Victory over leprosy draws nearer

18 World Health • SlstYeor, No. 2, Morch-April 1998 Victory over leprosy draws nearer As early as 1914, the Office International d'Hygiene Publique (OIHP) - a forerun- ner of WHO - ordained that there should be compulsory notification, as well as surveillance or isolation, of cases of leprosy. The disease was very clearly an international public health problem, and in the year of WHO's founding, 1948, the International Leprosy Association was among the first nongovernmen- tal organizations to be brought into official relations with the infant organization. Shortly afterwards, an expert advisory panel was estab- lished whose members helped to prepare for the first meeting of the Expert Committee on Leprosy, held in Rio de Janeiro and Sao Paulo in 1952. That Expert Committee con- firmed two important points: "that leprosy is not in most cases a highly infectious disease, and that, with the introduction of sulfone therapy, a good proportion of cases can be cured". The experts also "accepted that temporary isolation might still be necessary, though for infectious cases only, but it was suggested that ambulatory and domiciliary treat- ment could be safely and satisfacto- rily given to most patients". The First Ten Years of WHO, published in 1958, reported that the clinical results of treatment with diaminodiphenylsulfone - also known as dapsone - "tend to confirm the favourable results already re- ported in medical literature on the treatment of leprosy patients in specialized institutions". Over- optimistically, it claimed that "lep- rosy patients no longer tend to avoid treatment because of its possible association with segregation. They now come forward spontaneously." There was also a mention of trials with BCG vaccination (the anti- tuberculosis vaccine) and of vaccines prepared with other myco- bacteria, This leprosy patient in Sudan has just received the blisterpack of drugs she needs to cure the disease. Photo WHO "which appear to offer a certain degree of protection against lep- rosy." In 1968 The Second Ten Years of WHO reported: "Participants in the seminar on leprosy control orga- nized at Belo Horizonte, Brazil, in 1958 were agreed that compulsory isolation of patients should be abol- ished and replaced by effective control of foci through the treatment of all patients and surveillance of their contacts - hospitalization being restricted to cases in need of special medical or social care." Later that year, the Seventh International Congress of Leprology, held in Tokyo, stressed that, from the epi- demiological point of view, "it is more advantageous to reduce infec- tiousness in many patients than to ~liminate infectiousness in a few." Poor patient compliance The Second Ten Years struck a gloomy note. "Poor follow-up and attendance of out-patients for regular treatment continue to be a main obstacle in leprosy control programmes. Leprosy control has been based primarily on chemother- apy with sulfones, and surveys have shown that 73% of lepromatous patients require more than three years to become bacilli-negative. Unfortunately, the longer treatment continues, the less regular it tends to become." It went on: "The special- ized leprosy control services need the active cooperation of the general health services, and leprosy control should be progressively integrated into the work of the health centres at the local level." All this was remarkably farsighted. There was the insistence that leprosy patients should not be segregated or isolated from their communities. There was the tantaliz- ing vision of a drug that would actu- ally cure leprosy without requiring many years of treatment. And there was the problem of maintaining patient compliance with drug regi- mens. Above all, there was the strong recommendation that leprosy control should be integrated with general health services, in fact with what was later to be called primary health care. Certainly the drug dapsone seemed to offer some light at the end of the tunnel. Its use spread around the world in the next decades, thanks largely to the work of WHO and of its partner nongovernmental organi- zations, many of them members of what was to become the Interna- tional Federation of Anti-Leprosy Associations (ILEP). But then dap- sone ran into trouble. The long duration of treatment made patient compliance a big problem; it was World Health • 51 st Year, No. 2, Morch-April 1998 rather a lot to expect a possibly disabled person to travel several miles every month to a health post to obtain the drugs. A patient who noticed an improvement - perhaps the disappearance of skin lesions - saw no further point in going on taking the pills. Worse still, Mycobacterium leprae - like so many other agents of disease that plague our planet - began to develop resistance to the drug. It looked as if mankind 's only safe weapon against leprosy was about to become use- less. Better drugs needed The WHO Expert Committee on Leprosy, in its fifth report published in 1977, struck a note of alarm when it declared "there is an urgent