communicable diseases Cover: Beware : person-to- person infection ! Orig inal design by Peter Davies IX ISSN 0043-8502 World Health is the officia l illustrated magazine of the World Health Organization. Editor: John Bland Deputy Editor: Christiane Viedma This Month's Theme Editor: Catheri ne Dasen Art Editor: Peter Davies News Page Editor: Peter Ozorio World Health appears ten times a year in English, French, Portuguese, Russian and Spanish, and four times a year in Arabic and Farsi. The German edition is obtainable from German Green Cross, Schuhmarkt 4, 3550 Marburg, FRG. Art icles and photographs not copyrighted may be reproduced provided credi t is given to the World Health Organization. Signed articles do not necess- arily reflect WHO's views. World Health, WHO, Av. Appia, 1211 Geneva 27, Switzerland. Contents Communicable diseases by Giorgio Torrigiani and William Parra . 3 Vaccines and vaccination by Gordon L. Ada . . . . . . . . . . . . . . . . . . 5 Influenza is preventable by Yu ri Ghendon . . . . . . . . . . . . . . . 8 Hepatitis B : eradicable? by Wolfgang Ji lg and Friedrich Deinhardt. 10 Leprosy: light at the end of the tunnel by John Maurice 13 " Information may be their only defence" by Martha Leslie-Harwit and Andre Meheus . . . . . . . . . . . . . . . . . . 16-17 AIDS in Mexico by Jaime Sepulveda Yellow fever gains ground 18 by Thomas P. Monath . . . . . . . . . . . . . . . 20 Sleeping sickness-re-awakes by Pi erre Cattand 24 From surviving smallpox to preventing measles by Edna Adan lsmail . . . . . . . . . . . . . . 26 Cooperation with industry by John F. Dunne . . . . . . . . . 27 Talloires: a quiet revolution by Robert Walgate . . . . . . . . . . . . . . . . . 28 News Page . 30 2 W ORLD HEALTH, Ju ly 1988 Communicable diseases by Giorgio Torrigiani and William Parra Or Giorgio Torrigiani is Director of WHO's Division of Communicable Diseases and Mr William Parra is Management Support Officer for the same division Communicable diseases , in WHO's parlance, are those which are transmitted either from human to human, from ani- mals to people , carried to us by in- sects or other "vectors," or con- veyed to us in the air we breath , the water we drink and the very ground we tread on. A large number of them are so firmly entrenched in human com- munities that we tend to take them for granted- infections like the common cold, or influenza , or chickenpox. It is easy to forget that, for at least two millennia to our knowledge, smallpox too was " tak- en for granted" by generation upon generation ; yet just 13 years of global effort sufficed to wipe it from our planet. Many of these communicable dis- eases, in fact , are fostered by low standards of environmental sanita- tion , malnutrition, inadequate so- cial and economic development, and general ignorance of simple changes in behaviour that could help to avoid infection. And some diseases contribute to levels of sick- ness , disability and death-parti- cularly in children aged under five in the developing world- that are simply unacceptable in the closing decades of the 20th century. · Acute diarrhoea! diseases alone (including cholera) represent the primary cause of child mortality in developing countries and contri- bute to one-third of the 15 million deaths in this age group each year. Another one-third result from acute respiratory infections , pri- marily pneumonias. In addition, these infections are the leading cause of sickness in virtually all countries. Parasitic diseases , in particular malaria , filariasis, schistosomiasis and trypanosomiasis , remain as se- rious public health problems on a WORLD HEALTH, July 1988 global scale, and put the brake on attempts to develop many tropical areas. Efforts to control them may drain a sizeable proportion of the available resources in countries where these diseases are endemic. An estimated 17.5 million people are infected with onchocerciasis (river blindness) and about 340,000 are blind as a result; an additional Vaccination has proved to be one of the most cost-effective methods of protect- ing human health. Left: A household put at risk by inade- quate housing in the Western Pacific. Photos W HO/Zafar one million individuals are consid- ered to have suffered significant loss of sight , leaving them partially disabled. Tuberculosis and leprosy still constitute significant public health problems, while viral haemorrhagic fevers continue to have a major im- pact , particularly during epidemic outbreaks, in many countries . Sex- ually transmitted diseases are on the increase throughout the world , with a general shift towards youn- ger age groups. And even while the number of pathogens found to be sexually transmitted has been in- creasing in recent years, the disease spectrum in this area has been fur- ther complicated by the emergence of acquired immunodeficiency syn- drome (AIDS) and its various dis- ease manifestations . A matter of persistent concern is the increasing resistance of mi- crobes to drugs as well as resistance of insects and other vectors to chemical pesticides- trends that im- pede progress in disease reduction and increase the costs of control operations. Rapid expansion of the cities, the boom in travel and popu- lation movements , and increasing trade in human and animal foods within and between countries- all these have increased the risk of dis- eases being rapidly transmitted from one country or region to another. The burden of many communi- cable diseases could undoubtedly be reduced by environmental man- agement, by which we mean pro- viding safe water supply and the sanitary disposal of refuse , waste- water and excreta, ensuring ade- quate housing , safeguarding the en- vironment from chemical pollution and other control technologies. But building up these control measures is , of necessity, a slow process. In big cities, they require a large capi- tal investment, while in the vast ru- ral areas of the Third World , envi- ronmental management can only take place as part of the overall social and economic development. So emphasis will continue to fall on traditional methods of prevent- ing and controlling communicable diseases . These methods include setting up and maintaining surveil- lance systems to enumerate and 3 Communicable diseases evaluate all cases that occur, a ma- jor first step in determining the distribution , responsible factors, severity and extent of each com- municable disease. This in turn provides the necessary base-line information for setting the right priorities for applying disease con- trol strategies. Other control efforts include building up manpower resources through training programmes in technical and managerial areas, in- creasing the number of skilled per- sonnel engaged in communicable disease control activities, and de- veloping simple diagnostic tech- niques and inexpensive means of treatment that primary health care workers can deliver even in remote villages. And today there is re- newed interest in " health promo- tion" aimed at showing people how Tuberculosis remains a significant pub- lic health problem in many countries. This young Burmese mother is being treated for TB in her own home. Photo WHO 4 to avoid disease , to actively seek health and maintain healthy life- styles, all of which will directly con- tribute to the prevention or early treatment of many communicable diseases. Research is another important component of disease prevention and control activities, and thanks to modern biotechnology the hunt is on for new and inexpensive drugs , diagnostics and vaccines. It is par- ticularly important to develop new drugs to counter the many disease- causing organisms which are be- coming increasingly resistant to existing antibiotics. Vaccines, by contrast , have proved in recent history to be one of the most cost-effective methods of protecting human health . The in- tensive immunization programme mounted by WHO was the key to the global eradication of smallpox by 1977. Inspired by this success, WHO initiated , in 1974; the Expanded Programme on Immunization, a programme designed to immunize the children of the world against six common childhood diseases. AI- though no reliable figures on immu- nization coverage were available at that time, it could be estimated from the total quantities of vaccines being used , that fewer than five percent of children in their first year of life were receiving the vital third dose protecting them from polio , as well as diphtheria , whoop- ing cough and tetanus (DPT). As a result , some five million children died each year from vaccine-pre- ventable diseases; another five mil- lion more were crippled, blinded or mentally damaged. Today, immunization coverage in the developing countries (excluding China) had increased to 50 percent in 1987 for a third dose of DPT or polio vaccine. The stage is now set to add newly available vaccines to existing immunization schedules, and to further strengthen national managerial capabilities to ensure immunization and other kinds of health care for mothers and children. WHO continues to promote and support several programmes aimed at developing vaccines, whether to control more effectively those dis- eases for which vaccines do not ex- ist, or to improve the efficiency of existing vaccines. Theoretically at least, it should now be possible to design vaccines which provide long- term protection without any of the side effects observed in the past. Despite encouraging results, new vaccines for general use are not go- ing to be available overnight. So WHO is not slackening its ef- forts to prevent and control com- municable diseases by existing and conventional means. But a research and development effort of this mag- nitude , and the introduction of improved disease prevention and control strategies, cannot be under- taken without encouraging coun- tries to build up still further their national capabilities in such fields as epidemiology, biological re- search and health systems research. In turn the essential elements of these new strategies have to be in- corporated rapidly into the curri- cula of training institutions, and health staff will need continuing education and complementary train- ing facilities. It goes without saying that WHO will continue to do its ut- most to collaborate with Member States and strengthen their capacity and efficiency in all these fields. • WORLD HEALTH, July 1988 Vaccines and vaccination by Gordon L. Ada Professor Gordon L. Ada is visiting Professor at Johns Hopkins University, USA I n ancient times , it was observed that those who survived an in-fectious disease seldom suffered a second , similar sickness; and this was particularly apparent in the case of a disease like smallpox which left characteristic pockmarks on the skin. Sometimes a mild in- fection could be related to the site of the disease symptoms , and this led to the practice of deliberate in- fection with the disease agent at these sites-a hazardous procedure. The first demonstrably safe pro- cedure for preventing infection -the process now called vaccina- tion- was carried out in 1796 by Edward Jenner. He inoculated a boy with infectious material from cows (cowpox virus) and then showed that he was immune from smallpox by injecting him with ma- terial from a victim's smallpox scab! Louis Pasteur later developed (initially by chance) the means of changing the properties of microbes so that their potential for causing disease (a property called viru- Lence) was much reduced without greatly affecting their ability to in- duce an immune response. This process of attenuation was subse- quently used to develop some of our most successful vaccines, par- ticularly to control diseases caused by viruses. Viruses and many bacteria cause disease by damaging or killing the cells they infect; consequently, a vaccine aims to prevent infection of these cells by the virus or bacteri- um. Many vaccines consist of the live , attenuated organism; or, if such a preparation is either not available, or cannot be made, the virus or bacteria is inactivated (killed) before being administered. Other bacteria secrete powerful poisons which damage the host's cells, so protection against these bacteria called for a different strat- egy. The isolated poison was made W ORLD HEALTH , July 1988 the basis of the vaccine but it had to be inactivated in a special way be- fore it could be safely administered. The six vaccines against the com- mon childhood diseases which form the basis fo WHO's Expanded Pro- gramme on Immunization are pre- pared by one or other of these three procedures : the measles and polio vaccines are attenuated strains of these viruses , and an inac- tivated preparation of polio virus is also available; BCG against tuber- culosis is an attenuated form of the tubercle bacillus; the pertussis vac- cine is an inactivated preparation of the bacteria that cause whooping cough; the diphtheria and tetanus vaccines are composed of the inac- tivated poisons (toxins converted to toxoids) secreted by those bacteria. Cowpox sores on a milkmaid's hands inspired Dr Edward Jenner to develop the vaccine that eventu- ally eradicated smallpox. Photo WHO There are about 50 vaccines for human use currently approved or under trial. With few exceptions, they are for the control of viral or bacterial diseases , and those in common use vary in their efficacy. The live attenuated viral vaccines are generally the most effective. World-wide use of the smallpox vaccine, based on vaccinia virus (vacca is the Latin for a cow) and progressively developed since Jen- ner's day, achieved the ultimate goal of a vaccination programme- the eradication of the disease itself. Measles, rubella (" German mea- sles"), yellow fever and polio vac- cines can give life-long protection from these diseases. Though vac- cine administration may cause some side-effects, a comparison of the incidence of complications fol- lowing infection with the wild-type measles virus versus the vaccine dramatically demonstrates the ad- vantage of vaccination. In the Uni- ted States, immunization of chil- dren with measles vaccine prior to school entry is now required by law, with the result that indigenous measles has virtually disappeared from that country. Though widely used, BCG has given variable re- sults . It has proved to be an effec- tive vaccine for infants but has giv- en variable results in adults . A trial of this vaccine in South India showed such poor protection against tuberculosis that , because of the continuing global importance of this disease, it was clear that we needed more detailed knowledge of the biology of the bacterium and of the immune responses that would give immunity from infection. This led to the establishment , in 1984, of the WHO Vaccine Development Pro- gramme which supports research on a number of viral and bacterial diseases for which new or improved vaccines are needed. These vaccines have reduced the burden of infectious disease to a much greater extent in developed than in developing countries , partly because of wider coverage of the population in the former but also because the other infections are much more prevalent in the latter countries. The wHo Programme on Tropical Diseases Research (TDR) was established to support research aimed at controlling one bacterial (leprosy) and five parasitic diseases prevalent in these countries. At present, a vaccine to control lepro- sy and several preparations aimed 5 at different stages of the life-cycle of the malaria parasite are under trial. Similarly, WHO's Diarrhoea! Diseases Control Programme (CDD) aims to develop means of controlling diseases of the gastro- intestinal tract , while new vaccines to control rotaviral infections , which cause serious diarrhoea in in- fants, and cholera are being tested. The need for these and other vac- cines is great. A third of the world's population is at risk of malaria infection and millions suffer from simultaneous infection by several parasites. The appearance of AIDS due to infection by the human im- munodeficiency virus, HIV , is al- ready of major concern in devel- oped countries but seems certain to have devastating consequences in some developing countries. What can the new knowledge of immuno- logical processes and the new tech- niques of the molecular biologists contribute to making effective vac- cines to control these diseases? Serious reaction following Broadly speaking, there are two main new approaches towards vac- cine development. The first at- tempts a synthetic approach by making in the test tube those parts of the virus or bacteria or parasite which are thought to be the most important for stimulating the im- mune response. The synthetic pre- paration, composed of peptides, should provide an entirely safe vac- cine, by contrast with existing vac- cines which may cause side-effects, sometimes serious, in a very small proportion of recipients . However, the as-yet-unresolved question is: will such vaccines be as effective in preventing disease as the con- ventional approach? If used by themselves , the answer is No! They must be combined with other molecules and administered with an adjuvant (a preparation which enhances the immune response to the peptide). The second approach is to use techniques which involve isolating For every 100,000 cases Measles Pneumonia Convulsions Brain damage Early death infection 5,000 720 280 10 Measles ' vaccination 1 60 0.1 0.02 6 Above : To remain potent vaccines must be kept cold: in a hospital in Thailand, a user's guide is printed on the refrigerator. Photo WHO/Zafar Left : At a research centre on influenza in the United Kingdom, nasal washings are obtained from patients in order to isolate viruses. Photo WHO/D. Henrioud Far right: There are about 50 vaccines for human use; bacterial vaccines are produced by fermenting bacteria in these huge vats. Photo Swiss Serum and Vaccine Institute © the DNA coding for antigens , transforming cells with the DNA so that the antigen is now produced by these cells and can be used as a vac- cine . A variation of this approach is to incorporate this DNA into an ex- isting vaccine , such as the smallpox vaccine , so that this well-tried vac- cine can be used to protect against another disease, such as malaria. The smallpox vaccine did however cause side-effects , with occasional deaths. Fortunately, novel ways of making such a " hybrid vaccine" both more safe and more effective than the parent vaccine have re- cently been described , but such preparations have yet to be licensed for human use. There have also been advances in developing oral vaccines. A "gene- tically-disabled " form of a Salmo- nella organism, which can be taken orally , has been successfully used to protect against typhoid fever in tri- als in Egypt. DNA coding for an important antigen of the organism causing cholera has been incorpo- rated into this Salmonella , and tri- als are in progress to establish whether this hybrid vaccine will now also give protection against cholera. If so, it can readily be ap- preciated that such hybrid vaccines offer the possibility of developing multivalent vaccines . In other words, WORLD HEALTH, July 1988 Vaccines and vaccination some day a single vaccine may pro- tect against several diseases- a pre- cious boon in tropical countries where there is so much infectious disease. Scientists working in these areas are justifiably confident that apply- ing these new approaches should lead to the development of vaccines against many diseases, particularly such parasitic diseases as malaria . But the future is not entirely rosy. Infectious micro-organisms have eo-evolved with man over millen- nia , and the " cleverest " micro-or- ganisms have developed means of by-passing man's defences so that they continue to survive and to plague us. One example i.s the influ- enza virus. By continually changing its properties , this virus escapes pre-existing antibodies and infects susceptible cells. This is why the currently available vaccines are only partially successful. The virus can be controlled at a later stage, but not before it has caused the Or Barry Bloom, in his Presidential Address to the American Associa- tion of Immunologists in 1986, pre- sented a graphic summary of the situation in tropical and other developing countries. "This is the Third World, in w hich 75 per cent of the planet's population lives, where 86 per cent of all children are born and 98 per cent of all infant and child deaths occur, and where 10 kids die of vaccine-preventable illness every minute." symptoms of influenza and has spread to other people. It is the " perfect " virus; most people easily survive an attack and the virus con- tinues to flourish! In the process of adapting to hu- man hosts, HIV is still a major kill- er and, unfortunately, it seems to have nearly all the cards on its side. As well as the trick of changing its properties , like the influenza virus, it infects and destroys those cells which are an essential part of the immune system. For these reasons , it is difficult to develop a vaccine which would protect those at risk from infection by this virus. Our hopes for controlling AIDS rest on educating people about transmis- sion of the virus, and on the not un- realistic hope that an effective drug to control the infection will speedily be developed . • WORLD HEALTH, July 1988 Influenza is preventable by Yuri Ghendon Or Yuri Ghendon is Senior Virologist with WHO 's section of Microbiology and Immunology Support Services I nfluenza-'flu-is for most people an unpleasant illness that sends them to bed for a few days and leaves them feeling weak. But it is also a potential killer. In the United States alone for ex- ample, in 1957, the Asian strain of influenza virus caused an estimated 70,000 deaths; the Hong Kong strain that appeared in 1968 caused about 30,000 deaths in the same country. Even in years not associat- ed with antigenic shift in the virus, many people die as a result of influ- 8 enza infection. In fact , 10,000 or more excess deaths have been do- cumented in the USA during each of 18 different epidemics from 1957 to 1985. Some 80 to 90 per cent of the ex- cess deaths attributed to pneumo- nia and influenza during epidemics have occurred among persons of 65 years of age or more, although 'flu- associated deaths among children or previously healthy adults under 65 years of age are reported during major epidemics. This excess mor- tality is not only a direct result of pneumonia, but also of cardio-pul- monary or the chronic diseases that are exacerbated during influenza infection. In addition , the days lost from school and work, and the hos- pital care required for complica- tions, result in a very high cost of influenza to society. Three types of human influenza viruses, A , B and C, were discov- ered in 1933, 1940 and 1947 respec- tively. Only type A is associated with pandemics. WORLD HEALTH, July 1988 Manufacturing influenza vaccines in Switzerland. But doubts still linger about their efficacy. Photo Swiss Serum and Vaccine Institute © Below: For most people, 'flu means a bout of sneezing and a few days in bed. But it is a potential killer. Photo W HO/D. Henrioud These viruses are variable and can change the antigenic specificity of their envelope proteins- haemag- glutinin and neuraminidase. They thus escape the neutralising anti- bodies that we have developed through previous infections or vac- cinations and that ought to protect us. That is why the strains of viruses used for the production of influenza vaccines have to be changed every one or two years. WHO's influenza programme essen- tially consists of rapidly isolating and characterising all new strains in order to make available for produc- tion laboratories those that show substantial variation from the cur- rent strains. WHO Collaborating Centres for influenza in London and in Atlanta, USA, together with 110 national institutions for influen- za in 79 countries all carry out sur- veillance activities. Each year, to- wards the end of February, WHO holds a consultation to draw up rec- ommendations for the composition of influenza vaccines for the forth- coming season. It is now possible to recombine the new antigenic vari- ant with a strain that has been trained to grow rapidly in chickem- bryos, or with the cold-adapted at- tenuated master strain , and this re- duces the time needed to get into large-scale vaccine production . Two sorts of vaccines are now available : those that are inacti- vated, concentrated and purified for administration by injection and live , attenuated, cold-adapted vac- cines destined for instillation or pulverisation into the upper respi- ratory passages. Even though this disease is a widespread problem in many coun- tries , the existing 'flu vaccines are among the least used vaccines avail- able . The need for annual revacci- nation , misconceptions about the capabilities of the vaccines-many . recipients expect them to prevent all respiratory infections- and ques- tions about their efficacy have led many physicians to conclude that vaccination against influenza is not worth the effort. W ORLD HEALTH, July 1988 In fact there is plenty of evidence to show that influenza vaccines can protect individuals and indeed, if used properly , may protect 70 to 80 per cent of vaccinees in the com- munity as a whole. Vaccination strategies have two main objectives: to protect individ- uals who are at particular risk from disease (the elderly, the chronically sick, people living in institutions under crowded conditions and so on) ; and to protect other defined sectors of the population (such as schoolchildren, or factory work- ers). In the last case , vaccination may have direct benefit for the indi- viduals involved and for the com- munity as a whole. But it should be noted that in closed or semi-closed settings, maximum benefit from im- munization is likely to be achieved when more than about 75 per cent of the population are vaccinated , so as to exploit the advantages of " herd immunity. " Besides vaccines , there are good antiviral preparations against the disease. Amantadine and rimanta- dine have proved in many con- trolled trials to be effective against influenza A infections , both pro- phylactically and therapeutically (administered between 24 and 48 hours after the onset of symptoms). In prophylactic use , a 70 to 90 per cent reduction in infection has been achieved . It is unfortunate that these drugs have been so little used to protect against influenza A infections. On the other hand, chemopro- phylaxis with these drugs is not a substitute for vaccination, because there is no protection against the B virus , and also because patients may fail to take the drug for the full 6 to 12 weeks of an epidemic peri- od. Aerosolised ribavirin has been recommended against influenza B , but its usefulness would possibly be restricted to patients confined in hospital. Influenza is not a trivial disease . It kills many thousands of patients every year and the cost of its depradations to any country's econ- omy is enormous. But influenza is preventable. By means of the vaccines and antivirals now avail- able it is possible to protect indivi- duals both in the high-risk groups and in defined sectors of the population. • Hepatiti~ B ; eradicaBle ? by Wolfgang Jilg and Friedrich Deinhardt Drs Wolfgang Jilg and Friedrich OeiQhardt are with)the Max van Pettenkofer Institute, University of Munich R ecent progress in developing hepatitis B vaccines has brought much closer the ul- timate goal of controlling and elimi- nating this disease- much as that other viral disease, smallpox, was eradicated. Hepatitis B today remains one of the most important global infec- tious diseases ; every year, around 40 million people die from the con- sequences of chronic hepatitis. About six million people develop hepatocellular carcinoma, a disease which is also associated with hepati- tis B virus (HBV). Between 200 and 300 million people carry HBV chronically, and they constitute the major reservoir of this infectious agent. Hepatitis B is highly endemic in South-East Asia and in Central and Southern Africa. Some 70 to 80 per cent of people living in these re- gions have had contact with the vi- rus, of whom five to ten per cent (in certain areas even 20 per cent or more) are chronic virus carriers. In industrialised countries, such as the United States and the western and northern parts of Europe , the hepa- titis B prevalence is rather low, not exceeding five or ten per cent, with a chronic carrier rate well below one per cent. In these countries, 10 it is a disease of particular risk groups, such as medical personnel , patients needing frequent blood products (for instance , haemophi- liacs and chronic haemodialysis pa- tients) , persons with close contacts to HBV carriers , drug abusers who share contaminated needles, male homosexuals and prostitutes. The prevalence of HBV infection ranges from about 20 per cent in medical personnel to more than 90 per cent in haemophiliacs who have received frequent treatments with non-inactivated clotting factors pre- pared from unscreened human blood. The acute disease caused by HBV does not differ from hepatitis due to other viral agents, such as hepatitis A virus or the hepatitis non-A, non-B viruses. In a typical case, the disease starts after an in- cubation period of two to six months. For several days , there are only vague symptoms similar