Hansen's disease: a vanishing disease?

The introduction, implementation, successes and failures of multidrug therapy (MDT) in all Hansen's disease endemic countries are discussed in this paper. The high efficacy of leprosy treatment with MDT and the global reduction of prevalence led the World Health Organization, in 1991, to establish the goal of elimination of Hansen's disease (less than 1 patient per 10,000 inhabitants) to be accomplished by the year 2000. Brazil, Nepal and East Timor are among the few countries that didn't reach the elimination goal by the year 2000 or even 2005. The implications of these aspects are highlighted in this paper. Current data from endemic and previously endemic countries that carry a regular leprosy control programme show that the important fall in prevalence was not followed by the reduction of the incidence. This means that transmission of Mycobacterium leprae is still an issue. It is reasonable to conclude that we are still far from the most important goal of Hansen's disease control: the interruption of transmission and reduction of incidence. It is necessary to emphasize to health managers the need of keeping Hansen's disease control activities to better develop control programmes in the future. The recent international proposal to interrupt the transmission of leprosy by the year 2020 seems to unrealistic and it is discussed in this paper. The possibility of epidemiological impact related to the human immunodeficiency virus/Hansen's disease coinfection is also considered.

Hansen's disease: a vanishing disease?

The introduction, implementation, successes and failures of multidrug therapy (MDT) in all Hansen's disease endemic countries are discussed in this paper. The high efficacy of leprosy treatment with MDT and the global reduction of prevalence led the World Health Organization, in 1991, to establish the goal of elimination of Hansen's disease (less than 1 patient per 10,000 inhabitants) to be accomplished by the year 2000. Brazil, Nepal and East Timor are among the few countries that didn't reach the elimination goal by the year 2000 or even 2005. The implications of these aspects are highlighted in this paper. Current data from endemic and previously endemic countries that carry a regular leprosy control programme show that the important fall in prevalence was not followed by the reduction of the incidence. This means that transmission of Mycobacterium leprae is still an issue. It is reasonable to conclude that we are still far from the most important goal of Hansen's disease control: the interruption of transmission and reduction of incidence. It is necessary to emphasize to health managers the need of keeping Hansen's disease control activities to better develop control programmes in the future. The recent international proposal to interrupt the transmission of leprosy by the year 2020 seems to unrealistic and it is discussed in this paper. The possibility of epidemiological impact related to the human immunodeficiency virus/Hansen's disease coinfection is also considered.

Tuberculin conversion in HIV seropositives.

The human immunodeficiency virus (HIV) epidemic is associated with increased incidence of tuberculosis. There is a need to provide prophylaxis for the same. Mycobacterium w, a non-pathogenic, atypical mycobacterium, shares antigenic determinants with Mycobacterium leprae and Mycobacterium tuberculosis. The tuberculin response, which is a delayed hypersensitivity reaction, indicates the status of cellular immunity against tuberculosis. The objective of this study was to evaluate potential of mycobacterium w for tuberculin conversion in HIV seropositives. Fifty HIV positives (tuberculin negative) were enrolled in this study and were administered intradermal mycobacterium w. In all the patients, Mantoux test was performed to determine tuberculin like delayed type hypersensitivity reaction, by measuring the area of erythema and induration at baseline and then after ninety days. The results of the study revealed that forty-eight out of fifty, had tuberculin conversion after ninety days.

Tuberculosis control in resource-poor countries: alternative approaches in the era of HIV.

PIP: WHO projections suggest that the annual number of tuberculosis (TB) cases worldwide will reach 10.2 million by the year 2000. HIV plays a dominant role in this increase in many resource-poor countries. The internationally recommended treatment regimens for TB combine some of the six major antituberculosis drugs: isoniazid, rifampicin, pyrazinamide, ethambutol, streptomycin, and thiacetazone. WHO treatment guidelines give priority to patients according to the nature of their disease and recommend two regimens of 6-8 months duration, the longer regimen incorporating thiacetazone. Recently, WHO has favored a 6-month treatment regimen given as directly observed therapy (DOT). The disadvantages of the standard approach are the heavy workload of smear examinations, the complexity of some drug regimens, and the low rates of therapy completion. With the increasing TB case load in areas of high HIV infection prevalence, laboratories cannot do initial as well as follow-up smear examinations. In Botswana the proportion of smear-positive TB cases declined to 40% in 1992, but the overall proportion of patients who had smears performed had declined (52% in 1992). The multiple regimens in use cause confusion and nonadherence to guidelines. Nonadherence is the major risk factor for the emergence of drug resistance, and low completion rates are the most obvious signs of inadequate control programs. Alternative approaches mean ensuring high completion rates and using the most effective drugs. Regarding diagnosis, research might show that the number of smears could be reduced depending on the initial reading. There is no reason why a rifampicin-based short-course regimen could not replace the multiple regimens now in use. Rifampicin-containing regimens of 62-78 doses given intermittently have been effective and are suitable for use within a DOT program. For prevention of drug resistance, only pills combining different drugs should be used and rifampicin should be limited to the treatment of TB and leprosy.^ieng