72: Filariasis

Classification: ICD-9 125.0, 125.1, 125.6; ICD-10 B74.0, B74.1, B74.2

Syndromes and synonyms: Bancroftian filariasis, Brugian filariasis, lymphatic filariasis, Malayan filariasis, Timorean filariasis.

Agent: Wuchereria bancrofti, Brugia malayi, and B. timori, threadlike nematode worms 80 to 100 mm long (W. bancrofti), or 43 to 55 mm long (B. malayi).

Reservoir: Mainly humans. In Southeast Asia, monkeys, wild carnivores, dogs, and cats may also be infected with B. malayi. W. bancrofti has no known reservoir host.

Vector: For W. bancrofti: Culex quinquefasciatus, Anopheles spp., and Aedes spp. in the Pacific Islands; for B. malayi: Mansonia, Anopheles, and Aedes; for B. timori, An. barbirostris. Anopheles spp. transmit parasites less efficiently than Culex spp., and Culex spp. are more abundant in urban settings.