Longevity of Wuchereria bancrofti var. pacifica and mosquito infection acquired from a patient with low level parasitemia.

Abstract Two cases are reported which illustrate important epidemiological aspects of lymphatic filariasis—prolonged longevity of the adult parasite and the possibility of transmission by individuals with ultra-low level microfilaremia. These cases demonstrate that people can remain carriers of microfilariae in the peripheral blood for many years without reinfection, and even those with a low level microfilaremia can constitute a significant reservoir of mosquito infection. Such cases represent one of the most serious obstacles to the eradication of lymphatic filariasis in regions where control is based on chemotherapy.