ZOONOTIC ASPECTS OF FILARIAL INFECTIONS IN MAN

Abstract

An account of the filarial parasites [Wuchereria bancrofti, Brugia malayi, B. timori, B. pahangi, Onchocerca volvulus, Loa loa, Mansonella ozzardi, Tetrapetalonema perstans, T. streptocerca, Dirofilaria immitis, D. tenuis and D. repens] found in man and the potential transmissibility to and from other vertebrate animals under natural and experimental conditions was given. Those species that are regarded as being primarily parasites of other vertebrates, but which also infect man, are dealt with in detail. These include the subperiodic strain of B. malayi and perhaps also B. pahangi, both of which are found in wild and domestic carnivores and monkeys, and Dirofilaria spp. of dogs and racoons. The Brugia parasites develop to maturity with the production of microfilaremia and clinical manifestations in man similar to those caused by periodic B. malayi in man. Human dirofilariasis represents a transmission cul-de-sac for the parasite. Clinical manifestations are mild or absent and generally the worms do not mature and, even if they do, they rarely give rise to microfilaremia. D. immitis causes pulmonary dirofilariasis, and D. repens and D. tenuis give rise to subcutaneous nodules in man. The diagnosis of dirofilariasis depends on an awareness of the infection in the animal reservoirs and of the possibility of man being exposed to bites of infected vectors.