valleys hope. It was essential to establish the infra- structure for the programme. The HQ obviously housed the Office of the Director of the Programme who was responsible for coordinating general pol- lcy; maintaining relations with public health bodies; organizing the statutory meetings of the programme; producing reports and documentation lor these meetings, and ensuring that these were available in the correct language for the anglophone and francophone areas of the programme. In addition to work in Alrica, the Dlrector of the programme has always travelled, attending regular individual meetings with donors, representing the programme at \À.,T{O Headquarters in Geneva and at the World Bank in Washington, and erther hosting or attending meetings of the committees assisting the OCP Dr Jacques Pierre Zeigler, the first direc- tor and Mr Marc Bazin his successor were both from outside Africa. They performed their role with aplomb launching and developing the pro- gramme. Dr Ebrahim Malick Samba, the dy,riamic Gambian who took over as the programme's thirci director in 1980 1ed the trend towards Africanization from the highest 1evel. Dr Samba because of the changing fate of the programme made sure that he continued to present a positive public face as often as possible to all the interested parties around the world. A policy continued by his able successors Dr Kofi Yankum Dadzie and Dr Boakye Boatin, both of whom worked for the programme before becoming its director. An Admlnlstration and Management Unit carried out the routine personnel, finance and supplies duties associated with run- ning any organization of this kind. In the eariy years, as part of the process of sensitizing the staff and officers of the national governments and the general population, an Information/Communi- cations Officer worked for the pro- gramme. One of the functions of this job was the production of Oncho Flash a public lnformation newsletter. The Information/Communications Officer was also kept busy with radio, television and press interest in the programme. Camera crew from several of the donor countries üsited West Africa to record this bold effort. As needs arose specialist staff were appointed for short periods to carry out support projects. Accurate flight and larviciding activities depended upon good maps. When it became apparent that pilots struggled with the usual scale of I:250,000, a cartographer joined the Ouagadougou team to create larger scale maps for the programme. ln L976, a Transport Manager was made responsible for the growing fleet of Oncho vehicles. When asked to reflect on the difference working for the pro- gramme had made to their lives, OCP staff often replied that being able to have a vehicle on hand, for immediate response to a problem was vital. Such things facilitate the efforts to achieve what must be done, but they cost money. As seconded government emPloYees they lamented that such resources were not always available under more restrict- ed national budgets. Moreover under the terms of lhe intercountry agreement signed by the participating countnes. just as aeroplanes and helicopters could fly over the programme area's ai.rspace regardless of national boundaries, on the ground, vehicles, material and staff could cross borders with the same {lexibility The Transport Manager ensured vehicles were kept in good mechanical order and oversaw the logistics associated w.ith this task. Bulk deliveries ofspare parts had to be distributed to the appropriate sector and sub-sector offices. When the pro- gramme expanded so did this kind of balancing act: ensuring that a crate of engine parts, cleared customs at the port and arrived where it was supposed to, when it was supposed to, was part of the success of the OCP As with other areas of the OCB training was provided for drivers and mechanics to support the work of the programme. In the early years such staff were pald at UN rates, which represented a much higher salary than they would otherwise have received. In the 1990s when the value of the dollar dropped, the curren- cy of the OCP budget was rocked by world economic difficulties, Dr Samba promised the donors savings in return for continued support and persuaded a category ofhis staff to accept a change to national salary scales. It is a credit to the programme that their loyalty and pro- ductivity was maintained after their financial rewards decreased. To assist the programme, the OCP set up an autonomous radio network, connecting all the sectors, air bases and the Ouagadougou Headquarters. The Radionet naturally required agreement from the participating countries and the selection of appropriate equipment and radio frequencies. It greatÿ facilitated rhe schedule and gave practical meaning to the OCP maxim that'information should flow'. The radio briefing room became the weekly nerve centre for information com- ing in and flight plans going our. Radio brieling. Moreover, if assistance or clarification were required, since everyone attended the radio briefing it was possible to do this quickly and efficiently. At the human level it brought the staff togerh- er, making sure that those hundreds of miles away from each other had contact and could share in the ups and downs affecting their colleagues averting isola- tion and disenchantment. The Radionet will remain a ütal part of improved dis- ease surveillance in West Africa. The Economic Development Unit (EDU) established in February 1976 proüded advice and informatron for the national governments. The development aspects of the programme were strong and com- mitment high, ensuring that freed land could be settled as soon as appropriate. In some cases this would involve encour- aging people who had fled to retum ro their own abandoned lands. Alternately, where there had been no previous settle- ment, governments apportioned lands to families helping them to leave less fertiie, often over-cropped land, and settle in the valleys. As the National Onchocerciasis Committees of each country gained strength, they assumed responsibility for much of this work. In the I980s it was decided thar rhe Unit in Ouagadougou could be closed and [urther advice sought from the Committee of Sponsoring agencies: the FAO and UNDP involvement no\M came into its own. In 1985 a new unit. was created at Ouagadougou, Biostatistics and Infor- mation Systems (BlS). Developments in computer technology, particularly in lowering the cost and increasing the power of personal computers allowed data storage to be transferred from the WHO Headquarters in Geneva to Wesr Africa. The potential for on the spor data analysis, development o[ entomological and epidemiological models and training of OCP personnel and national reams in these skills was an exciting prospect. The Ouagadougou Headquarters also housed the fundamental units of the programme: Vector Control and Epidem i ological Evaluation. An Administrâtion and Management Unit carried out the routine personnel, finance and supplies duiies associated with run- nlng any organization of this kind. In the early years, as part of the process of sensitizing the staff and officers of the national governments and the general population, an Information/Communi- cations Officer worked for the pro- gramme. One of the functions of this job was the production of Oncho Flash a public information newsletter. The Information/Communications Officer was also kept busy with radio, television and press interest in the programme. Camera crew from several of the donor countries visited West Africa to record this bold effort. As needs arose specialist staff were appointed for short periods to carry out support projects. Accurate flight and Iarviciding activities depended upon good maps. When it became apparent that pilots struggled with the usual scale of 1:250,000, a cartographer joined the Ouagadougou team to create larger scale maps for the programme. In I97 6, a Tiansport Manager was made responsible for the growing fleet of Oncho vehicles. When asked to reflect on the difference working for the pro- gramme had made to their lives, OCP staff olten replied that being able to have a vehicle on hand, for immediate response to a problem was vital. Such things facilitate the efforts to achieve what must be done, but they cost money. As seconded government employees they lamented that such resources were not always available under more restrict- ed national budgets. Moreover under the terms of the intercountry agreement signed by the participating countries, just as aeroplanes and helicopters could fly over the programme area's airspace regardless of national boundaries, on the ground, vehicles, material and staff could cross borders with the same flexibility The Tiansport Manager ensured vehicles were kept in good mechanical order and oversaw the logistics associated with this task. Bulk deliveries ofspare parts had to be distributed to the appropriate sector and sub-sector offices. When the pro- gramme expanded so did this kind of balancing act: ensuring thai a crate o[ engine parts, cleared customs at the port and arrived where it was supposed to, when it was supposed to, was part of the success of the OCP As with other areas of the OCB training was provided for drivers and mechanics to support the work of the programme. In the early years such staff were paid at UN rates, which represented a much higher salary than they would otherw.ise have received. In the 1990s when the value of the dollar dropped, the curren- cy of the OCP budget was rocked by world economic difficulties, Dr Samba promised the donors savings in return for continued support and persuaded a category of his staff to accept a change to national salary scales. It is a credit to the programme that their loyalty and pro- ductivity was maintained after their financial rewards decreased. At the Core ll: The Vector Control Unit - Aerial 0perations and the Entomological Evaluation Network Until the lntroduction of the community distribution of ivermectin, the OCP was a vertical programme of vector control. Throughout its life the OCP carried out a weekly larviciding schedule. This was the basis of the programme and the overall success is ln large part due to the work of those involved in making the larviciding accurate and effective, week after week, year after year. To appreciate the heart of the programme it is essential to understand this process. It is also important to realize that although aerial operations and entomological evaluation had distinct jobs to do, these were inti- mately related. One fed i.nto the other to form a series ol cycles during the prepa- ration phase, weekly larvicidinÿassess- ment schedule, and over the life of the programme in total. Entomological eval- uation results become the basis for aerial operaiions larviciding, the results of which, measured by entomological eval- uation become the new instructions lor aerial operations and so on, and so on... With their central role, aerial larviciding and entomological evaluation consumed the majority of the budget; much of the applied research sought to solve entomo- logical problems and by far the largest number of the staff were involved in entomological evaluation. The Vector Control unit was thus the operational crux of the programme. It also provided the key intersection between HQ and the programme area, divided into a serles of sectors and sub-sectors. As the pro- gramme area grew so did the number ol these sectors and sub-sectors. Equally, when areas were rendered free from the black [1y long enough to interrupt trans- mission, as the programme moved towards closure so the number of sectors and sub-sectors declined. Within this general pattern o[ expansion and con- traction, from time to time lor opera- tional or logistical reasons the sectors and sub-sectors were reorganized: fluldi- ty within a well defined structure, one of the hallmarks of OCP success. Getting ready to spray Good preparation was the key to suc- cessful larviciding operâtions. In the lield, much oî 1974 was spenl seu.ing up the Aerial Operations