Trends in leprosy over fifty years in Gudiyatham Taluk, Vellore, Tamil Nadu

This paper presents epidemiological trends over a fifty-year period observed in a defined population served by the Schieffelin Leprosy Research and Training Centre (SLR & TC), Karigiri, Vellore District in Tamil Nadu. It covers three distinct periods, namely, the pre-MDT era with dapsone monotherapy, the MDT era under a vertical leprosy control programme and the MDT era after leprosy control services were integrated into the general health services. Prevalence rates have declined steadily from 125 per 10,000 population at the time of introduction of MDT in 1982 to 5 per 10,000 at the time of integration in 1997 to less than 1 per 10,000 in 2005. The new case-detection rate was 5.4 per 10,000 when the field programme started in 1962, and held steady at 15-20 per 10,000 between 1970 and 1980. It then showed a gradual fall from 10.8 per 10,000 in 1985 to 3.9 at the time of integration, and continued to fall in the post-integration period and was 0.8 per 10,000 in 2005. The mean age at detection showed a gradual increase from 23.4 years in the dapsone era to 31.2 years in the post-integration period. The male: female ratio showed a preponderance of males almost throughout the reference period. While polar types of leprosy (TT & LL) were common in the dapsone era, more of borderline leprosy (BT & BL) cases was seen more recently. MB rates that were high initially, declined steadily during monotherapy and stabilized between 10% and 12% during the vertical MDT programme and is showing an increase in the post-integration-period. The proportion of cases with Grade 2 disability at registration showed a gradual decline during the monotherapy period, remained relatively unchanged at 8%-10% during the the MDT period, and showed a sharp rise in the immediate post-integration period before falling. Analysis of trends of leprosy in a well-defined geographical population over a fifty-year period gives useful information on how the disease has evolved over the years. It provides opportunities to explore the reasons for the changes observed, though one has to be cautious while interpreting such data due to changes in definition, the play of operational factors, and changes in policies and strategies.     

Leprosy control in 7 districts of south Sulawesi, Indonesia, 1986-91.

This paper describes the leprosy control programme in 7 districts of the South Sulawesi Province in Indonesia. This province is reported to have the highest prevalence of leprosy in the country. The programme started in 1986 with re-registration of all patients on the cumulative registers. Strict criteria for admission of patients to MDT were initially applied. In 1990 it appeared that these criteria had been too strict, thus necessitating a second re-registration of patients still on DDS monotherapy. More flexible criteria for admission to MDT led to an increase in MDT coverage from 45% to 78% within 6 months. By April 1991, 5 years after the start of the programme, the registered prevalence had decreased from 4.4 per 1000 in 1986 to 1.6 per 1000; the coverage with MDT had increased from 6% in 1986 to 78%, and the case detection rate remained stable around 4 per 10,000 after an initial increase at the start of the programme.     

Epidemiological trends of leprosy in an urban leprosy centre of Delhi: a retrospective study of 16 years

This study was done by collecting the retrospective data from 1994 to 2009 of patients attending the urban leprosy centre attached to the department of dermatology, STD & leprosy of PGIMER & Dr. R M L Hospital, New Delhi. The data was analysed according to age, sex, type of leprosy, leprosy reactions, deformities and relapse and compared with the national figures by comparison of proportions after taking the national data per 10,000 population. A total of 3659 patients attended our ULC (Urban Leprosy Centre) among which 2741 were male and 945 females (M:F-3:1). 669 patients (18.2%) were children. The data analysed show a gradual decline in new case detection rate with a marginal rise in 2005 and 2008. Percentage of MB cases was falling consistently till 2005 after which it showed an abrupt rise. The incidence of type 1 reaction varied from 21% in 1994 to 10% in 2009 in PB patients and from 6% in 1994 to 8% in 2009 in MB patients. The trend of type 2 reactions in MB patients showed a slow declining trend. MDT completion rate showed an impressive improvement from 56% in 1994 to 90% in 2009. The number of patients revisiting the ULC with features of relapse also showed a decrease in number. The pattern of visible deformities showed an almost constant trend similar to national figures. Improved MDT completion rate helps in reducing the disease transmission, severity, reactions and disabilities.     

