FILARIAL VECTOR STUDIES IN A DIETHYLCARBAMAZINE-TREATED AND IN UNTREATED VILLAGES IN PAPUA-NEW-GUINEA

Entomological studies were undertaken in three villages in the East Se pik Province of Papua New Guinea. The inhabitants of one village, Nana ha, had been treated with diethylcarbamazine (DEC) to reduce the preva lence and density of microfilaraemia of Wuchereria bancrofti. No inter vention was undertaken in the other two villages, Yauatong and Musenau , in which bancroftian filariasis was present but with markedly differ ent human prevalence rates and mean parasite densities. In Yauatong, i nfection rates in anopheline vectors (Anopheles punctulatus and An. ko liensis) varied from 20.5 to 46.6% with infectivity rates of 0-1.4% wh ile these rates were 10.9-14.3% and 0-1.1% respectively in Culex quinq uefasciatus. In Nanaha after DEC treatment, infection rates were as hi gh as 16.3% in An. koliensis and infectivity rates reached 7.0% for An . punctulatus despite a 45% reduction in the number of people with det ectable micro filariae (mf) and a 94% reduction in mf density in those who remained positive.