Infectious diseases : global alert, global response [full issue]

THE MAGAZINE OF THE WORLD HEALTH ORGANIZATION sOTH YEAR, NO. 1, JANUARY-FEBRUARY 'I997 Iheme ortirles [et's work logether io conlrol inledious diseoses HiroshiNokoiimo Emerging inledious diseoses Dovid Heymonn WHO response lo epidemirs Gu6noEl Rodier Cholero: o thollenge for the 2l sl (enlury Morio Neiro Ropid diseose surveillonre Shivo Murugosompilloy J{ew touses lor new diseoses John M. Lo$ Resislonl slroins ol micoorgonisms Jocques F. Acor Emerging foodborne diseoses Monis E. Poller, Yosmin Motoriemi, & Fritz K. Kriferstein Emerging zoonoses Frongois"Xovier Meslin, Klous Stt)hr, & P. Formenty AIDS oflects us oll Michel Thurioux & Suzonne Cherney Tubertulosis need nol kill 2? litendro Tuli Resurgenre ol rommunitoble diseoses in Europe 24 Sieghort Dinmonn Hospilo! inlettions 26 Louise Tenn, Anne Wynes, & lrene Goldstone Feolures News lrom the Regions ?7 Heolth briels ?B WHO odvises. .. . 30 WHO publkotions 3l ,,ravW THE MAGAZINE OF THE WORLD HEALTH ORGANIZATION ,ru***o,ffir**.*; Front cover: WHO. A plogue vict'im is hunied t'o the hosptfol by his relot'ives Photo: Still Pict'ures/P Chandra a poge 2 I t0 17 t4 l6 IB 20 poge 22 World Heolth r 50fi Yeor, No. I Jonuory-Februory 1 99i tx lssN 004&8502 [onespondence should be oddresed to the fditor, World Heolth l/\ogozine, World Heohh 0rgonizolion, CllI 2 I I Genevo 27, Swiizerlond, or directly to oulhors, whose oddreses ore given ot lhe end of eoch orticle. For subscipiions see orderform on poge 3i. World Heolthisthe offiriol illuslroled mogozine of the World Heolth 0rgonizotion. lt oppeors six times o yeor in English, french ond Sponish, ond four times o yeor in Arobk ond Forsi. The Arobic edition is ovoiloble from WH0t Regionol 0ffke for the [oslern Mediterroneon, P.0. Box I 5l 7, Alexondrio 21 5 1 1, tgypt. The foni edilion is obtoinoble from the Publit Heolth [ommittee, lron lJniversity Pres, 85 Pork Avenue, Teheron 1 5875.4748, lslomk Republic of lron. o World Heolth 0rgonlzotion I 997 All rights reserved. Arfides ond phobgrophs thot ore not subiedt0 seporote copyright moy be reproduced for non<ommerciol purposes, provided thol WH0's ropyr(hi is duly orknowledged. Signed orticles do not necesorily reflerl WH0's views. The designolions employed ond lhe presentotion of moteriol published in Vlorld Heolkdonolinply fie expresion of ony opinion whoBoever on fie pori of fie 0rgonizotion concerning the legol stotus of ony couniry, terrilory, (ity 0r 0re0 or of iis 0uthorities, or concerning the delimitotion of its frontiers or boundories. World Heolth r 50th Yeor, l,lo. l, JonuorrFebruory 1997 ffid'6rmr#m# Dr Hiroshi Nokolimo, DireclorGeneral of WHO. Photo: WHO/H. Anenden. by using World Health Day (April T) as a catalyst, countries will be able to take a realistic look at these problems and concentrate on rebuilding the health system as the foundation of disease surveillance and control. Both the public and the private sec- tors must be encouraged to research and develop better techniques for surveillance and control, and new antibiotics to replace those which are no longer effective. We have to face the fact that infectious diseases are a cofllmon threat which demands urgent atten- tion, especially at a time when people all over the world are being brought closer together by international travel and trade. Communicable diseases respect no frontiers. We must work together globally to control them. I ,1, lel's work together to (ontrol infedious diseoses ntil quite recently there was a widespread feeling that the struggle against infectious diseases was almost won. The means of controlling most of them seemed either available or discoverable without undue difficulty. Spectacular progress has indeed been made: smallpox has been eradicated and six other diseases will be eradicated or eliminated soon. But, tragically, with optimism came a false sense of security, which has helped many diseases to spread with alarming rapidity. Major diseases such as malaria and tuberculosis are making a deadly comeback in many parts of the world. At the same time, diseases such as plague, diphtheria, dengue, meningococcal meningitis, yellow feveq and cholera have reappeared as public health threats in many coun- tries, after many years of decline. In addition, previously unknown infectious diseases are emerging at an unprecedented rate. In the last 20 years, more than 30 new and highly infectious diseases have been identi- fied. They include the virulent Ebola- type haemorrhagic fever, HIV/AIDS and hepatitis C. For many of these diseases there is no treatment, cure or vaccine. Antibiotic resistance is another important threat to human health which has emerged during the last 20 years. Drugs which once could be counted on for protection against many infectious diseases are becom- ing less and less useful as resistance to them spreads. In addition, fewer new antibiotics are being produced, owing partly to the high costs of development and licensing. As the treatment of communicable diseases becomes less effective, more people need hospitalization, illnesses last longer, treatment costs more and absenteeism from school and work increases. There are many reasons for the appearance of new diseases and the resurgence of communicable dis- eases once thought to be well under control. These include the rapid increase in international air travel and the growth of mega-cities with high population densities and inade- quate safe water and sanitation. The risk of foodborne diseases has been heightened by the globalization of trade and changes in the production, handling and processing offood. Environmental factors can lead to the exposure of humans to previously unknown diseases. For example, man is destroying forests and moving into previously remote animal and insect habitats which carry high risks of exposure to disease. Meanwhile, in rich and poor countries alike, resources for public health are being reduced as limited funds are spent on other priorities. As a result, the appearance of new diseases, the re-emergence of known diseases, or the development of antibiotic resistance may go un- noticed until it is too late. A recent striking example is the human im- munodeficiency virus (HIV) which was recognized only after it had already infected large numbers of people in many countries. If diseases of epidemic potential are detected early enough, epidemics and pan- demics can be prevented in some cases, in others minimized. For these very pressing reasons, the theme "Emerging Infectious Diseases: Global alert, Global re- sponse" has been chosen for World Health Day 1997.It is my hope that, llimhi Nokoiimo, ltl.D., Ph.D. WorldHeolth r 50thYeor, No. I, Jonuorv-Februoryl99i Emerging infertious diseqses Dovid Heymonn The emergtunce or re- emr;rgence of infectious diseoses slemsfrom the inueosing world populofion, ropid internotionoltrovel on o large xole, ond inueosed r,xposure of humon beings to diseose vecfors in nofure. j,. , report published by the United '. , States Institute of Medicine in '' ' 1 1992 called attention to signs that the fight against infectious diseases was far from won, despite great advances in the development of antibiotics and vaccines. The report cited emerging or newly identified infectious diseases as evidence for this and also highlighted re-emerging or resurgent infectious diseases hitherto thought to have been over- come. It is now clear that the emergence or re-emergence of infectious dis- eases is partly the result of a shift of resources away from infectious disease control, public health and sanitation. It is aggravated by the fact that antibiotics which were once effective against some of the most common human infections have gradually become ineffective. In addition, changes to the environment may bring the animals and insects that carry disease into closer contact with human beings. During the past 20 years, more than 30 new micro- organisms have emerged, some of which cause dramatic and lethal disease in localized outbreaks or over great distances, at the cost ofenor- mous suffering and expense to soci- ety. Meanwhile many common diseases have re-emerged and spread rapidly after periods when they were Mtnguinhos fovelo in Rio de Joneuo. S/ums ore fertile breeding grounds for tnfectious dlseoses. Phofo: Keyst'one o. no longer considered to be a problem. The term "emerging infections" refers to newly identified and previ- ously unknown infectious diseases which cause public health problems, either locally or internationally. They include: a fatal respiratory disease caused by a virus called sin nombre ; a variant Creutzfeldt-Jakob disease which is suspected, though not proven, to be associated with a similar disease in cattle called bovine spongiform encephalopathy; HIV infection, which is now a worldwide cause of human suffering and death and a heavy economic burden; and some rare but equally devastating diseases such as Ebola haemorrhagic fever. These diseases may be new in human beings, or may have been present for a long time but not recog- nized. But many emerging diseases are thought to be the result of people coming into closer contact with natural reservoirs of disease in the environment, which has permitted a jump of the infectious agent across the species barrier from animal to human being. Other examples of new or newly detected infectious diseases of global concem include Legionnaires' disease, haemolytic uraemic syndrome caused by E sche richia c oli Ol57 :H7, Lyme disease, hepatitis C and E, and a new form of cholera caused by Vibrio cholerae 0139. WorldHeolth I 50lhYeor, No. 1, Jonuory-Februory1997 Re-emerging infectious diseases are infections that have been known about for some time but had fallen to such low levels that they were no longer considered a public health problem. They often reappear in epidemic proportions. Well-known examples are: tuberculosis, which is increasing worldwide partly owing to its close association with HIV infec- tion; cholera, which has been reintro- duced into countries where water and sanitation systems have deteriorated; and dengue or "breakbone" fever, which has occurred in urban areas where mosquito control has broken down. Drug resistonre Resistance to antibiotics is a phe- nomenon common to both emerging and re-emerging infections. Many well-known antibiotics are no longer effective against common inf-ections such as pneumonia, gonorrhoea and tuberculosis. At the same time, fewer new antibiotics are being released on the market, partly be- cause of the high cost of developing and licensing them and partly be- cause they have a potentially short life because of the development of resistance. Ifthe arsenal ofdrugs against infectious diseases loses its power, the future for patients with even a common local infection will become bleak. Several factors contribute to the emergence and re-emergence of infectious diseases, but most can be linked with the increase in the num- ber of people and in population movements, rapid intemational travel, overcrowding in cities with poor sanitation, changes in the han- dling and processing of large quanti- ties of food, and increased exposure of human beings to the carriers and natural reservoirs of disease. Other factors include a deteriorating public health infrastructure which is unable to cope with population demands, and the emergence of resistance to antibiotics resulting from their in- WHO ensures thot int'ernotional ropid response teoms con be mobilized in cose of epidemtc threots. Phofo: WHO/G. Rodier. creased misuse. Travel has always been a means by which disease has spread across the world. In the 14th century in the city-state of Venice it resulted in protective legislation which has evolved, over the centuries, into the current International Health Regulations. Today, well over 50 million people use international air The lnternofionol Heolt'h Regulations require cetoin infect'ious dlseoses to be reponed. This imponoil bol for slopprng the spreod of epidemics ocross boundories ts now being revised io mole tt more opplicable to infection conlrol in lhe 2l sl centurv lnternotionol Heolth Regulotions The first recorded quorontine regulotion wos written in Venice in 1377 to protect the cily-stote from diseoses corrled by shipborne rots. Neorly five centuries loter, in I B5l , the first lniernotionol Sonitory Conference loid down certoin principles for proteciion ogoinsl diseose, but onoiher century elopsed before o wide voriety of meosures were forged inlo the lnternotionol Sonitory Regulotions of I 951 . ln I 969, the lnter- notionol Heolth Reguloiions (lHR) were odopted, oimed ot ensuring moximum securiiy ogoinst the internotionol spreod of diseose. The officiol reporting of three communicoble diseoses - choiero, plogue ond yellow fever - is required under the lHR, bui no internotionol body - not even WHO - hos ihe mondote to enforce this reporting. Consequently some outbreoks go unreported when o country believes its economic interesls might be odversely offected. When Peru wos hit by cholero in I 99 I , ond when lndio suffered on outbreok of pneumonic plogue three yeors loter, both countries prompily reported the foct. Their trode ond trovel losses were estimoted ot US$ ZOO million ond $ I 200 million respectively. Todoy, new ond re-emerging infectious diseoses not deolt with under the IHR hove the some potentiol for spreoding ocross notionol boundories. The 1995 outbreok of Ebolo hoemorrhogic fever in Zolre wos fortunotely contoined before it could spreod beyond the frontiers. Simllorly, the 1993 oulbreok of hontovirus pulmonory syndrome in the United Stotes provoked notionol olorm obout the possibility of cross-border tronsmission, but ogoin the IHR were not opplicoble. Following o World Heolth Assembly resolution in 1995, WHO is now revising ond updoting the IHR to moke them more opplicoble to infection control in the 21st century They will cover "defined syndromes representing diseose occurrence of internotionol importonce" ond will set out the meosures notionol heolth outhorities should instrtute to protect their territorles from infectious diseoses. *ffiixtff#:* hho4Ne^6&fu WorldHeolth r 50thYeor, No. 1, Jonuory-Februoryl997 transport each year. The concerns expressed in Venice related to cholera, plague and smallpox which were transmitted from one continent to another by ship. Now it is not only possible but quite likely that a disease will appear days after the arrival of an infected traveller rather than during the voyage. Emerging and re-emerging infec- tions reflect the constant struggle of microorganisms to survive. primar- ily by finding breaks in the barriers which normally protect human beings from infection. Such breaks may result from high-risk human behaviour" failure of disease detec- tion systems, failure to control mosquitos and other carriers of disease. breakdown of water and sanitation systems, and deforestation which forces forest animals closer to human settlements in search of food. These breaks have developed rapidly in just a few decades, at the same time as interest in inf'ectious diseases has waned and resources for their detection and control have decreased. Because such diseases appeared to pose a declining threat, funds for their control were chan- nelled to efforts against other prob- lems. Experts on infectious disease retired or left the field and students turned to more rewarding subjects than viruses and bacteria - in short. the infrastructure for control of communicable disease began to crumble. WH0t response Since 1992 the alarm over emerging and re-emerging diseases has echoed around the world. Great concern was expressed by the Member States of WHO in a resolution of the World Health Assembly in 1995, which urged