to those of other viral infections. They include fever, anorexia, weakness and headache ; a more specific symptom is right upper quadrant pain with local tenderness. This so- called "prodromal" phase is fol- lowed typically by jaundice (yellow- ing of the skin and mucous membranes) lasting for about two to four weeks. This typical course of acute hepatitis B has several variations. In about one per cent of cases , acute fulminant hepatitis de- velops with an often lethal out- come; by constrast, many infec- tions cause a mild illness without jaundice ("anicteric hepatitis ") or may even occur without any symp- toms at all. Two characteristics make infec- tion with HBV so important: the development of chronicity (persis- tence over a long period of time) , and the association of HBV with a type of cancer called hepatocellular carcinoma. Most patients recover from acute hepatitis, but five to ten per cent continue to carry the virus in their livers for a long time , even for a lifetime. And even patients without any signs of acute hepatitis may develop chronic infections. These chronic HBV carriers may remain asymptomatic or they may develop chronic hepatitis, of which there are two forms : chronic persis- tent hepatitis , which may eventual- ly resolve itself; and chronic active hepatitis, which usually proceeds to cirrhosis , chronic liver failure and death. Irrespective of the clinical condi- tion , all chronic carriers are a po- tential source of infection to others, WORLD HEALTH , July 1988 and all are at a considerable risk of developing hepatocellular carcino- ma. This malignancy is one of the most common tumours in such ar- eas of high hepatitis B endemicity as South-East Asia and Central Africa. Although at a molecular level the relationship between HBV and the development of hepa- tocellular carcinoma is still unex- plained, epidemiological data have shown that this tumour is indeed associated with chronic hepatitis B infection. The hepatitis B virus (HBV) is a spherical particle measuring 42 nano- meters ( 42 thousand-millionth of a meter) in diameter. A protein en- velope called hepatitis B surface antigen (HBs antigen or HBsAg) surrounds the virus core, which contains deoxyribonucleic acid (DNA) as carrier of the viral genet- ic information. HBV has a very narrow host range ; only man and the great apes are susceptible to this virus. But in recent years simi- lar viruses have been detected, in- fecting woodchucks, ground squir- rels and peking ducks ; and all these viruses together with HBV are clas- sified as "hepadna" (for hepatitis- DNA) viruses. Hepatitis B virus is present in the blood of chronic carriers, and can WORLD HEALTH, July 1988 also be present but in considerably lower concentrations in other body fluids such as saliva, tears or se- men. Faeces and urine, as long as they are not contaminated by blood, can be assumed not to con- tain HBV. Transmission is only possible when infectious virus en- ters the bloodstream. This may take place by direct percutaneous inoculation, through skin cuts or scratches, or through mucous mem- branes which sometimes have small breaks allowing the virus to enter. Intact skin, however, cannot be penetrated by HBV. Before the screening for HBs antigen was introduc:ed, transfusion of HEY-contaminated blood was a common mode of transmission. This is still a frequent means of trans- mitting the disease in areas where donor screening is not customary. In medical surroundings, one of the most important ways of trans- mission is through inadvertent inju- ry, for example, by a contaminated needle, scalpel or similar instru- ment, but it may also be passed from patient to patient by inade- quately cleaned and sterilised in- struments used in -dentistry, cardiac catheterisation and endoscopic pro- cedures. Transmission is also common in Port~ait i of the hepatitis B virus. HBV has iJ very narrOJY host rqnge ," Only man and the great apes are susceptible tq this virus. Left: A visiting Chinese scientist carry- ing out radio-irrimuno assays to detect hepatitis.B infection atFairfield Hospi- tal, Melbourne, Australia. paramedical situations where poor hygiene is prevalent, such as the use of insufficiently or non-steri- lised instruments for acupuncture, tattooing or ear and nose piercing. In the household setting, too, there are possibilities for percutaneous inoculation and transmission of HBV; there is a considerable risk of contracting hepatitis by sharing razors, toothbrushes, nail brushes, nail files or scissors or similar in- struments of personal hygiene with acutely infected persons or chronic virus carriers; contaminated work surfaces which may come in contact with injured mucous membranes or skin are also a danger. This danger is increased by the persistence of in- fectivity of dried serum for at least a week. The most important routes by far, however, are the infection of new-born babies by infectious mothers, transmission by close per- sonal contact (especially between mother and child and between chil- dren), and transmission by sexual contact. Infections during the neo- natal period or during early infancy are particularly frequent in regions where HBV endemicity is high. In- fected new-born babies almost in- variably become chronic carriers, and infections in young infants fre- 11 Hepatitis B: eradicable? quently progress to chronicity ; this explains the high rate of chronic carriers in certain countries . We have no specific therapy , so prevention of hepatitis B by hygien- ic measures, passive immunization and active vaccination is vitally im- portant. In the medical field , hy- gienic measures include wearing gloves while taking blood , care- fully cleaning and sterilising instru- ments , and using disposable sy- ringes , needles and other instru- ments whenever possible. Similar measures must be adopted in para- medical situations , for instance , the strict use of sterile instruments for ear piercing or tattooing. Passive immunization with hepa- titis B immunoglobulin (HBig) is a specific means of preventing the disease . HBig is an immunoglobu- lin preparation which contains anti- bodies in high concentrations against HBsAg, the envelope com- ponent of HBV; these antibodies neutralise the virus : that is they in- hibit its infectivity. The main disad- vantages of this method are the lim- ited period of protection (only about three months) and its very high cost; so such passive immuni- zations against hepatitis B are only used, for example , after an injury with a contaminated needle or for the new-born children of HBV-car- rier mothers. Today, in both of these instances , passive immuniza- tion should be combined with ac- tive vaccination. Active vaccination avoids the dis- advantages of HBig; it produces a long-lasting immunity and is cheap- Drug abusers who share needles are at particular risk of contracting hepatitis B. Photo WHO/P. Laurie er. The first hepatitis B vaccine , prepared from the plasma of chron- ic HBV carriers , is highly immuno- genic, very effective and safe . Its use is indicated in areas where there is a low prevalence of hepati- tis B in high-risk groups such as health care personnel, haemodia- lysis patients , intravenous drug abusers , male homosexuals and babies newly born to HBV-positive mothers. In high prevalence areas , this vaccine should be given to all children or at least to all children of carrier mothers. But it is expensive because both the starting material , human plasma, and the extensive purification procedures are costly. Whereas industrialised countries can afford to vaccinate the relative- ly few members of high-risk groups , it is impossible for other countries to immunize large numbers of people. A new vaccine produced by re- combinant gene technology was the first step towards reducing these costs. First licensed in 1986 in the United States and the Federal Republic of Germany, it is made from HBsAg-producing recombi- nant yeast cells . At present , it is only slightly cheaper than the plas- ma vaccine , but the production costs can undoubtedly be reduced in the future . Other techniques such as the use of synthetic peptides-small parts of the surface protein of HBsAg-are currently being investigated in the hope of producing alternative vac- cines. And transfer of technology to countries of the Third World, without lowering the standards set by WHO for hepatitis B vaccines , will enable those countries to pro- duce their own vaccines from local- ly obtained plasma, thus reducing the costs considerably. WHO's Expanded Programme on Immunization (EPI) has included the elimination of hepatitis B among its goals, and even though it will be long before we can vaccinate everyone at risk, plans for mass vaccination programmes are not utopian . We could begin to put these plans into practice in the near future. And as the costs of vaccines drop further, it will become possi- ble to vaccinate all people at risk , so preventing disease and death among millions of people and lead- ing- ultimately- to the eradication of hepatitis B. • W ORLD HEALTH , July 1988 Leprosy : light at the end ol the tunnel by John Maurice Mr John Maurice, a Scottish freelance science writer living in the Geneva area, formerly worked as Communications Officer for the uNoPIWorld Bank/wHo Special Programme for Research and Training in Tropical Diseases (TOR) I n busy Manaus, capital of Bra-zil's Amazonas State , anyone in a hurry at 3 o'clock in the after- noon should not take bus number 63. The chances are it will stop for no obvious reason at a street corner while the driver, Amauri de Oli- vera, disappears into a soft-drink bar. He will return five minutes later, a grin on his face. His regular passengers grin back. They know that he has just taken his monthly dose of a new treatment. They know that thanks to this treatment he will not lose his fingers, toes or eyebrows. That he will not go blind. That his hands will not twist into rigid claws. That purulent ul- cers will not appear on his feet pre- venting him from walking. That he will not contaminate his family or his passengers. They know that in a few months he can stop taking the pills because he will be cured of a disease that up to now has been considered incurable. Bus driver de Olivera is one of over two million leprosy patients throughout the world who have been or are receiv- ing multidrug therapy (MDT). MDT is WHO's answer to a threat that could have spelled catastrophe for the 1,600 million people, includ- ing the estimated ten to twelve mil- lion leprosy patients , who live in the 53 countries where leprosy in endemic: the threat that dapsone , virtually the world's only anti-lep- rosy drug for the past 40 years, would become ineffective. By the early 1980s, studies set up by the UNDP/World Bank/wHo Special Pro- gramme for Research and Training in Tropical Diseases (TDR) were disclosing resistant strains of Myco- bacterium leprae in up to one-third WORLD HEALTH , July 1988 of cases in several endemic coun- tries. In some areas, large numbers of patients were failing to respond to dapsone , a drug that has to be taken for years to be effective. Ac- tion had to be taken urgently. In 1981, WHO hastily convened a Study Group, which came up with a treatment scheme based on a com- bination of three drugs : rifampicin, a powerful bactericidal compound ; clofazimine, a weak bactericidal drug but with potentially useful an- ti-inflammatory effects; and dap- sone itself. Patients with mild pau- cibacillary leprosy ( = with few bacilli) would be given dapsone and rifampicin for six to nine months. Those with more severe (multiba- cillary) leprosy would receive dap- sone, rifampicin and clofazimine for 24 to 48 months . Rifampicin and clofazimine would be given under strict superviSion. Dap- sone would continue to be self- administered. The Study Group's recommenda- tions were based on : - laboratory evidence that leprosy bacilli resistant to one drug would succumb most probably to a second and almost certainly to a third drug ; - preliminary results from early clinical trials suggesting that within a few weeks of starting this treatment , over 99 per cent Soon, the disfiguring signs of leprosy, such as those affecting this young girl in Malawi, will be less common, thanks to multidrug therapy. Photo WHO/J . Maurice 13 of the ten thousand million or so leprosy bacilli infecting a patient would be killed and that the pa- tient would thus be non-infective to others; - the assumption that effective treatment limited to six months at best, 24 months at worst, would stand a much better chance of being accepted and taken regularly than treatment of limited efficacy prescribed for years. MDT has been adopted by 45 of the 53 leprosy-endemic countries or territories of the world (that is , with a prevalence equal to or greater than 1 per 1000 inhabitants), and al- together by 96 of the 152 countries or territories of the world reporting any cases of leprosy to wHo. Of the over five million registered leprosy patients in the world, some 2.1 mil- lion have been put on MDT. Of these, over a quarter have complet- ed their treatment. They continue to be examined at regular intervals , however, in case of relapse or any untoward reaction as a result of the leprosy bacilli that have been killed by the treatment but not yet cleared from the body. Statistics give only one side of the picture. Interviews with a cross-sec- 14 tion of patients-over 200 in all-in five countries where MDT is being enthusiastically applied (Venezuela and Brazil in Latin America, Ethio- pia and Malawi in Africa , and In- dia) give an equally bright picture . A 60-year-old rancher, for exam- ple, interviewed at his farm in Ven- ezuela's Portoguesa region cries from relief when he is told that his 25-year search for a cure is about to end, thanks to a definitive, two- year course of MDT. His wife, who has just been found to have a white patch on her back-an early sign of the disease-does not cry when she learns she has leprosy , since she is told that MDT will rid her of infec- tion within a few months. In the East Godavari district of southern India's Andhra Pradesh state, a young woman proudly shows off her vigorous 18-month child. She calls him her "MDT child" because during her pregnan- cy she refused , against medical advice , to give up her therapy. "I couldn't stop ," she explains. "It was making me a live person again." A farmer in Ethiopia's Shewa re- gion mounts his mule before dawn to reach an MDT treatment point held on market days under a warka India's leprosy control programme is district-based and relies on almost mili- tary strategies. Left: In Malawi, preventing disability through early treatment with