Progress towards elimination of leprosy as a public health problem in India and role of modified leprosy elimination campaign

India (population 943 million) has seen a highly significant decrease in the prevalence of leprosy since the introduction of multi-drug therapy (MDT) in 1981. From a prevalence rate of 57/10,000 of the population in March 1981, the figure has declined to 5.2/10,000 in March 1999. This was possible due to the creation of a completely vertical (specialized) infrastructure for leprosy control in the 218 endemic districts of the country and skeleton vertical staff in the remaining districts, coupled with the recruitment of additional staff on contract basis to provide MDT through vertical staff in endemic districts and mobile treatment units in the moderate and low endemic districts. Despite all efforts, however, new case detection has not shown a decline over the last 14 years due to the presence of hidden (and undiagnosed) cases. Therefore, in order to intensify and hasten progress towards elimination (less than 1 case per 10,000 of the population) in the whole country, it was decided to implement a massive leprosy elimination campaign (LEC) in all the States/Union Territories (UTs). The reports of 22 States/UTs indicate that 415 out of the total of 490 districts in the country were covered by modified LEC (MLEC), with 85% coverage of the population. The campaign used in India was modified from the pattern previously described by the World Health Organization. The detection of hidden or suspected cases took place within a short, intensive period of 6-7 days and relied heavily on house-to-house searches by General Health Care staff trained in leprosy detection and confirmation was made by appropriately trained staff. This MLEC received widespread Government and public support, resulting in the detection of 454,290 hidden cases of leprosy, whilst providing training to a large number of General Health Care staff and volunteers and creating widespread awareness about leprosy and the availability of treatment free of charge for all cases. This programme proved to be one of the most successful health care interventions undertaken in India in recent years, particularly in the states of Bihar and Orissa. Although a few states in India are unlikely to reach the current WHO goal of elimination before end of the year 2000, the results of the MLEC strongly support the possibility that elimination levels will be achieved in the majority of states by the end of the year 2000 and at national level by the end of the year 2002.     

Trends in leprosy case detection worldwide since 1985

Trends in case detection and case detection rate (CDR) since 1985 are described at regional and national levels. Annual case detection by WHO Region was available for 1994-2000. Using different sources, complete time series for case detection were constructed for 1985-1998 for a group of 33 endemic countries cumulatively (top 33), and for 14 individual countries (top 14). Population statistics were used to derive CDRs. India contributed 79% to global case detection in 1998. Africa, the Americas and South-East Asia each contributed about 30% when India is excluded. During 1994-2000, case detection did not decrease in these three WHO Regions. The 33 countries contributed 99% and 98% to global case detection in 1994 and 1998, respectively. Cumulative case detection for the top 33 minus India gradually increased, overall almost doubling. The contribution of the top 14 to case detection of the top 33 hardly changed over time, equalling 96% in 1998 (81% when India is excluded). In terms of annual case detection, Brazil was always ranked second after India; it accounted for 27% of 1998 case detection in the top 33 except India. In 1998, seven of the top 14 countries--including India and Brazil--had CDRs above 2 per 10,000. The CDR did not exceed 1 per 10,000 for the other half. Decreasing tendencies in CDR, either for the whole period or in the 1990s, are observed for four of the top 14 countries (Guinea and three Western Pacific countries: China, Vietnam and the Philippines). In conclusion, there is no general decline in case detection to date, and several important countries still have high CDRs. Prevalence is an irrelevant indicator for monitoring epidemiological changes in leprosy. Trends in the transmission and incidence of leprosy are still completely unclear, necessitating further research. The target to eliminate leprosy as a public health problem, defined as a prevalence of less than 1 per 10,000, is therefore also an inadequate yardstick for decision making on leprosy control.     

Trends in prevalence and case finding in the ALERT leprosy control programme, 1979-1999

From 1979 to 1999, the ALERT leprosy control programme has covered a well-defined area in central Ethiopia using standardized case finding strategies. During this period, the leprosy prevalence has decreased more than 30-fold, there has been a 3-fold decrease in case detection and a 6-fold decrease in the case detection rate. The proportion of MB patients among new cases increased by around 80% and the proportion of children among new cases decreased by around 60%. Several factors may have contributed to these trends. The impact of the introduction of MDT and the shortening of the duration of the MB regimen are shown, but other factors are also discussed at length: an increase in the population of the area, cleaning up of the registers, changing case definitions, changes in staff motivation and fluctuations, even small ones, in case finding intensity and coverage. Do the observed trends reflect a reduction in the transmission of the leprosy infection? Because of the many confounding factors, it would be difficult to answer that question positively at present. Additional rigorous data collection and analysis is required.     