all countries to strengthen surveillance for infectious diseases in order to promptly detect re- emerging diseases and identify new ones. The success ofthis resolution depends on the ability to obtain information about infectious dis- eases and a willingness to communi- cate this information nationally and internationally. WHO therefore established the Division of Emerging and other Communicable Diseases Surveillance and Control (EMC), which is charged with strengthening national and interna- tional surveillance and control of communicable diseases, including lhose that represent new. emerging and re-emerging public health prob- lems, for which it must ensure a timely and effective response. One of the main functions of WHO, through EMC, is to provide technical assistance and training in communicable disease surveillance and control, and in public health laboratory support. EMC has also set up mechanisms for timely ex- change of information on the current communicable disease situation worldwide and on the experiences of countries in disease surveillance and control. This infbrmation may be obtained from printed WHO publi- cations and through the EMC World Wide Web site on http://www.who. ch,,iprogrammes/emc. WHO's col- Iaborating centres, linked electroni- cally with WHO headquarters and regional oflices, form a worldwide network for infectious disease moni- toring and early alert of outbreaks. The International Health Regula- tions are being revised and adapted to the scale of international traffic and trade expected in the 2 I st century. Another crucial role of WHO is to assist countries to respond to epidemic emergencies. EMC en- sures that it is possible to mobilize international rapid response teams of WHO statT and other experts in response to epidemic threats. in collaboration with the Division of Emergency and Humanitarian Action. WHO, through EMC and in partnerships with other bodies, will provide the key to cost-effective action for a world which is on the alert and able to contain infectious diseases. I Dr Dovid Heymann is Dtrector of the Division of Emerging ond other Communtcoble Dlseoses Survetllance and Conlrol, World Heolth Orgonizotion, l2I I Geneva 27, Swilzerlond. A globol portnership A worldwide portnership of coun tries, NGOs, internotionol orgoni- zolions ond individuols is required to respond odequotely to the threot of emerging diseoses. The logo se- lected for this yeor's World Heolth Doy (see bock cover) tries to show how this portnershlp ensures lheir ropid detection ond effective con- toinmenl. As one of the portners in this globol effort, WHC is strength- ening three globol monitoring systems. These bring together spe- ciolized loborotories ond diseose surveillqnce systems from oll coun- tries, ond feed informotion electron- icolly to lhe World Wide Web ond other internotionol electronic ond print medio. The first is the WHC system of colloboroting cenires, speciolized oborotories ond institutions wilh ex- pertise in the diognosis ond epi- demiolooy of infectious diseose. During recent epidemics it hos be- come cleor thoi some loborotory centres hove not kepi up with chonges in technology, while oth ers hove foiled to develop expertise in some of the newer infectious dis- eose chollenges. 1n strengthening this sysiem of colloboroting centres, WHO is urging governments to pro- vide the resources to keep the cen- tres up io dote, to increose the number of centres in developing couniries ond to ensure thot o I cen- tres ore linked electronicolly The second system consists of Mo WHC networks: WHONET for monilori ng ontimicrobiol resistonce, ond ihe progromme for moniloring gonococcol oniibiotic susceptibil' ity Through these, WHO regu orly obtoins stondordized ond quolity- ensured informotion on the currenl stote of ontlmicrobiol resistonce, ond helps countries to use this infor- motion for sound notionol drug poli cies. The third system is the Iniernotionol Heolth Regulotions (lHR), currently the only internotionol public heolth legislotion which re- quires reporting of infectious dis- eoses (see box on poge 5) WHO is revising the lHR, ond it is foreseen thot the regulotlons will eventuolly require reporting of clinico syn' dromes of potentiol worldwide im' portonce so thot there con be on immediote ond oppropriote inler- nolionol response. WorldHeolth r 50thYeor, |lo. l, Jonuory-Februoryl997 WHO response to epidemks Gu6no6l Rodier lurt when recent medical odvonces hod convinced us th of co m m u ni cobl e diseoses no longer posed o moior threot, the outbreok of Ebolo hoemorrhogic fever in loire highlighted the return of old foes ond the emergence of new threots. Ebolo: the return of old foes and fhe emergence of new threots. Photo: Keystone/AFP/C. Simon @ ou may remember it: suddenly the whole world was looking fearfully at this tiny spot on the map of Africa and the world media started to cover, day after day, the gruesome count of victims. We could read: "Within days of the first reports that trickled out from Zaire, virus experts worldwide went on full crisis alert." We heard about the "plague warriors" and the inter- national effort. Eventually, we were reassured that the deadly virus had been brought under control. How did WHO respond and how is the world prepared to deal with such unexpected events? First of all, we must realize that the world is changing rapidly. Changes that have an important impact on the way diseases occur include dramatic population growth in some countries. uncontrolled urbanization. an ageing population in developed countries, increased poverty in both developed and developing countries, high-tech medicine, the increasing complexity of the food chain, expanding interna- tional trade and migration, massive use of antibiotics, incomplete immu- nization campaigns, deforestation and other environmental changes, war and other man-made disasters. Such changes have increased the opportunities for infection, multi- plied the population groups that are susceptible, and eventually influ- enced the microbe world to adapt itself to these changes. In fact, the 1995 outbreak of Ebola haemorrhagic fever inZaire was not the only epidemic that year, but it offered a striking example of the return of an old threat - infec- tious diseases. Besides the 1992 yellow fever outbreak in Kenya, the adult respiratory distress syndrome first diagnosed in Texas in 1993, and the 1994 international panic about plague in India, we have seen the continuing spread of cholera world- wide, shigella outbreaks, the increas- ing incidence of tuberculosis, AIDS, malaria and visceral leishmaniasis, the identification of numerous organ- isms resistant to antibiotics, and other tangible examples of emerging or re-emerging infections. Recent medical advances - the eradication of smallpox in 1980, the imminent eradication of polio and guinea-worm infection, and the imminent elimination of leprosy as a public health problem - have led us to believe that communicable dis- eases no longer pose a major threat. But suddenly theZaire outbreak highlighted, for the public, the return of old foes and the emergence of new threats. The silent beginning On 9 April 1995, a 35-year-old male laboratory worker from Kikwit II hospital inZaire was transferred to Kikwit General Hospital suffering from severe bloating and high fever. He underwent surgery and abnormal bleeding was found in the abdomen. Despite a second operation, he died three days later. What seemed an unfortunate medical episode was, in fact, the silent beginning of an epidemic. On 7 May 1995, rumours about a possible outbreak of Ebola haemor- rhagic fever in Zaire, together with a request for assistance, reached WHO in Geneva. Experts knew that Ebola had the reputation of a killer virus, that there might be a very serious disease spreading in the remote city of Kikwit and that they had to re- spond quickly. The diagnosis was rapidly confirmed by the Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia, USA, a WoddHeolth r 50lhYeor, No. l, Jonuory-Februory'1997 WHO collaborating centre for re- search on the pathogens that cause haemorrhagic fevers. Within three days, a three-man team had flown to Kikwit where Professor Muyembe of Kinshasa University was struggling against the outbreak, desperately looking for help. At WHO headquar- ters, an Ebola haemorrhagic fever task force was set up to coordinate the multidisciplinary activities required to respond during the emergency phase of the outbreak. WHO's Division of Emergency and Humanitarian Action took responsi- bility for resource mobilization and operational support, and designated a "response unit" which was staffed round the clock. A donor meeting was organized during the first week. In the field, the WHO team led and coordinated the international response, working closely with the local authorities and nongovernmen- tal organizations such as M6decins Sans Frontidres, the Red Cross and the local Catholic mission. The work was difficult. As a journalist put it, "Kikwit General Hospital exceeded their worst expectations. There was blood on the mattresses, the floors, the walls ... The wards were full of Ebola cases." The hospital had no running water, linen, sterile syringes or essential supplies and the staff had not been paid for months. More resources of all kinds had to be brought into the "hot zone". A strict isolation ward was organized; the definition of an Ebola case was agreed on and was then used to sort patients and provide them with appropriate care. After a few days, the management of cases was under control. A special office was set up for checking rumours. It began collect- ing information from the population and the international team on re- ported deaths, suspected cases and anything that could help to unravel the complex chains of transmission of the disease and, possibly, trace the source of the epidemic. Special teams toured the region on foot, by bicycle or in four-wheel drive vehi- cles and maintained daily radio contact with remote villages. This effort led to the identification of a 35-year-old charcoal maker who had died on 13 January 1995 in Kikwit General Hospital and who, in retro- spect, seemed to have been the first of a series of cases that occurred over the four-month period leading up to the dramatic hospital outbreak. In Geneva, the task force focused on operational support to the field operations, facing complex logistical problems, not least because of the geographic inaccessibility of the outbreak zone and the intense media interest in the epidemic. A satellite link with WHO headquarters in Geneva maintained communica- tions. By late May, the epidemic was under control, a regional sur- veillance system for Ebola haemor- rhagic disease was fully functional and the emergency phase was over. The epidemic command post, from which the international team of physicians and scientists success- fully controlled the outbreak, re- mained in place until October 1995. So far, the question of where the Ebola virus hides itself between epidemics - so important for disease surveillance and control - remains unanswered. A research programme on the reservoir of the virus has been set up in Cdte d'Ivoire. In Kikwit, the toll was 316 cases, of whom 124 women and 121 men lost their lives. A long-term surveil- lance system was set up in the Kikwit area. ready to examine any unexplained death. In Geneva, learning the lesson of Kikwit, the World Health Assembly called for vigilance against emerging and other communicable diseases. This led, in October 1995, to the formal creation of WHO's Division of Emerging and Other Communicable Diseases Surveillance and Control. In March 7996, an international conference organized by WHO and held in Kinshasa, Zaire,reviewed the international response to the Ebola epidemic in Kikwit, in order to share the scientific data and en- sure that WHO will be fully pre- pared to face future outbreaks. When the virus hit again in C6te d'Ivoire in December 1995 and in Gabon in March and September 1996, the WHO field teams greatly benefited from the understanding of the disease gained during the Kikwit epidemic. I Dr Gu6nat:lRodier ts Chief af the Diseose Surveillonce ond Control Unit, Dtvision of Emerging ond other Communicoble Diseoses Surveillonce ond Conlrol, World Heolth Orgonizotion, l2l I Genevo 27, Swilzerlond. ln sudden oufbreoks, collecting informotion is vitol for t'rocing ond monoging oll coses. Phot'o WHa/G. Rodier. World Heolth r 50thYeor, No. l, .lonuory-Februory 199/ Cholerq: o chqllenge for the 2lsl cenlury tlorio Jleiro Becouse of the millions of deoths thof cholero hos coused over lhe yeors, fhe diseose's ossociotion with disoster hos become legendory, provoking o deep- seoted feor in the minds of mony people. he dramatic modern history of cholera began in I 8 17, when the disease spread from India to trigger what we now recognize to have been the first of seven pan- demics. Yet Hippocrates, as long ago as the 5th and 4th centuries BC, and Galen, in the 2nd century AD, de- scribed a disease similar to cholera although we cannot be certain that it was the same. The first known description of cholera came from a Portuguese historian, Gaspar Correa. Inhis Legends of India, he described a disease "worse than poison", known locally as moryxy, an epi- demic which in the spring of 1543 killed so many people in Calicut (now called Kozhikode), India, that "it was impossible to bury them". Many other reports about a devastat- ing disease which scythed its way through India followed that of Correa, proving the existence of periodic waves of cholera throughout history. In 1817, cholera started its first deadly world tour. During that first pandemic, the disease spread from India to the Arabian peninsula before following the trade routes of the period to reach Africa and the Mediterranean shores. The total number of victims can never be known, but we know that more than 100 000 perished on the island of Java alone. In the second pandemic (1829- 1849), cholera spread for the first time throughout Europe and the Americas, sowing terror and leaving thousands of victims in its wake, like the 5000 who died in the New Orleans area of Louisiana, USA. The most devastating year in the history of the disease was probably 1854, when it killed more than 23 000 people in the United Kingdom. Because of the millions of deaths that cholera has caused over the years, the disease's association with disaster has become legendary. Few diseases, apart from plague, have provoked for genera- tions such deep-seated fear in the minds of so many people. Even today, because of its past history, cholera can still cause excessive reactions of panic, shame and disorder. Since those terrible years of cholera, we have made great progress in understanding the disease, its causes and how to prevent and treat it. While it no longer poses a threat to countries with a minimum of healthy living conditions, cholera is still a challenge for countries where access to safe drinking-water and adequate sanitation cannot be guar- anteed. The fear this disease arouses has put pressure on many countries to improve their sanitation. In 1996, cholera was responsible for more than 200 000 cases and 5000 deaths throughout the world. Although these figures are less dra- matic than those recorded during the epidemics of the past century, they Some coses of dehydrotion due to cholero r equi re i nlrovenous rehydt otion. Pholo: Keyslone @. are totally unacceptable since - by contrast with the other pandemics - we do today have the means of pre- vention and treatment. Cholera is a disease that is closely linked to poverty; fighting to control it means fighting to control poverty itself. Will we win the fight against cholera in the 2lst century? I Dr Morio