bases and under- taking entomological evaluation. Vector control staff surveyed the rivers, making inventories of black fly breeding sites. This had to be done twice because ol the difference in breeding sites in the dry and wet seasons. They also established baseline entomolog- ical data. They identified which species of the Simulium damnosum complex were present and determined the biting rates and transmission potentials against which the success of larviciding could be measured. Finally the position of the capture sites for lhe vector collectors or fly-catchers - the outposts in the battle against the Ilies-were also decided. Without the use o[ helicopters, collectlon of this data would have been impossibly slow. Helicopters were also essentiai for treating smâ1ler rivers fringed with gallery iorest. For larger rivers rt was pos- sible to use fixed wing aircraft that could carry a Iarger payload of larvicide. In addition to these entomological preparations, there were also logistical considerations. The PAG mission report considered that a specialist company with expertise in aerial spraying should be contracted to conduct the larviciding. This recommendation was accepted and following review o[ tenders, an American company, Evergreen was chosen for the first contract. In October 1974, Evergreen established an air base with maintenance flacllities at Bobo- Dioulasso, Burkina Faso. ln the bush, the OCP arranged impro- vised heliports and depots of fuel and lar- vicide. During the wet season it would be difficult to reach depots by road and therefore sufficient supplies had to be taken before the rains. In the case of lar- vicides, logistical needs'had to be bal- anced by the risk of deterioration of the stored product. This became even more complicated in the 1980s when the system of rotational larvicides involving seven products came into operation. But then no one ever said controlling onchocerciasis wouid be easy, iust that it was feasible. Sometimes it was necessary to visit the local people and explain that tampering with the barrels of fuel or chemicais was personally dangerous and could serious- ly affect the outcome of the programme. Stranded pilots were generally not very happy people! Moreover, it was ineffi- cient to have healy fuel loads because thls reduced the amount of larvicide that could be carried. But, adequate explana- tions and gentle persistence triumphed as the benefits brought by the OCP were realized. Aerial Operations are go! Once the various preparations were complete in the Phase I area, Iarviciding could begin. Early in the morning o[ December 3, 1974, the Chief of Aerial Operations and the Chief of the Vector Control Unit climbed into the pro- gramme's fleet of aircraft: a Fairchild- Hiller Heli Porter pC6 fixed wing aero- plane called 'Romeo' and a Bell Jet Ranger 2068 helicopter called Juliette'. When Romeo and Juliette took to the air, the OCP could have been said to have begun in earnest. But things did not quite go according to plan. After a short time, Romeo was in difficulties. Dirty fuel had blocked the filters and necessitated an emergency landing as soon as possible. There was no time to reach an airfield and so the pilot head- ed for a dirt strip at a nearby hunting Iodge. All ended well enough. The pilot managed to land Romeo safely and the emergency radio message had alerted Juliette to come to the rescue later that day. If the first day of larviciding had not gone quite according to plan, a valuable lesson, about the potential quality of the fuel supplies had been learned. Aerial Operations introduced stringent measures to ensure that only clean fuel was used for the duration of the programme. After this and a few other hiccoughs the continuous weekly larviciding routine began in February 1975. In line with the planned expansion of activi- ties over Phases II, III East and III West a similar process of entomological and logistical preparations was followed by larviciding. A second air base was opened at Tamâle airport in Ghana but after difficulties following political instability, aerial operations were trans- ferred to Kara in Togo in December 1982. It was necessary for the OCP to be aware of the changing human envi- ronment in West Africa in the same way that it remained responsive to the flies and parasites. As the original area became progressively oncho-free, the Bobo-Dioulasso base closed and opera- tions transferred to Odienné in Côte d'Ivoire. Ovcr tirne, aerial larvicicling rvas carried ont entirely using only helicopters. Iach pilot followed a specif ic schedule, issuecl alte r the radio brie[ir-rg on Monday nrr'rrnrngs. Tlrese scheclules represented the nrost eccrnomical route in terms o[ [1ight hours, chemicals and f'r,rel. There r,r'ere predetermined locaLions ior refuelling, taking on boarcl lurthel larl'icide ancl stopovers. In additior.r to the need lor precision flying, dragging drums lrom the bush depot and lllling the fuel and larvicicle tzrnks oI a I.rclicc'rpter in the heat o[ the Alrican savannah is not an easy' 1ob. OCP staff spoke highly of the commitrnent o[ the pilots. 1-hey were employecl clirectly by the helicopter companres, Evergreen or Viking, rvho won contracts r,vith OCP Mar.ry r-rl.those who likecl the work and stayed rn Alrica [or longer periods oI time became friends of OCP and 'colleagLtes' in Vector Control. Vector Control ancl Aerial Operations staff, OCP scientists and consllltants olten accompanied the pilots. In addi- tion to sr-rpen,ising pilots during their training in iarviciding operations, heli- copters were routinely used for prospec- tions of breeding sites difficult to reach by road. In the er,ent of an unexplained rise in the number o[ fiies for example or dr-rring operational research expeditions heli- copters provided the most cost-effective wa)r to cover the vast distances of the programme area. Crossing the skies of Africa inevitably provided some hair- raising experiences for the OCP staff. Many remember, with a wry chuckle, incidents such as narrot'ly missed power lines. On one occasion a violent dust storm necessitated a forced landing. The pilot managed to get the helicopter onto the ground, but couldn't switch off the rotor blades until the storm abated for fear the strong winds would cause the blades to touch as they slowed down. Imagine sitting in a helicopter in the heat o[ Africa, not being able to see through the swirling dust: waiting and hoping that all would be well very soon. Fortunately this did not involve any injury or loss o[ life. Overall despite the hundreds o[ thousands of flight hours there have been only two serious crash- es with three latalities unfortunately. Larviddes At this point it is necessary to say some- thing about the larvicides used in the programme. Devastating as onchocerci- asis is, its control could not be achieved at the expense of the wider aquatic envi- ronment. It would be unethical to endanger the food chain ol both animals and humans and to destroy non-target fauna. It was important that the nation- al governments could be confident on behalf ol their populations that it was quite safe for OCP aircrafts to enter their airspace and spray chemicals into the rivers. The choice o[ a suitable larvicide was a signi[icant factor irr assessing feasibility during the PAG mission. The product initially chosen, ternephos, an organophosphate with the proprietary name Abate@ met the necessary criteria. Temephos has no residual effect, i.e. it does not last long before biodegrading; can be concentrated in the river at the height the larvae preferred to inhabit; and was non-toxic for man and the fish and their food chain in the dosages needed to kili the lan'ae. Fish from the rivers, lakes and reserr,oirs in West Africa are a significant source of protein. Any further larvicides introduced into the programme would have to meet the same strict rules. From the outset, an Ecological Group (initially the Ecological Panel) support- ed the activities of the OCB reassuring the donors and participating countries alike. This independent group of experts from around the world was asked to advise the programme about specific products and also provide an external monitoring system to ensure there was no adverse environmental impact. Rachel Carson's book Silent Spring published in i962 shocked the world with lts reports of the build-up of DDT in the food chain. Her work concentrated on the somewhat indis- criminate use of this chemical in rou- tine crop spraying rather than the kind of focused use of chemicals envisaged in the OCP, but the wider issues were significant. Under Ecological Group recommenda- tions a monitoring network was estab- lished. The work was initially shared between the Institute of Aquatic Biol- ogy in Accra, Ghana; the University of Salford in Manchester, UK; and ORSTOM in Bouaké, Côte d'Ivoire. In addition to their monitoring activities, the ORSTOM hydrobiologisrs trained scientists and technicians from the par- ticipating countries, so that they could take over the work: an early example of the important general policy o[ transfer- ring activities to national teams as soon as appropriate. In hydrobiology, as in many other aspects, OCP has been a training ground, something that is appreciated within and beyond Wesr Africa. The ability of living organisms to develop resistance to chemicals was a spec[re grinning malevolently at the OCP Mosquito resistance to DDT had played havoc with malaria eradication. In time, black fly resistance to temephos would come to challenge the programme. Are we getting it right? Entomological Evaluation The landscape of West Africa is beautiful and flyrng over these areas can be given a glamorous tint, but the fine details of the sprayrng schedule \,ÿere generated on the ground, each week by the activities of the entomological evaluation network. In many respects the unsung heroes of a programme like OCP are the vector coi- lectors whose quantitative and qualita- tive measures of flies and onchocerciasis transmission rates, proüded the raw data to determine how much, when and where to spray.Ihe OCP!'fly-boys'are just- ly proud o[ their involvement \ rith the proSramme. Entomological evaluation started at the sub-sector level, the smallest division of the programme area. Sub-sectors formed the basic cell or working unit under the leadership of a specialized technician- the sub-sector chief -who managed three or four teams. Each team consisted initialÿ of two {ly-catchers and a driver with a dedicated vehicle. When the need to cut costs arose, driver/catchers and mechanic/catchers were introduced and this helped reduce the total number of personnel but the work remained essen- tially the same. The teams conducted weekly or fort- nightly captutes of adult black flies, sittlng from 7.00am to 6.00pm and trapping unsuspecting hungry female flies that alighted on them in the hope of a blood meal. The number of flies caughr consrirur.ed the daily biting rate. When totalled together the carches provided the Annual Biting Rate, which represenrs rhe theoretlcal total number ol bites that a person would receive il they spent all their time at the caprure point on a daily basis for 12 months. The Annual Biting Rale exceeds the actual exposure of the local community because of the natural movement of people during their nor- mal life but it was an important entomo- logical index measuring the success of the programme in iniernationally recog- nized quanriliable terms. Captured flies were kept alive in individual glass tubes for forwarding ro rhe sub- sector laboratory at the end of the day. Speciai lorms were prepared to record the total number of flies caught and the hour-by-hour count. At the laboratory the sub-sector chief and technicians identified the species of captured black flies and dissected a pro- portion o[ them. There were two reasons to det.ermine the species oi the caught female flies: first to assign them to either savannah or forest groupings and second to decide if they were species that carry r.he Onchocerca