multi-drug therapy has priority over care for those already disabled. Right: In Venezuela, the health worker (in cap) tracks down every suspected case in the family. Photos WHO/J. Maurice tree-a four-hour journey across boulder-strewn tracks that disap- pear every few miles beneath rush- ing streams. "You'd have to take my mule from me or chop off my legs before you'd stop me coming for my treatment," he declares . Generally , patients say they " feel better" on MDT. But their enthusiasm may also stem from the greater attention MDT brings them. They now have a regular monthly date with a health care worker and, of course, with other fellow leprosy patients-under a banyan tree in the Indian country- side, in a mobile health-care house- boat in the Amazon, between rows of perch drying in the sun on the shores of Lake Malawi. "For many patients , MDT is like an opening in the sky , a light at the end of a long dark tunnel," says a leprosy control officer in Maracay , Venezuela. " We can begin to use the word 'cure' when we talk to patients. " The enthusiasm of health work- ers for MDT is often tempered by the increased initial workload it re- quires- more paperwork to ensure careful recording of drug adminis- tration and clinical changes, and more travelling to reach the treat- W ORLD HEALTH, July 1988 ment points that are located as close to patients' homes as possible. But the workload diminishes quick- ly as the treatment programme gets under way. Examples : Over the past three to four years the number of cases has dropped from 30,000 to 4,000 in Srikakulam District , India ; from 1,900 to 300 in Kambata re- gion, Ethiopia ; from 9,000 to 2,500 in Malawi. So dramatic is the drop in some areas that leprosy control staff hired and trained to deal with hun- dreds or thousands of patients face imminent unemployment or con- version to other health work. Some of the reduction in case-load may be due to the " weeding out" of in- active or dead patients in pre-MDT screening surveys. On the other hand, the drop is occurring despite the still fairly constant intake of new cases in many countries . (The very existence of MDT can bring an influx of previously "hidden" pa- tients wishing to take advantage of the new treatment.) Two key questions remain: Is MDT medically effective? And if so , for how long? MDT was something of a gam- ble , admits Dr Shaik K. Noordeen , who heads the Leprosy Unit at W oRLD HEALTH , July 1988 WHO's headquarters in Geneva. "We were finding resistance to dap- sone wherever we looked for it. We had to do something. There was simply no time for careful , long- term study ." So far, clinically and epidemio- logically, MDT is living up to ex- pectations, although it is too early to talk of victory. Many leprosy control officers say MDT seems to reduce the bacterial load in patients more quickly than dapsone alone. It may also reduce the frequency of the dreaded leprosy "reactions," with their concomitant pain , swell- ing and risk of permanent nerve damage and deformity. It also seems to be effective in preventing or delaying the onset of resistant bacilli - the relapse rate in MDT- treated patients seems to be well under one per cent in most areas. A further benefit of MDT is that it does not require hospitalisa- tion but keeps patients in their communities , and thus helps to erode the social stigma which was fostered by forced isolation of patients m hospitals or leprosaria. MDT is not without its critics, though. Sceptics fear that it will take more than 6 or 24 months of drug treatment to get the better of a disease that has an incubation time of up to 15 years. It is true that many paucibacillary patients still have leprosy patches after their six-month MDT course , but these lesions nearly always disappear over the next year or two. Other critics say too much emphasis is be- ing put on drug therapy and too lit- tle on care for the estimated one to two million patients who are disfig- ured or disabled, and who require physiotherapy, surgery or special footwear. In Ethiopia and India, for example , facilities are clearly lack- ing to care for such patients , and in Malawi prevention of disability through early MDT treatment has deliberately been given priority over care of the disabled . Whatever its merits and short- comings, MDT must be credited with mobilising national and inter- national resources to bring into the light of day a disease that for centu- ries has remained out of sight and often out of mind. It is forcing on communities the realisation that the walls of the leprosy ghetto can be pulled down , and that leprosy- like any other disease-can be diag- nosed, treated and , perhaps one day , prevented. • 15 '' Information may be their only defence " by Martha Leslie-Harwit and Andre Meheus Or Martha Leslie-Harwit served as an intern in WHO 's Programme for Sexually Transmitted Diseases and Or Andre Meheus is Chief of this unit Sexually transmitted disease (STD) and unwanted preg-nancy are major health prob- lems for sexually active young people aged between 15 and 24. WHO has had an STD prevention programme since its inception in 1948. To the list of STDs has now been added infection with Human Immunodeficiency Virus (HIV) which may lead to Acquired Immu- nodeficiency Syndrome (AIDS). The major strategy we have to limit the extent of the HIV epidemic is health education directed towards behavioural change. And even be- fore AIDS began to be a major public health problem, the increas- Unwanted pregnancy and venereal dis- eases are major health problems for youngsters all over the world. Photo WHO!T. Urban 16 ing rates of viral STD such as geni- tal herpes or genital papilloma (warts) underscored the importance of preventing infection through health education. Young people in virtually every culture are sexually active. The me- dian age at first intercourse is 14 to 15 years in Africa , and 16 to 20 years in Europe and North Ameri- ca. Frequency and complications of STD are highest in sexually active young people . Access to reliable , modern contraceptive methods also is a major problem for them in most regions of the world. Except in parts of Western Europe , sex edu- cation programmes and the avail- ability of contraceptives to young people have been slow to develop. The causes range from ideological beliefs that sexuality should not begin prior to stable, long-term, monogamous relationships , to lack of adequate funding for education programmes. The need to educate all people about STD is urgent , given that treatment is available for many and early treatment is often necessary to prevent blindness and infertility. It is even more urgent because of the STDs that are not treatable. This is particularly true for young people , who are just beginning to explore their sexuality and have not yet been permanently harmed. Information may be their only defence. In planning a health education programme for young people , the timing of the communication, both as regards the life stage of the young person as well as the particu- lar hour, day , and date , is impor- tant. Different information sources have particular strengths and weak- nesses; content and timing have to be modified appropriately. The mass media are effective in putting the message across to large populations , including that hard-to- reach group of adolescent school dropouts whose often destructive behaviours may put them at partic- ularly high risk of unwanted preg- nancy , and of STD. But these presentations must be carefully planned. Messages must be fairly simple and direct. Complex and frightening messages risk being only partially .understood , and people withdraw rather than listen to them. Repetitious material tends to bore readers or listeners. Ideally the information should be present- ed clearly, simply , and specifically, but with sufficient variability be- tween presentations so that the au- dience remains interested. For young people it is most effective if they can identify with the speaker, WORLD HEALTH, July 1988 and a dialogue format enhances their sense of involvement. Clear recommendations of health-pre- serving behaviour tend to elicit the greatest degree of acceptance and action. Credibility can be further increased by involving well-known and respected hero figures-includ- ing rock music stars. France has found that media campaigns which are most effective in reaching those at high risk of STD present their information through comics strips, posters and advertising cartoons. In the Nether- lands, popular guides called " Looklet" on sexuality are avail- able to all young people, and reas- suringly discuss specific self-protec- tive behaviours , stressing mutual responsibility and respect for one's partner. The Swiss have created several brochures on AIDS, from plain leaflets to cartoons or illus- trated magazines. The United States has set up a "hotline " tele- phone service to provide informa- tion on STD and AIDS. Several de- veloping countries have their own information programmes , making use of radio announcements and television spots . UNICEF has spon- sored the production of a short ani- mated film to teach street chil- dren-many of whom are forced into prostitution by economic need- how to avoid AIDS. The mass media can provide an initial introduction to the subject to the greatest possible audience . The next most successful method to continue rapid learning is the small discussion group composed of young people themselves and a group leader. Such groups offer an opportunity to share views in an in- formed , concerned and responsible setting ; they also encourage and endorse self-esteem. The role of the group leader is to facilitate dis- cussion, and to provide clear, cor- rect information as subjects arise. Comprehensive programmes for STD and family life education have a high success rate. The low rates of adolescent pregnancy and preva- lence of STD in Sweden and the Netherlands attest to the value of such long-term programmes. Even less comprehensive programmes do succeed in teaching important in- formation to adolescents, although it may be hard to determine whe- ther behaviour is also changed. Courses most likely to succeed in W ORLD HEALTH, July 1988 In virtually every culture today, young people are sexually active. All too few have access to counselling, information and education about the risks and how to avoid them. Photo W HO!T. Urban causing behavioural change are those which , besides providing basic scien- tific information on reproduction, also discuss at length the social contexts of sexuality. Information is not presented in isolation, but is made directly relevant to each young person as a decision-maker aware of the consequences of the choices available. These courses in- volve the young person in thinking about his or her life situations, and in making informed choices. Preventing the problems of sexu- ally transmitted disease and un- wanted pregnancy is an important goal , and several creative health education efforts are under way to meet this need. WHO itself has re- cently convened a group of experts to discuss what national and inter- national initiatives can help to pre- vent STD and AIDS in young people, and how to improve those programmes. • 17 I t is now evident that AIDS has different epidemiological pat-terns in every society and that societies react to AIDS differently , according to their social context. So it is important to study both the be- haviours of the disease as well as that of the society in order to better contend with the problem. In the case of Mexico, we now know from retrospective studies that the first cases of AIDS in this country occurred in 1981. At the beginning of the epidemic, practi- cally all cases had a history of sex- ual contacts in the United States, and most of them were affluent ho- mosexuals. Nowadays the cases are not so clearly stratified, as they have spread progressively to lower social and economic groups, both in the cities and in the countryside. The number of cases has increased exponentially, numbering over 1,000 by the end of 1987. In fact the total has doubled every eight months so far, which allows us to estimate that there will have been up to 25 ,000 cases by 1991. Mexico has the distinct peculiari- ty of sharing 2,000 miles of border with the United States. And after Mexico City and Guadalajara , the two largest metropolitan areas in the country , the highest rates of 18 AIDS are found in those states which border our giant neighbour. As happens everywhere, the age groups most affected are young adults, by virtue of being sexually active. In Mexico , AIDS has affect- ed men predominantly, with a sex ratio of 20 males for each female with the disease. Close to 90 per cent of the cases have occurred in homosexual or bisexual men. The rest are recipients of blood prod- ucts (7 per cent), and heterosexual people (3 per cent). Very few cases have been associated with intra- venous drug abuse , since this form of drug addiction is almost non- existent in our country-a fact explained more by the high costs associated with this habit than by moral constraints. Among the regional variants of the AIDS pandemic, one aspect pe- culiar to Mexico concerns both the nature of the problem and the pub- lic health response to it: this is the existence of professional blood do- nors. Until recently , one-third of the blood supply in Mexico came from people who made a living - however precarious-by selling their blood. It was not until May 1986, when a law making HIV screening mandatory in all blood units was passed, that we started CON DON notlcmg a high sera-prevalence among professional blood donors . This social phenomenon is not , as yet, fully understood, and is the subject of current research. Not all donors everywhere were infected ; there was a marked clustering in a few metropolitan areas, with a mean sera-prevalence of about seven percent. Compared with al- truistic donors, who had a sera- prevalence of HIV infection of 0.1 per cent , the professional donors therefore constituted a high risk group. Given the magnitude of the prob- lem with the blood supply , the au- thorities decided not to wait for an explanation of this phenomenon, but simply to curtail it. Our Con- gress banned all commerce with blood in the country, in April1987. This measure , along with the screening of all blood units , has made our blood supply safe. It has also made us face two predictable consequences: opposition from those who made juicy profits by commercialising blood and blood products , and a transitory short supply of blood. The blood bank owners did not in fact present a major problem, be- cause of the overwhelming support that the public