Neiro is Coordinotor of lhe Globol Tosk Force on Cholero Control, in the Diseose Surveillonce ond Control Unit of the Division of Emerging ond other Communicoble Diseoses Surveillonce ond Control, World Heolth Orgonizotion, l2l I Genevo 27, Switzerlond r0 WorldHeolth r 50thYeor, No. 1, Jonuory-Februoryl997 Rqpid diseose surueillsnce Shivo turugosompilloy Laborofory surveillonce of diorrhoeol diseoses. Photo: WHO/A Ruwende emergencies has been fostered within the public health system so as to ensure quick action in response to disease incidence rather thanjust managing health services at the usual routine pace. The late 1980s saw a resurgence in southern Africa of such old infec- tious diseases as cholera, epidemic bacillary dysentery, plague, malaria and now meningitis and influenza. There has also been an emergence of new diseases such as HIV/AIDS with associated epidemics of tuberculosis and Kaposi sarcoma. This situation is probably partly due to the appear- ance of new disease agents or changes in existing agents, with increased infectiousness and ability to spread, and increased resistance to various common drugs, but it is also due to ecological changes and greater population movements as tourism. other travel and the numbers of refugees increase. These are some of the diseases or health problems we know, but there are others we have yet to detect or still need to find out more about. This requires continu- ous vigilance. Iimely response Disease or public health surveillance supports national health systems in describing and monitoring events. The objective is timely preparedness for epidemics and the effective planning, implementation and evalu- ation of epidemic and endemic dis- ease control programmes. Zimbabwe has long recognized the need for a strong suryeillance system to identify and treat cases quickly before they become numer- ous and re-establish the disease in the population. The public health ser- vices have maintained such a system since the 1950s. This focuses on the diseases that are notifiable under the Public Health Act and provides an information base at central level to fulfil the requirement for the Chief The development of ropid diseose surveillonce in Iimbobwe hos proved thot it b feosible to creofe o ropid surveillonce system in o developing country fo monitor the heolrh situofion through the detection of outbreoks ond of chonging frends in diseoses. public health service cannot be developed without attention to the control of major potentially epidemic and endemic diseases. Besides causing serious mortality, morbidity and disability, these dis- eases have a substantial social and economic impact on individual, family and national development. Traditional communicable diseases such as cholera, plague and malaria have received attention in the past due to their dramatic appearance as epidemics. Less attention has been paid to the more gradual epidemics of communicable diseases such as tuberculosis, or to noncommunicable health problems such as injury, cancer, diabetes and cardiovascular diseases associated with rapid urban- ization, increasing lifespans, chang- ing lifestyles and changing environments. The primary role of national ministries of health and international public health agencies is to watch over changes in the disease situation and respond rapidly to ensure that effective and sustained action is taken to reduce illness, death and disability. The Ministry of Health and Child Welfare in Zimbabwe takes this public health responsibil- ity seriously at district, provincial and national levels. A comprehen- sive and integrated health informa- tion system was initiated in Zimbabwe in 1986 and has been progressively developed to support the planning and management of the health services. Since 1989 it has been recognizedthat, in order to mobilize public health attention and action, there is a need for a rapid disease surveillance system (RDSS). This early warning system monitors the nation's health, keeps track of the disease situation, and quickly activates a public health response to any threat. This increased focus on potential WorldHeolth r 50thYeor, No. l, Jonuory-Februoryl99/ Recording polient informolton in o distncl hospifol Photo: WHO/A Ruwende. Health Officer or the Secretary for Health to present annual reports to parliament. The notifiable disease reporting system has been strengthened since 1991 by the development of the RDSS. Week by week this focuses on epidemic preparedness, epidemic reporting and investigation, and case investigations to support disease control and disease eradication. It provides an early warning system on health and disease. Although the whole population is supposed to be under surveillance through the RDSS, the health units that are able to report on a weekly basis still account for only 40Va of the entire health care system, but because of the large numbers they serve and their wide geographic distribution they can be taken to be representative of the whole country. At present there are six target diseases in the RDSS: malaria, dysentery, watery diarrhoeal disease, measles, neonatal tetanus and polio. Other diseases, such as plague, rabies and anthrax, are included for specific periods of time depending on the occurrence of an epidemic. Case definitions have been formulated for each of the diseases and are widely circulated to all health workers. The targets for RDSS have been deter- mined as: major diseases of public health importance with epidemic potential, such as malaria or diar- rhoeal diseases; new diseases (such as epidemic dysentery, shigellosis- SD I ), which have been introduced Notlono/ weekly survetllonce cenlrol lerminol Photo: WHO/A Ruwende. into the country recently and are associated with high morbidity and mortality; and diseases such as polio and neonatal tetanus which are tar- geted for elimination, so that every case requires active detection and investigation. The target diseases are reported by the primary health care centres and district hospitals. At the begin- ning of 1996,601health units were reporting weekly. with a reporting coverage of 60Vo-85Vo. Timeliness has been monitored since 1994 at national level and has shown consid- erable fluctuation - the most difficult periods being during public holidays. The case definitions have been grad- ually developed over the years and have undergone periodic revisions on the basis of the recommendations of control programmes. The weekly data are analysed and presented in the form of tables and graphs in some districts and some provinces, and at the national level. The RDSS rapidly picked up the cholera epidemic of December 1994. The system enabled the disease to be monitored and control measures to be implemented until the epidemic was eliminated by April 1995. The subsequent appearance of epidemic dysentery in 1995 has been kept under surveillance through the RDSS, and focused control measures brought it under control in 1996. A localized plague epidemic was iden- tified in September 1994 and full control was achieved by November 1995, while measles outbreaks were picked up rapidly in 1994 and 1995. The RDSS has shown that diar- rhoea, cholera and dysentery have a marked seasonal pattern, apparently associated with climatic factors such as high temperature and humidity, and it has permitted the timely prepa- ration of epidemic control measures. Malaria too shows a seasonal pattern, but this is confused by the occur- rence of influenza during the winter months. The development of the RDSS in Zimbabwe has proved that it is possi- ble to create a rapid surveillance system in a developing country to monitor the health situation through the detection of outbreaks and chang- ing seasonal and annual trends in diseases. Such a system can be developed only ii there is a strong public health orientation within the health system with a firm commit- ment to timely collection and feed- back of information, and a readiness to react quickly in controlling diseases. I Dr Shivo Murugosompilloy is Chief Epidemiologist ond Dtrecfor of lhe Depotment of Epidemiology ond Diseose Control, Mintstry of Heolth ond Child Welfore, P.O. Box CY I 122, Cousewoy, Ztmbobwe. t2 WoddHeolth r 50thYeor, No. l, lonuory-februory l997 New couses for new diseoses lohn t.lost Noturol chonges in the world's ecosystems ore now being loined by humon-induced chonges os the triggers for oufbreoks of emerging ond r e-e m er gi n g i nf e cti o ns. or better or worse, the risk of many infectious diseases is influenced by human alteration of local, regional or global ecosys- tems. Death rates from gastrointesti- nal disease declined in industrial nations early in the 20th century in part because of the invention of the internal combustion engine. Cars replaced horses as the main means of getting about; and cars didn't leave heaps of manure as breeding places for disease-carrying fl ies. Conversely, in the tropics and sub- tropics, dams to store water for irrigation and hydroelectric power have introduced water-borne diseases such as schistosomiasis to communi- ties where they previously did not exist. Day-care centres are popular in an age of small families and working mothers. They are also an ideal setting for transmitting infections among infants and toddlers, who are naturally affectionate so they touch, hug and kiss one another but are not yet trained in personal hygiene. The common cold, diarrhoeal diseases and more serious infections can spread like wildfire and - taken home by the children - they infect parents and other children in the house. Air-conditioning is widely used in hotels and hospitals in warm countries. But dilapidated air-condi- tioning units accumulate many kinds of moulds and microbes, including the microorganisms responsible for "Legionnaires' disease" (a dangerous form of pneumonia) or some forms of meningitis. International trade carries many "passengers" along with the articles transported between the nations of the earth. Consignments of used tyres imported into the United States in the 1980s, for instance, contained small pools of water in which Aedes albopictus, a variety of mosquito not native to the Americas, found an ideal environment to lay its eggs. These insects are able to transmit dengue fever. which now occurs in the southern USA as well as in Central and South America. Globolworming The greenhouse effect, mainly due to fossil fuel combustion, is changing the world's climate. Mosquitos that carry malaria, yellow feveq dengue and viral encephalitis are extending their range into temperate zones, higher altitudes of tropical regions and large cities like Nairobi and Harare. By the middle of the 21st century there may be several hun- dred million more cases of malaria each year as a result, many of them in regions now free of malaria. Not all ecological changes are caused by human activities. The tropical Pacific Ocean current El Niflo undergoes periodic warming. In the early 1990s, such a change was accompanied by the prolifera- tion in coastal waters of South America of blue-green algae. These harbour the cholera vibrio which can survive for lengthy periods in vari- ous forms of plankton. The flight of landless peasants from rural areas in developing coun- tries means that by the year 2000 over half the world's population will live in big cities. Many will live in slums which favour the transmission of infectious diseases like tuberculo- sis and HIV/AIDS. Tuberculosis has always flourished in conditions of poverty, overcrowding, poor nutri- tion and illiteracy; HIV infection spreads when women must resort to prostitution in order to survive, and when intravenous drug abuse with needle-sharing occurs. Finally, there have been several recent cases of a variant of Creutzfeld-Jakob disease, a progres- sive and fatal degenerative brain Stored waler permils irrigotion ond elechic power. However, il moy introduce diseoses /ike schislosomiosis info communities where lhey prevtously did not exisf . Photo. WHO/AKF/J.-1. Roy WoildHeolth r 50thYeor, No. 1, lonuory-Februoryl997 disease of cattle - is thought to be caused by the agent of scrapie. a TSE of sheep. Sheep's offal has been used to prepare protein supple- ments fed to cattle. Although not yet proven, the circumstantial evidence is persuasive and worrying: the inf'ectious agent seems to have passed from sheep to cattle to human beings. This may be an example of the consequences of human interfer- ence with natural processes - in this instance feeding animal protein to a vegetarian species. I A day-care centre tn Albonto. lnfecttous diseoses con spreod roptdly among young chrldren. Photo: WHO. disease, in the United Kingdom and France. These cases are thought to be due to exposure to an unconven- tional infectious agent belonging to the group responsible for transmissi- ble spongiform encephalopathies (TSE). One of these. bovine spongi- form encephalopathy (BSE) - a Dr.lohn M. Lost is Emerilus Professor of Eptdem iology o nd Con n u nity Med ici ne Unrversit'y of Ot't'owo, 45I Smyth Rood, affawa, Onlorio KIH BM5. Conctda. A sole woler pump tn Zimbobwe. Counlrtes lhol ensure minimum heolthy living condittons hove o good chonce of wiping out cholero. Photo:WHO 1$P Hubley Cleoning up dirty woter ond keeping it deon In mony ports of the developing world, drinking-woter is collected from sources outside lhe home. lt moy be contominoied ot the source or during storoge. Slrotegies to reduce wqterborne dlseose tronsmission musl sofeguord ogoinst both possibilities. New products ollow fomilles to disinfect drinking'woter immediotely ofter collection, ond newly designed norrow-mouthed, closed storo ge vessels prevent reconlo m i notion. This Mo-component prevenlion strotegy is o prociicol ond inexpensive woy for households ond communities thot Lock sofe woier to protect themselves ogoinst o voriely of woterborne pothogens, ond con progressively decreose woterborne diorrhoeol diseoses. The method hos been tested in vorlous ports of Bolivio by the United Stotes Deportment of Heolth, the US Centers for Diseose Control ond Prevention, the Pon Americon Heolth Orgonizotion ond the United Stotes Agency for Inlernotionol Development. Well occepted, it hos significontly improved the quolity of stored woter ond brought obout o decreose in diorrhoeol diseoses, especioliy omong infonts under one yeor. The method could be on effective tool ogoinst woterborne diseoses such os typhoid fever ond cholero ln such seitings os doy core centres ond old people's homes, ond could be used dur,ng feslivols Cllnlcs, schools ond even street vendors ore ottroctive potentiol torgets for this intervention, which encouroges the woshing of honds, foods ond kitchen utensils in Woter should be kepl in norrow'mouthed vesse/s rn order t'o minimize exlernol contominolion. Phofo: WHO/H Anenden. order to reduce diseoses tronsmitted by personol contoci or contominoted food. The next generolion of vessels, currently being pilot- iested omong Guotemolon street vendors, will hove o built-in soop dish to promote hond-woshing With the commitment of communities, ministries of heolth, United Notions ogencies, nongovernmentol orgonizotions ond privote industry, this low-cost, effective intervention could be implemented on o brooder scole. Adopted fron o conlribution of fhe lJnited Stotes Cenfers for Diseose Confrol ond Prevention to the World Heolth Repon 1996, p.44 rsee p. ? I of rhis i>sue for fu,rhe, details o{ the Report] World Hmlth r 50thYeor, No. l, lonuory-Februory l99i Resistont slrsins of mrcroolgqnrsms locques L Aror There ore o greof number of complex mechonisms by which resistont stroins of bocteria evode destructton by meons of survivolin o hostile ,,ir-;a uring one of his lectures at the ' ; SColldge de France in 1933, the if :if 