Case detection, gender and disability in leprosy in Bangladesh: a trend analysis.

A trend analysis is presented of all newly detected leprosy cases over an 18-year period (1979-1996) in a highly leprosy endemic area of Bangladesh. A total of 23,678 new cases were registered, with an average of 860 new cases per year in the first 12 years, and increasing to around 3000 in 1996. The male:female (M:F) ratio decreased from 2.3 to 1.4. The proportions of newly detected cases with MB leprosy and of newly detected cases with any disability decreased over time. These reductions were more marked in the higher age groups of both sexes. The reduction in disability was primarily attributable to a decline in grade 2 disability. New case detection rates (NCDR) of all leprosy patients per 10,000 general population increased for males from 3 to 6; and for females from 1 to 4, while the NCDR of MB leprosy decreased in males from 1.4 to 0.6, and in females fluctuated around 0.45. The NCDRs of leprosy patients with disabilities showed an initial decrease in the first period, especially in males, but later showed an increase. The NCDR of males with disability was about twice as high as that of females. Finally, female NCDRs in the ages between 15 and 30 were low by comparison with the male NCDRs at the same time. This may be due to the sociocultural characteristics of the Bangladeshi society, with gender differences in exposure, health seeking behaviour and opportunities for case detection. Operational changes in the control programme have contributed to the changed profile of newly detected cases. This study shows that the application of general population statistics is essential for understanding the dynamics in leprosy control programmes under changing operational conditions. Combining case detection figures with such statistics helps to identify population groups that are possibly not benefiting sufficiently from the services provided, and to clarify the dynamics in control programmes and the future trends and programme requirements.     

Leprosy control in the Republic of Yemen: co-operation between government and non-government organizations, 1989-2003

Although the prevalence rate of leprosy in the Republic of Yemen has dropped below the WHO elimination level of less than one case per 10,000 of the population, it is still regarded as a serious public health problem calling for continued vigilance, notably in the detection and treatment of hidden and undiagnosed cases. In the past, religious misinterpretation has generated adverse behaviour patterns towards people affected by leprosy, characterized by aggression, negligence and isolation. Until about 1982, following a visit of a leprologist (Dr S. K. Noordeen) from the World Health Organization, there was no leprosy control programme and attempts to establish one remained ineffective until in 1989, when an agreement was signed between the Ministry of Public Health and Population and the German Leprosy Relief Association. This led to the development of a leprosy control programme in four governorates, later extended to the rest of the country. This paper describes the progress made in the control of leprosy in the Yemen, 1989-2003, by the Ministry of Health and Population and the GLRA, in association with two local societies.     

Reduction in caseload after multidrug therapy in an urban leprosy control programme--a retrospective study in Bombay

A fall in the active registered case prevalence rate together with a fall in the active caseload per worker after the introduction of multidrug therapy (MDT) is becoming a managerial issue in leprosy control. A retrospective analysis was undertaken to assess the caseload per paramedical worker with reference to active cases for treatment (3341), cases for surveillance (2227) and cases for care after cure (165) at the end of December 1989. All these cases were under the care of 24 paramedical workers. The analysis showed that the caseload per worker was 239 (active cases 139, plus surveillance cases 93, plus care after cure cases 7), though active registered case prevalence rate declined from 1.82/1000 (before starting MDT) to 0.79/1000 by the end of December 1989. The case detection rate was 0.49/1000 by the end of 1989. So, although the active registered case prevalence rate declines, the worker will have enough to do because of the need for surveillance and the detection of relapses, early neuritis, early disabilities and care after cure. Simultaneously, new case detection and treatment must be continued. All these aspects need to be considered when programme managers are reviewing leprosy control strategy.     

The impact of leprosy control on the transmission of M. leprae: is elimination being attained?