showed for the new WORLD HEALTH, July 1988 law. The supply of blood has now been secured through altruistic do- nation campaigns and by encourag- ing donation from relatives of those in need. In addition, guidelines for the proper prescription of blood transfusions have been distributed to doctors and hospitals. This story illustrates the value of epidemiological surveillance in de- tecting an emerging problem, but also the extensive public health benefits that can stem from a sim- ple (though politically complicated) legal action. In the absence of vaccines or drugs, we have to rely on two mea- sures to prevent the spread of AIDS : education and sanitary con- trol. The former is aimed at chang- ing the behaviour of individuals , while the latter protects society as a whole. I believe it is the responsibility of governments worldwide to ensure a safe blood supply. Some simple measures only require political will to be implemented. Self-exclusion of blood donation from members of high-risk groups is both effective and advisable . Inactivation of the virus in blood products is easy and also very effective. Banning com- merce with blood-where it occurs -is highly recommendable . The last and mosi effective measure to en- . sure safety in blood is to screen all blood units for HIV antibodies. Al- though this is expensive for the budgets of most developing coun- tries , prevention will always be less onerous than the costs of keeping people in hospital. Educational campaigns for AIDS should be designed and oriented towards specific audiences: the general population, medical care providers, and people with high- risk behaviour. The scope and con- tents of the education materials should vary accordingly. In Mexi- co , given the inherent delicacy of the topic and the prevailing moral values, we decided to take a "step by step" approach in mass media messages for the general popula- tion. The first step was to combat the myths about the disease , and to inform people how it can be transmitted. Thereafter, we recom- mended ways to prevent acquiring AIDS, including the use of con- doms . This has been a landmark in mass media communication, since even partial nudity is prohibited on W ORLD HEALTH, July 1988 television screens, and the word "condom" is still shocking to many. Doctors have received guidelines for the medical care of AIDS patients and recommenda- tions on how to prevent transmis- sion. Finally, members of high risk groups have received explicit mate- rial about "safe sex " and a supply of condoms . Mexico's National AIDS Com- mittee (CONASIDA) is formed by representatives of public and pri- vate institutions in the health sector and by experts in the field and Facing page :" Still life with condoms ": part of Mexico 's arsenal of weapons di- rected against the spread of AIDS. Photo WHO/V. Abramov Below: Mortuary f eet. A warning poster says : " It's everyone 's risk; yes, AIDS (SIDA) can kill. " operates within the Ministry of Health to advise health institutions throughout the country. Its man- dates are many , including the epi- demiological surveillance of the epidemic; supervision and evalua- tion of all related activities; re- search on epidemiological , labora- tory , social and educational issues; guidelines and recommendations for preventing transmission ; and administration of budget and fund- raising. It is still too soon to evalu- ate the benefits of CONASIDA's actions , but my own view is that they are very positive. In less developed nations AIDS is competing for resources with other diseases , at a time when resources are most meager in the health sector. In Mexico , we are convinced that it is better to allo- cate resources to preventive actions -at a time when the problem is still one that can be curbed. • a 0 0 () Yellow lever gains ground by Thomas P. Monath Or Thomas P. Monath is Director of Vector-Borne Viral Diseases, Centers for Disease Control, U. 5. Department of Health and Human Services, Fort Coffins, USA I n September 1986, doctors at Yahe Lutheran Hospital in the northern part of Cross River State, Nigeria, recognised an un- usual occurrence of illness, jaun- dice and death among villagers in the area. Within a month, health workers were making similar obser- vations in adjacent areas of Benue State. Schools closed down because of deaths among pupils, and school- rooms were converted into treat- ment centres to deal with the expanding epidemic. Serological examinations indi- cated that yellow fever virus was responsible for the outbreak. An immunization campaign started but encountered many difficulties in delivering the vaccine. An inter- national team of virologists, epide- miologists , and entomologists spon- sored by WHO reached the affected area in mid-December, while the epidemic was still in progress. When it subsided in late December, at least 9,800 persons had fallen ill and 5,600 had died. Many people are surprised to learn that yellow fever remains an important public health problem in the 1980s. Despite advances in environmental health, and the dis- covery of vaccines which rendered yellow fever entirely preventable during the first half of this century, the disease continues to appear in epidemic form and threatens to in- vade countries from which it has long been absent. Both 1986 and 1987 witnessed a major resurgence of yellow fever in West Africa, and a reappearance of the disease in cities for the first time in over 40 years. What are the reasons for the continuing spread of this deadly disease? And what can be done to control it? Yellow fever virus is transmitted by the bite of an infected mosquito. Roughly one person among every five who are infected with the virus becomes severely ill , and of these about 20 per cent succumb to the disease. In its most severe form , the disease begins with fever, head- ache, and muscle pains , and pro- gresses within several days to a tox- ic stage, with the appearance of signs of damage to vital organs, in A rapidly deployed information cam- paign helped to contain a yellow fever epidemic in Nigeria two years ago. Photo WHOfT. Monath particular the liver, kidneys , and heart. Patients develop jaundice , kidney failure, bleeding from the stomach and elsewhere, and finally circulatory collapse and coma . At the present time there is no specific drug or treatment , although good supportive care in hospital may pre- vent complications and decrease mortality. Unfortunately, those af- fected by the disease most often live in remote areas served by ex- tremely limited medical resources . Yellow fever was the first infec- tion of humans shown to be due to a virus and the first virus shown to be transmitted by a biting insect , the mosquito Aedes aegypti. From the 18th to the early 20th century, it was one of the great plagues of humankind. From endemic areas of Africa and South America , the disease was introduced by ships into port cities of the Caribbean, Central and North America, and Europe , creating much havoc and social disruption. In 1900 Major Waiter Reed and his colleagues working in Havana obtained proof that the mosquito transmitted the yellow fever virus. This finding led to sanitation cam- paigns against the urban , domestic mosquito , first in Cuba and Pana- ma, and subsequently in other countries in the Americas. These efforts were successful and led to a marked reduction in the frequency of Aedes aegypti-borne epidemics. The last major outbreak in the Americas involving this mosquito vector occurred in Brazil in 1942. Until the 1930s, it was generally accepted that yellow fever was an exclusively human infection, trans- mitted only by Aedes aegypti , which breeds in containers holding water in and around houses. The discov- ery of a jungle cycle of transmission .in South America and Africa , involv- ing passage of the virus between WORLD HEALTH , July 1988 monkeys and tree-hole breeding mosquitos , shattered hopes that the disease could be eradicated . Cities and towns infested by Aedes aegypti would be continuously at peril of re-introduction of yellow fever vi- rus from the jungle cycle. To elimi- nate this threat and to reduce the cost of perpetual aegypti control programmes, Dr Fred L. Soper de- veloped the concept of eradication of this species. Under the aegis of the Pan American Health Organ- ization (PAHO), eradication pro- grammes undertaken in the Ameri- cas between 1940 and 1965 met with some successes. Alas, these suc- cesses have now largely been reversed. Development of the 17D vaccine in 1937 by Dr Max Theiler and Dr Hugh H. Smith of the Rockefeller Foundation was a landmark in the control of yellow fever. Produced in chicken eggs , the 17D vaccine has a remarkable record of safety and efficacy and is now produced in 12 institutes around the world. WHO plays an important role in the international regulation of yellow fever vaccination, granting approv- al of laboratories for manufacture and testing of the vaccine. It may be given to infants as young as nine months (even at six months in situ- ations of high risk), and produces solid immunity lasting at least ten years - the limit recognised for the purposes of international travel - and probably for life. In the Americas, only 50 to 300 cases of yellow fever are officially reported to WHO annually. The true incidence is probably 10 to 20 times greater. Countries reporting the largest number of cases are Bolivia, Brazil, Colombia and Peru. All cases result from exposure to forest mosquitos which have acquired the virus from infected monkeys. So the risk is greatest in young adult males engaged in clearing forests for agriculture , road construction and harvesting timber. Several countries have long-established, systematic programmes of routine immunization , aimed mainly at res- idents of endemic jungle areas. A disquieting problem in recent years has been the reappearance of Aedes aegypti in Brazil, Bolivia, Colombia, Ecuador and Panama, infesting areas from which it had previously been eradicated. The pace of re-infestation of South W ORLD HEALTH , July 1988 Torch in hand, this Nigerian health worker tracks down larvae of the Aedes Aegypti mosquito in a house- hold water jar. Photo WHOfT. Monath America is accelerating inexorably, and epidemics of another aegypti- borne virus - dengue fever- have affected hundreds of thousands of people. These events underscore the increasing risk that yellow fever will again cause urban epidemics in South America, and that the virus will spread to receptive areas of the Caribbean basin , Central and North America. In Africa, the epidemiology of yellow fever stands in stark contrast to that in the Americas. In most countries, surveillance of the dis- ease is rudimentary or non-exis- tent, and sporadic, individual cases such as occur in South America go unrecognised. Instead, explosive epidemics appear at irregular inter- vals, often involving thousands of deaths. Even during epidemics the disease is greatly under-reported , and official notifications , which have numbered only about 3,000 cases between 1965 and 1985, re- flect less than one per cent of the true incidence. Important out- breaks have arisen in Ghana (1977- 1979), Gambia (1978) , Burkina Faso (1983) , Nigeria (1986-1987) , and Mali (1987). Investigations suggest- ed at least 30,000 cases and 10,000 deaths during these episodes. The ecology of yellow fever in Africa is considerably more com- plex than in the Americas. In addition to a jungle transmission cycle (involving tree-hole breeding mosquitos and monkeys) and an " urban" transmission cycle (in- volving domestic Aedes aegypti and humans) , there exists in Africa a " savanna " transmission cycle in- volving tree-hole breeding mosqui- to species and both monkeys and humans. ·Most yellow fever epidem- ics have been of the latter type, oc- curring in relatively remote areas. In Africa , the term "urban" transmission cycle is a misnomer, since A edes aegypti is common in both cities and villages - wherever 21 Yellow fever gains ground people store water in pots and other containers in and Mound the home. In contrast to the Americas , where this domestic mosquito has not been responsible for yellow fe- ver epidemics for decades , Africa has been repeatedly plagued by aegypti-borne outbreaks. The most recent and most fright- ening example of " urbanisation " of yellow fever occurred last year in Nigeria. The 1986 epidemic in Cross River and Benue States oc- curred in a relatively remote area ; but there was considerable move- ment of people in and out of the region. Concern that the virus might thereby spread to densely populated areas, where Aedes ae- gypti was prevalent , was justified by the appearance in March 1987 of a large epidemic in Oyo State, west- ern Nigeria , some 500 kilometers away from the original focus . Mor- bidity in the cities of Ogbomosho and Oyo was high , cases appeared in Ibadan and other localities, and the virus spread subsequently to parts of northern Nigeria. Aedes aegypti populations were exceedingly high , largely due to the breakdown of piped water supplies 22 in the affected towns, with the re- sult that residents were compelled to store water in and around the home. With more than seven mil- lion people at risk in the epidemic areas, the authorities were faced with the need for a mass immuniza- tion campaign that stretched avail- able resources to the limit. Prevention and control Two approaches exist to prevent and control yellow fever: immuni- zation of the population at risk ; and elimination or reduction of the mosquitos responsible for transmit- ting the virus. The 17D vaccine , which provides effective , long-lasting immunity , has been available for 50 years. Yet most countries in Africa have never used the vaccine as a preventive measure (or have discontinued its use), and rely upon emergency mass immunization in response to epidemic spread of the disease. This is invariably initiated too late to effectively combat epidemics. The main obstacle to preventive use of yellow fever vaccine in Afri- ca has been the high cost of large- scale immunization, requmng sup- plies of the vaccine, methods to maintain the live vaccine at low temperatures in the field , and both mobile teams and fixed vaccination centres staffed by trained person- nel. As a long-range strategy, add- ing yellow fever vaccine to the rou- tine schedule of childhood vaccines as part of WHO's Expanded Pro- gramme on Immunization (EPI) may overcome the problems associ- ated with mass immunization. Another aspect of concern to health planners is the limited pro- duction capability and supply of the 17D vaccine. The methods for vac- cine manufacture in eggs, devel- oped in the 1930s, are cumbersome, and