parasite. Control of non-carrying species was not part of the programme's mandate. Identification relied initially on morphological char- acteristics, which was not entirely satis- factory. In some cases ii was necessary to undertake a cytotaxonomic study o[ the Iarvae produced by the captured flies. This involved examining the giant chromosomes ol the salivary glands- a painstaking process and not easily done in the fieldl One of the programme's applied research prqects searched flor improved differen- tial identification of Simuliam damnosum species that the evaluation network could use. Improved morphometric techniques were introduced in 1993. Ir was an OCP priority to ensure that entomologists and technicians were immediately trained in new procedures. Staflf enjoyed refresher courses to maintain standards and Iearn new methods. DISSEOION OT A SAMPI.E OT TUE§ ANSWERED lwo KEV QUr$tor{S filst, were the flies young and had they bred locally, or were they older and flrom outside the programme area? This could be determined by how many had reached the egg lay- ing stage in their lives. Young Ilies I i i II I I l 1 ( ( l I \à. that n,ere nr-rlliparor-rs, i.c. had larcl nr) eggs, u,or-rld be local ancl rcpre- scntccl continr,red breeding, ii4-rich rcclr.rrred [nrther treaimenl. Parous ItntaIcs, olcler cgg-laf ing l1ies, r.r,or-rld nrr)st lilicl), bc fr-onr outside the area itttcl eotrItl ICI)rcsrnt rcilrvi'tsjr)n. SgCOnd, \\'lrirl w(rc tlle trirnsnrissi()r'r rates? Technicians clisscctccl the hclrls ,rI lrlrrlt I.cnralc flies, c,rutttittg the nurnber oI infictive l:rrvac ol the Onchocerca r.l,on-n. l-'hc resltlts r've rc fed into an cclr-ultion, which gavc l ligure for the Anr.rr-ral Transmissior-r Potential. This proviclcc[ irnothcr internationally recognizecl theorcti- czrl rneasure, Lhe exposure o[ an indi- vidual to infection with the parilsite, ,,\ signilicirnt inrprovemenL in this basic llllttcnr ol u,orli camc r.viLh the aclvcnt o[ nrolcctrlar biolouy ancl the introductrrrr-r ol DNA probcs. Fronr .Jirtruarl' 1992 rathcr thrn .jr-rst linou,inu the nunrbcr o1- lirn'irc ;trcscr-rt, lllt Dt,lÀ l,lLrrlrliur;i in Bor-ral<é, Côtc cl'lVoirc (lirtcr nroVC(l tL) Ortagackrugou) itiu I d lrt I I 0 tP': rr tiirtr,t11i :ii 1,, ',';irirlt ':,r,.r.(, :.i rrrrrt:,,.-,, : i,,'. ' i 1' . [rr:ioirged. In Novcnr]rcr 1c)t)l thc pro- grarînre introcltLce cl ir nc\\' urcthr)cl ()l calculating thc AnnurI Trrrrsnrission P()tcnlial in liglrr ,rl llrs rr()r(' l)r'('( r-(' clirtir \\rhile the u'cck1y cntor.nologicirI clrrtrr rl'ere usecl to cletcrrnr rre t hc lirn'ierding schedule , lvhen aual),sccl in its cr-rmulatir,c form, the z\nnr-ral ll.irnsmissitrn Potential in partrculiir I)r()\'i(lecl rru ir11portant source ol inior- nr.rtion [or thc cprdemiological evalua- tion r.rnLt. The entomological team also collected additional information such as the results of searches for pre-adult forms o[ the [res, river gauge readrngs and mete- orological data. Unusual mortality of lish and other non-target fauna, and the use of insecticides for agriculture or fishing would also be reported. Collecting larvae was often a difficult and dangerous busi- ness, because o[ their preference for locating in fast flowrng waters. Durlng the wet season when the rivers are lull and currents especially danger- ous, prospections for larvae were nec- essarily restricted. Sector and sub-sec- tor chiefs would personaily lead poten- tially difficult or unusual expeditions into the bush. Memories of str,tnded vehicles, bogged dorrun in the mud oI almost impassable tracks, where local villagers would come to the rescue often several limes, now raise a smile. The name ONCHO became synony- mous with aircraft passing very lorv overhead and 4-wheel drive vehicles nosing their way through Ihe bush ro reach the most isolated vi1lages. In time ONCHO also came to mean freedom from flies and from blindness. People became only too glad to lend a hand knowing that by doing so they were ulti- mately helping themselves. Africa can be a hostile environment in other respects too. Working in the bush means working with the-wild life nearby. Close encounters with lions, snakes and crocodiles presented hazards on the ground. In addition to the data on adult flies, Iar- vae ancl pupae, the schedule was adjust- ed in response to a variety o[ other infor- mation for instance the level of water in the riv-ers depending on the season of the year. During the rains, the increase in water and speed of the rivers meant bet- ter carriage ol larvicide down stream. During the dry months, the decrease in water slowed the flow and increased the number of larviciding points along the river. Sometimes the weekly data on a river's discharge rate \À/âs not sufficiently accurate, leading to too much or too lit- tle larvicide reaching the breeding sites. After i984 the programme began to use sophisticated hydrological beacons, which relayed information by sateilite directly. This is a good example of OCP's characteristic updating of technology to improve its performance. Following the week's work with the flies, it was the job of the sector chief to for- ward the results of entomological evalu- ation to the Vector Control Unit at Headquarters, ready for the Monday moming radio briefing. Although OCP had access to a computer in Geneva for overall storage o[ data, before the advent of the personal com- puter, many weekends were spent analysing the complicated results. Asked about changes in the programme, former sector chie[s applauded the introduction o[ computers to help them perform this crucial task. After Vector Control at HQ looked at the overall picture, instructions lor the coming week's larviciding schedule were returned to the Aerial Operations bases. Here the quantities of insecticide applied at each release point, upstream of the black fly breeding sites were worked out. Each pilot received his own unique instructions, prepared on a coded map and the necessary flight authorization. The results of the entomological evalua- tion network \Mere therefore put into practice the week after they were made and so when the pilots took off at dawn on Tuesday morning the cycle began again. Take otf from Xara. If entomoiogical evaluation revealed there were no flies and larvae, larvicid- ing could be suspended and the ento- mological situation monitored, breeding sites being treaied once more should Onchocerca-carrying flies reappear. It was a relatively straightforward process to commence treatment once more, but it was crucial to find out why the flies had returned. In this case the routine fly-catching duties would be augmented by further prospections. in the first instance, Sector Chie[s could contact their teams to check the results. Then a personal visit by road or helicopter might resuit in the discovery of a new breeding site on an untreated tributary. In additlon to the speed of response offered by helicopters, lmmediate aerlal treatment could be carried out following the calculations of the entomologist 'on the spot' of how much and which kind of insecticide ro use. One o[ the programme's entomologists remarked wryly that it is a fortunate side effect of the cumulative nature of the onchocerciasis infection, that a week's resurgence in black flies would not in itself rock the programme. It was essen- tial to nip any appearance ofonchocerci- asis-carrylng flies in the bud, but the necessary length of exposure required before infection provided an operational safety net not available for example in malaria control where one bite from an infected mosquito can lead to disease. The programme, however, aimed to make as little use as possible of this piece of epidemiological good fortune. When there were significant problems, reinva- sion of black flies and their resistance ro larvicides, the response was as swift as humanly possible. Where things went wel1, and they gener- ally did over the programme area as a who1e, it was necessarily part of the plan that larviciding would cease permanent- ly not just at isolated breeding sites but along entire river basins. But this would happen only when the entomological and epidemioiogical findings indicated that it was safe to do so. An Annual Tiansmission Potential of less than I00 for a period of four or five years was taken as the cut-off point. When this figure had been reached consistently and larviciding stopped, the entomological and epidemiological evaluation units began a 2-year post-larviciding study, ensuring discovery of any potential recrudescence. The red light goes on when the ratio of infective female flies is greater than I per 1000 eggJayng females caught (i.e. 1000 parous flies). Should this be the case, treatment with ivermectin could be introduced (after 1989) and if that was insufficient, larvi- ciding commence again. These studies not only protected the programme area, but also provided valuable lessons and data ïor the future, particularly to guide the national onchocerciasis teams who would take over from OCP as part of the transfer process in the later 1990s. What could appe^r to be lifeless routine was in fact a highly sensitive, delicately balanced operation, constantly moni- tored by a range of feedback loops. Whenever technical advances could be { a I l applied the OCP embraced them. The programme evolved and became more sophisticated over time, but the basic principles remained the same. Through its dedicated staff and flexible approach the OCP functioned as a live predator. After all, its enemy was a biological target in the natural wor1d, where change ls the only constant feature. Designing the programme to be rigid enough to hold together over a long period and yet sensitive enough to remain responsive is one of the key aspects of its success. At the Core lll: The Epidemiological Evaluation Unit, later renamed Planning, Evaluation and lransfer Unit ln health programmes such as the OCB which are based on vector control, immediate measures are related to the vectors. Are there any flies? If so, how many flies and of what species? Are the flles carrying any parasites? And so on. Even with the introduction o[ iver- mectin, the programme remained one of interrupting transmission rather than curing disease. Until there is a macrofila- ricide there will be no cure for onchocer- ciasis. But since the ultimate aim of the programme was to eliminate onchocerci- asis as a major public health disease and as an obstacle to socio-economic devel- opment it was vital to know, over the Iong term, what effects vector control had on the human disease. Enter the Epidemiological Evaluation Unit.'EPI', as it was termed was small in compari- son to Vector Control and worked ln rather different ways, but nevertheless performed a series of essential functions. Llke the early work of the entomological evaluation teams, epidemiological evalu- ation began by making inventories in the programme areaby taking health inven- tories of a sample of the local popula- tion. To be as comprehensive as possible, epidemiological evaluation had to take i.nto account two main variables. First, the diversity of the endemic situation, ranging from hyper through meso to hypoendemic foci and second, the differ- ing parasites in the savannah, forest and combined savannah/forest regions had to be included. Whole üllages, with a pop- ulation of approximately 300 people were chosen as the epidemiological units. In remote areas, in hlperendemic regions smaller villages proved accept- able. Where possible sample villages were located near fly-catching sites. This allowed the clinical and parasitological data to be correlated with the Annual Biting Rates and Annual Transmission Potentials as determined by the pro- gramme's entomologists. The proximity to catching points also meant that the sampie villages were concentrated ln the hyperendemlc areas o[ the programme. â" Thc epiclenriokrgical tcams were con- frontecl il'ith the u,orst elfecrs ol the Lrncontrollecl diseirse ancl rvere tl-ms able to nreasure and appreciate at a scientilic and a hur.nan level the changes that the