4i511nguished bacteriologi st Charles Nicolle declared: "Infectious disease carries all the characteristics oflife itself; it derives those charac- teristics both from its own nature and from its target - the living host." The agents that cause disease are of different types. The most numer- ous are bacteria, viruses, parasites and fungi. Some of these disease agents are capable of triggering disease when they penetrate the human organism and multiply there. Such infections can be cured by the natural defences of the patient's body, helped by drugs (where they exist) that destroy the microbes within the body. It was penicillin, discovered by Alexander Fleming in 1928, which ushered in the antibiotic era. The discovery of antibiotics revolution- ized medicine and the prognosis of bacterial diseases. At last a simple cure was available for infectious diseases that would otherwise have been fatal or would have left chronic after-effects - diseases such as bac- ontibiotiu; it is o perfectly noturol phenomenon for o Evoding destrudion living orgonism to develop the terial meningitis, puerperal fever, typhoid fever, syphilis and rheumatic fever. Antibiotic drugs have sharply reduced infant mortality and, by making it possible to prevent and treat infections, they have opened up the wonders of modern surgery and resuscitation techniques. Within a few years of penicillin first being used, microbiologists realized that bacteria were able to protect themselves against antibiotics by developing some means of resis- tance. The staphylococci, for in- stance, produced an enzyme called penicillinase which was able to inactivate penicillin. I will not try to describe the complex mechanisms that resistant bacterial strains use to evade destruc- tion by antibiotics. Suffice it to say that there are a greatnumber of such mechanisms and that it is a perfectly natural phenomenon for a living organism to develop the means of survival in a hostile environment. This is a normal process that takes place equally among bacteria that are pathogenic in animals and human beings, and among bacteria that are not pathogenic in the environment, plants, animals or human beings. The fact is that antibiotics are first and foremost natural substances produced from fungi or bacteria and only secondarily are they drugs that are developed and improved by our chemists. Because they have been so widely used in treating diseases in human beings and in farm animals, antibi- otics have triggered the evolution of resistant bacteria all over the world. The medical consequences of this evolution are, of course, very impor- Sir Alexonder Fleming llBBl-1955) won the Nobei Prize for h;s discovery of penicillin, which wos lo revolulionize medicine ond lhe prognosis of bocferiol diseoses. Phot'o: WHO. tant to us all. When a strain of bacteria proves resistant to an antibi- otic that is habitually used in treat- ment, the physician is obliged to look for a radically different ap- proach. A bacterial strain that is resistant to several antibiotics is an even harder problem to solve. Furthermore, a strain of bacteria that is resistant to several antibiotics survives more readily in a setting where antibiotics are frequently used. This is so in hospitals, for instance, where bacterial strains are usually resistant to most of the antibiotics currently in use. Bacteria are most frequently spread by one person contaminating another, which is how epidemics start. The more resistant the bacteria and the more capable they are of surviving against the antibiotic in use, the more they can spread. This is why it is very important to be alert to the develop- ment of resistance among the strains ofbacteria that can cause serious epidemics. WorldHeolth r 50lhYeor, No. l, Jonuory-Februory1997 t5 Where onfibtolrcs ore frequenily used, such os in hospilols, o bocteriol stroin resistont to severol anfibiol;cs survives more ss5ily. Pholo: Keys/one @. which they are indicated, and only when they are prescribed by a physi- cian. It is a practice that aims to limit the development of resistance to antibiotics as much as possible with- out depriving those patients for whom antibiotics are necessary. This is a far-reaching task; it calls for close cooperation between physi- cians, their patients, the public au- thorities, the pharmaceutical industry and basic research. Resistant strains of bacteria have attracted a great deal of attention in the medical literature. The tubercu- losis bacilli, the pneumococci and the dysentery bacilli are major examples. Yet all living organisms that are able to cause infection are also able to develop resistance mechanisms, thus WHO Surveillonre nelwork Recognizing the emergence ond spreod of bocteriol stroins resistont to ontimicrobiol ogents os o prioriiy problem, the World Heolth Orgonizotion is reinforcing its octivities to improve surveillonce of ontimicrobiol resislonce ot nolionol ond globol levels. This surveillonce network will provide continuos informotion on ontibiotic resistonce to heolth core speciolists ond drug developers ond will serve os o worning system on the emergence of resistont stroins. Doto occumuloted within the surveillonce system will offer guidonce on the development ond use of new ontibiotics ond recommend woys to preserve the efficocy of old ones. obliging us to look at them ln a new light. Take for example the case of the malaria parasite becoming resis- tant to chloroquine, the resistance of fungi to antifungals, and above all the resistance of viruses to antivirals - herpes and the human immunode- ficiency virus (HIV) are only the first of a long list. Every time an effective treatment is discovered against an infectious organism, there will be a price to pay in terms of the eventual development of resistance. This is the dynamic of life which Charles Nicolle sought to underline. It is our responsibility to develop sensible strategies for the use of antibiotics and to improve our surveillance systems in ways that will keep the resistant strains of bacteria under control. I genes. Good medirol It is also possible for a resistant bacterial strain to spread resistant genes in the form of plasmids or transposons which are able to pene- trate quite different species of bac- teria. This process is known as horizontal dissemination of resistant Procti(e The medical consequences of anti- biotic resistance in the agents that cause disease have grown more serious in recent years, just as the number of newly developed anti- biotics has diminished and their cost has risen. "Good usage ofanti- biotics" means using antibiotics only in the treatment of those diseases for Doses musl be corefully counted out: uncontrolled use of ontibiofics con leod to fhe development of drug resislonce. Photo: Still Pictures/P. Chondro @. Dr Jocques F. Acor is Professor of Medicol Microbiology of the Universil6 Pierre et Morte Curie, Fondotion H6pifol Sotntloseph, 185 rue Roymond Losserond, 75674 Poris Cedex 14, Fronce. 16 World Health • 50th Yem, No. 1, January-February 1997 Emerging foodborne diseases Morris E. Potter, Yasmin Motariemi, & Fritz K. Kiiferstein Poultry moy harbour the risk of salmonellosis. Food for supermarkets, as here in the United Kingdom, goes through many checks to protect consumers from such diseases. Photo: Still Pictures/N. Oickinson ©. Both industrialized and developing countries face the emergence of new or newly recognized foodborne diseases. oodborne disease is a common and serious public health threat everywhere. The industrialized world experiences large numbers of illnesses that are sometimes life- threatening, while the developing world suffers even larger numbers of illnesses and infant and childhood deaths due to diarrhoea! diseases, almost always linked to unacceptable standards of food and water hygiene. In addition, both industrialized and developing countries face the emer- gence of new or newly recognized foodborne diseases, which frequently have severe health consequences. Emerging infectious diseases, including those transmitted by food, can be defined as infections that have newly appeared in a popula- tion, or have existed previously but are rapidly increasing in incidence or geographic range. Some previously unrecognized diseases may also be considered emerging due to increased knowledge about them or better methods of identifying and analysing the agents that cause them. Salmonellosis has been important for decades , but within the past 20 years it has increased on many continents. In the Americas and Europe, Salmonella enteritidis (SE) has become the predominant strain. Investigations of SE outbreaks indicate that its emergence is largely related to eating poultry, or eggs from hens whose ovaries are colo- nized by SE. The colonization causes contamination of the contents of eggs, although the eggs appear to be normal. While cholera has devastated much of Asia and Africa for years, its introduction for the first time in almost a century into the western hemisphere in 1991 makes it another example of an infectious disease that is both well-recognized and emerg- ing. It is often waterborne, but many foods also transmit infection. In Latin America, ice and raw or under- processed seafoods are important epidemiological features of cholera. Major (Ouse of diarrhoea Infection with Escherichia coli serotype 0157:H7 was first de- scribed in 1982. Subsequently, it has emerged rapidly as a major cause of bloody diarrhoea and acute renal failure; it can be fatal for children. Outbreaks of infection, generally associated with beef, have been reported in Australia, Canada, Japan, the United States, many European countries and southern Africa. As there is little evidence that it caused infections before the 1970s, it is an example of the evolution of a new foodborne pathogen. Listeria mono- cytogenes (Lm) is considered emerg- ing because the role of food in its transmission has only recently been recognized. It can cause abortion and stillbirth in pregnant women, and may lead to septicaemia and menin- gitis in immunocompromised people and newborn babies. Foodborne trematodes are also emerging as a serious public health problem, especially in south-east Asia, partly due to a combination of increased aquaculture production, often in unsanitary conditions, and underprocessing of such foods. Foodborne trematodes can cause severe acute liver disease, which may lead to liver cancer. Some emerging diseases have characteristics that suggest that they might be foodborne although we lack adequate data to confirm this. An example is Helicobacter pylori infection, first identified in the 1980s. Most infections probably spread from person to person by the faeca l-oral route, but foodborne transmission through contamination with faecal matter is also possible. Helicobacter causes peptic ulcer disease and can lead to severe anaemia due to chronic gastric blood Be pre In times of disasters and emergencies, the safer foodborne disease ou tbreak is ever present. For become contam ina ted by surface water, sewa· pa thogenic bacte ri a. The breakdown of life-l in electric ity and waste removal a lso has a negativ\ been cut, cold storage is more d ifficul t and foods and bacteri a l growth. This may happen at a ll households. Lack of water and sanitation servicE increases the risk of food conta mination. Ra ts, ' may prol iferate in the aftermath of disasters; so I stand ing water or organic matter mixed with det Foods may be damaged by smoke, chem ical from explosions or damage to conta iners. Man the environment, includ ing foods, with hazordm centres for refugees ore extremely favourable to < All of these si tuations call for meticulous p lc authorities before emergency and disaster situa ti, World Health • 50th Year, No. 1, Jonuory-Februory 1997 loss. Infection may also cause gas- tric carcinoma. Why these diseases emerge New foodborne disease threats result from increased international travel and trade, microbial adaptation, and changes in food production, human demographics and behaviour. Factors associated with the emer- gence of foodborne infections in- clude the following: • Globalization of the food supply means that people are exposed, through foods purchased locally, to pathogens native to remote parts of the world. For instance, a large outbreak of Shigella sonnei infections occurred in Norway, Sweden and the United Kingdom in 1994 due to contaminated lettuce imported from southern Europe. • Pathogens may be inadvertently introduced into new geographic areas. One theory is that Vibrio cholerae was introduced into waters off the coast of the south- ern United States when a cargo ship discharged contaminated ballast water in 1991. It is likely that a similar mechanism intro- duced cholera for the first time this century into Latin America in 1991. • Travellers, refugees and immi- grants are exposed to unfamiliar foodborne hazards in foreign of the food supply is at stake and the risk of a xample, duri ng floods or hu rricanes, foods may e and wastewater carry ing faecal matter and services such as water supply and sani tation, effect on food safety W here the electricity has may be subject to time-tempera ture deterioration stages from food production to preparation in s hampers the hyg ienic preparation of food and rermin and stray anima ls such as dogs and cats DO may fl ies and other quick-breeding insects in Iris. d · f· f· ht· th h · I it· ; use 1n 1re- 1g mg , or o er c em1ca s resu mg 1made catastrophes frequently ca use pol lution of Is chemica l agents. Condi tions in mass feeding ~ utbreaks of foodborne disease . Inn ing and preparedness on the part of heal th bns actua lly arise. I 17 A family sits down to a meal in India . All cultures have rules for the safe handling and cooking of food which need to be supported by food safety measures in the community. Photo . WHO/j & P Hubley. countries. It is estimated that about 90% of cases of salmonel- losis in Sweden are imported. • Changes in microbial populations can lead to evolution of new pathogens, development of new virulence factors for old pathogens, development of anti- biotic resistance making a disease more difficult to treat, or changes in the ability to survive in adverse environmental conditions. • People are becoming increasingly vulnerable. The numbers of highly susceptible persons are expanding worldwide because of ageing, HIV infection and other underlying medical conditions, use of immunosuppressive drugs, and malnutrition. More and more people in industrialized countries are at increased risk of food borne infections because of advanced age. In developing countries, high birth rates have resulted in large numbers of young people, in addition to the old, being at greater risk. Young and old have either not developed protection from infection or partially lost it. People who have underlying medical conditions, including HIV infection and cancer, are more likely to become seriously ill from infection with Salmonella , Campylobacter, Listeria, Toxoplasma, Cryptosporidium and other food- borne pathogens. In developing countries, reduced immunity due to poor nutritional status renders people (particularly infants and chi ldren) more susceptible to foodborne infections. • As lifestyles change, there is insufficient education about food safety. With increased urbaniza- tion, industrialization and travel, more people eat meals prepared by restaurants , canteens, fast food outlets and street vendors, with an increased risk of unhy- gienic preparation of food. To deal wi th these problems, a comprehensive strategy is needed at national and international levels. This must be based on effective food control, improving agricultural practices, app lying food technolo- gies to reduce or eliminate pathogens, and educating