Brugia malayi in Kresek, West Java, Indonesia: the effect of environmental changes of filarial endemicity.

A survey was conducted in Kresek, West Java, Indonesia and 813 persons from six villages examined for filariasis. Only eight had microfilaremia and one male person had elephantiasis. Comparing results obtained approximately ten years earlier and the present survey, there was a marked decrease in the microfilarial rate in Kresek, especially in Penameng, during the interim. There was no drug treatment, insecticide application or any dramatic population movement. The development of a well-organized irrigation system and the conversion of the swamps into rice-fields resulted in a decrease of breeding sites for Mansonia mosquitoes and subsequently a decrease in filariasis.