OCP bror-rght. Members o[ the epidemiological evalua- tion Lrnit worked as mobile teâms com- posed oI a sociologist, an epiderniologist and an ophthalmologist The sociologist assessecl the soe io-cconomic situation and determined quantiliable measures o[ change to assess the developmental aspects ol tl-re programme. Over time the epicleniiologists and ophthalmologisrs constructed a changir-rg prolile ol oncho- cerciasis in the programme area. AII members ol the epidemiological leam, indeed all those r.vho rvorked in the lield nnder either unit, were charged with cxplair-ring the nature oI thc discase . t]re associatir-rn betrvecn fiies and the syrnp- toms ol onchoccrciasis, and hor.v the programme rvas helpirrg combat this clis- ease. When the team arrived they would (0ndu(t a health (ensus 0f the whole village, rvhich was then repeated approximatel), every lhree 1.6315. These were often signiflicant events in the lives of the r.illagers. The combined elfects of rural isoLation and limlted resources o[ national budgets tr-rrr-red the OCP epiclemiological visits into rhe mosr comprehensive rnedical cirrc ar.ailable. h-r acldition to the equipment necessary lor assessing the extent of onchocerciasis (slit lamps, ophthalmoscopes, special punches and physiologicaI serurm [or {{- § Measures of visual acuity. skin snips, and surgical tools for remov- ing nodules) teams also carried basic medicines and offered an open clinic, treating problems such as intestinal worms and fevers. An epidemiologist attached to the programme described how the villagers' response to the inter- est taken in them resulted in the com- munity working together to improve the basic dispensary building, fitting doors and windows and assigning each mem- ber of the team a hut in the village dur- ing their stay. The health census provided general base- line data for future comparisons. The specific measures of onchocerciasis were made through ophthalmological and parasitological examinations. The eye examinations required a specialist oph- thalmologist. In the early days of the programme these were hard to recruit; only a very limited number of doctors had the necessary specialist training in onchocerciasis. Using a slit iamp, it was possible to coun[ the number o[ microfi- lariae in the cornea or the anterior cham- ber of the eye. Eye examinations also provided fligures to determine the rate of blindness and the extent o[ irreversible onchocercal lesions in the eye (sclerosing keratitis, iridocyclitis, optic atrophy and choroidoretinitis). Measures of visual acuity and reduction in visual field were also made. The parasitological examinations involved skin snips and in some cases the removal of onchocercal nodules. Two small samples of skin, about 3 to 5 mm2 in size were taken from the iliac crest, the skin above the pelvic bone and placed in distilled water for 30 minutes. A count was then made, using a micro- scope, of any microfilariae that emerged. If no microfilariae were seen the skin snips were left for 24 hours in physio- Iogical serum and then re-examined. Removal of all the palpable nodules in selected üllages provided information on the numbers of adult \Morrns per nodule and the percentage o[ sexually active females. This was part ol on-going research to determine the active lifespan of the females: a crucial measure for the long-term strategy of the programme. Although the epidemiological proce- dures involved some minor discomfort, OCP staff reported good initial auen- dance and repeat attendance during their visits. Over time some of the village pop- ulation would be lost due to death and emigration but, after five years, between 40 and 50olo of those originally examined were still available for [ollow-up. New babies and immigrants were also includ- ed in the subsequent surveys. ln effect the river basins in the participating countries became a giant open-air labo- ratory adding greatly to the world's store of knowledge of onchocerciasis. The data generated from these sample villages has formed the basis for a long-rerm study of the onchocerciasis, essential for the programme, but immensely valuable for the scientific wor]d in general. At the local level, the r.rllagers were gen- erally curious ro know abour the pro- gramme. In the early days they offered their own explanations for the disease: the effects ol evil gods who wanred [o keep the land by the river lor them- selves. Instead the OCP staff explained that it was a disease carried by the black flies that caused the problem: when the flies are gone it will be sale to reiurn ro rhe riverside. lt was very important ar this point that rnany ol rhose who were first engaged by the programme \À/ere known and respected members of their commu- nities who could speak locai languages and empathise with the üllagers. The usual rule that WHO staff cannot work in their own country was waived during the early crucial phase. A high percent- age of early OCP staff had personal knowledge of the effects o[ onchocercia- sis. So well was the message conveyed - black flies are responsible for carrying the disease - when larviciding operarions stopped and the flies rerumed, albeit now without any parasites to transmit, lhere was much constemation. Those involved in the various longitudi- nal studies often lollowed the work closely During early ivermectin trials in the I980s a young boy who had taken part for 2 years watched, as the results of dissections o[ flies fed on him, and left for seven days for the parasites to mature, were entered into the research report. He asked if the fiies fed on him had produced any parasites. When he heard the answer no, he exclaimed with I ! I i 1 l ii l I( i l I joy'l am free of oncho'. The researchers were surprised that he understood the basis of their work not ônly its personal implications but also the complicated nuances of the life cycle of parasites and flies. This gave hope to those charged with reassuring the 1oca1 people that flies could return without the disease coming back. Successful larviciding was translated into greatly improved epidemiological meas- ures revealed in the scheduled follow- up studies. For a variety oI reasons, including paucity of hard data before the programme started, it was decided to concentrate on the incidence of the dis- ease in children born since the beginning of vector control when assessing the numbers of new cases. Among these children, the incidence of new infections was extremely low. And remember, that being infected with the worm no longer leads to damaged skin and eyes. The results were best in the central part of the programme. Here the incidence had dropped by 99'/o by 1994. Where problems occurred, in the reinvasion areas, or where stubborn foci continued to requlre larviciding, slightly poorer results ensued. These posed challenges to be met. For the most part, by 2002 and closure of the programme, vigilance has been rewarded. Most significantly they served to show the importance of pro- tecting against the dlsease from outside the programme areaby the most appro- priate means. The hard work, financial assistance and goodwill that launched APOC is also part of the message of OCP's epidemiological evaluation. On the ophthalmological side, there was also a conslderably reduced risk of the lesions leading to blindness. Counts of the microfilariae in the eye revealed a diminution over time: very small num- bers - between I and 3 per person - were found in less than 2o/o of those examined. With transmission interrupt- ed and no additional parasite burden, lesions in the front of the eye that were still reversible showed spontaneous improvements. Changes in the lesions at the back o[ the eye stabilized, except for those over 50 years of age where they tended to contlnue to progress. As the older blind people died, who sadly had a shortened life expectancy (of about l2 years), the overall rate of blindness in the community decreased. The inci- dence of blindness up to 30 years of age was zeru a startling transformation. Ihe ON(H0S!M mode! With the benefit of 2Syears hindsight, the epidemiological results proüde an over- view of the changing disease profile. But during the working life of the programme there was concem that there was too much of a time lag between the com- mencement of operations and measurable changes in the health of the population. Worries about being unabie to satisfacto- rily quantify the duration of vector con- trol (and its costs) were allayed by the introduction ol epldemiological model- ling, using all the programme's rich resource ofstored data. In 1985 the dura- tion of vector control was confirmed at 14 years and everyone heaved a sigh of relief, they were on target after all. But this was just a start for com- puter simulation of the dlmam- ics and interactions of the trans- mission cycle o[ onchocerciasis between the three populations concerned: humans, vectors and parasites. In 1988 collabo- ration between OCP and the Public Health Institute of the Erasmus University of Rotterdam, in the Netherlands produced the ONCHOSIM model. This model mimics the real life situa- tion of vector control and made it possible to determine when larviciding could be interrupted without running the unaccept- able risk of recrudescence of infection and ultimately of the disease. When tested against archive data in the literature and OCP's own research, the results were satisfactory but as in all the other aspects of the programme continual development took place to increase the reliability and sensitiüty of the simula- tion, including the advent of the use of ivermectin. Beyond the Core The OCP did not work in isolation and some of the liaison and support groups need a quick mention. IMPACT OF 15 YEARS OF VECTOR CONTROL RECRUDESCENCE OF THE DISEASE AFTER AN EARLY CESSATION In West Africa, ORSTOM and OCCGE continued to provide scientific support when requested, helping with opera- ( I { tm ll0 100 90 gm 8m e8ro +g50À o40 ÈR 30 N lo 0 oa E tI EI ôÀ o IR t2î lt0 100 90 80 m «, ,0 40 30 N l0 0 y' .'' :' ' .t^TP .i"v: j(tm- tional research and proüding training programmes for potential OCP techni- cians and entomologistS. The National Onchocerciasis Committees in each of the participating countries served as liai- son points and their role increased over time becoming particularly important in the 1990s when transfer of activities began in eamest. In Geneva the WHO Headquarters housed first a Support Unit (1974-76) and then a Liaison Office (1976-2002) to help with initial coordination of the pro- gramme and communication with onchocerciasis scientists, donors and other sponsoring agencies. The drug search projects were based in Geneva. In Washington the World Bank opened an Onchocerciasis Unit, to house their staff, to liaise with the donors and to man- age the donations to the OCP Trust Fund. Equally important are those groups who had no specific institutional affiliation, but met regularly to oversee the pro- gramme and offer help and advice: The (ommittee of Sponsoring Agencies (formerly the Steering Committee), responsible for over- seeing and supporting the pro- gramme, and ensuring coordination between the cosponsors made up of representatives of WHO, UNDB FAO and the World Bank. The foint Progtamme (ommittee (formerly the Joint Coordinating Committee), the supreme governing body of OCf; made up of representa- tives of the panicipating countries, donors and sponsors. It has met once a year in December, altemately by invitation in one of the partici- pating countries in Africa and in one of the donor countries. The JPC had overall supervision of the program- me acti\rities, scrutinised the Plan of Action and Budget for the coming year and made recommendations for future activities. The Ecologica! Group (formerly the Ecologrcal Panel), an invited group of five independent experts affiliated to the Expert Advisory Committee. The remit of the EG was to ensure there are no adverse environmental impli- cations as a result of the programme's activities, with special reference to larvicides and