some manufacturing institutes have outdated facilities and equip- ment. The increasing threat of Ae- des aegypti-borne epidemics in the Americas ; the potential for similar events in Africa as human popula- tions expand and concentrate in cities; and the possibility of yellow fever virus reaching into Asia all demand a high level of prepared- ness for emergency production of vaccine. Promoted by WHO, efforts are now under way to develop and WORLD HEALTH, July 1988 Left: A deep well not only protects the water supply but also prevents the mosquito breeding. Right : Vaccination by air-gun to counter yellow fever in a Nigerian village. Photos WHOrr. Monath evaluate a new 17D vaccine pro- duced in cell cultures rather than in eggs, and to increase the stocks of seed virus required for rapid manufacture. In the face of an on-going epi- demic, the most effective means of interrupting virus transmission would be to use insecticide sprays to kill the adult, infected mosqui- tos. Unfortunately, this approach is not as easy as it sounds and is of unproven efficacy under the condi- tions faced in most yellow fever epidemics. In the Americas , control or eradication of Aedes aegypti has been successfully used to prevent urban yellow fever. Yet most pro- grammes have suffered set~backs or reversals in the past two decades. To add insult to injury , an exotic mosquito species , Aedes albopictus has recently invaded the Americas from Asia, and threatens to fill a niche similar to those mosquitos in- volved in the savanna transmission cycle in Africa , with an enhanced risk of epidemic spread. Among the factors responsible for the breakdown of the Aedes ae- gypti eradication programme in the Americas are the growth of cities and poor sanitary conditions which encourage breeding sites. The in- creasing rapidity and scale of com- merce and travel allows greater movement of mosquitos and infect- ed persons between countries. The rising cost of vector control , as well as the competition for manpower and funds with other public health and environmental priorities , have led to a diminished commitment to the programmes. As the situation worsens, the pendulum is swinging back toward recognition of the need for effective control and eradication of Aedes aegypti. The next decade will deter- mine whether our fears of expand- ed aegypti-borne epidemics are just, and may witness a rebirth of vector control and immunization programmes in the Americas and in Africa. • W ORLD HEALTH, July 1988 Yellow fever gains ground 23 Sleeping sickness-re-awakes by Pierre Cattand Mr Pierre Cattand is Training Officer with the Trypanosomiases and Leishmaniases unit at wHo headquarters in Geneva W ith 50 million people at risk , 36 endemic countries and some 20,000 reported infections every year, sleeping sick- ness remains an important public health problem for Africa. The ex- tent of the problem can be better appreciated with the knowledge that , if untreated, infected individ- uals will die of this disease , more correctly known as human African trypanosomiasis. Precise numbers of its victims cannot be evaluated. The most con- servative estimate would be consid- erably higher than the number of actually reported cases , which is based on very limited surveillance and on infrequent and localised surveys. The African continent has paid a heavy price in the past. On the northern shores of Lake Victoria , in the Congo basin, particularly along the Ubangui, the largest trib- utary of the River Congo , and in the territories lying within the big arc of the River Niger, thousands of people died of the disease early in this century. One of many re- ports states : " ... From the 1st to the 15th February 1918, we surveyed nine villages in the Koumi valley (Central African Republic) and examined 1,243 villagers out of a population of 1,260 and found 722 infected individuals; during that same period we personally wit- nessed 35 deaths due to the dis- ease ." In a 1920 report of the Uban- gui-Shari medical sector, we can read : " ... In this population of 100,000, we examined all the inhab- itants one by one. We found 5,347 sleeping sickness cases , 170 lepers, 159 cases of various mycoses, 13 cases of elephantiasis, ... Sleeping sickness on its own is the cause of one-third of the total mortality in that region." Similar situations 24 WORLD HEALTH , July 1988 have been described in East and West Africa. Today, the increase in the num- ber of patients observed in the same historically endemic areas , the discovery of new cases in places A classic case of sleeping-sickness in Africa. Below: Not invaders from outer space, but a novel trap to catch tsetse flies , which transmit spleeping sickness. Photos WHO and C. Lavessiere © previously free of sleeping sickness, and the large number of suspects found during spot-surveys all sug- gest an important recrudescence of the disease . This is particularly the case in Southern Sudan , Uganda and Chad and, to a lesser extent , in Cameroon, Congo, Cote d'Ivoire and Zai·re. If we ignore past evidence of the disastrous impact of sleeping sick- ness and fail to take immediate ac- tion, it may soon become an un- bearable burden for a great number of African countries. The flare-ups that have recently occurred or are occurring in many parts of the con- tinent demonstrate what can hap- pen when surveillance activities and coverage are reduced. Control and preventive measures must be put into effect now before village com- munities feel the devastating effects of sleeping sickness and once again are forced by the tsetse fly to aban- don their fertile lands. In 1916 in Brazzaville, Dr Eugene Jamot elaborated his preventive guidelines for sleeping sickness which are still valid today. Based on the fact that man is the reservoir for the protozoa Trypanosoma gambiense that cause the disease and the tsetse fly is the vector that transmits it, J amot defined a two- fold objective to control the dis- ease, namely the simultaneous de- struction of the parasite and the vector. He knew that the disease concentrates in local areas and that imported cases from these old foci are the origin of new ones. Conse- quently, as many patients as possi- ble had to be treated in the existing foci and all possible neighbouring areas where the disease could prop- agate itself had to be kept under surveillance. In order to ensure ear- ly diagnosis and eliminate the hu- man reservoir, preventive services have to reach all the people ; they cannot wait for the people to come to them. On the basis of these principles, control and preventive services have worked successfully in the past to contain sleeping sickness. Results obtained by the Trypanoso- miasis Control Mission in Angola illustrate this success. The annual surveillance of 500,000 to one mil- lion persons at risk over a period of 25 years, between 1949 and 1973, has resulted in the number of new cases diagnosed each year dropping from 4,318 to just four. Because of the epidemiological differences between the West and Central African T. gambiense and the East African T. rhodesiense forms of the disease, control of the latter requires a greater emphasis on dealing with the tsetse fly than on active surveillance of the human population. In T. rhodesiense infec- tions, the signs and symptoms are so acute and the evolution of the disease so rapid that patients will seek medical help; well-organized passive detection can therefore be an efficient tool for controlling the disease. This is not the case with gambiense sleeping sickness, a chronic disease whose early signs and symptoms are so mild that they may even go unnoticed. This asymptomatic period- may last for months, and sometimes years. The consequences of reducing surveillance for the gambiense form can be very serious. In one endemic country, the number of surveyed persons was reduced in 1961 from WORLD HEALTH, July 1988 A WHO expert advises health workers in Kenya on strategies to combat the disease. Photo WHO/P. Cattand almost one million to 300,000; as a direct result, the number of new cases rose successively in the fol- lowing three years to 9, 66 and 117. Surveillance was then enlarged to cover 800,000 people and was maintained at that level. Six years later, only four cases were diag- nosed, three of which had, un- doubtedly, been infected outside the country. I could cite many other similar examples. These alarming demonstrations of the potential danger of leaving endemic foci unattended have cre- ated an increased awareness at national and international level, and have activated research to- wards finding better technical solu- tions to prevent and control sleep- ing sickness. The last decade has witnessed the development of several new meth- ods for diagnosing the disease. Field-adapted serological (blood se- rum) assays are now available, while refined parasitology tech- niques enable health workers to confirm a greater number of sus- pects. Parameters defining the stage of the disease can now be de- termined with greater accuracy, us- ing modern laboratory technology and equipment that are well-adapt- ed to field use. A promising new compound known as DFMO is under experiment for patients who do not respond to the classical trypanocidal drugs. Vector control techniques have also improved considerably. Bush clearing has been replaced by effi- cient, simple and inexpensive tsetse trapping methods which are envi- ronmentally safe. We can certainly expect further progress. The specific and sensitive serological tests available today will undoubtedly be made more simple to use. Parasitology techniques will become more efficient and cheap- er. Cerebrospinal fluid analysis will be made easier to perform and drugs will become safer and simpler to handle. However, these antici- pated improvements should not provide an excuse to delay or post- pone indefinitely vital prevention and control activities. This is why, in 1984, WHO launched a programme entitled: "Primary health care approach to- wards the control and prevention of sleeping sickness," aimed at pro- moting national programmes and providing endemic countries with the information and the expertise required to design, set up and maintain such activities. The major objective is to participate with the health authorities of endemic coun- tries in designing and formulating country programmes. The pro- gramme arranges training courses in the new laboratory diagnostic techniques and in vector control methods, makes available technical documentation, and provides a sup- ply line for equipment, material, reagents and drugs that are often complicated to obtain. Finally it of- fers countries the assistance they may need to mobilise bilateral or multilateral support. • 25 From surviving smallpox to preventing measle$ by Edna Adan lsmail Mrs Edna Adan lsmail is a Technical Officer in the unit of Maternal and Child Health at WHO's Regional Office for the Eastern Mediterranean in Alexandria "Why do children die of mea- sles when a vaccine exists and the disease is prevent- ab!~?" The person asking this question was no ordinary man. It was Ali Maow Maalin, the Somali hospital cook who, 11 years ago, became the world's last-ever case of endemic smallpox. The spots that blossomed on his face back in October 1977 resulted in photographs that have been re- produced around the world. He was "the exception that proved the rule ; " smallpox had finally been backed into a corner, in this case the small Somali port of Merka; Ali Maow Maalin-the world's last case of smallpox 11 y~ars ago-is today a health worker in Somalia campaigning against another communicable disease. Photo WHO/E. lsmail the chain of transmission had been well and truly broken, and a disease that had scourged mankind for mil- lennia no longer existed on the planet Earth. Ali was lucky in that he survived, but he was ill enough to spend some time in a quarantine camp. Today, aged 34, he says: "I was so weak that I was sure I was going to die, and wanted to be near my fam- ily." Gradually, he regained suffi- cient strength to resume working his family's land in the Lower She- beli region. He knew he had had a near miss from a serious diseas~ and that smallpox was now eradi- cated. But he was unaware that vaccines also existed to prevent otherwdiseases. "During the last ten years, our village and community have lost many, many children. Usually each family loses half of the children born to the women- and often the mothers die as well," he explains. "Women and children are so weak that I thought perhaps the world was still searching for a vaccine that was strong enough . t() protect them against all the diseases that fre- quently afflict them and which kill them so easily. " Tragedy struck once wore this year when · the little sister of Ali Maalin Maow died from complica- tions following measles. Just before she died, the child was taken to the nearest primary health care unit for help. At that stage, nothing could be done to ·save her, but her family were told that she could have been protected through immunization against measles as well as against whooping cough, diphtheria, polio, tetanus and tuberculosis. The day after they buried the girl, Ali walked to the District Medical Office and volunteered to be trained how to administer immu- nizations. He needed no training in promoting the idea of immuniz- ation since he was far more moti- vated than some of his trainers. He was the living witness, and a survi- vor, of one of the" oldest and most virulent "plagues"-one which had been eradicated through single- minded and international efforts and actions. For the past few months, Ali has actively lived up to his pledge to devote his life to the eradication of measles. When he is asked "Why only measles? ", his angry answer is : · "Because it killed my sister! Be- cause it occurs so frequently ! Be- cause it spreads in the same way as smallpox and has a rash ! And fi- nally, if I succeed in convincing parents to protect their children against measles, then I can explain and also give the other immuniz- ations that are available. First of all, I need the people's trust. I don't want them to lose a sister or a daughter before they discover too late that the child need not have died!" This trust, Ali certainly enjoys. Being from the village and speaking the same dialect as the people he serves; the world's last smallpox case is now a dedicated primary health care worker whom any com- munity would be lucky to have. Mahadsanid (Thank you), Ali Maalin Maow. • WORLD HEALTH, July 1988 Cooperation with industry by John F. Dunne Or John F. Dunne heads WHO's Pharmaceuticals programme Just 100 years have elapsed since the roots of the modern re-search-based