persons who handle food. Improved surveil - lance programmes are essential for limiting the spread of food borne diseases before they take on pan- demic proportions. Protecting the public from emerging foodborne diseases also means keeping track of new events in agricultural and pro- cessing practices and the environ- ment from which our food comes, while climatic and environmental changes need to be monitored for potential negative effects on the food chain. • Or Morris E. Potter is Assistant Director for Food borne Diseases, Division of Bacterial and Mycotic Diseases, Center for Infectious Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road N. E. , Atlanta, GA 30333, USA. Or Yasmin Motariemi is a Scientist in the Food Safety Unit of the Division of Food and Nutrition, and Or Fritz K. Kaferstein is Chief of the Food Safety Unit, World Health Organization, 121 I Geneva 27, Switzerland l8 World Heolth r 50lh Yeor, No. ), Jonuory-Februory I 997 Emerging zoonoses Irongois-Xovier tleslin, Klous Stiihri & P. Iormenly 'Mod cow" olert in Europe. The heods ond ofher offol of cottle sloughtered in the United Kingdom ore dyed blue to ensure thot fhey ore disposed of ond ore not usedTor humon or onimol food. Photo: Still Pictures,/N. Dickinson @. everal of the human pathogens which have emerged or re- emerged worldwide in recent years are agents originating from animals or from products of animal origin. The animal species and the categories of agents differ widely. For instance, wild animals (bats, rodents) as well as draught animals (horses) and food animals (poultry, cattle) have been implicated in the epidemiological cycles of certain diseases, while the agents responsi- ble for other new infections and diseases in human beings have in- cluded viruses, bacteria, especially enteric bacteria (salmonellae, Escherichia coli) aad parasites (Cryptosporidium) of animal origin. Outbreaks of otherwise endemic zoonoses such as rabies, brucellosis, leptospirosis, anthrax and arbovirus infections involving production animals (Venezuelan equine en- cephalitis, Congo-Crimean haemor- rhagic fever) have appeared in many developing countries in Africa, Asia and Latin America. The zoonotic nature of some other important human diseases - "potential zoonoses" - is suspected but not yet demonstrated. For exam- ple, the natural cycle of Ebola virus is not known and its reservoir (possi- bly an animal which plays an essen- tial role in maintaining the agent and its life cycle) remains to be identi- fied. On the other hand bovine spongiform encephalopathy (BSE), a fatal disease ofcattle, is suspected - although no scientific proof of a link yet exists - to be the origin of a new variant form of Creutzfeldt-Jakob disease (CJD) in human beings. These potential zoonoses have re- cently had a considerable impact on public health and on animal produc- tion worldwide in view of the need to minimize the potential risks for human beings. BSE ond CJD BSE first came to the attention of the scientific community in November 1986 with the appearance of a newly recognized form of neurological disease in cattle in the United Kingdom. Between November 1986 and 3l May 1996 about 160 000 cases were confirmed on 33 400 farms in the United Kingdom. Epidemiological studies suggested that the source was cattle feed pre- pared from the carcasses of rumi- nants such as sheep. Modifications of the physical conditions of the process used for preparing cattle feed introduced in 1981-82 may have created a risk factor by not eliminat- ing the disease agent from the feed. By May 1996, BSE had been reported from 10 other countries and areas. In France, Ireland, Portugal and Switzerland the disease occurred in native cattle and could be linked to importation of potentially infected cattle feed from the United Kingdom. In Canada, Denmark, the Falkland Islands, Germany, Italy and Oman, cases of BSE were identified only in cattle imported from the United Kingdom. BSE is one of several different forms of transmissible brain disease of animals. A number of similar severe, and fatal, neurological human diseases are due to nonconventional agents. These include kuru, a disease transmitted by ritual handling of bodies and brains of the dead and identified in Papua New Guinea in the 1950s, and the various forms of CJD, which is a rare disease with a worldwide distribution. When it was shown that these UlorldHeolth r 50thYeor, No. l, lonuory-tebruoryl997 t9 diseases (called transmissible spongiform encephalopathies) could be transmitted experimentally to a range of animals, WHO arranged four consultations between l99l and 1995 to review the possible public health implications, with special emphasis on BSE. The sudden announcement by the United Kingdom in March 1996 that 10 people had been identified with what appeared to be a variant ofCJD led to a fifth and then a sixth consulta- tion at WHO since - although there was no direct evidence of a link - the most likely hypothesis was that these cases might be related to exposure to BSE. These consultations issued recommendations designed to mini- mize risks for consumers in relation to food products of animal origin, and proposed a protocol for global surveillance of the new variant form of CJD. Ebolo ond Ebolo-reloted viruses ln 1976 the Ebola virus attracted worldwide attention with outbreaks at Nzara, Sudan, with 284 cases and at Yambuku, Zaire,with 318 cases. In both instances there were very high mortality rates (53Vo in Sudan andSSVo inZaire). The first patients may have been in contact with in- fected animals or their products (bats or rodents in Sudan, meat from monkeys or wild antelopes inZaire) but investigation of a possible animal reservoir remained inconclusive. Between 1977 and 1989 a few rela- tively small Ebola outbreaks were reported. Then in 1994 a Swiss ethologist became infected by a new Ebola variant after doing a post- mortem on a chimpanzee originating from the Tai forest in C6te d'Ivoire. The chimpanzee proved to be in- fected with Ebola and a number of deaths reported among these animals in the same area were associated with this agent too. In January 1995 a new Ebola epidemic was reported in Kikwit, Zare, with a total of 3 16 cases and 245 deaths. In January 1996, an outbreak occurred in Makokou, Gabon, with 37 cases and 21 deaths. In Gabon the investiga- tion showed that most of the patients had been in contact with a dead chimpanzee which they had butchered. Nothing definite is known about the reservoir of the Ebola virus, although a number of hypotheses have suggested that rodents or in- sects may be involved and even that the virus may be of plant origin. There is general agreement that the species of monkey and apes in which the virus strains have been isolated so far are only victims of the disease since, in view ofthe high mortality rates the infection causes, these groups of animals could not sustain themselves or the disease agent for very long. WHO has initi- ated a multidisciplinary study on mammals, birds and insects in the Tai forest of C6te d'Ivoire aimed at identifying the natural reservoir of the virus. The study involves scien- tists from Canada, France, Sweden, Switzerland, United Kingdom and USA. Identifying the reservoir is essential to understanding the mech- anisms for transmission in nature and helping to prevent future Ebola outbreaks. In both developing and developed countries, a number of zoonoses have emerged either as new pathological entities or as already known agents, appearing in areas or species where they had not been previously re- ported. The reasons for this increas- ing trend are complex but they include: I alteration of the environment, influencing the size and distribu- tion of certain animal species, and the vectors and transmitters of infectious agents that affect human beings; I increasing human populations, thus favouring an increased level of contact between humans and infected animals; I industrialization of animal pro- duction; I changes in food processing and consumer habits. As such problems are likely to con- tinue, the surveillance of animal diseases and zoonoses will need to be Plotforns ond footbridges ore buih in the conopy of lhe Toi Fotest in C6te d lvaire so thot onimols con be couohl ond checked for infecfion with the Ebololirus. Photo: WHO/D. Heymonn & P. Formenty. reinforced and maintained at na- tional and international levels. Further collaboration is essential between all professions involved in the development of food technology and control of the food industry in order to ensure that health risks in the food chain are minimized every- where. I Dr Froncois'Xovier Meslin ond Dr Kous Stohr ore Scienfists in the Division of Emerging ond other Communicob/e Diseoses Surveillonce ond Control, World Heolth Orgonizotion, l2l I Genevo 27, Swizelond. Dr P Formenl,y is Scienli/ic Coordinoror of the WHO Ebolo-Toi Forest Project in the C6te d'lvoire. His oddress is c,/o the WHO Represenlotive, 0l Boile postole 2494, Abidjon 0l , Cote d'lvoire. 20 WoddHeolth I 50thYeor, No. l, Jonuory-Februory'199/ AIDS qffecls us oll tlirhel fhurioux & Suzonne Cherney AIDS hits fontlies. Eoch child with o roised hond hos lost either o fother or o mother, or both porenls. Photo: Still Ptctures/J. Tim @ An eslimoted 8.4 million coses hove occurred since the slort of the epidemic ond over 22 million people, induding 800 000 children, ore todoy infected with the virus. But whol exocily does AIDS he first descriptions of the dis- ease we now know as AIDS (acquired immunodeficiency syndrome) date back to 1981. We now know that the human immunod- eficiency virus (HIV) had struck before that date, but in our collective memory it remains a recent disease, which has spread so rapidly that by 1996 no part of the globe was spared. While Africa is the hardest hit, there is currently an upsurge of the disease in other regions, for instance South- East Asia and the former Soviet Union. Up to December 1996, a total of over one and a half million cases of AIDS had been officially reported to WHO, an increase of 20Vo compared with the figures in December 1995. But it is estimated that about 8.4 million cases have actually occurred since the start of the epidemic and that over 22 mlllion people, includ- ing 800 000 children, are today living with the virus. As so often, the figures may be horrifying, but they do not tell the whole story, and certainly do not answer the question "What exactly does AIDS mean?" At the individual level AIDS is a tragedy. Akin to cancer in our col- lective imagination, the AIDS virus, for whoever harbours it, represents "the enemy within", which gnaws away at us and changes our entire being. Even though recent drug treatments offer hope that its pro- gression can be slowed down and that it might eventually become "another chronic disease", AIDS is still for the time being perceived as inevitably fatal. Besides, those treatments are far from universally available; 907o of those infected with the virus and of those with full- blown AIDS live in poor environ- ments or settings, where the cost of treatment may represent several times the average living costs of each individual for a whole year. AIDS strikes selectivelv at the young and people in the prime of life, but their illness all too quickly compensates for their inexperience. Friends and family frequently re- mark on how much people living with AIDS have to offer and teach to others - not only about courage or patience but also about prevention. adaptation, management and the rethi n ki ng of priorities. The epidemic aflects more than individuals; it affects communities and whole societies. In some coun- tries, about one young adult in five is seropositive; millions of children are being orphaned while millions of grandparents are having to bring up their grandchildren. Although no place is spared, the epidemic strikes unequally; the heaviest price is paid by the least developed countries, and by poor and marginalized people in every country. AIDS is more than a personal or a social tragedy. In our minds, the infection is closely linked to aspects of life that are hard to talk about, such as sexuality (heterosexual or homosexual) and drug injecting. So to sickness and death must be added the burden of unspoken fears, isola- tion, social exclusion and the popu- lar belief that "AIDS is other people". This very image of AIDS is part of the problem, and persists even though, directly or indirectly, we are all confronted by the fact of AIDS with increasing frequency. For all these reasons, this disease - perhaps more than any other - has changed and will continue to change our perceptions. our reactions, our concept of health and illness. What can a man or woman think of health, of their own health, of themselves, when, aside from any obvious physi- cal symptoms, they have to learn to live with the virus and with all the personal and social consequences of the disease for months and years? What must the HlV-positive but symptomless person think? What must our attitude be towards them? meTn? WorldHeolth r 50thYeor, No. l, Jonuory-februoryl997 2l A heolth educafor in Swifzerlond shows odolescents how lo use o condom fa prevenf HIV fronsmisston. Photo: WHO,/E. Mondelmonn What can we say, what can we do in countries where the cost of treatment today and in the future is prohibitive? It is plain to see that a multitude of problems arise from AIDS. Quite apart from health, they concern all aspects of development, whether personal, economic or social, but also education and demography in its broad sense. This is why, since 1996, six agencies and programmes of the United Nations system (UNICEF, the UN Development Programme, the UN Population Fund, UNESCO, the World Bank, and WHO) have harmo- nized their activities within the Joint UN Programme on HIV/AIDS (uNArDS). A home hos been creoted tn Brozrl for children up fo 7 years of oge who ore ltving with AIDS Photo: WHO/PAHO/A Wook. As the advocate for all co- sponsors ofthe global action on HIV/AIDS, UNAIDS is called upon to "lead, strengthen and support an expanded response aimed at prevent- ing the transmission of HIY provid- ing care and support, reducing the vulnerability of individuals and communities to HIV/AIDS, and alleviating the impact of the epi- demic". The six cosponsoring organiza- tions of UNAIDS ensure that issues linked with HIV/AIDS are integrated in their respective fields; within WHO, this is the task of the Office of HIV/AIDS and Sexually Transmitted Diseases. An emerging communicable disease, AIDS is above all an infec- tion which is evolving and changing, and it is changing us. It is a condi- tion with which everyone must learn to live, directly or indirectly. AIDS is not "other people"; it concerns each and every one of us. Whether or not we have the virus, its emer- gence affects us all. I Dr Michel Thurioux.is on Epidemiologisf with rhe Diviston of Lmetginq ond other Communicoble Diseoses Survetllonce ond Control, World Heolfh Orgonizotton, l2l I Genevo 27, Switzerlond, ond Ms Suzonne Cherney is o Senior Wrifer wifh lheJolnr UN Progromme on HIV/AIDS /UNA/DS/, l2l I Genevo 27, Switzerlond. The prevention ond treotment of sexuolly tronsmitted diseoses lnfection with sexuolly tronsmitted pothogens including HIV is preventoble. The odoption of sofer sex proctices ond the increosing ovoilobllity of condoms os o result of strotegies for HIV prevention oppeor 1o hove coniributed to the declining rotes of sexuolly tronsmitted diseoses {STDs) thot hove been reported in some countries. WHO recommends o comprehensive opprooch to the prevention of these diseoses which includes promotion of sofer sexuol behoviour ond widespreod ovoilobillry ond offordobility of condoms. Troditionol STDs ore curoble, ond curotive core for these diseoses should be integroted into oll bosic heolth core focilities. So should good-quolity cose monogement, including use of oppropriote drugs, educolion ond referrol to counselling if feosible; provision of condoms ond treotment of sexuol portners; promoting eorly use of heolth core services by people with sexuolly tronsmiited diseoses ond their porlners; ond screening for "silent" diseoses such os syphilis in pregnoncy. The occurrence of lroditionol STDs increoses the risk of HIV tronsmission by o foctor of up to 20. Recent observotions in the United Republic of Tonzonio ond elsewhere hove now shown thot preventing ond curing troditionol STDs con reduce the incidence of new infections by 4O%. All WHO recommendotions ore feosible within the scope of primory heolth core services. For women, services for the control of STDs con be integroted inlo moternol ond chlld heoth ond fomily plonning services. But the high number of new infections reported in ,l995 indicotes thot the problem is for from being solved. The lock of comprehensive policies ond insufficient occess to the necessory drugs ore but two of the obstocles encountered. 