hydrobiology. The Expeil Advisory Committee, (encompassing the original Econo- mic Development Adÿisory Panel, the Scientific Advisory Panel, and the Scientific and Technical Advisory Committee) was a l2-member expert group drawn from the global oncho- cerciasis scientific community, which included entomological, epidemio- logical, economic and development aspects of the programme in its remit. Like the donors, those who have served on these various committees and groups, have sustained a keen enthusiasm over the life of the programme. [lRE N ilËTP! E LIVING ALON ruUffi ERADXCAT BLrrNül{E§ T 70,00t #ASII Meeting the challensês: Conceptualising 0CPt history The last section gave some idea of how the OCP worked. But how did it evolve and respond to change? What did it look like over time? The history of the OCP is represented here as an astending spiral. Beginning in 1968 with the Tunis meeting, it shows how the programme expanded, reaching its peak in the 1980s when the largest number of staff were lnvolved ln the most diverse range of activities, over the biggest area. In 1989 an area of over one million km2, home to over 30 million people, was under aerlal operatlons and OCP employed nearly 1,000 people.The spiral continues upward to December 2002 but begins to contract because as the goals began to be realized and larviciding began to wind down, so everything began to decrease in size. Throughout its history, the programme's complex routines required the kind of sensitive maintenance described in the previous section. However, there were also some significant changes from out- slde the programme, which had to be accommodated. There were four thlngs that former OCP staff most often men- tioned when asked about changes in the programme and they are not all badl On the left side of the helix are the four significant events: reinvasion by black llies, resistance to current larvicides, the introduction of ivermectin and the emphasis on transfer as the programme drew to an end. /j^q*-.-.-.-.- ' ,--'r-l ]- /, I -.'i -l \ - ,/l ) ))('1.-/, t I Sourcês ol W ) r6'nv.ibnsl\L,IIYit j-L.-.-.r:-.---.-.È---"_--'- --_-_--\ Lrd ol arsa 600 h lrom mn \.,/ unreabd hablbts ôt D, t\* =)/hilial lirYlt O@ Y -r' .___ { ._.-t. Reinvasion We begin with some geography ihe orig- inal programme area of 654,000 kml covered the savannah regions in Benin, Burkina Faso, Côte d'Ivoire, Ghana, Mali, Niger and Togo. In this region the savannah group of black flies in the Simulium damnosum complex carried the most pathogenic strain of the Onchocerca par- asite hence the severity of the disease. To the north the increasing dryrress pro- vided a natural barrier. ln the south the programme stopped at the edge of the humid savannah and took advantage of ecological barriers proüded by the two reservoirs created by damming the Volta to form Lake Voita in Ghana and the Bandama to form Lake Kossou in Côte d'lvoire. The reservoirs eliminated black fly breeding sites for hundreds of kilo- metres upstream by slowing the water flow. There were some serious foci south o[ this area, where parasltes and vectors of the savannah type occurred although mixed with the less severe lorest kind but they were initially left untreated. Tô the east and west, the borders of the pro- gramme area took on a more arbitrary feel, following the country borders of Nigeria in the east and Guinea in the West. Given the contemporary knowledge o[ the flight range of the target savannah black fly species, the programme area was theo- retically large enough to prevent the introduction o[ parasites by flies from out- sâvannah-typê veclors side. Entomologiss estimated that black flies could travel at least up to 80 km, but did not l«row about the size, periodicity, and direction of these long-distance migrations. Thus it was not a total sur- prise when as earÿ as May 1975, the first full year of larviciding, large numbers of black flies began to be caught where none should have been found on the Bou, the middle White Bandama and pars of the Lêraba rivers where control had been effective for many weeks before hand. lf not a complete surprise it was still disap- pointing to face such a challenge so earÿ Before assuming the worst it was essen- tial to check that there was no posirive sites and no treatment failures. Howeveq the entomological evaluation netvÿork confirmed there were no larvae in the rivers: it was not going to be that simple. In the Aerial Operations room at Bobo- Dioulasso, the chief of Vector Control decided to take the acrion to the flies. In helicopters, 4-wheel drive vehicles and boats, teams set out from the sector office to investigate the situation in southern Mali and northern Côte d'Ivoire. Moving painstakingly south, along the rivers, research confirmed the flies were old and had not hatched in the programme area. Thus successful larvi- ciding greatly helped in determining the cause of these adult flies. Further surveys, conducted with the help of ouside consultants, revealed that the flies had originated from at least 150 km away and, that some had travelled as far as 600 km helped by the prevailing monsoon winds. Hence the timing of reinvasion ApriVMay to July when a v/eather front, the 'Inter-troPical', moved north-east with the rains. During the survey period the esublished larvi- ciding routine continued as appropriate. This was important because the migrant flies would settle to lay their eggs and take a blood meal before moüng on again, potentia§ beginning transmis- sion again if there was no intervention. But it was also expensive, especialÿ in the long term because treatment would have to be continued here longer than had been forecast to maintain the gains already made.(ompli(aled river syslem (Léraba a0d White Bandama Iiver§). Reinvasion was not a freak occurrence but proved to be an annual phenome- non. As the planned phases became operational, so the area vulnerable to relnvasion expanded to five hot spots around the west and south of the periphery of the programme. Thus dealing with reinvasion became a regular part of the OCP year. The staff became resigned to the black fly's further bad habits, but if it was no longer a dis- turbing event, a long-term solution was still needed. Attempts to use insecticides against the adult flies were unsuccessful. The most sensible operational solution was therefore to consider extension of the programme area in the south and west. The first expansion ro the south in Côte d'Ivoire, in the Marahoué and Bandama Upper basin and the Léraba Resistance Resistance in insects like black flies means doses of insecticide that previous- ly would have been lethal no longer have an effect. It arises in a population because natural selection favours those indlviduals whose genetic make-up allows them to survive through some kind of advantage. As they breed they pass on this genetic advantage to their offspring and so the number of resistant flies quickly increases. In the second half oI the 20th century, resistance to one insecticide group or another appeared in alI insects oI medical interesr. excepr virtually eliminated the usual reinva- sion. It proved a very successful way of dealing with a problem and also brought several severe foci of disease under the auspices of the programme. The Joint Programme Committee urged a similar extension to the west, covering Senegal, Guinea, Guinea-Bissau and western Mali, increasing the number of people protecied by the programme and elimi- nating reinvasion and voted to fund explanatory studies in December 1983. But then resistance took hold and preoccupied the programme. Only after extensive research into new larvicldes and their approvai by the Ecological Group could rotational larviciding begin with permethrin and carbosulfan in southern Ghana, Togo and Benin (1988), Guinea (1989) and Sierra Leone (ree0). tsetse {lies. Thus, as with reinvasion, resistance did not catch the progrâmme out, but the staff still dreaded its appear- ance despite being forewarned that lt could happen. Resistance to temephos first appeared on the lower Bandama Rlver in Côte d'Ivoire in 1980. It was found in the forest species of Simulium. A similar organophosphate compound, chlor- phoxim, was substituted for temephos at breeding sites where resistance was iden- tified. This became rhe standard rreat- ment over much ol the southern part o[ Côte d'lvoire. By the end of 1981 post-treatment eval- uation reported poor results: the breed- ing sites were perslstently remalning posi.tive after lreatment. The sector chief ca11ed the OCP technician i.n charge of the larvicide tests who was in Bouaké and together they spent the morning making prospections to collect larvae for specific resistance tests to be run in the afternoon. After dinner, unable to wait to know the worst, the sector chlef returned to the Gauthier Falls where the insecticide team had run the test. The initial results were positive the local Simulium damnosum larvae at the Gauthier Falls were resistant to chlor- phoxim. The next morning the sector chief asked the team to re-run the test and confirm the results. The adult flies were so numerous the team was compelled to work inside a large mosquito net. By 1982 widespread resistance to chlor- phoxim was confirmed. Things looked bad. The only acceptable substitute larvicide available was a formulation ol Bacillus thuringiensis or B.t. H-14. This biological adversary acts differently to the organophosphates. Rather than act as a neurotoxin or development inhibitor, B.t. H-14 selec- tively destroys the gut llning in black fly larvae. It is thought that reslstance to this larvicide product is very unlikely to develop, however, it was also much more expensive and less potent than the organophosphates and could not be used on rivers with a hrgh rate o[ flow, because oI operational limitations. lndeed the OCP pioneered the use of a liquid concentrate ol B.t. H-I4. Temephos had to be used where B.t. H-14 could not. When resistance to temephos arose against savannah Simulium in 1983 it seemed that the end had come. The pro- gramme soldiered on although the com- bined problems of rei.nvasion and resi.st- ance were causing rumours around the world that the OCP could not survive such an onslaught of problems. Early in the 1980s they even reached the ears of the incoming Director, Dr Ebrahim Malick Samba. 