In 1991 the World Health Assembly decided to 'eliminate leprosy as a public health problem' by the year 2000. Elimination was defined as reducing the global prevalence of the disease to less than 1 case per 10,000. In 2000 the World Health Organization (WHO) announced that elimination was reached globally. Conventionally control of disease is defined as the reduction of disease burden to a locally acceptable level. Elimination of disease is defined as the reduction to zero of the incidence in a defined geographical area, and eradication is defined as the permanent reduction to zero of the worldwide incidence of infection caused by a specific agent. In leprosy however, WHO limited elimination to control instead of transmission, by using prevalence instead of incidence of disease. Leprosy statistics usually report on prevalence and new case detection. Prevalence is linked to length of treatment, which has changed over time. Trends in new case detection rates only reflect trends in incidence rates when no changes occur in case detection, but in the past 25 years case detection in leprosy has been determined strongly by operational factors. For the leprosy elimination strategy it was assumed that MDT would reduce transmission of M. leprae, but there is no convincing evidence for this. Data for evaluating the impact of MDT on transmission are not readily available because leprosy has a long incubation period. Also declines in case detection may have other causes, such as BCG vaccination. Mathematical modelling of the transmission and control of leprosy showed that the elimination strategy reduces transmission slowly, with a predicted annual decline in incidence ranging from 2% to 12%. Early case finding was the key factor to attain this decline. Future projections of the global leprosy burden indicated that 5 million new cases would arise between 2000 and 2020, and that in 2020 there would be 1 million people with WHO grade 2 disability. It is concluded that substantial progress has been made to control leprosy, but when elimination of disease is defined as the reduction to zero of the incidence, leprosy is definitely not eliminated. To attain elimination of leprosy it is necessary to find effective interventions to interrupt transmission of M. leprae and practical diagnostic tools to detect levels of infection that can lead to transmission. This requires extensive research in the areas of epidemiology and microbiology.     

Rapid survey on case detection of leprosy in a low endemic situation, Zhucheng County, Shandong Province, The People's Republic of China

The prevalence of leprosy fell below 1 per 100,000 in Shandong province in 1994. Since then, a few incident leprosy cases have been reported each year over the past 10 years. In order to explore whether or not the reduction in case detection in the province was due to the stopping of active case-finding activities, a rapid village survey was conducted in a formerly endemic county, using skin disease service. Ninety-one villages in 23 townships, covering a total population of 104,885, were surveyed. No leprosy case was detected. The results of the survey, along with other evidences, such as higher MB/PB ratio among newly detected cases and late onset of the disease, suggest that leprosy is dying out as a disease in the county as well as in Shandong. The efforts of the leprosy control programme should shift to other services such as prevention of disability and care for the disabled.     

Leprosy control in Zimbabwe: from a vertical to a horizontal programme

In Zimbabwe leprosy control services were re-established in 1983, following the war of independence. Its main objectives were the nation-wide implementation of multiple drug treatment (MDT) and the integration of leprosy control into the general health services. The MDT regimens have led to a rapid reduction of the prevalence of leprosy. At the beginning of 1989 357 patients were on treatment and 1299 under follow-up. Six hundred and twenty-seven new cases have been detected since 1984, which represents an annual case detection rate of 1.6 per 100,000. This seems a fair reflection of the incidence rate, as the new cases are characterized by a minority of patients under the age of 15 (4%) and a lepromatous percentage of 50%. As the budget of the programme has remained unchanged integration of leprosy control into the general health services has become imperative. However, this transition is now hindered by a number of obstacles that were not foreseen at the start of the programme, because they are in measure corollaries of the successful implementation of MDT. Most of the problems that leprosy control is facing in Zimbabwe could have been avoided if instruction in leprosy had been introduced into the curricula of the (para) medical training schools 20 years ago.     

A comparison of Rapid Village Survey and Leprosy Elimination Campaign,detection methods in two districts of East Java,Indonesia, 1997/1998 and 1999/2000

A Rapid Village Survey (RVS) was planned to estimate the extent of the leprosy problem in two well documented endemic districts of East Java, Indonesia. Furthermore, the aim was to investigate the efficacy of the routine programme in detecting new and early cases, as well as the feasibility of RVS in detecting disabled people affected by leprosy in the community. A random sample survey (RVS: a simple method compared to a Population Sample) was used to determine the extent of the leprosy problem. In addition, a Leprosy Elimination Campaign (LEC), was used particularly to detect new and backlog cases in the community. Both RVS and LEC involve a health education campaign followed by the examination of persons voluntarily reporting. Routine programme case finding, involving passive case finding and contact examinations, was also carried out. The RVS prevalence rate of 12 per 10,000 was more than twice the known prevalence rate of 5 per 10,000. The LEC prevalence rate was less than the rate found by RVS, but was within the RVS confidence interval. During the RVS, many children with leprosy were detected, and 10% of all RVS new cases already had disability grade II. The population disability grade II rate due to leprosy was 9 per 10,000. Despite the fact that an active leprosy control programme had been carried out in the surveyed endemic area over a period of many years, the actual prevalence rate found was more than twice the known prevalence. Many children were found during the RVS, thus indicating continuing widespread transmission. In general, it seems that there is still a serious delay in detecting new cases under the routine programme. Consequently, there are substantial numbers of persons affected by leprosy in those districts in need of rehabilitation.     

