Many leprologists have reported that incidence rate on house-hold contacts of leprosy patients is higher than that on non-contact children. To prevent the incidence on the children, BCG Vaccination has been tried in several areas and chemo-prophylaxis trial also has been carried out by Dharmendra and so on. The author has tried chemo-prophylaxis for 162 leprosy house-hold children since 1970 in Okinawa. One hundred and twenty-five children were administered with DDS (2mg/kg) every day for 2 years and 37 children were administered with the same drug in combination with RFP (10mg/kg) once a month for 6 months.
Thirty-five contact children (DDS group) were examined immunologically by FLA-ABS test and Mitsuda test before and after chemo-prophylaxis. Fourty-nine percent of contacts were immunologically unchanged by FLA-ABS test and sixty-nine percent were increased by Mitsuda test.
The incidence rate on leprosy among chemo-prophylaxis group was 0.71%, on the contrary the rate on non-prophylaxis group was 2.1%. The chemo-prophylaxis trial for leprosy house-hold contact children in Okinawa is fairly effective.