need for controlled clinical trials of com- bined chemotherapy in multibacil- lary leprosy" and called for research into alternative drugs to dapsone, with the cooperation of research institutes and the pharmaceutical industry. In due course, newer and better drugs came on the scene, in particular rifampicin and clofaz- imine, which proved to be both highly effective and well-tolerated by patients. As a result, a WHO Study Group which met in Geneva in October 1981 proposed a multi- drug regimen consisting of these two drugs in combination with dapsone, since they did not merely kill M. leprae in quick time but also prevented the bacillus from develop- ing resistance to any of the three. It was this multidrug therapy or MDT which provided the break- through that at last made it possible to envisage putting an end to lep- rosy. Today, even people with the more severe form of the disease, multibacillary leprosy, can be guar- anteed a total cure within the space of 12 months. Relapses - the recur- rence of the disease after stopping treatment- are very rare, constitut- ing well under 1 % of cases. One unexpected result of the amazing success of MDT has been to put the never very hopeful quest for a viable vaccine on the back burner. At the World Health Assembly in May 1991, the Member States of WHO made a formal commitment to bring about the elimination of lep- rosy as a public health problem by the year 2000. This means reducing the number of cases to less than 1 case per 10 OOO people. A full account of how WHO and its part- ners are prosecuting the war against leprosy appeared in the May- June 1996 issue of World Health. In the mid-1980s, there were an estimated 12 million cases (and 5.4 million registered cases) in the world. Today that estimate has been revised to only around one million, while the number of registered cases - there- fore receiving MDT - stands at around 800 OOO. Where there were 122 countries with prevalence rates above 1 per 10 OOO in 1985, there are today fewer than 50. So the goal of elimination is not far away - but neither is the target date of the year 2000. Aside from the purely medical aspects of the drive against leprosy, there is the human and social side. While the cure is certain for every person with leprosy who comes forward for MDT, many still face "I want it eliminated" 19 ostracism from their own communi- ties, even from their own families . The social suffering lingers on and, together with the totally unjustifiable loss of human rights, adds a heavy psychological burden to the physical damage that they have undergone. So it is essential for everyone con- cerned in public health to spread the word that leprosy is curable, that it is extremely hard to "catch," and that sufferers need not and must not be shunned. Unless this message reaches every patient in every vil- lage, and unless they come forward for the drugs - which should be available at every clinic and primary health care centre in the leprosy- endemic countries - the disease will still lurk in isolated and dangerous pockets. It is important to avoid triumphalism and the tendency to count our chickens before they are hatched. But provided the impetus is maintained and provided there is no shortfall in the human and finan- cial resources required we should be able to put paid to this age-old dis- ease and ensure a leprosy-free world in the 21 st century. • In his novel A Burnt-Out Case, set in a " leproserie" in cen tral Africa , the noveli st Graham Greene invented the word " leprophil " for people w ho appeared to prefer the disease to the people who suffered from the disease. The phys ic ian in charge, Doctor Colin, says : "You remember that li ttl e leproserie in the bush tha t the nuns ran. W hen DDS [da psone] w as discovered to be a cure, they were soon reduced to half a dozen patients . Do you know what one of the nuns said to me? ' It's terrible, doctor . Soon we' ll have no lepers at al l.' There surely was a leprophil. " Another character comments : "A ll the same, doctor , you 've said it yoursel f, leprosy is a psycholog ical problem. It may be very valuable for the leper to feel loved ." Doctor Colin replies : "A patient can always detect whether he is loved or whether it is only his leprosy w hich is loved . I don't wan t leprosy loved . I want it eliminated. " Greene dedicated his novel, published in 1961 , to Dr Michel Lechat w hose leprosy hospita l at Yanda in the Congo he had vis ited. The foreword expressly says: "I hope you wi ll accept the ded ication of this novel , w hich owes any merit it has to your kindness and patience .... Doctor Coli n has borrowed from you his experience in leprosy and noth ing else." Professor Michel Lechat \s a di st inguished leprologist. Formerly President of the School of Publ ic Health, Cathol ic Un iversity of Louvain in Brussels , he is Presiden t Emeritus of the Internationa l Leprosy Asssociation (ILA) and President of the International Leprosy Union (ILU). (Read his article "History of a Disease" on page 8 of the M ay-June 1996 issue of World Health. )