Re-establishment of cutaneous leishmaniasis after cessation of anti-malaria spraying.

Decrease or interruption of transmission of cutaneous leishmaniasis as a result of spraying of human dwellings with residual insecticides has been reported by several investigators. In this report the behaviour of the disease after cessation of spraying in the villages of Isfahan is studied. In 16 villages sprayed with DDT from 1966 through 1969, the incidence decreased from 8.2 per 1000 in 1965 to 0,7 per 1000 in 1969 but in 1970, the first year after cessation of spraying, the incidence increased to 15 per 1000, a 20-fold increase. The control villages did not show these changes, still having the incidence figure of more than 9 per 1000 per year. The study shows that insecticide spraying is not the fianl answer in the control of leishmaniasis.