Current status of leprosy and leprosy control in Bangladesh: an ongoing collaboration

Elimination of leprosy as a public health problem, defined by a registered prevalence of less than one case per 10,000 population, was achieved by Bangladesh in 1998, and steady reduction in prevalence is ongoing. It is less certain whether a sustained reduction in case detection is occurring, with little overall change in some longstanding programme areas, though the overall annual new case detection rate has fallen by over one-third between 1996 and 2004, from 9.8 to 6.1 per 100,000. Concerns about 'hidden' cases have been raised in Bangladesh as elsewhere, though the National Leprosy Elimination Campaign of 1999 detected relatively fewer new cases than in other countries, and mainly in low endemic areas. Investigation into the correct diagnosis of leprosy and recording and reporting practices has not suggested high levels of over-diagnosis or 'over-registration'. Both before and since achievement of the elimination target at national level, the collaboration of Non-Governmental Organizations with the national Leprosy Elimination Program has been considerable. NGOs now support ongoing leprosy control efforts in rural and urban populations, moderate to high endemic for leprosy, amounting to 50% of the entire population, and NGO staff look after 75% of all new cases in Bangladesh. This close collaboration has highlighted the potential for large-scale partnership in disease control, and has expanded to extensive partnership in tuberculosis control, which will hopefully enhance cost-effectiveness and quality of both programmes. Further challenges remain in the area of urban leprosy control, where leprosy case finding represents 30% of the whole country, but public health infrastructure and community organization is weakest. Sustaining of leprosy services in the long term is a significant concern, and new modes of collaboration, with a more technical, supportive role for NGOs in some areas is being piloted.     

Treatment outcome and impact of leprosy elimination campaign in Sokoto and Zamfara states, Nigeria

A Leprosy Elimination Campaign (LEC) was implemented in 37 districts of Sokoto and Zamfara states, Nigeria from 13 August to 30 November 1998. The campaign utilized intensive community mobilization and training of local health personnel to detect hidden leprosy cases. During 8 weeks of case finding, 160,127 persons were screened; 353 new cases of leprosy were detected and placed on MDT; 236 (67%) of new cases detected were classified as MB, 64 cases (18%) suffered visible deformities and 24 patients (6.8%) were children. Follow-up in December 1999 of patients placed on MDT revealed 97% PB and 96% MB cure rates, respectively. Detection of cases in communities led some community leaders to ask for repeat surveys in their communities. Repeat surveys continue to yield new cases. The authors recommend that LECs be maintained for 3 years to accelerate leprosy elimination in the region. The cost effectiveness and impact of LEC in Sokoto-Zamfara are discussed.     

Epidemiological trends of leprosy elimination in CLTRI rural field operation area, Tamil Nadu, India

The analysis of computerized data of patients in our Rural Field Operation Area (Kunrathur Taluk, Kancheepuram District, Tamil Nadu) from the start of MDT in 1986 has shown a decrease of leprosy prevalence from 275/10000 in 1986 to 0.7/10000 in 2005. Leprosy has been eliminated as a public health problem after 19 years of MDT implementation. Although the control programme was started in 1962, MDT implementation began only in 1986. The new case-detection rate has declined significantly from 27.3 in 1987 to 2.4/10000 in 2005 (y = -1.6x + 2325.1, p = < 0.05). The age-specific cumulative detection rates calculated showed highest case-detection at 10-14 years for total, 10-14 years for PB, 50-54 for MB, and 10-14 for both males and females. MB percentage was more among new cases in the last three years as compared to the initial three years, and this difference was found to be statistically significant, but there was no significant difference between the first three and the last three-year periods in child, male and disability rates (grade +/-2) among new cases. Thus, the declining trend in NCDR has not reflected any change in sex and age-groups of new cases. This analysis strengthens the hypothesis of sub-clinical cases possibly transmitting the disease and MB cases accruing after long incubation period.     