22 WorldHeolth r 50thYeor, No. l, Jonuory-[ebruoryl997 Iuberculosis need not kill litendro luli "l wos told thot if I compleled my treotment under supervision, lwould be oble to return fo my fields in o few months. I did os I wos told, ond here I om, working from sunrise fo slnset." anwar, a young farmer, is back in his fields after a break of a few months. "This is where I belong, this is my life", he says, stacking up bundles of freshly harvested maize. A few months ago, however, Manwar could never have imagined that he would be able to put in the strenuous hours at work that farming demands. That was when he was stricken with tuberculosis. "I never thought I would survive. Thanks to the insis- tence of my wife and some others in my family who took me to the health centre, I am alive today and able to narrate what happened to me," he explains. As Manwar recalls, he developed a nagging cough just over a year ago. He consulted the vlllage vaid, or traditional healer, who gave him some herbs to boil in water and asked him to drink the water when cool, three times a day. The healer also gave him some pills. When this treatment did not work, Manwar consulted anangrezi, or allopath, who prescribed antibiotics. "These were very expensive, but after taking them for a few weeks I felt no better. In fact, worse," he says. The persis- tent cough became more severe and Manwar would go into spasms, particularly at night. After one such bout, his wife noticed specks of blood in his sputum. The next morn- ing she insisted on taking him to the A pot'tent receivtng hrs medtcine under direct observofion. Photo: WHO health centre, which was an hour's bus ride from their village. At the centre, Manwar had his sputum collected for examination. The technician on duty asked them to return in a few days for the report, when the doctor would also meet them. When Manwar returned, the doctor was waiting for him and told him that he had tuberculosis. "I was totally shattered by the news," re- veals Manwar. "I thought it was the end. What would my poor wife and young children do? Who would look after them? What would the villagers say? Would I be shunned by them?" He was also worried about the long duration of treatment - perhaps for years - and also whether he could afford to buy all the necessary drugs. The doctor was very understanding and explained that tuberculosis is an entirely cur- able disease. There is no reason for anyone to feel ashamed about it, nor is it a disease that should lead to any kind of isolation. Health workers in the area have been taught that tuber- culosis is curable, but only if the treatment is taken regularly, without breaks, to ensure a complete cure and avoid the danger of drug resis- tance. After a couple of weeks of treat- ment, patients feel so much better WorldHeolth r 50thYeor, No. 1, Jonuory-Februory)997 23 that they think it is no longer neces- sary to take the medicine. For this reason, health workers are trained to observe each patient directly, to ensure that they not only receive their medicine but actually swallow it, each and every time. In fact, Manwar was told that, in accordance with the revised strategy of Directly Observed Treatment, Short Course (DOTS) recommended by WHO, the treatment period had been reduced considerably. His fears about the cost of the drugs were allayed when the doctor informed him that all the necessary drugs would be given free of charge. "I was told that if I com- pleted my treatment under supervi- sion, I would be able to return to my fields in a few months. I did as I was told, and here I am, working fiom sunrise to sunset," he says with a broad smile. While at the health centre, Manwar was surprised to learn that more than three million people in the South-East Asia Region are infected with tuberculosis every year. This is nearly 40Vo of the world's total. He was even more surprised to learn that an estimated 1.2 million people in the region had died ofthe disease in 1995. The economic loss sufTered as a result of tuberculosis is estimated to be over 1000 crores ofrupees (US$ 300 million) every year for India. And yet tuberculosis is one of the diseases lor which treatment is the most cost-effective. Curing patients is the cheapest and most effective form of tuberculosis pre- vention. he was told. Manwar. of course, did not have to pay fbr his treatment as he could get the medi- cine he needed fiom the health centre. But he had been told that the cost ofthe drugs was very high. "I calculated the cost of the treatment and was shocked to know that it was as much money as I would earn in a year. But for the government facil- ity, I would never have been able to afford the treatment," he says. Having been cured, Manwar is now convinced that tuberculosis need not be f'eared. In fact he has become a welcome ally of the health centre. and has himself become a supervisor of DOTS treatment for a fellow villager. As he eagerly ex- plains to anybody willing to listen: "Tuberculosis need not kill. I am proof enough." And people believe him. I Mr litendro Tult wos formerly lnformolion Of{tcer ot WHO's Regronal Offtce for Sout'h Eost Asio, World Heolth House, New Delhi- / I a002. lndia. The doctor reossures fhe palienl thot fuberculosis is curoble: the heolth service will moke sure that he follows the treotment until he ts completely cured. Phofo: WHO/J Kumoreson. !nlectious diseoses in South-Eost Asio The WHO South-Eosi Asio Region is populous ond heterogeneous, with complex ond voried socioeconomic conditions. Most countries depend on ogricu lure but ore increosingly turning to industriolizotlon. Poverty ond illiterocy ore still widespreod ond noturol disosiers cloim on importont port of scorce resources. However, the Region hos ochieved noiiceoble success ogoinst o number of infectious diseoses. The Exponded Progromme on lmmunizolion conducted by most countries hos resulted in o remorkoble decline of poliomyelitis, neonotol tetonus ond olher childhood diseoses. Guineq-worm diseose is heoding towords erodicotion ond the incidence of visceroi leishmoniosis hos olso dec ined considerobly. The less optimistic side of lhe regionol heolth situotlon is coused by high incidence ond prevo ence of ocute respirotory infections, diorrhoeol diseoses, molnutrition ond nutritionol deficiency disorders, vecior'borne diseoses - especiolly molorio - ond tuberculosis. Chollenges for the fuiure ore the persistence of molorio ond tuberculosis; the resurgence of plogue; the emergence of chronic noncommunicoble diseoses such os cordiovoscuor diseoses, concer ond diobetes; ond the emergence of other infectious diseoses such os dengue hoemorrhogic fever, Joponese encepholitis ond cholero (El Tor). Though HIV/AIDS is becoming o serious problem, there hove been o few notoble successes in some countries due to the increosed use of condoms ond peer educotion progrommes which hove resu ted in o decline of sexuolly ironsmiited diseoses. Leprosy is on importont public heoith problem in South-Eost Asio, occountinglor 70% o[ oll coses regislered worldwide. The nine couniries where leprosy is endemic ore implementing notionol plons for the eliminoiion of the disdose by the yeor 2000 Forecosts for the next 5-10 yeors envisoge thot the moin couse of morbidity ond mortolity will still be infectious diseoses, with the beginning of o shift towords chronic noncommunicqble diseoses. However, the HIV/AIDS epidemic will be present lhroughout the region ond is expected to spreod ropidly in mosi countries. Summcttzed from the World Heolth Report 1996, p.100 (see p.3l for further rnformotion) 24 WoddHeolth r 50thYeor, No. 1, Jonuory-Februoryl99/ Resurgen(e of (ommunicoble diseoses in Europe Sieghort Dittmonn Bosnion refugees on the move. Civil unrest ond sociol upheovol tncreose lhe potent'iol for lhe ropid spreod of communicoble diseoses. Photo: Keysfone,/Comero Press/P. Horris @. (holero Cholera had disappeared from Europe by the end of the last cen- tury. A few isolated imported cases were reported occasionally from some countries of the region, usually the result of increased travel and tourism to cholera-endemic coun- tries. Since 1990, howeveq larger outbreaks of this waterborne disease have occurred, affecting hundreds of people in Albania, Kazakstan, Moldova, Romania, the Russian Federation and Taj ikistan. Molorio The number of indigenous malaria cases has exploded in recent years, from 20 000 in 1992 to more than 100 000 in 1995, with most cases found in Azerbaijan, Tajikistan and Turkey. In addition, some 3000 to 4000 imported malaria cases are reported each year in other countries of the European Region, some of them misdiagnosed or diagnosed too late and therefore resulting in death. AIDS ond HIV infection HIV is continuing to spread, and now affects particularly groups of drug users in several eastern European countries. HIV infection has risen dramatically among intra- venous drug users in Ukraine, and the start of a similar pattern has been reported from Belarus. Sexuolly tronsmilted diseoses Almost all countries of the former USSR have in recenl years experi- enced a sharp increase in the inci- Since the beginning of the l?90s,0 serious r. re-emergence 0r communr coble diseoses hos been threofening Europe. ollowing a general improvement in living conditions, the success of immunization programmes and the treatment of life-threatening infections in Europe in recent decades, communicable diseases seemed to be losing their importance as a major public health issue. Since the beginning ofthe 1990s, however, a serious re-emergence of communi- cable diseases has been threatening the European Region of WHO. This mainly affects the countries of cen- tral and eastern Europe and particu- larly the newly independent states (NIS) of the former Soviet Union. Economic hardship, rapid social change, greater opportunities for travel, increased numbers of refugees and displaced persons caused by civil unrest in many areas, and the shorl- age of essential vaccines and drugs have all increased the potential for a more rapid rise in the transmission of communicable diseases. The resur- gence ofdiseases such as cholera, diphtheria, malaria and syphilis in many eastern European countries has become a very serious problem, and not only for the people of the coun- tries involved. Frontiers may act as checkpoints for people and goods crossing from country to country but, as new and re-emerging diseases threaten, no country can seal off its borders from risks to public health. Diphtherio Epidemic diphtheria has re-emerged on a massive scale in the NIS, begin- ning in the Russian Federation in 1990 and affecting all 15 countries by the end of 1994. More than 907o of all diphtheria cases reported worldwide during 1990-95 were reported from the NIS. Since the epidemic began, more than 125 000 cases and 4000 deaths have been reported in the NIS, and imported cases have occurred in other coun- tries of Europe and Asia. WoddHeolth r 50lhYeor. No. l. Jonuory-tebruory1997 dence of syphilis, gonorrhoea and certain other sexually transmitted diseases. Together with the increase in intravenous drug use, this indi- cates an increased risk of HIV trans- mission. Tuberrulosis Morbidity and mortality due to tuberculosis are increasing in many countries of the eastern part of the European Region. The downward trend in tuberculosis in western Europe has levelled off, with 3V5OVo of new tuberculosis cases occurring among migrant popula- tions. Tuberculosis strains resistant to drugs are spreading. Globolthreots The problem of emerging and re- emerging diseases is of growing concem to all countries of the world. The situation described above, as well as recent outbreaks of plague in India and of Ebola fever inZure, should underline the importance of improved surveillance, prompt epidemiological investigation, the need for adequate laboratory capac- ity and the global implications of the problem. One of the most alarming aspects of the threats presented by new and emerging infections is antibiotic drug resistance. Coolition of ollies In view of these changes in the panorama of communicable dis- eases, WHO's Regional Office for Europe has stepped up efforts against communicable diseases in Europe by reallocating resources. A broad coalition with other interna- tional, governmental and nongovernmental organizations has been developed to assist the eastern European countries in their fight against these diseases. Considerable support for disease control, through immunization and the completion of primary immunization in children in the NIS, has also been provided by the international donor community, including the Interagency Immunization Coordinating Committee for the NIS, created in 1994in Kyoto, Japan. The secre- tariat of this coordinating committee is located in WHO's Regional Office for Europe. In September 1995, the annual meeting of the European Regional Committee, which was attended by official delegates from the 50 Member States of the Region, called for a much stronger effort to support Member States in re-establishing effective progftrmmes to control communicable diseases. Priority actions and targets, with emphasis on support to countries in central and eastern Europe, are as follows. I Surveillance for early detection of emerging and re-emerging dis- eases, including resistance to antibiotics, must be improved in Europe by setting up a network of national collaborating centres. The epidemic of diphtheria in the NIS must be controlled by carry- ing out sEategies, recommended by WHO andUNICEF, focusing on mass immunization of the affected populations, appropriate case management and greater surveillance. Surveillance, prevention and control of AIDS, HIV infection, syphilis and other sexually trans- mitted diseases must be improved, in close cooperation with UNAIDS. The transmission of wild polio- viruses in the European Region should be intemrpted by the end of 1997, using coordinated mass immunization campaigns across national and regional borders, and the surveillance of poliomyelitis should be strengthened in order to certify Europe as a polio-free region. National immunization prograrnmes with specific targets should be strengthened in all countries ofEurope, and new and improved vaccines should be introduced. Tuberculosis control in all European countries should be strengthened and supported by putting into effect WHO- recommended policies. The countries of central and eastern Europe should be assisted in applying WHO-recommended strategies for the control of diar- rhoeal and acute respiratory diseases. I I I I I I I Dr Sieghon Diftmonn is Coordinotor, Connunicoble Diseoses ond lmmunizotion, WHO Regionol Office for Europe, 8 Scherfigsvej, DK-2 I 0O Copenhogen, Denmork. A mossive epidemic of diphtherio reemerged in the Newly lndependenl Sfoles of eostern Europe in the 1990s. Thonks to moss immunizolion, oppropriote cose monogement ond greoter surueillonce, the situotion improved greotly in 1996. Groph byWHO. 