Transmission of Onchocerca volvulus by secondary vectors in Guatemala
Porter, C.H.; Collins, R.C.
American Journal of Tropical Medicine and Hygiene 39(6): 559-566
1988
ISSN/ISBN: 0002-9637 PMID: 3207176 Document Number: 306301
A comprehensive study of the transmission of Onchocerca volvulus at 4 locations in Guatemala with different prevalence rates of onchocerciasis included observations on potential secondary vectors, the most prevalent of which were Simulium metallicum, S. callidum, and S. gonzalezi. Filariae encountered in S. metallicum were primarily of a Dipetalonema-like species, but third-stage larvae indistinguishable from O. volvulus were found in 4 flies of this species. [The authors'] findings suggest that O. volvulus may occasionally be transmitted by S. metallicum, but such transmission is likely limited to areas having both a high parasite prevalence maintained by S. ochraceum and a relatively high host-seeking density of S. metallicum. Two third-stage larvae that could not be differentiated from O. volvulus were found once in S. gonzalezi; however, transmission by this species appears to be inconsequential.AS/B.R. Laurence A comprehensive study of the transmission of O. volvulus at 4 locations in Guatemala with different prevalence rates of onchocerciasis included observations on potential secondary vectors, the most prevalent of which were Simulium metallicum, S. callidum and S. gonzalezi. Filariae encountered in S. metallicum were primarily of a Dipetalonema-like species, but 3rd-stage larvae indistinguishable from O. volvulus were found in 4 flies of this species. The findings suggest that O. volvulus may occassionally be transmitted by S. metallicum, but such transmission is likely limited to areas having both a high parasite prevalence maintained by S. ochraceum and a relatively high host-seeking density of S. metallicum. Two 3rd-stage larvae that could not be differentiated from O. volvulus were found once in S. gonzalezi; however, transmission by this species appears to be inconsequential.