'You're not going to take on a lailing programme?' they said. But the stafl of OCP dug deeply into therr reserves of commitment to achieving the goals of the programme. With characteris- tic tenacity the OCP launched a multi- faceted attack on the problem. The World Bank representatives'got on the road' and asked the donors to keep supporting the programme and if possible give more to preserve the gains made while research was conducted to solve the technical problems. They proved persuasive and donors increased their donations to match the larger budget. Chemical com- panies were asked to send potential prod- ucls lor screening. The programme inten- sified its support to the Pierre Richet Institute at Bouaké, Côte d'lvoire, which conducted larvlcide screening while at the same time moving to establish its own facilities. The small start in Kara (1982) and Lomé (1983) in Togo, was upgraded to the Insecticide Research Unit and moved to Bouaké (1986). The result of this combined effort was the development of a rotational strategy, which used 7 lar- vicides - temephos and chlorphoxim, then phoxim, pyraclofos, carbosulfan, permethrin, B.t. H-I+ in two formula- tions with the trade names Têknar@ and Vectobac@, and etofenprox, trade name Vectron@. The rotation was determined with reference to a range of criteria - the discharge rate of the river, effects on non-target fauna, cost-effectiveness, levei of susceptibility of the fly larvae to the larvicide and the number of weeklv lvermectin In 198I an independent review of the OCP lamented the lack of a safe, effec- tive, easily administered macrofilaricide to kill the adult Onchocerca yolyutus. The report recommended that the long- term prospects of the programme would be well served by a drive to develop such a drug. The Joint Programme Committee responded positively at its December 1981 meeting. In response the Oncho-cerciasis Chemotherapy project (OCT) (later renamed Macrofil, 1990) was founded jointly with the WHO TDR filariasis group. Feelers were put out to industry to form collabora- tions to develop any existing com- pounds that showed promise. The research and development of new drugs and passage through animal and clinical trials is dlfflcult, expensive and cycles in which the product has abeady featured. The rotational larviciding schedule put the OCP back on track and facilitated the start of spraying operations in the extension zones. It was with considerable pride that a former staff member recailed performing the f,irst systematic larviciding in Sierra Leone in 1990. This was not just a personal first but deserved pride ln triumph against adver- sity. For the record, the system of rota- tional larviciding has become a model [or other programmes using vector control and guarding against resistance. time consuming. Where the potentiai markets are in underdeveloped coun- tries commercial companies seem increasingly reluctant to take the risks with such little potential for monetary reward. The chemotherapy project tried to combat this with adequately funded research contracts. But the need for a drug to be in use before the end of the programme raised the stakes still further. It is a credit to both the chemo- therapy arm of the programme and Merck 6s Co., Inc. that they succeeded in achieving these almost contradictory aims The emphasis on a macrofilaricide was related to the deleterious side effects of other existing microfilaricides, which could cause blindness as the body react- ed to sudden increase in the number I l l i ( I l 'l l( i i l I : r i of dead micofilariae. However, the result was ivermectin, trade name Meclizan@, a microfilaricide. Originally produced by Merck 6r Co., lnc. as a veterinary com- pound, and still used in animal medi- cine, ivermectin was not the hoped for macrofilaricide but it was not 'just ânother microfilaricide' either. Clinical trials began in 1982 and from 1983 onwards the Onchocerciasis Chemo- therapy project collaborated with Merck as these expanded. It has proven to be effective, well tolerat- ed and safle for large-scale treatment since i.ts introduction in 1987. It is active in a single annual dose and does not cause serious allergic reactions or aggravate ocular disease even at high dosages. To obtain the maximum benefit from iver- mectin, it must be taken regularly over an extended period of time because o[ the limited effect on the adult worm and on transmission. For reasons o[ cost-effec- tiveness, ivermectin treatment was first instituted in the highly endemic zones where the risk of onchocercal blindness was highest thus providing immediate relief to the most exposed populations. For that reason, its use in the extension areas that were under larviciding was particularly indicated not only because of the endemicity but also because o[ the combined effect o[ ivermectin treatment and larviciding on the transmission o[ the parasite. In the first year o[ Iarge-scale treatment f989-90, 60,000 people received ivermectin. lt was only later that the areas at a lower risk of onchocercal blindness (those which were not under larviciding and not constiLuting a source of reinvasion for the hyperendemic zones) received the drug. At first ivermectin was delivered to the affected communities by national mobile teams with technical and financial support from OCP Certain NGOs con- cerned with preventing blindness also began supporting the community-based approach. Indeed their involvement greatly facilitated the development of community selfl-treatment, empowering the local people to assume responsibility for this aspect o[ onchocerciasis con- trol. The resuit: Community-Directed Treatment with Ivermectin (CDTI), which has gradually replaced large scale, mobile treatment under OCP auspices. CDTI has now been instituted in most of the basins of the Programme area. It has the advantage of being cheaper, more effective in terms o[ therapeutic coverage and sustainable over the long period nec- essary for onchocerciasis control. CDTI makes üllage communities responsible for their owrr treatment. Since the begin- ning of large-scale distribution, the number of individuals treated with iver- mectin within the OCP area has been increasing with over 7 million people, in approximately 20,000 villages under annual treatment. CDTI encourages the local people to select distriburors from within their own mldst who are trained to deliver ivermectin to a group of fami- iies under the supervision o[ the nurse or health worker from the nearest heahh centre. CDTI has been a wonderful example for other health rare interventions and its success as a model for health-care related interventions is now being used to help strengthen primary health care ln some o[ lhe most deprived communities. CDTI was chosen to deal with onchocer- ciasis beyond the geographical limits of the OCP area, in particular in areas o[ southern Côte d'Ivoire, Ghana and Guinea where the nature of the gallery lorest make sprapng of water courses impossible. In Sierra Leone where cirnl war disrupted aerial larviciding it proved easier to recommence control with CDTI. Studies from clinical and community tri- als have shown that in the short-term, ivermectin reduces the average number of microfilariae in the skin by g6 to 99a/o bringing immediate relief from itching and rapid regression ofacute skin condi- tions. As ivermectin has no effect on the adult worms, the community microfilar- ial loads rise once more to about 40olo of their initial value a year alLer treatmenr, as the female continues to release micro- filariae. But then it ls time for a further dose. Repeated annual doses significant- ly reduce the numbers of microfilariae in the eye, leading to a regression of lesions t I I l 1 / I ,t 1 I in the front part o[ the eye and stability in the lesions ol the back part. Moreover, because of its generai filarici- dal propertles, ivermectin also clears intestinal parasites. Thls welcome side- effect raises the profile of ivermectin among the loca1 people and helps ensure that attendance for the annual treatment is sufficiently high to help the communi- ty by interlering with transmission, in addltion to its indivldual benefits.The lack of an effect on the adult worm means that ivermectin distribution cannot by itself reduce the prevalence of infection in the way that vector control dld, although continued research indicates that multi- ple doses o[ the drug may make an impact on the population o[ adult worms within thelr human hosts. In 1991 a Devolution Unit was estab- Iished at Ouagadougou. This was the first major operational step in a process that had been discussed even as the plans for OCP were being laid down. The difficul- ty was that although no one disputed the need to ultimately devolve or transfer onchocerciasis control and surveillance activities to the health authorities of the particlpating countries, a vertlcal larvi- ciding programme, as such, couldn't be transferred. It was ivermectin and the mechanlsm of community distribution that made the difference. Forecasts based on the ONCHOSIM model indicated that Vector control could reduce the transmis- slon potential of the parasite to zero by removing a1l the black flies in the area under larviciding, but research shows that ivermectin has a role to play here too. Combined lvermectin and larvicid- ing reduces the Annual Transmission Potentlal at a faster rate than larviciding a1one. This allowed a reduction of 2years in the total time needed for larviciding operâtions, when combined with iver- mectin. Although it was a private decision, Merck 6s Co.'s gift of ivermectin, free ât the port of entry for use in public health pro- grammes, for as long as it is needed, was lostered in the atmosphere the OCP had generated around the wor1d. by 1994 larviciding would be virtually finished in the original OCP area. Thereafter vector control operations would be concentrated in the extension zones. With reguiar progress in breaking the transmission cycle it was essentlal to step up the implementation of transfer activities. The original estimate of a twenty-year larviciding cycle had been reduced to 14 years following research on the lifespan of the parasite. The effects of combining ivermectin distribu- tion with larviciding operations reduced thls again to 12 years, which gave a final end date of 2002lor OCP Over to you: Ihe process of Transfer Armed with the means and an accurate time frame, effecting transfer took on a new priority In response to the OCP's Devolution Unit, the participating countries each formed a National Devoiution Committee and reaf- firmed their commitment to maintaining the achlevements of the OCP The Ministers of Heaith of the participating countries signed a resolution to this effect in December 1995. It was decided that surveillance of onchocerciasis should be part of a larger endemic disease surveil- lance network. Thus each country drew up a national plan including two or more of the followrng diseases: gurnea-worm, human trypanosomiasis, schistosomiasis, malaria, leprosy, yaws, tuberculosis aiong with onchocerciasis. This was a further example of the translation of a once verti- cal, single disease approach into a hori- zontal programme, working towards the goal of Health for All by 2000. Following all party discussions it was agreed that OCB the participating countries and the donors would each have distinct responsi- bilities in the transfer process which would run until 2002 when the OCP ended. 0(P was to proüde the appropriate diag- nostic tools and methods of control to the nationals. The participating countries should institute effective recrudescence and control meas- ures along the OCP guidelines and where possible make use of the highly trained staff of OCP whose contracts were coming to an end- Ihe donors were asked ro conrinue funding at a level that would see rhe transfer process effected without financial restraints, as part of the final phase of OCP Each played its part and following an OCP review and a series of country workshops in 1995 the pace of transfer increased. In 1996 at OCP Headquarters in Ouaga- dougou the increasing focus on transfer led to some internal rearrangements. Epidemiological evaluation, Devolution and Biostatistics and Information Systems were merged to form Planning, Evaluation and Tiansfer (PET). The Unit worked closely with Vector Control to ensure that larviciding was maximally effective so rhar the best possible epidemiological situation could be handed over to the participating countries. Work continued within PET to strengthen the national capacity particu- larly in the fields of epidemiological evalu- ation and surveillance. This was achieved by the methods that OCP had used to such good effect since the 1970s - opera- tional research, education and training, and collaboration. Skin snips had become increasingly unpopular among the locai populations. The desire for a non-invasive technique was joined with the people's fear of the spread of hepatitis and HIV Trials of the DEC patch - a test based on the local reac- tion to the drug diethylcarbamazine, which kills microfilariae in the small area of skin covered by the patch - were suffi- ciently good to begin training narional staff from 1997 onwards. I I l I l i Ihe DE( patches were to be used in the partici- pating countries in a network of sentinel vil- lages, each with a population of three to four hundred located in formerly hyperen- demic areas, near what used to be active breeding sites before vector control began. Villages would be visited once on a three- year cycle. The success of this proposed surveillance system received a strong fillip when a recrudescence was detected (although not by DEC patch test) and treated in Burkina Faso entirely by the national teams. Innovations