26 WorldHeolth r 50thYeor, No. l, Jonuorv-Februoryl99/ Preuenting hospilol infedions louise lenn, Anne Wyness, & lrene Goldstone The docfor's visit ot t'he hospitol. Constonf surveillonce is needed lo prevenf "nosocomtol infecfions" from spreodtng omong pottents, vtstfors, ond heolth stoff. Phofo: Keysfone @. gence of new diseases have forced health care workers to re-examine strategies to protect health. The donger of HIV precoutions bosed on the Reloxed vigilonce principle thot every individuol Hospitals have long been recognized as environments in which the utmost care is needed to prevent the trans- mission of infections. However, widespread use of sulfonamides and antibiotics since the early 1940s, and reliance on these drugs to prevent and control infections, may have contributed to the development of both drug resistance and lack of vigilance. Moreover, the increased use of invasive approaches to diag- nosis and treatment in the high technology environments of modern hospitals has made patients more vulnerable to infection. Many hos- pitals today have therefore had to reconsider ways of preventing hospi- tal infections - they are known as "nosocomial infections" - and stopping transmission from patient to patient, patient to health care worker, and health care worker to patient. The emergence of HIV in partic- ular forced a re-examination of infection control practices in hospi- tals. Although hepatitis B had been is p ote nti olly i nf e cfi ous tronsmission led fo a,, n epidemic is an occurrence of$ ffi disease that clearly exceeds Sfihno*ur or expecteci rrequency in a community or region. One of the first recorded epidemics in the western world was that of bubonic plague during the Middle Ages, while other major epidemics have included cholera, smallpox and influenza. Sometimes an epidemic wanes and reappears; although bubonic plague had declined by the 1800s, Hong Kong experienced an epidemic of the plague late in that century. By that time, however, it was possible to identify the causes of many infections so that steps could be taken to protect the health of communities. Today, infectious diseases pre- sent new challenges and new poten- tial for epidemics. Globalization, the resurgence of long-standing infectious diseases and the emer- recognized as a highly infectious bloodborne pathogen, it was the advent of HIV that led to precautions based on the principle that every individual is potentially infectious. This contrasts sharply with the previous approach, which depended on the patient's symptoms or a confirmed diagnosis. The emer- gence of HIV and the re-emergence of tuberculosis have made it more necessary than ever for health care workers to be knowledgeable, vigi- lant and consistent in applying infection control procedures. To the extent possible, they have to ensure the complete absence of all causes of infection. Health care workers and commu- nities have the responsibility of protecting the health of the public. In many countries, hospitals now maintain continuous surveillance to reduce their nosocomial infection rates. Guidelines and resources are needed for carrying out infection control measures. The importance of multidisciplinary education and training in infection control for all hospital staff cannot be overempha- sized. Health care workers need to help people not only in hospitals and clinics, but also in schools, homes and workplaces, to learn and use basic techniques for preventing infection in everyday life. Funda- mental practices that protect health, such as hand-washing, covering the mouth when coughing, the safe preparation and storage offood, and safe sex, are essential elements of health education programmes for all. I Professor Louise Tenn is Senlor lnstructor, Schoo/ of Nursin g, ond Foculty Assoclofe, lnstitufe of Heolth Promotton Reseorch, Universir'y of British Columbio, T20l -22 I I Wesbrook Moll, Voncouver, B.C. V6T 285, Conodo. Dr Anne Wyness is Associole Professor ot the Schoolol Nursing, Universrfy of Brit'ish Columbto; ond Dr lrene Goldstone is Director, Professionol Educotion ond Core Evoluolion, British Columbio Centre for Excellence in HIV/AIDS, St. Poul's Hospitol, Voncouver, Conodo. World Hodlh r 50th Yeor. No. l. lonuorrFebruory 1997 27 News from the Regions Hunling the Eholo virus in Cite {lvoire lhe diseoses we feor mo$ ore those with no known cure. Ebolo hoemonhogic I fever is currently one of them. Efforts ore going oheod, howevel to find out more obout the virus thot couses Ebolo. The first $ep is to discover the noturol reservoir of fie virus in order to understond how Ebolo is tronsmitted ond how future outbreoks con be prevented. Recorded Ebolo outbreoks hove never offected more thon o few hundred people, but the diseose - which couses severe hoemonhoging - kills o lorge proporiion of those who become infected. One who wos lucky enough to survive wos o Swiss onimol reseorcher who fell seriously ill ofter corrying out on outopsy on o chimponzee - one of o group thot died my$eriously in ttre loi forest of COte d'lvoire in I 994. The chimponzees were loter found to hove died of Ebolo ofter eofing the flesh of deod colobus monkeys. Colobus monkeys connot be the noturol reservoir for Ebolo since the diseose kills them too. Mo$ likely the ho$ is some other creoture - probobly o smoll mommol, bird or insect - thot the monkey comes into contoct with. Since the colobus monkey lives in the tops of the trees, thot is where the seorch for [bolot nofurol reservoir is now concentroted. Reseorchers hove built o network of plotforms ond connecling lodders high in the trees of the loi fore$. Ihere they ore studying whot the colobus monkeys eol ond whot other onimols they meet. Ihe finy ueotures in the high bronches ore being exomined for signs of the Ebolo virus. No one knows for sure, but it seems likely thot one of ftose creotures is ho$ to Ebolo. Finding which it is ond how the virus is tronsmitted will not defeot Ebolo, but it will meon thot the fight ogoin$ the spreod of this killer virus will hove token o very big step forword. Dengue hoemorrhogit fever Dengue ond dengue hoemorrhogic fever ore endemic in most of the We$em Pocific Region. There ore periodic outbreoks in mo$ of the tropicol counlries. ln 1995, I l9 /60 coses were reported to WHO from l4 Member Stotes. The overoll cose fotolity rote in the Region is usuolly les thon 2%. The [ombodion epidemic in .l995 wos, however, more serious, with l0 I l9 coses reported ond 424 deoths (on overoll cose fotolifl rote of 4.2%). ln some rurol oreos, cose fotolity wos 10|i,-l200hot the stort of the epidemic. When the government begon intensive dengue intervention octivities, the number of coses quickly went down ond cose fotolity fell to 3%. Diphtherio An outbreok of diphtherio storted in Mongolio in September 1994 ond by April 1995 hod become o lorgescole epidemic. A widespreod immunizolion compoign fint torgeted 600 000 children oged 3-l 5 yeon in Moy 1 995, then wos followed by two rounds of voccinolion for 900 000 odults oged l6-40 in November ond December I 995. As o resuL the number of diphtherio coses in Mongolio fellfrom 128 in .l995 t0 l6 in the first holf of .l996. ln Moy I 996, onother outbreok occuned in the Loo Peoplet Democroiic Republic. WHO delivered 500 viols of onli{iphtherio toxin to offected oreos in July, followed h 50 000 doses of diphtherio voccine in eorly Augu$. E rterilrtocofr A polhogenic $roin of fscherkhio colr, nomely E. coli0]5/:H7, seriously offected severol oreos of Jopon in I 996. The worst outbreok wos in Sokoi City, 0soko, where more thon 6000 schookhildren out of 48 000 in ttre city suffered from food poisoning ond dysentery{ike symptoms. 0ver I 00 children devel- oped hoemolytic uroemic syndrome, the most severe form of the infeciion. School lunches were the suspected source of the pothogen, but the inve$igo- fion did not deorly locote ony food contominoted with the bocilli. fhe number of coses of cerebrospinol meningilis in the Africon Region went I up shorply lo$ yeor. From 1 Jonuory to 4 0ctober countries in the region reported I 49 I 66 coses of cerebrospinol meningilis, with I 5 783 deoths. Ihe figures ore the highe$ever reported to WHO for 0 single yeor in Africo. During the first nine months of I 996, olmo$ 95% of ttre coses of cerebrospinol meningilis in the region were in iust four countries. Lorge outbreok in Burkino Foso (42 I 29 coses, 4226 deoths), Moli (7244 coses, 83.l deoths), Niger (16 050 coses, .l493 deottrs) ond Nigerio 05 069 coses,8440 deoths) hod on overoll cose fotolity rote of I 0.6%. The outbreoks were coused by o $roin ol Neisserio meningilidisserogroup A Disease outhreoks in the Western Contribuled bv Dr Kouichi Morifo, WHO Reqionol Office for the Western Poc;t'ic, P.O. Box 2932, lO99 Monilo, Philippines Pocilic Region !n 1995 ond 1996, the We$ern Pocific Region foced o number of serious loutbreok of diseose. Cu ebr wplnol neningilis incr eose s in Ahico Cholero Cholero is endemic in some countries in the Western Pocific Region. ln .l995, o totul of l7 8li coses were reported in the Region, olthough the cose fotulily rote wos les thon l% in most countries. However, the cholero oulbreok in the loo People's Democrolic Republk in .l995 wos porticulorly serious, wittr l26l coses reported ond l6l deoths (o cose fotolity mte of l2%). The government ond WHO lounched on extensive diseose intervention progromme to contoin ttreepidemic. ln 1996, r\4oloysio wos oho offected by on ouftreok of cholero; 1222 coses were reported in Penong in Moy. Prompt meosures were token ond the outbreok wos under conlrol by June. World Heolth r 50lh Yeor. No. I . Jonuorrr-Februory '1997 Heolth briefs Keeping o close wolch on influenzo !u$ how mony of us will cotch influenzo the next lime it comes oround will Jdepend portly on o group of experls who will meet ot WHO in Februory. The group, which meels every yeor, will decide which virus stroins ore likely to be dominont in the next influenzo seoson. Phormoceuticol componies use the groupt odvice when formuloling influenzo voccines. [very yeor influenzo epidemics occur oll over fie world. lt is o potenfiolly fotol diseose, so WHO recommends voccinolion ogoin$ it, especiolly for certoin risk groups - the elderly, people with immunodeficiency, diobetes potients, ond lhose wittr chronic heort or lung diseose, for instonce. However, the voccine is useful only if it is mode from viruses similor to those thot couse the diseose. This seosont voccine formulo is effective ogoin$ B/Beiiing, ArlSingopore ffi I NI) ond A,lWuhon (H3N2) stroins. The expert group will bose its decision obout next seoson's viruses on informulion obout vorionls of influenzo fiom oround the world. lnfluenzo lrends ore monitored by four WHO colloboroting centres (in Austrolio, Jopon, United Kingdom ond USA) ond notionol influenzo loborotories in 83 countries. lf there's o good motch between the voccine ond the virus $roins thot ore in circulofion, eight out of I 0 people who ore voccinoted will be protected ogoin$ ttre diseose ond ih impocton fie re$willbe reduced. Diseoses on lhe woy out oliomyelitis h torgeted for globol erodicofion by the yeor 2000. There ore now I 45 countries completely free of the diseose. leprosy is $eodily being defeoted ond is not expected to be o significont puhlic heolttr problem in o few yeors' time. Guineo-worm diseose (drocunculiosis) is olso well on the woy to erodicolion. Since .l986 the number of coses worldwide hos follen from 3.5 million to obout .l20 000. River blindness (onchocerciosis), coused by o porosite thot is conied by blockflies, is being eliminoted from I I We$Afticon countries. Chogos diseose, o disobling diseose ilrot con couse heort domoge ond deottr in chronic sufferers, is being eliminoted from Argentino, Bolivio, Brozil, (hile, Poroguoy ond Uruguoy. fhe world's biggest killer diseoses f[ bout 52 million people died from oll couses in I 995, occording to theA Woild Heolth Report 1996.0f these, more thon I 7 million were killed by infedious diseoses. Whot ore the I 0 bigge$ killer infecfious diseoses? r Acute lower respirotory troct infecfions - such os pneumonio - killed 4.4 million people, of whom obout 4 million were children. r Dionhoeol diseoses (induding cholero, typhoid ond dysentery), which ore spreod chiefly by contominoted woter or food, killed 3..l million, mo$ of them children. r Tuberculosis killed olmosr 3..l million, induding I million children. r Molorio killed 2.1 million people, induding I million children. r Hepolilis B infecfions killed more thon 1.1 million people. r HIV/AIDS killed more tfion I million people. r Meodes killed more thon I million children. r Neonotol tetonus killed olmo$ 460 000 infonts. r Whooping cough (pertusis) killed 350 000 children. r lntesfinol worm diseoses killed ot leost I 35 000 people. Putting o price on infections fhe domoge coused by infectious diseose omounts to for more thon the I humon toll of ill-heolth ond deoth. lnfections reduce the quolity of life of millions of people, hinder educotion, cul productivity ot work ond use up household resources. Ioking molorio os on exomple, the co$ of 0n overoge cose in sub-Sohoron Africo hos been cokuloted os equivolent to I 2 doys of productive octivity. Studies of the effects of molorio show fiot r in Burkino Foso, eoch cose of molorio cosls more thon I 9 doys of productive outpul; r in Rwondo, the overoge co$ of eoch cose of molorio in I 987 wos eslimoted ot USS I 1.8; r in Sudon, those offected by molorio could not work 1or 220kof the fime during the coune of o yeor; r in Solomon lslonds, eoch child with molorio misses 0n overoge 5.3 doys of school. 