pharmaceutical industry were first established along the Rhine Valley in Central Europe. Inspired chemists then sensed that newly-developed tech- niques for producing virtually un- limited numbers of aromatic com- pounds from coal-tar derivatives held important implications for medicine as well as for the manu- facturing industries. Even they , however, could never have fore- seen where their visionary commit- ment would lead. It is providential that outstanding early achieve- ments in drug development, such as the demonstration of pain-killing activity in aspirin and phenacetin , assured the long-term survival of a commercially-sustained research activity. Some 40 years were to elapse before the discovery of the sulfon- amides heralded the subsequent ex- plosion of innovative pharmaceuti- cal chemistry that has transformed the basis of therapeutic practice within the professional life-span of a single generation of clinicians. Fifty years further on the pace of innovation shows no sign of slack- ening. Indeed, the rapid develop- ment of DNA recombinant tech- nology has provided the basis for a second pharmaceutical revolution , by creating a biological mechanism for synthesising a virtually unlimit- ed range of complex naturally- occurring enzymes and vaccines with unprecedented ease . This prodigious innovative capac- ity should assure the industry of an exemplary commercial image. Paradoxically, however, companies have too often found themselves to be targets for vociferous allegations regarding promotional excesses and abuses of trust , not least in some developing countries. The relation- ship between the pharmaceutical W ORLD HEALTH, July 1988 industry and WHO should be one of productive partnership in health care delivery, but all too often the dialogue has been diverted to issues of ethical precept such as advertis- ing norms and the rational use of drugs . The industry's responsibility to health care may never be totally reconciled with its commercial obli- gations. Nonetheless, both health objectives and the image of the in- dustry will suffer unless individual companies find a basis for effective rapprochement with the govern- ments which constitute their major trading partners, and unless they act spontaneously to exorcise activ- ities that are perceived to exploit rather than to support the commu- nities they are entrusted to serve. Tons of pharmaceutical products await- ing shipment from the UNECEF ware- house in Copenhagen, Denmark. Photo W HO/E . Mandelmann Governments also hold manifold reponsibilities that are not readily reconciled one with another. They need to contain health-care expen- diture in the public sector within re- alistic limits, but in the industria- lised world they must also remain sensitive to the need to conserve a socially-responsive programme of research within the pharmaceutical sector. This is necessary not only to advance standards of health but even , in some instances , to retain the status quo. The advent of AIDS has delivered a dramatic demonstration that man exists tenuously in an unstable envi- ronment; that infectious disease remains a potential hazard every- where-and not only in those under- privileged countries where it has never ceased to inflict an inadmis- sible burden on society. In fact, viral diseases remain singularly resistant to treatment , and the conquest of the bacterial diseases remains de- pendent upon an unrelenting battle against drug-induced resistance. Over the years, this phenomenon has successively compromised the value of the sulfonamides, many of the broad-spectrum antibiotics in- cluding the aminoglycosides, and successive generations of penicillins and cephalosporins. It has created a challenge that has recently resulted in the development of quinolone derivatives , antimicrobial agents with a fundamentally different bac- tericidal mechanism. These are of particular significance since they may ultimately provide a more se- cure means of stemming the rising tide of hospital-acquired infections that are at present unresponsive to most conventional antibiotics. This same phenomenon of resis- tance is responsible for frustrating earlier hopes of eradicating malaria and for the sharply rising attack rates in many of the countries where the disease is highly endem- ic. Not only is the most virulent of the malaria parasites commonly be- coming resistant to previously effective drugs , but the mosquito vectors have become resistant to available insecticides. Innovative pharmaceutical research alone holds the potential for stemming the ravages of the disease. The re- cent discovery of not one but three promising antimalarial substances has at least provided a basis for temporarily alleviating the situation while research goes on towards the 27 Cooperation with industry longer-term goal of developing an effective vaccine. This is not an isolated instance of successful and continuing research into the therapy of transmissible tropical disease . wHo itself has col- laborated directly with pharmaceu- tical companies over the past de- cade in the initial screening and development of many other com- pounds with antiparasitic activity. In less than a decade , drugs have emerged from these activities that are safe and effective enough to be employed in mass chemotherapy of schistosomiasis , intestinal ascariasis and, most recently, onchocerciasis (river blindness). Other compounds with promising activity against filar- ia! worms and trypanosomes main- tain the momentum of these pro- grammes. No less urgent , and of prime importance in the face of predictions that populations of some of the least developed coun- tries are set to increase fourfold by the middle of the next century , are analogous collaborative attempts to develop contraceptive methods that are culturally as well as technically acceptable to the communities in greatest need . The ultimate challenge for both partners in this research is to assure that the end products ultimately be- come widely available where they are most needed. More is at issue , however, than an assurance of ade- quate deliveries of the products. Workable systems of drug registra- tion and procurement need to be instituted within the target coun- tries to provide an effective frame- work for their subsequent distribu- tion and control ; supply channels have to be upgraded to assure the quality of the products up to the time of their delivery ; objective prescribing information needs to be issued to ensure they are employed effectively; and new cadres of health workers may need to be trained in how to use them. Several companies have already made valuable contributions to these objectives but the task re- mains daunting and cannot , in many instances , be separated from the need to strengthen the whole infrastructure of health delivery. The hope is that the existence of more effective drugs will attract the multilateral and bilateral support on which success is ultimately dependent. • 28 Talloires : a quiet revolution by Robert Walgate Or Robert Walgate is the Editor of the London-based Panos Features Service A" quiet revolution" in world health care was announced a few weeks ago at a meeting of health leaders in a lakeside priory under the snowclad foothills of the French Alps . The revolution, which will combine high technology with basic primary health care, was in- spired by the successes of the Expanded Programme on Immuni- zation (EPI) which was started in the 1970s in a bid to immunize all children against six killer diseases of childhood - tetanus, measles, whooping cough, diphtheria, tuber- culosis and polio . A special " Task Force for Child Survival " links W HO with the UN Chil- dren's Fund (U NICEF), the UN Develop- ment Programme (uNoP), the World Bank and the Rockefeller Founda- tion. In four years of work it has raised money, engaged govern- ments at the highest levels, and pro- vided and delivered cheap and effec- tive vaccines to 50 per cent of the world's children using existing health structures. lt is therefore halfway to- wards the eventual target of reach- ing 80 per cent of the world's chil- dren by 1990. Vaccines are now saving a million children's lives each year, and are protecting another quarter of a mil- lion children from crippling polio. That's a result that gave a boost to the 60 delegates attending the meeting in Talloires, beside Lake An- necy in France - delegates who in- cluded health ministers from each continent, international agency lead- ers and donors. Mr James Grant, Executive Direc- tor of UNICEF said that in 1984-when untold numbers of children were dying from vaccine-preventable diseases-the prospects for achiev- ing universal immunization seemed very uncertain . By late 1985, when the target was reviewed at a meet- ing in Cartagena, Colombia, "it was like Spring : there were a lot of green shoots coming up, so it looked as if the idea might work . " Reviewing the progress towards Universal Childhood Immunization (UCI), Mr Grant said: "We've seen the figures. Immunization rose from just 10 per cent in 1980 and less that 20 per cent 1n 1984 to 50 per cent in the autumn of 1987 -with an expectation of reaching a worldwide average of over 80 per cent by 1990. " As a result of this global success, Talloires saw a number of barriers broken, new agreements forged. On the one hand, the technologists learned from the UCI work that health was not just a matter of injec- tions, but was a social process of education, inspiration and "empow- erment" of the primary health care movement. They learned that, how- ever magical a treatment, it is use- less unless a willing, effective health system can deliver it year in year out to, say, an African woman giving birth in her hut or a boy in a Calcutta slum. On the other hand, those who had been highly suspicious of "Western" technologies and their champions had learned that life-sav- ing vaccines, at least, had now been delivered to half the world 's children . Dr Halfdan Mahler, Director-Gen- eral of the World Health Organiz- ation, has always believed that UCI (a UNI CE F term) should not be just a target to satisfy " institutional vani- ty" but a campaign to provide lasting benefit. UCI should lead, Dr Mahler always insisted, to two further goals: continuing immunization for successive generations of children, and lasting improvements in local health systems. But he summed up the mood of the Talloires meeting exactly when he said that development consisted of "knowledge-and motivation," that the immunization campaign was delivering both, and that the result was not the weakening that had WORLD HEALTH, July 1988 once been feared but an "empower- ment" of the primary health care movement. But "revolution" ? Is that not go- ing too far? lt was Or V. Ramalingas- wami, past Director-General of the Indian Council of Medical Research and now special advisor to UN ICEF, who called it a "quiet revolution . " And the President of the World Bank, M r Barber Conable spoke of "a grand alliance for health in which the World Bank would be proud to serve, in whatever capacity." The new philosophy that emerged at Talloires is "can do, will do" ; the conviction that technology can be applied sustainably to medicine in the developing world and in such a way as to strengthen primary health care . Certainly, those who work to deliver vaccines and other primary health care into remote villages and into the anonymous, sprawling slums of cities will continue to face enormous problems . Health workers often lack electricity to refrigerate vaccines , and must deal with very low levels of literacy, poor training and ignorance which ensure that the very poor will still remain the hardest to reach. There are great tasks ahead, and much variation in present achieve- ments. For example, according to WHO's March 1988 statistics, only 16 per cent of pregnant women re- ceive immunization with tetanus toxoid - the treatment needed to halt the present 800,000 annual deaths from neonatal tetanus. Mea- sles vaccine has reached 91 per cent of children in Botswana - but only 16 per cent in India, where fully one-eighth of the world's un-immu- nized children now live. Through a massive campaign, India has ap- proached the global average of im- munization of 50 per cent of its chil- dren (including tetanus toxoid but excluding measles) . But there have been press reports in India of misuse of vaccines by little-trained health workers . And while in some areas there is now public demand for more vaccination, in others there has been "consumer resistance . " As a result, the federal government in New Delhi is setting up an expert group to study the question of public acceptance . Highly organized China, on the other hand, appears to be on target for UCI even earlier than 1990, according to Minister of Health Or Chen Mingzhan. He faces difficul- ties, principally in management and training-and in reaching populations in the remote mountains where, as he said, it can take a health worker a WORLD HEALTH, Ju ly 1988 day to move from one family to another. In Latin America, average immuni- zation against polio has reached an all-time high of 80 per cent. But in Ecuador the necessary three shots of polio vaccine have reached only 50 per cent of the nation's children-and even fewer in the slums of the coastal city of Guayaquil. In Latin America the city slums must be the "top, top priority," says Or Ciro de Guadros of the Pan American Health Organization. In the Arab-speaking world, child mortality has tended to remain em- barrassingly high despite increas- ing wealth. But Egypt is a bright spot. According to Mr Grant of UNICEF : " Egypt has achieved a mas- sive breakthrough in immunization and oral rehydration to save babies from dehydration during diarrhoea. This year 80,000 to 100,000 children will be saved because of these interventions." Mr lames Grant, Secretary-General of UNICEF, speaking at the Talloires' meet- ing earlier this year. In the audience- WHO's Director-General, Dr Halfdan Mahler. Photo W HO!T. Farkas Funding is an important issue in Africa . Private donors such as Rotary International have made enormous contributions, amounting to hun- dreds of millions of dollars. But in Uganda, Or Ruhukana-Rugunda, until recently Minister of Health, is wor- ried about how the UCI campaign could be continued beyond 1990-if UCI staff and the funds that back it were then withdrawn or reduced. So far the Ugandan Minister has raised immunization levels against the six diseases of the UCI campaign from 5 per cent three years ago to 50 per cent today, with a target of 75 per cent by 1990. But this has been using the rela- tively cheap, widely available vac- cines on which the UCI programme