such as the DEC patch test were incorporated in the epidemiological surveillance manuals prepared by the OCP Whereas in the past 'on-the-job' training in specific areas, such as hydro- biology, had been the norm, now the emphasis was on proüding a compre- hensive scheme for the nationals. On the entomological side, it was decid- ed to train villagers to collect black flies which could then be forwarded to the DNA laboratory where any parasites they might contain couid be analysed. The discovery that many larvae found in the heads of black flies belonged to the cattle parasite Onchocerca ochengi which are harmiess to humans, improved the precision of entomological evaluation: 'high-tech' laboratory studies could therefore be harnessed very effectively with'1ow-tech' catching methods. The progressive shift from OCP mobile teams delivering ivermectin to the com- munity-based delivery under the author- ity of the National Onchocerciasis Coordinators, accelerated during the rransfer period. By 1998 distribution was entirely in the hands of the nationals. ln the interim, Coordinators and OCP staff evaluated distribution programmes ensuring that optimum strategies were used and continued to be effective. l-ate in the programme the securing of ivermectin supplies from the Mectizan Donation Program (MDP) was also trans- ferred to the national teams. ln this way distribution afrcr 2002 could be done entirely without the suppon of OCP Transfer was a brave but necessary step. Ensuring that the proper facilities, staff and procedures are in place is the final test of OCP's abllity to adapt and face challenges. The continued ügilance of the participating countries is currently assured by their strong commitment. A commitment which reflects the improved health and socio-economic conditions prevailing in their countries; an appreciation of the trust placed in Africa by the intemational community; and perhaps most important of all, the empowerrnent that comes from deter- mining destiny yourself.

Achieving the objectives or 'the hard facts file' As long ago as the opening page ol the PAG mission report in 1973, iL was stat- ed that 'Ihe main objectives of the Programme envisaged are twofold: to combat a dis- ease that is widespread and severe in the area, and to remove a major obstacle to economic development.' In addition it was considered essential '...for the Participating (ountries to main- tain this achievement.' Now at the close of OCP lt is possible to say in reply: 40 million people are now ptotected from onchocerciasis, eithet because the dsk of contmcting the disease has been eliminated thtough the absence of the parasite, or because the on- going work of APOC, the offspring of 0(Q, is delivering chemotherapy which will protect exposed populations from new infections. Thus, more than 2 mil' lion people who were severely infect- ed by onchocerciasis at the beginning of the conttol opemtions and there- fore at risk of developing ocular lesions are no longer exposed to that risk: in excess of 600,000 cases of blindness have been avoided through the interuention of the OCP. Looking back: Success in Africa The protection of 40 mlllion people also implies that all the children born since the beginning of the programme will be spared the risk of going blind from onchocerciasis. These 'eyes of hope' are now lighting up the faces of close to 18 million children and adolescents. Because the programme has been sus- tained for the necessary duration, no mother has had to be told that the protection offered to one child is not available to the subsequent children: an important psychological issue for those delivering and receiving medical aid. In the river basins freed from the disease several years ago, onchocerciasis is today a disease of the past for the young who only know it from the stories told by those who were born before the begin- ning ol the programme. With respect to the promised socio- economic development the news is good here too. More than 25 million hectares of fertile land have been freed from the threat of onchocerciasis in the 11 coun- tries covered by the OCP (see Appendix 7). These millions ol hectares in the river basins will make it possible to feed 17 mil- lion people if they are exploited through traditional farming methods. According to the World Bank estimates, the annual cash value of food production in these liberated areas could amount to US$340 million. The resettlement of the onchocerciasis- freed zones in Burkina Faso is a wonder- ful illustration of the economic impact of OCP operations. Here, under the aus- pices of a specially created government office for national land development (ONAT), nearÿ 100 new villages have been established and the infrastructure of some 230 traditional villages strength- ened. More than 8,000 new farms have been creat- ed and at least 35,000 traditional farms have benefited" from improvements in farming methods involving 400,000 people and 250,000 hectares of devel- oped land. More than 1,000 km of rural roads have been built and about 700 wells and boreholes have been dug allowing for the supply of safe water in the order of 400 litreÿ house/day. Furthermore, 41 schools, 22 outpatient dispensaries and 111 üllage granarits have been constructed. The total value of the agricultural output. in 1990 was close to US$37 million, some US$2,700/îarm/ year, for a total OCP investment of US$30 million. In other words for Burkina Faso alone, this represents 6.41o of the total investment made by OCP between L974 and 1998 (US$504,2 mll- lion) an amount which is now gained annually from the production in the resettled lands alone. This result is only one compared to the overall potential of the oncho-freed zone in Burkina Faso. The return of the funds invested in the programme is substantial when all the eleven OCP countries are considered. The results of OCP control operations are also important for the improvement of living standards, especially as regards the health status of the populations. Thus, the construction of primary health care centres in most of the developed zones ensures access to healthcare and to essential drugs that would otherwise not be the case in isolated villages. Furthermore the agricultural production ensures food sufficiency for the farmers and may even allow for the sàle of their products. Taking the example of Burkina Faso again, a former food importel is now a food exporter. 'l I ( I .i Feeding the populations of the Sahel countries has been a serious issue for many years. The food production in the onchocerciasis-freed zones contributes significantly to solving local, national and regional nutritional problems. FAO sponsored projects are actively bei.ng pursued in all the programme countries. Of course this has been a relatively expensive process. The total budget over the 28 years of the programme's active life comes to US$556 million. However, it is possible to consider this from another perspective. The cost of protecting one person per year from disflgurement, blindness and the subsequent socio- economic effects is under US$l/year. It doesn't seem quite so much now, does it? A thorough cost/benefit analysis conduct- ed by the World Bank gave an economic rate of return (a standard measure for social sector projects) of 18o/o over the 28 years of the programme (1974-2002). Over a longer time 1974-2012, the rate is 20ok. The 38-year period takes into account the accumulation of gains towards the later stage of the project, which are expected to continue for at least l0 years beyond the end of the pro- gramme even without the planned sur- veillance and control measures. Normally the World Bank expects their projects in the productive sector (excluding social sector projects such as health and educa- tion) to have an annual rate of return of 10o/o. By the stringent measures of the World Bank, the OCP is doing well. Success can be seen in the healthy faces of the children, in the absence of blind people. But it is also to be found in the new found dignity of the villagers. Those who inhabit the riverine valleys no longer need feel ashamed to meet strangers because of the condition of their skin, and the incessant need to scratch. Their motivation for life has returned, and those who have never known onchocerciasis approach life with a wonderful zest. The OCP has not solved all the problems of the savannah region of West Africa but it has given hope and empowered the §ome less tangible benefits A new dignity These statistics make great reading, not least to those who have worked for most of their careers for the programme and have become imbued with a deep-seated sense of purpose that they were able to translate into commitment and high quality work. Former members of the OCP, when asked to describe the changes brought by the programme or how one might measure its success, ans\Mer by suggesting a visit to the vil- lages to see the people and talk with them as they have done in the course of their work. comnlLtnities to help themselr.es or t.o scek partncrships b1 participattng in ()nc oI the man1, FAO lancl prr-rjects currenrly undenva)' in the prograntrrle llrea. Where formerly' the village populatlons lvould be lelt ,,l,ithout the basic sentces on offer from the governments rhrough understandable fear of the disease this has changecl. Villages now har,e nurses and teachers. They are proud of their school buildings and keen to send their children to sr hool The clivision o[ labour in a lamily or vil- lage no longer has to c,-rmpensate for thosc u,ho are blind, parricularly the i'oung aclults rvho have so much to ofer their communities. Not least by helping to continue the sun,eillance measures argainst onchclcerciasis. 'Afro-optimism' The OCP has brought a change ol heart to West Africa or an 'Afro-optimisim'. The OCP has also changed the percep- tion ol Africa in the eyes ol others. The collaborations that har,e held together during the history of the programme are probably unique: A nolth/south collaborarion berrveen rhe rich industrial nations and the poor countries south ol the Sahara, the north not losir-rg laith in the south er,en in the face ol adversity and the south achieving what it set oLrt to do. A south/south collabolation berween the neighbouring countries in the pro- gramme area rvho have put aside an), clif- lerences to keep the OCP helicopters fly'- Feeding the populations of the Sahel countries has been a serious issue for many years. The food production in the onchocerciasis-freed zones contributes significantly to solving local, national and regional nutritional problems. FAO sponsored projects are actively being pursued in all the programme countries. Of course this has been a relatively expensive process. The total budget over the 28 years o[ the programme's active life comes to US$556 million. However, it is possible to consider this from another perspective. The cost o[ protecting one person per year from disfigurement, blindness and the subsequent socio- economic effects is under US$I/year. It doesn't seem quite so much now, does it? A thorough cost/benefit analysis conduct- ed by the World Bank gave an economlc rate of return (a standard measure for social sector prqects) of l8o/o over the 28 years of the programme (1974-2002). Over a longer time 1974-20L2, the rate is 20o/o. The 39-year period takes into account the accumulation of gains towards the later stage of the prqect, which are expected to coniinue for at Ieast 10 years beyond the end of the pro- gramme even without the planned sur- veiilance and control measures. Normally the World Bank expects their projects in the productive sector (excluding social sector projects such as health and educa- tion) to have an annual rate of return of 10o/o. By the stringent measures of the World Bank, the OCP is dolng well. Success can be seen in the healthy faces of the children, in the absence of blind people. But it is also to be found in the new found dignity of the villagers. Those who inhabit the riverine valieys no longer need feel ashamed to meet strangers