Chemoprophylaxis of leprosy with a single dose of 25 mg per kg rifampin in the southern Marquesas; results after four years.

In January-February 1988, a program of chemoprophylaxis for leprosy, using a single 25 mg/kg dose of rifampin, was conducted among 2786 (98.7%) inhabitants of the Southern Marquesas and 3144 South Marquesan "emigrants" and their families. Among the treated population, during the 4 years which followed the implementation of the program, two leprosy patients were detected, one of whom can be considered as a failure of chemoprophylaxis because she was not known by the leprosy control unit. During the same period (1988-1991), a decrease in detection rates for leprosy in the entire French Polynesian population has been observed, an event which makes the interpretation of these findings very difficult. Nevertheless, according to presently available data, the effectiveness of chemoprophylaxis with a single dose of 25 mg/kg rifampin is estimated to be about 40% to 50%. When considering not only the results of the present study but also the financial and logistic constraints raised by such a program, one is led to the conclusion that chemoprophylaxis, even with a single dose of rifampin, is not likely to become an effective component of leprosy control programs.