Abstract
Information on zoonotic Onchocerca species and their black fly vectors is reviewed in relation to zoonotic onchocerciasis in Japan. Ten Onchocerca species are known in five kinds of ungulates in Japan: O. cervicalis in horse (Equus caballus); O. gibsoni, O. gutturosa, O. lienalis and O. sp. in cattle (Bos taurus); O. suzukii and O. skrjabini in Japanese serow (Capricornis crispus); O. eberhardi and O. skrjabini in Japanese deer (Cervus nippon); O. dewittei japonica and O. takaokai in wild boar (Sus scrotus). Onchocerca dewittei japonica was determined as a causative agent of all 10 human cases of zoonotic onchocerciasis that occurred in Japan. Simulium bidentatum was found to be a natural vector of O. dewittei japonica. Five other black fly species, S. arakawae, S. japonicum, S. oitanum, S. quinquestriatum and S. rufibasis, were implicated as potential vectors of O. dewittei japonica. Natural vectors of other Onchocerca species were S. bidentatum for O. takaokai; S. arakawae, S. daisense and S. kyushuense for O. lienalis; S. arakawae, S. bidentatum, S. daisense and S. oitanum for O. sp., and potential vectors were S. arakawae and S. oitanum for O. takaokai; S. arakawae, bidentatum and S. oinatum for both O. eberhardi and O. skrjabini.