because of the condition of their skin, and the incessant need to scratch. Their motivation for life has returned, and those who have never known onchocerciasis approach life with a wonderful zest. The OCP has not solved all the problems of the savannah region of West Africa but it has given hope and empowered the Some less tangible benefits A new dignity These statistics make great reading, not least to those who have worked for most of their careers for the programme and have become imbued with a deep-seated sense of purpose that they were able to translate into commitment and high quality work. Former members of the OCP, when asked to describe the changes brought by the programme or how one might measure il.s success, answer by suggesting a visit to the vil- lages to see the people and talk with them as they have done in the course of their work. ing for the good ol their rural popula- tions and the resuiting economic devel- opment. A north/north collaboration between the donors and sponsors who have main- tained their support and not allowed their differences to affect the pro- gramme. A managemeflt collaboration, referring in particular to the division o[ labour and effective working relationship o[ the four cosponsors through the Committee of Sponsoring Agencies, particularly the commitment to unite health and devel- opment agendas through the WHO and the World Bank. A public/private collaboration, manifest in the larvlcide screening and develop- ment o[ ivermectin and its subsequent gilt by Merck §s Co., Inc. and the partic- ipation oI NGOs. At the centre of this collaboration matrix is West Africa. E OCP @unFi6 Collâbo.atlng @ndog fq opêEtional Eêarch Olhgr æùnties 0perational resear(h was conducted by the OCP in collaboration with several countries/institutions. Research and training The OCP has put onchocerciasis on the world map in many ways. Not the least of these are the results of the applied research conducted to keep the pro- gramme viable and up-to-date, but which have provided a resource for the rest of the scientific, health and development communities. The OCP ONCHOBIB database, created in 1993, reflects in part the huge amount of knowiedge generated by the programme. The OCP began, based on the best possible contemporary research, and the need to continue to hone procedures was a constant feature of the life of the programme. In the early years, operational research focused on basic vector biology and epidemiology and was carried out by consultants from the international onchocerciasis commu- nity who came into the programme area from the outside for a limited period of time. As the programme estabiished its own facilities and increased the expertise and diversity of its own staff, they con- ducted more operational research in col- laboration with experts from elsewhere. These became coileagues, part of the wider family The diversity of research re{lects both developments in late 20th century medi- cine and biology and the breadth of the programme over time. Highlights must include: Ihe phenomeîoî of Sinuliun migration and its effects on reinvasion The search for different new insecticides following temephos resistance and development of a rotational larvkiding strategy The development of methods of black fly and parcsite identification to assist in defining epidemiology and control ldentification of a new black fly species and pamsite strains ldentification ol Onchocerca ochengiin cattle as a (onfounding parameter in epidemiology with its subsequent use as a model for chemotherapy and immunology lntroduction of ivermectin for moôidity control Development of the ONffOSlM mode! Development of molecular techniques for routines in control: the DNA probes Development of computerization of aedal larviciding Utilization of telemetry for acquisition of hydrological information Extensive data sets on inveilebrate and fish fauna of West African dyer systems proyiding unrivalled information on population dynamics of aquatic fauna. This is an extensive list. Any university and school of public health or tropical medicine would be delighted to have achieved so much in 28 years. Research leads to new learnlng. In addi- tion to the basic entomological training for technicians, and advanced courses in the biology of black flies for aheady qualified entomologists, which were essential for the day-to-day work of the programme, the OCP has functioned as a 'training institute'. Africans and others have used the programme to gather data for their PhD theses and other hlgher qualifications. The number of those who profited from a scholarship scheme offering additional training at all levels runs into the hundreds and covers a variety of fields, including management and administration. ln the later years of the programme the earlier focus on sending individuals abroad to learn was replaced by an emphasis on 'within Africa' education. Improvements in facilities - the DNA laboratory and computer modelling- and concern about the risks of the 'brain drain'both contributed to this decision. Where better to learn about onchocerci- asis and health care management than the 'university without walls' that is the OCP? tlexibility in health care approaches The OCP was launched in the era that championed primary health care. lt saw the end of the troubled malaria eradica- tion programme when vertical, single disease programmes were put aside in favour of horizontal multi-disease approaches to health care, often using Iocal 'bare-foot' personnel, rather than highly trained physicians and surgeons. Given the available technology, a verti- cal programme of aerial larviciding was the only viable means to control onchocerciasis. With the advent of iver- mectin, a drug that could be distributed by trained community health workers with great success, the programme was able to develop a horizontal approach: CDTI. Despite this new strategy, the ver- tlcal element, vector control, continued on the same schedule due to the com- mitment of donors and programme staff to bring the programme to its projected end in 2A02. The lesson here must be that flexibility of approach rather than rigid adherence to policy can give good results. i'1 'l ,,ÿ{ f utureThe This is a retrospect on a remarkable achievement. But it is impossible to close without a glance to the future. After all, that is what OCP has given to so many people, the gift of clear sight. APOC, the African Programme for Onchocerciasis Control, is now 6 years old. Launched in 1996 it continues the spirit of OCP It does not rely on aerial Iarviciding for control of the disease but instead uses the drug, ivermectin. APOC is a partnership of NGDOs concerned with blindness prevention, WHO, the World Bank, governments o[ endemic countries, the sponsoring agencies and donors. APOC reaches out to help the HIV/AIDS, malaria, lymphatic filariasis, schistosomiasis, guinea-worm and tra- choma, as well as maintaining the con- trol of onchocerciasis. And, if the past is any guide to the future, the OCP shows that the collabo- ration upon which the programme \Mas built is possible and profitable: working together, working hard and working well, brings success in Africa. onchocerciasis sufferers also in countries that border the OCP area. Thus preserving the suc- cess of OCP while helping oth- ers. The valuable infrastructure of the OCB the headquarters com- pound in Ouagadougou with the DNA laboratory, document reference centre and Radionet will become a Multi-disease Sur- veillance Centre (MDSC) of the World Health Organization, Regional Office for Africa. For this sub-region of Africa, it will help in the fight against public health problems such as Appendix 1 Donors to the Proglamme Countries Belgium Canada Denmark European Commission Finland France Germany lraq Italy JaPan Korea (Republic of) Kuwait Luxembourg Merck and Co., lnc. (mectizan donation) The Netherlands Norway Portugal Saudi Arabia Switzerland United Kingdom United States of America { l I I 0rganizations/l nstitutions African Development Bank Al Sabah Foundation Gulbenkian Calouste Foundation 0PEC Fund for lnternational Development UNDP WHO World Bank I r I l NGD0s associated with OCP Christoffel-Blindenmission Helen Keller lnternational Organization for the Prevention of Blindness Sight Savers lnternational Appendix 3 Directors of the OcP Dr Jacques Pierre Ziegler, 197 4 - 1976 Dr Marc Ls Bazin, 1977 - 1980 Dr Ebrahim Malick Samba, 1980 - 1994 Dr Kofi Yankum Dadzie, 1995 - 1999 Dr Boakye A. Boatin, 2000 - 2002 Appendix 4 Contributors (oral and written) to this history . 0r Hyacinthe Agoua . Mr Assi Aké . Dr L. K. B. Akpoboua . Mr (ompaoré Boureme Apollinaire . Dr David A. T. Ealdry . Mr oumarou Barry . Dr Essosolem Jean-Paul Batchassi . Mr Bernard Bayala . Mr Bruce Benton . Dr René Le Berre . Dr Yiriba Bissan . Mr Gondo,ean Blessy . Dr Boakye Boatin . Dr Ole Worm Christensen . Mrs Constantine Compaoré . Mrs (atherine Cross . Dr Kofi Yankum Dadzie . Mr Abdulai Daribi . Dr John Davies . Dr Ahmed Kémoko Diallo . Mr Youssouf Diallo . Dr Brian 0. l-. Duke . Mr Georges Kwaku Fiasorgbor . Mr Marc Fossoungo . Dr Herbert Gilles . Dr Colin Ginger . Mrs Marie josèphe Gounabou . Dr Pierre Guillet . Dr Jean Marc Hougard . Mrs Marie Paule Kaboré . Dr Joseph Kaboré . Dr Marc Karam . Dr ï. Karsa . Mr Mabo Kassambara, . Mr Bruno Ki . Dr Sawa Koffi . Mr Ahoutou Kouadio . Dr Halfdan Mahler . Dr Douglas Marr . Mr Davin McLaughlin . Mr Rolf Meyer . Mr Donald E Miller . Mr Jacques Moboye . Mr Abdulai Adam Mogli . Dr David H. Molyneux . Mr Mamadou Nawayama . Mr Seni Pierre Nikiema . Mr Balo Rigobert Ouando . Mrs Déborah Ouattara . Mr Maxime 0uédraogo . Dr Assimawe Paul Pana . Mr Poudiougou Pangalet . Dr Bernard Philippon . Dr Ebrahim Malick Samba . Dr Souleymane Sanou . Mr Madi Sawadogo . Prof Ram Christophe Sawadogo . Mr Sébastien R Sawadogo . Dr Azodoga Sékétéli . Mr Kadzo Kouma Sewa . Mr Bayor l. Sibiri . Dr Edoh Soumbey-Alley . Mr Samuel Adjei Sowah . Dr Laurent Ioé . Ms Rosemary Villars . Mr Timothy G. Wahlberg . Dr Laurent Yaméogo, . Mr Dolourou Yeo . Mr Doro Gaston Zerbo, . Villagers of l-inoghin and Wayen in Burkina Faso . Mr Ram Adama Ouédraogo (translator) . Mrs Kanzié Maria Goretti Sawadogo (Agricultural agent) . Villagers of Toblao in Togo ,t l l I' I I Appendix 5 , ,, , 1{?i. lrli' =':,it *- .- lIï*'.ï**, *:#,m," ,",*r*, il,**l ,,,*Ë,,;.$'#ffiffi ', ,'',,i, :ii jl,"*ll:l :'ll.;, ;;,::.,',, ri,;,1;1,,'*îï'-""'i"*:mXiiï*f*i*Ë"îilk;:::îü, :l;::.':li': lrqrl,l il'" & o"" r% r "'. ,-& â qrffiïjË";#§§ffiê&§r $ "r ;' {I '\ $ rmrTÿâa'TtÊdlrIï ^# i.L*.ilrLr{$LiÇLif I j I l I I t t :..,... .,1)- lô;.:.... ,..-,,,r:.rtl.;t! 1,+l I I .t ! i i l '1 I I ;ïïîi:.***ying dra*in6 ' I "aàiia luoiat' li i l'ii'i'; ltiii::ll 1l i '. !:" - 'i, .l:,itrr1,r:r;':'_lii,,slr,,;,rllrt,l'.:.1.,,,,'.',,'-_.\i.,'i,.,r'iri-.r':'..r ., i:, .,-,.r1,r,,,,,!. ;l 1l''i1 "'' , ''':.., .,,,,l.,,,1 1-'1',t"'r'f,i1,,,,t, , ,,,'.;:l::.l'.,;"'1 ,, 1,,',1:',,, . f'. :, .']''.";. . ,, ,,i..,:,:l i, ', r]i11l1l1i]1:l'...",r...i'.,l1,llll,.,''. :,1 i.i:: lt::_: "ll1'fi Appendix 6 Geogmphical distribution of onchocerciasis in Africa and the Arabian peninsule ffi Endemic onchocerciasis '1. Oâxaca tocus 2. Northem Chiapas locus 3. Southern Chiapas locus 4. Huehuetenango locus 5. Solola-Suchitepequez locus 6. Escuintla tocus 7. Sanla Rosa locus 8. North-central focus 9. Norlh€astern,ocus 10. Southern locus 1 1. Amazonas+loraima locus 12. L6pez dê Micay locus 13 Narino locus 14. Esmeraldas locus Geographical distribution of endemic onchocetciasis in the Americas Appendix 7 ,i\ tl'ruÂroN 'N rrrrl lstruAnoN rN rrr4l I conotidârion I i{:{iifif" - Mninl€mnæL-J (6-lo voarrJ f_----t l0 years ruinrenanceL-J @mole!€ct ^. ,"riî;. TlÉ boundarrer of rhc lhree subdivrsioôs in rho Wesr6rn Exleôtion srên hsve t»€n drawn lor illu3trotive puræiâs onty. 0OZr lO.2 & 10-3 will ênrêr second half ol maintsnane Ër'od in 1997 3nd I998 respcctrvelv. whcn ràtuin,nq areàl hôr â[ârdv hôd tO yedrg or more maintenand, lExcepr OOZ3 Og ànd l0.l -t '(.. t\ i I Proiected operational development : Ihe Strategy