Biomaterial Database

Transmission of Onchocerca volvulus by secondary vectors in Guatemala. 1988

C H Porter, and R C Collins

Medical Entomology Research and Training Unit, Center for Infectious Diseases, U.S. Department of Health and Human Services, Atlanta, Georgia 30333.

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. Our 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.

UI	MeSH Term	Description	Entries
D007303	Insect Vectors	Insects that transmit infective organisms from one host to another or from an inanimate reservoir to an animate host.	Insect Vector,Vector, Insect,Vectors, Insect
D007814	Larva	Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.	Maggots,Tadpoles,Larvae,Maggot,Tadpole
D009854	Onchocerca	A genus of parasitic nematodes whose organisms live and breed in skin and subcutaneous tissues. Onchocercal microfilariae may also be found in the urine, blood, or sputum.	Onchocercas
D009855	Onchocerciasis	Infection with nematodes of the genus ONCHOCERCA. Characteristics include the presence of firm subcutaneous nodules filled with adult worms, PRURITUS, and ocular lesions.	Onchocerciases
D004153	Dipetalonema	A filarial nematode parasite of mammalian blood with the vector being a tick or small fly.	Dipetalonemas
D005260	Female		Females
D006166	Guatemala	A country in CENTRAL AMERICA bordering the North Pacific Ocean, between EL SALVADOR and MEXICO, and bordering the Gulf of Honduras (Caribbean Sea) between HONDURAS and BELIZE.
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012843	Simuliidae	A family of insects in the order DIPTERA, which include black flies, buffalo gnats and simulies. Several species are intermediate hosts (vectors) for the parasitic disease ONCHOCERCIASIS.	Black Flies,Simulium,Blackflies,Black Fly,Blackfly,Flies, Black,Fly, Black,Simuliums