0ther diseoses hove their own price. Drocunculiosis, or guineo-worm diseose, costs rice produdion in Nigerio obout I 2% of penondoys thot would oilrerwise be ovoiloble for lobour. ln Rwondo, the co$ of treoting known AIDS coses potenliolly omounts to 60% of the public heolth budget. Ihe overoge medicol expenses ot the fime of on illnes in C0te d'lvoire exceed the fulHime eornings (ot the rote of the minimum woge) lo$ os o result of the illnes. And os osseB such os live$ock ond property hove to be sold to poy for medicol core, 24% of lond tronsoclions in Kenyo ore the result of ill-heolttr. Better heolttr contributes to overoll development, occording t0 Wll0. As o result of WH0! onchocerciosis conlol progromme. which $orted in We$Africo in 1974, more thon 1.7 million odditionol yeon of productive lobour hove become ovoiloble. ln Jomoico, treotment of intestinol helminth infection improved schookhildrent performonce in cognitive function tests ond reduced the number of times they missed school. ln the United Republic of Tonzonio, lreotment of schistosomiosis omong sugor cone cutten increosed productivity. WorldHeolth r 50thYeor, No. l, lonuory-Februory1997 Escherkhio coli ond food poisoning vherkhio rolr is o bocterium thot lives in the inte$ines of onimols ond humon beings. Mo$ $roins of it ore hormless, but some couse more horm thon others. Stroins such os f. colr 0l 5l.Hl ,lu instonce, (0n couse very severe food poisoning, producing toxins similor to those of shigello dysentery. Such stroins ore known os enterohoemorrhogic f. rolr. Ihe 0.l5/:H/ $roin grows in o number of different foods (homburgen, opple cider, cheese, solomi ond cooked moize hove oll been implicoted in 015/:H/ outbreoks) butcon be destroyed by cooking food fill oll porl's reoch o temperoture of 70'I or higher. Cottle seem to be the moin noturol reservoir lor [. coli 015/:H/. Humon beings pick up the bocterium moinly by consuming contominoted foods such 0s rorrv 0r undercooked meot products or row milk. Drinking-woter ond other foods moy be contominoted by foeces. Enterohoemorrhogic f. roficon survive ond grow on solod vegetobles. E. coh0157:H/ couses oomps in the obdomen ond wotery dionhoeo thot con develop into bloody diorrhoeo (hoemorrhogic colitis), os well os fever ond vomiting. Mo$ potients recover in l0 doys but some, especiolly young children ond the elderly, con get dongerous complicotions such os hoemolytic uroemic syndrome. from food is by heoting or irrodiotion. Leishmoniosis ond HIV energe os co-infeclions o-infeclion of viscerol leishmoniosis ond HIV is becoming more (0mm0n 0s AIDS spreods to suburbon ond rurol oreos oround the world. Viscerol leishmoniosis, which is the mo$ serious form of leishmoniosis infection, is endemic in 62 countries ond is spreoding in severol nerrir 0re0s. Around 200 million people live in the endemic oreos ond holf o million new viscerol leishmoniosis coses occur eoch yeor. Leishmoniosis is coused by porosites spreod by sondflies. Ihe commone$form produces skin ulcers on fhe foce, orms ond legs, leoving permonent scors. Another form ottocks the mucous membrones of the nose, mouth ond throot. The viscerol form, which kills mony of those infected if left untreoted, couses feve[ sub$ontiolweight los,0n0emi0, ond swelling of the spleen ond liver. Leishmonio/HlV is considered to be on "emerging diseose", especiolly in southern Europe where 25-70% of odult coses of viscerol leishmoniosis ore reloted to HIV infecfion ond 1.5-9% of AIDS potients hove new or reoctivoted viscerolleishmoniosis. ln this ueo,700/oof coinfected potients ore introvenous drug users. While in on endemic oreo up to one-quorter of the populotion moy be infected but not show symptoms for yeon, the diseose oppeors qukkly when immunity is offected. ln 1995 there were more ihon 1000 leishmonio/HlV co-infections in the Mediterroneon oreo. ln the Americos, mo$ of the co{nfections ore in Brozil. Leishmonio/HlV coinfecfions hove olso been reported in Africo ond Asio. WHO hos set up o network of institutions in I 0 countries to collect informotion on leishmonio/HlV. fosk force will odvise on drug resislonce H0 hos set up o tosk force to keep trock of resistonce to drugs thot ore used to control infections. The losk Force on Resistonce to Anli-infecfive Drugs oims to odvise WHO on motters reloting to diognosis, surveillonce ond the rolionol use of onfi-infecfive drugs; to promote coordinotion of vorious WH0 divisions ond progrommes in this oreo; ond to provide o forum for discussion ond exchonge of informofion. Resistonce to onti-infective drugs (induding onlimicrobiol, ontivirol ond onlimo- loriol drugs) is becoming more frequent oround tfre world. lt is o moior ob$ode to efforls to control o number of infeclious ond porosific diseoses. Severol WHO pr0gr0mmes ore involved in ontimicrobiol resistonre monitoring, contoinment ond the rotionol use of onfi-infeclive drugs. honges in the eortht dimote con do worse thon bring us bod weother. ttrey con be domoging to heolth. Concern obout dimote chonge ond destobilizolion of the worldt ecosystems hos usuolly focused on floods, $orms ond heotwoves. 0n o lorge scole, these would be bod enough, but indirect chonges could toke on even biggertoll ofhumon heolth. Mosquitos ond other insects spreod mony infectious diseoses, including molorio, Africon tryponosomiosis (sleeping sicknes), Americon tryponosomio- sis ((hogos diseose), dengue fever ond plogue. Ihe dimote influences where insects, ond other corriers of diseose, con live ond how eosily they con breed. Foctors such os temperoture, wind, roinfoll, humidiry ovoilobity of surfoce woter, vegetotion ond the presence of predotors oll offect the spreod of the diseose corrie[ ond ofthe diseose itself. A rise in temperoture, for instonce, would meon thot molorio mosquitos ond other corrien of diseose would be oble to spreod t0 new 0reos, infecting new populotions. Ihe proportion of the world's populotion exposed to the risk of molorio could rise in 100 yeors from ttre present 45% to oround 60%. Diseoses such os cholero, ond other infections tronsmitted through woter ond food, would olso be likelyto increose with ttre proliferolion of mkroorgonisms. WH0 Director-Generol Dr Hiroshi Nokoiimo hos colled f0r "new ond better methods for clorifying the relotionship between public heolth ond noturol ond humon-induced dimote chonge". A report on Climote chonge ond humon heolth hos been lointly issued by the United Notions fnvi,on ment Ptogromme, the World Meteorologicol Orgonizolton ond WHO. The 300-page book (order no. 1993aOQl / cosrs Sw.fr 3A. /US $ZZ OO (Sw fr 21 - in developtng counfries) ond is ovoiloble from Distribufion ond So/es, WHO, l2l I Genevo 27, Switzerlond. Climate chonge con domoge your Good hygienic proctices on forms ond in sloughter-houses help reduce f. roli he1lth infedion in milkond meot, butthe onlyeffectivewoyof eliminoling the bocterium WorldHeolth r 50thYeor, No. l, lonuory-Februory 1997 WHO qduises ooo Moke sure your food is safe to eot oodborne diseoses ore omong the mo$ widespreod heolth problems in the modern world (see orticle on poge I 5). ln both rich ond poor countries, they con couse mild indispositions or they moy be fotol. Food con be contominoted with chemicols or by o wide ronge of bocterio, viruses ond porosites. Hygienk preporotion of food is esentiolto good heolth. WHO hos issued o list of 1 0 "golden rules" for sofe food preporolion, os follows. The WHO golden rules for sofe food preporolion l. Anose fods pocessed lor sofety While mony foods, such os fruit ond vegetobles, ore be$ in their noturol $ote, others simply ore not sofe unles they hove been processed. For exomple, olwoys buy po$eurized os opposed to row milk ond, if you hove the choice, select fresh or frozen poultry treoted with ionizing rodiotion. When shopping, keep in mind thot food procesing wos invented to improve sofety os well os to prolong shelf'life. Certoin foods eoten row, such os lettuce, need thorough woshing. 2. Cookfoodthoroughly Mony row foods, mo$ notobly poultry, meots, ond unpo$eurized milk, moy be contominoted with diseosetousing orgonisms. Thorough cooking will killthe pothogens, but remember thot the temperoture ol oll ports of the food must reoch ot leo$ /0"[. lf cooked chicken is still row neor the bone, put it bock in the oven until itt done - oll the woy through. Frozen meot, fish, ond poultry mu$ be thoroughly thowed before cooking. 3. Eot cooked loods imnefrotely When cooked foods coolto room temperoture, microbes begin to proliferote. Ihe longer the woit, the greoter the risk. Io be on the sofe side, eot cooked foods iu$ os soon os they come off the heot. 4. Store cooked loods corelully lf you mu$ prepore foods in odvonce or wont to keep leftoven, be sure to store them under either hot (neor or obove 60'C) or cool (neor or below I 0"[) conditions. Ihis rule is of vitol importonce if you plon to store foods for more ihon four or five hours. foods for infonts should preferobly not be stored ot oll. A common error, responsible for countles coses of foodborne diseose, is putling loo lorge o quonlity of worm food in ttre refrigerotor. ln on overburdened refrigerotor, cooked foods connot cool to the core os quickly os they mu$. When the centre of food remoins worm (obove I0'C) too long, microbes ttrrive, quickly proliferoting to diseosecousing levels. 5. Reheot cooked loods thoroughly This is your be$ protecfion ogoinst microbes thot moy hove developed during $oroge (proper storoge slows down microbiol growth but does not kill the orgonisms). 0nce ogoin, thorough reheoting meons thot oll ports of the food mu$ reoch ot leost /0"C. 5. Avoid contoct between row lnds aml cooked loods Sofely cooked food con become contominoted through even the slightest contoct with row food. This crostontominotion con be direct, os when row poultry meot comes into contoct with cooked foods. lt con olso be more subtle. For exomple, don't prepore o row chicken ond then use the some unwoshed cutting boord ond knife to corve the cooked bird. Doing so con reintroduce the diseosecousing orgonisms. 7. Wosh honds repeotedly Wosh honds thoroughly before you $ort preporing food ond ofter every interruption - especiolly if you hove to chonge the boby or hove been to the toilet. After preporing row foods such os fish, meot, or poultry, wosh ogoin before you $ort hondling other foods. And if you hove on infection on your hond, be sure to bondoge or cover it before preporing food. Remember, too, thot household pets - dogs, cots, birds, ond especiolly turtles - often hofiour dongerous potfrogens thot con pos from your honds into food. 8. Keep oll kitchen surloces neticulously cleon Since foods ore so eosily contominoted, ony surfoce used for food preporotion mu$ be kept obsolutely cleon. Think of every food scrop, crumb or spot os o potentiol reservoir of germs. Cloths thot come into contoct with dishes ond utensih should be chonged frequently ond boiled before reuse. Seporote clottrs for deoning ttre floors olso require frequent woshing. 9. Protect loods fron insects, rodents, ond other onimals Animols frequently cony pothogenic microorgonisms which couse foodborne diseose. Storing foods in dosed contoiners is your be$ proteclion. 10. Use sole woler Sofe woter is iust os importont for food preporolion os for drinking. lf you hove ony doubts obout the woter supply, boil woter before odding it to food or moking ice for drinks. Be especiolly coreful with ony woter used to prepore on infontt meol. The WHO golden rules for sofe food preporolion ore ovoiloble os o wollchort. Copies ore ovoiloble in Arobic, Chinese, English, French, Germon, lfolion, Portuguese or Sponish. WHO's odvtce for food hondlers ond coterers is contoined tn o leoflet on Hygiene in food service ond moss cotering estoblishments. The leaflet is olso produced tn the form of o wollchort ond is ovotloble in Arobic, Chinese, English, French, Russion or Sponish. The wollchort on sofe food preporotion ond the leoflet and wallchart for caterers ore ovoiloble free of chorge by writing to Food Sofefy Unil, WHO, l2l I Genevo 27, Switzerlond WorldHeolth r 50thYeor, No. 1, Jonuory-Februory1997 3l WHO publicutions Publicofions con be ordered from Distribution ond Soles, WHO, I 2l 1 Genevo 27, Swilzerlond. Menlal heolth of relugees his monuol is o guide to the recognition ond treotment of mentol heolth problems in refugees ond other disploced persons. Prepored by WH0 in colloborotion with the Office of the United Notions High Commissioner for Refugees, the book is o response to the foct thot the troumo, tenor, los ond bereovement experienced by refugees con seriously threolen their mentol heolth. lvlentolheolth of refugeesis intended for non*peciolist relief worken. lt oims to help them become olert to mentol heolth problems ond show them how to give potients help - whether simple reloxolion exercises or refenol to o medicol speciolist. Ihe book emphosizes the mony simple things thot con be done to eose the suffering of refugees, even when conditions ore crowded ond resources scorce. It describes how to use counselling, self-help groups, modern drugs ond troditionol medicine. There is guidonce on helping refugees with functionol comploints ond common mentol disorders, ond speciol sections deol with ossistonce to refugee children, olcohol ond drug obusers, ond the victims of torfure or rope. Those working with refugees ore given numerous procticol tips, checkli$s, olerts to typicol symptoms, model question-ond-onswer iexts for counselling sessions, ond $ep-by*tep guides to oppropriote oction. The book olso indudes o section on the mentol heolth needs of relief workers. Mentol heolth of refugees (order no 1 150433) costs Sw.fr. 30.-/ US $)-.OO 1<w t,. ) 1 :. 6q1pl>ptnq. auqt!;er) Reseorch on the menopouse in the I 990s or most women oround ihe world, the menopouse occurs between the oges of 45 ond 55. As life expectoncy gets longer, women live on increosing port of their lives ofter the menopouse. The efferts thot the menopouse hos on o ln the next issue Childbirth should be one of the hopplest of events, but it moy turn into o trogedy when proper (0re is not given to fie mother ond the boby ot ihis cruciol moment. Mldwives ploy on involuoble role in supporting normol births ond in giving the necessory core before, during ond ofter birth. The MorchApril 199/ isue of World Heolth will show different ospects of this foscinoting profession. The issue will olso contoin feotures presenting o voriety of topics reloted to heolth. w0m0n's heolth ore the subiect of this report of o WH0 Scientific Group of 25 experts. Reseorch on the menopouse in the I 990sis on ossessment of whot is known obout the immediote ond long-term effects of the menopouse, ond obout how they con be treoted ond prevented. The report dl$inguishes between those oreos where firm conclusions con be reoched ond those where further reseorch is needed. lt stresses, however, thot the menopouse is iu$ one poini in o series of life stoges ond thot o womon's heolth ot this time will be determined lorgely by whot it wos like previously, by the number of children she hos hod, by her lifestyle ond by her environment. The report gives porticulor ottention to the benefits ond risks of hormone theropy ond to the queslion of whether the findings of reseorch in industriolized countries con be opplied to women ekewhere. Some 500 references to recent studies ore included. Reseorch on the menopouse in the 1990s (order no. I I 00866) is no. 866 in lhe WHO Technicol Reporl Serles. The book costs Sw.fr 2a.-/ US $18.00 (Sw.fr. l4 tn developinq counlnes). World Heolth Report 1996 Fighting diseose, fostering development" is the theme of WH0t lll/orld Heolth Report l996.lhe report provides on expert ossessment of the world heolth situotion in oll its complexity, giving porticulor ottention to infectious diseoses. lt combines the lote$ heolth stotistics with on onolysis of the foctors thot hove shoped the cunent situolion. By showing where we $ond in the fight to control infeclious diseoses, the World Heolth Repon 1996 oinsto show both the olorming implicotions of recent trends ond the posibility of controlling ttrem. More thon 50 old ond new diseoses - from molorio, tuberculosis ond cholero to HIV/AlDS, Ebolo hoemonhogic fever ond hepotitis I ond E - ore profiled in terms of their incidence, (ouses, opportunifies for control, ond impoct on heolth ond socioeconomic development. The World Heolth Report 1 996 lorder no 1 24 1 9966) costs Sw tr 15. /US $13 50 (Sw.fr. 9.- in developing countnes) Did you enioy this issue? ,Vl ,:o16[-oto 'b: pr o ot4o/d-^orload-1o,,^odrgobo l'-a,ld roo'l^oh lssues six limes o yeor )997 subscripiion prlces ore llsted be ow. WHOolsoollersllspopuor HeohhHorlzons subscription,ocomblnedsubscripiion(ot oreduced nte) ia Wold Heo/ih ond the quorterly World Heolth Forum. 0rder lorm L I Wor d Heo th (199/ subscr pl on) ot Sw fr 30 ,/US $25 00 I I Heolth Aorizons\)9Q7 subscription) ot Sw fr 90 /aS $72 Aa Poymenl enclosed Peose chorge lo my cred lcorc.l V so L I Amerlcon Express E u rocord,/Mostercord/Access Cord rumber Exp ry do'e Dote ol order Addr-^ss II E -l Wor d Heohh Orgonizotion, Distribution ond So es, I 2 I I Genevo 27 Sw tzelond Prhted in Greot Britoin by GreenShires Print [imited, (eltering, Northomptonshire, Inglond. THE LOGO SELECTED BY V/HO FOR WORLD HEALTH DAY 1997 TRIES TO SHOW HOW A V/ORLDV/IDE PARTNERSHIP OF COUNTRIES, NGOS, INTERNATIONAL ORGANIZATIONS AND INDIVIDUALS ENSURES THE RAPID DETECTION AND EFFECTIVE CONTAINMENT OF EMERGING AND OTHER COMMUNICABLE DISEASES.