Evaluation of national leprosy eradication programme in Satara District, Maharashtra

The aim of this study was to evaluate the impact of national leprosy eradication programme (NLEP) in Satara District. A retrospective record based study was conducted in the district leprosy control unit with evaluation indicators like prevalence rate (PR), new case detection rate (NCDR), percentage of cases released from treatment, proportion of female cases among new cases, proportion of multi bacillary (MB) cases among new cases, proportion of grade-2 disability among new cases and proportion of child cases among new cases and trend was analyzed for statistical significance by using Chi-square test. During study period from year March 2003-04 to March 2007-08, there was decrease in PR of leprosy from 2.46/10000 population to 0.62/10000 population, NCDR decreased from 3.46/10000 population to 0.77/10000 population and trend was statistically significant (p<0.001*, P<0.001*) respectively. Declining trend of grade 2 disability among new cases was noted and this was statistically significant (p<0.01*). Proportion of female cases among new cases showed little fluctuation from 43.3% to 47.5% but trend was statistically significant (p<0.03*). Proportion of MB cases among new cases increased from 44.4% to 53.6% while proportion of child cases among new cases decreased from 16.5% to 12% and trend was statistically significant (p <0.001*, p<0.001*) respectively. The NLEP has a favorable impact towards elimination of leprosy in Satara District, Maharashtra.     

Impact of MDT on leprosy with a special reference to monolesions and smear positivity among the new cases

The impact of MDT on the prevalence and incidence rate of leprosy was studied in a project area of 130,000 population over a period of 14 years, with a special reference to new monolesional cases and those presenting as smear positive cases. The prevalence rate showed a fall from 23 per 10,000 in 1986-87 to 1.33 per 10,000 in 1999-2000. The number of cases presenting with single lesion however showed a downward trend from 63.69% in 1986-87 to 26.09% in 1999-2000. The cases showing smear positivity among the new cases detected showed an ascent from 3.91% in 1986-87 to 4.35% in 1999-2000 with a peak of 25% in 1995-96. A similar trend was seen in the analysed figures of the 4 general surveys done.     

Monitoring impairment in leprosy: choosing the appropriate tool

OBJECTIVE: To assess to what extent the Maximum WHO Impairment Grade, the EHF Score and Impairment Summary Form (ISF) reflect changes in impairment, both in number(s) and severity. DESIGN: The impairment data at registration and at release from treatment of 444 persons affected by leprosy registered for MDT from 1994-2003 in Federal Capital Territory, Nigeria were analysed using three monitoring tools. RESULTS: Of the 444 patients, 92 people had a change (10 deteriorated, 70 improved while 12 had improvement in some parts of their body and deterioration in other parts) in their impairment between Registration and Release from Treatment. Of the 10 people whose impairment status deteriorated, the WHO Grade missed 7 and the EHF score missed 4. The ISF missed none. Of the 70 whose impairment status improved, the WHO grade missed 27; the EHF score missed 20 and the ISF missed 9. The WHO Grade had a sensitivity of 50%, the EHF Score 61% and the ISF 90%. Negative predictive values were 88%, 91% and 98% respectively. CONCLUSIONS: The Maximum WHO Impairment Grade use should be limited to an indicator of late case detection. The EHF score is better used at programme level than individual patient level. The ISF is a sensitive tool for monitoring impairments at patient level to aid clinical decision making.     

Epidemiological pattern of leprosy in Ethiopia: a review of the control programmes

Leprosy control started in a limited area of Ethiopia in 1956. Extended coverage of the country was achieved in the early seventies. Review of the data from the control projects since 1976 revealed that leprosy is a disease of the Ethiopian highlands where prevalence rates as high as 7 per thousand have been recorded in some provinces, while the cumulative national average for the last 13 years was 2.6 per thousand. The paucibacillary form was predominant. However, unlike other African countries, a relatively high proportion of multibacillary leprosy was found in Ethiopia. The male-to-female ratio was 2:1 with the highest prevalence in the 15-44 years age bracket. Detection rates for new cases have shown a gradual decline since 1982, a year before multiple drug therapy (MDT) was introduced into the country. For the last 5 years the number of new cases has stabilized at 4700/year. These trends probably reflect a general reduction in the prevalence of leprosy in the country, while the conspicuous decline in 1982 is most likely related to discharge of cases during screening before MDT. The new villagization policy of Ethiopia with its effective reorganization of the populations is believed to make control programmes and supervision of MDT easier and presumably more effective. Similarly, more reliable prevalence and incidence studies could be undertaken with success.