A LARGE-SCALE MALATHION TRIAL IN THE BANDAR ABBAS AREA

Abstract

From October, 1964, a large-scale Malathion trial was carried out in the Bandar Abbas area which covered 435 villages with a population of 138,570. Until April, 1966, five rounds of Malathion 2 gm/m2, were performed. From 1967, the lowland area was sprayed with two rounds of Malathion (March, August) and the highlands with two rounds of Malathion (April, August) and two rounds of DDT (Jume, October).The main Vectors of the area are An. stephensi mysorensis (resistant to DDT and DLD) followed by An. fluviatilis and An. dthali (predominantly in fie highlands).The results of entomological and parasitological evolution up to ]969 were as follows: in lowland areas, S rounds of Malathion spraying are able to control the predominant vector-An. Stephensi - and keep its density insignificant. In highland areas, due to the exophilic and exophagic tendency of the predominant vectors - An. fluviatilis and An. dthali - as well as outdoor sleeping habits of the local population, the complete interruption of transmission of malaria has not been achieved. The Annual Parasite Incidence (API) in lowland areas, which was 42.9 per thousand in 1965, came down to 2.2 per thousand in 1969.In highland areas, the API was reduced from 59.8 per thousand inn 1965 to 11 per thousand in 1969.