is based. The promised vaccines against the really big killers, malaria and diarrhoea, and other major tropi- cal diseases will certainly cost much more to develop. Although there is no definite pros- pect that outside donor support will be reduced, and indeed in the medi- um term it may even be increased ("There is life beyond 1990 ! " it was said at Talloires), the Ugandans' fears do reveal the other side of "sustainability" : the question of who will pay the US $2,000 million annually ($600 million of it in hard currency) that full, sustained global immunization is projected to cost in the ·far future. Though developing nations already pay globally some 80 per cent of the estimated costs of the UCI campaign, these are mostly for salaries in local "soft" curren- cies. hard currencies (for vaccines, for example) are another matter. These are some of the problems that must now be faced by the new, pragmatic health consensus that emerged at Talloires. But there was no sense of despair at the meeting- rather the thrill of excitement and ac- tion. "I'm just flabbergasted at the extent of the optimism, on the part of everybody, the ministers of health, the donors -everybody feels they're doing something ... " said one participant at Talloires. Indeed, looking forward beyond the UCI target of 1990, delegates felt able to discuss rational , sustainable plans for the year 2000 which included : - the global eradication of polio, which is still crippling 250,000 chil- dren a year in the Third World; - the saving of 95 per cent of the nearly two million children who now die of measles each year; - the near-elimination of tetanus in new born babies, which kills up to a million babies a year ; - a 70 per cent reduction in death due to acute diarrhoea in under- fives, which now occurs at a rate of 5 million per year; - a 25 per cent reduction in acute infections of the lung, which now kill 3 million children each year; - reducing infant and maternal mor- tality rates in all countries by at least half . As Or Ken Warren, Vice-President of the Rockefeller Foundation ('one of the Task Force members) said afterwards; "Talloires went way beyond the immunization efforts. it's brought about a total sea-change in how to deal with problems in the developing world. Now people are re-adjusting and trying to find their own place in it. That's what you saw happen here . " • 29 ...... .... .. ... . ...... .... . ..... . .......... . ••••••• •••• •• ••• • ••••••• • ••••••••••••••••••••••••• e•••••• •••• •• ••• • ••••••• •••• •• ••••••• •••••• ••••••• ... ... .. ... . ... ... ............... . ••• ••• •••• •• ••• • •••••• •••• •• ••• ••• •• • •••••• ••• ••• •••• •• ••• • ••••••• • •••••••••••••••••••••••• ... ... .... .. ... . ...... . ....................... . ••• ••• •• ••• • ••• ••• • •••••••••••••• ••• ••• •••• •••••••• ••••••• ••• • ••••••••••••••••••• ••• ••• •••• •••••••• ••••••• ••• • •••••••••••••••••• ••• ••• •••• •••••••• •••••• ••• • ••••••••••••••••• Editor: Peter Ozorio wHo Medals for Promoting Tobacco-Free Societies Some forty individuals and institutions outside the field of health were named recipients of commemorative certifi- cates and medals, inscribed "Tobacco or Health : Choose Health," issued by wHo to mark the World's 1st No Tobacco Day on 7 April, which was also its fortieth anniversary. Recipents were honoured for "achievement worthy of international recognition in promoting the concept of tobac- co-free societies." They were nominated by national and regional organizations, and on information available, selec- ted at WHO headquarters. Ouft der grossen weiten The awards were made to Welt ("The Air of the Great actors, athletes, cartoonists, Wide World"). a film that former presidents, legisla- portrays the reality behind tors, a philanthropist and the industry-created roman- taxi drivers, but the majority tic myth of smoking. went to journalists - appro- • Aeroflot, for introducing pnately enough as the day the smoke-free 4-hour flight ong1nated from a resolution in 1978, and for being the by WHO'S World Health As- first to make all internal sembly with a strong media flights smoke-free from content, askin~ pri~t and January 1982. ' elect~?n1c med1a to volun- • Peter Taylor, British jour- tardy refuse advertise- nalist for his book "The ments for a day. . Smoke Ring: Tobacco, As a result, some 1,000 Money and International letters of appeal were sent Politics " and for his tele- by Dr Halfdan Mahler, WHO'S vision production, " Death in Director-General, ask1ng the West," a story of cow- publishers of newspapers boys who smoke suffer and and news magaz1nes and die ' owners of rad1o and telev1- · sion stations to so act for • Maurice de Bevere, the "public good." "Morris," Belgian cartoon- The Medalists Presentation of the com- memorative medals were made in . Geneva ; New York ; Washington, D.C.; Alexandria, Egypt; Ade- laide, Australia; and Tokyo. The following were the medalists honoured in Ge- neva, with excerpts from their citations: • Reader's Digest, for car- rying in February 1924-long before the link to ill-health had been established -an article that asked " Does To- bacco Injure the Human Body? " and publishing some hundred articles over the decades that warned of the dangers of cigarettes and, r.ecently, of smokeless tobacco. • Mario Cortesi, film mak- er and editor of the Swiss daily Biei-Bienne, for pro- ducing independently Der 30 ist and creator of Lucky Luke, for taking the ciga- rette from the mouth of Eur- ope's favourite cowboy and replacing it with a hayseed. By that act he made a pow- erful point among millions of young readers-that their hero had quit. (The original of the design shown here of Lucky Luke refusing a mortician 's offer Special Report of a cigarette was present- ed to wHo by Morris. Says the cowboy: "Thanks, but no thanks. I've quit"). • Biman Mullick, graphic designer, and Bombay-born Londoner, for establishing Cleanair, a non-profit organi- zation, and for posters that deliver the message that "non-smoking is the norm." • Esther Rantzen, hostess of the British Broadcasting Corporation's television pro- gramme "That's Life," for an expose in March 1986 on "smokeless tobacco," a product that is chewed or sniffed, and the way it is being pushed. • Roger Zabel, host of Telematin on Antenne 2, for being France's first tele- vision personality to take a stand against smoking. An- nouncing on 1 June 1987 that he was quitting, he urged viewers to join him in breaking the habit (J 'arrete de fumer: faites comme moi). The other medalists were: North America • Victoria Brynner, for as- suming the responsibility for passing on the advice of her father, actor Yul Brynner: "Whatever you do, please don't smoke." A victim of lung cancer in 1985, he made that plea in a taped in- terview when he was near life's end. • Jimmy Carter, the 39th President of the United States, for his open letter to the Journal of the American Medical Association. For- merly a supporter of the to- bacco industry, he wrote in 1986 : "As the scientific evi- dence has . become stron- ger, I have become increas- ingly active in attempting to spare people from the to- bacco addiction." • Elman Folkenberg, pas- tor (posthumously) and Wayne McFarland, general practitioner (retired), for to- gether developing "The 5- Day Plan to Stop Smoking," which has given hope to millions throughout the world striving to break free from the tobacco addiction. • Good Housekeeping, for being the only major wo- men's magazine that has not accepted tobacco adver- tising, and for its editorial position that smoking is the antithesis of womanly qualities, leading to their subjugation rather than, as advertisements claim, their liberation. • Larry Hagman, . for his chairmanship over eight years of the Great American Smokeout. Out of respect for him, tobacco in any form is never portrayed in the world-renowned television series " Dallas," in which he plays the lead role, "J.R." • Frank King, chairman of the organizing committee of the Winter Games in Calgary, March 1988, for its policy of "fresh air" for athletes, which set an example for the Seoul Sum- mer Games. • Northwest Airlines, for being the first carrier in the world to fly, from April 1988, regular smoke-free routes internationally-from the United States to Canada, Mexico and the Caribbean. • The Toronto Globe and Mail (and its publisher Roy Megarry) for being the first metropolitan journal in Can- ada to voluntarily close its pages to tobacco advertis- ing, effective from 1 August 1986, on the basis that to not do so would be a viola- tion of the country' s code of advertising, which prohibits the promotion of harmful products. • Patrick Reynolds, grand- son of the founder of the to- bacco company that bears his name, for divesting him- self of all stock in the family business, and for his stated determination to raise con- W ORLD HEALTH , July 1988 sciousness "to how poison- ous cigarettes are," and for beakirig the habit he ac- quired as an unsuspecting teenager. • Tony Schwartz, founder of People for a Smoke-Free Indoors in New York City, for producing radio spots aimed at discouraging police officers from smoking; and for a cassette, " If You Love Somebody Who Smokes," directed at those who want to help others to stop. • lynn Smith, journalist and formerly publisher of the weekly Monticello Times, Minnesota, for founding the world's first D-Day (or "Don't Smoke Day") on 7 October 197 4, which was the inspiration for the Great American Smokeout, for tobacco-less days in other countries, and for WHO's World's 1st No To- bacco Day. • The Whig Standard of Kingston , Ontario (and its publisher, M ichael Davies). for being the first daily newspaper in all of Canada to put " its social con- science before its commer- cial interests," by voluntarily closing its pages to tobacco advertising effective from 1 January 1985. Latin America, Caribbean • Ziraldo Alves Pinto, "Ziraldo," Brazilian cartoon- ist, for posters of a light and wry touch that deflate the myth of the glamour of to- bacco and for donating his work to his government for health education campaigns. • Fidel Castro, President of Cuba, for at first, in 1981, pledging never to smoke in public as a measure to de- glamourize the image of a smoker and then breaking the habit as an example for his fellow citizens. W OR LD HEALTH , July 1988 • Alberto Kattan, Argen- tine lawyer, who estab- lished in a Buenos Aires court-for the first time ever in February 1986 - the toxic- ity of tobacco and who then called for an end to tobacco publicity on the grounds that his country's communication law bans the advertising of unhealthy products. • lorenzo Pepe, Deputy in the Argentine Congress, and author of legislation that, beginning in July 1986, limits the advertising of to- bacco on television and ra- dio to between 10 p.m. and 8 a.m. • Carlos Andres Perez, President of Venezuela from 1973 to 1978, for presiding over smoke-free cabinet meetings. • Ronald Thwaites, law- yer and moderator of a daily call-in radio programme in Kingston, Jamaica, for en- couraging listeners to avoid tobacco, and by so doing communicating for health. Europe • Michela Figini, Swiss ski champion, 1988 and Wer- ner Gunthor, Swiss shot put champion, 1987, for lending their reputation to health education posters saying "Sure, I'm a non- smoker." • The Palm Family, Swe- den, for persisting in the le- gal battle begun by Mrs Gun Palm, a non-smoker, who died of lung cancer in 1982. Their determination led to a precedent-setting legal de- cision that said "this case of lung cancer can be classi- fied as an occupational inju- ry due to passive smoking in the work-place ." • Kathimerini, a morning daily in Athens (and its pub- lisher Eleni Vfachou); and Politika Themata, a weekly news magazine (and its pub- lisher Costas Kyrkos), for re- sponding to a government information and education programme by voluntarily closing their pages to tobac- co advertising from March 1978. Western Pacific • Fiona Harari, medical re- porter, and Graeme O'Neil, science reporter of Austra- lia 's Age, a Melbourne pa- per, for a series ("Victoria 's Dying Habit") in June 1987, which played a major part in the passage of the Tobacco Act by the Parliament in Vic- toria, the first legislation of its kind in Australia. A key provision : the es- tablishment of a health promotion foundation to finance sports and cultural events from tobacco taxes. • Pat Cash, 1987 Wimble- don champion, for public service announcements on Australian television with the message "Smoking? No Way! " making the point that smoking and sports are incompatible. • Ryokichi Hirayama and Koichi Yasui, taxi drivers, for bringing about a change in transportation laws that allow drivers in Tokyo to designate cabs smoke-free . Theirs were the first two ve- hicles to win that right, ef- fective March 1988. • Nobuko Nakano, junior high school teacher, for founding the Women 's Ac- tion on Smoking, a group of civic-minded volunteers dedicated to raising con- sciousness about the bles- sings of a smokeless envi- ronment in Japan-an act unique among women's or- ganizations throughout the world. • Ryoichi Sasakawa, Jap- anese philanthropist, for un- swerving support, morale and financial, of WHO's Tobacco or Health pro- gramme, which is making possible initiatives in public information and health edu- cation for the World 's 1st No Tobacco Day. Africa • Yidnekachew Tessema, (posthumously) of Addis Ababa, and president, up to his death in August 1987, of the African Football Confed- eration, for his campaign that made the 4th All Afri- can Games, in Nairobi, the first ever without tobacco advertising in stadiums. " How can we ask African youth to become an instru- ment for the propaganda of tobacco?" he demanded . Eastern Mediterranean • Salah Muntassir, colum- nist for the Cairo newspaper AI Ahram, w ho, drawing on his own experience as an ex-smoker, consistently writes about the delights of breaking free from tobacco. The year that. .. marks Jhe 40tb aqniversary , ..of the ~orld ,,'He~ lth ; srgani~ 'atio~ , i.s al~o th~. ~.~nth an~ njyersary·. of th~ ~eql,ara tidn of Al~a-Ata-" sidped • at . the} mding of ~ .maJor UNI~EFIWHO conference on primary: hea,lt~,, csre in Soviet Kazakhstah · on 12 Septem~e( 1 WR Jhe ·August-S§ptember . issy§ Woflcf •· .. ,. He,~ltP1: . pyts An Indonesian mother brings her baby to be treated for pneumonia-yet another of the communicable diseases that trouble mankind. Photo WHO/J. Leowski
Organisation mondiale de la santé (OMS) · Journal articles
World Health: the magazine of the World Health Organization: July 1988 [full issue]: communicable diseases
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