Vector-parasite transmission complexes for onchocerciasis in West Africa.
Background In West Africa, there are two strains of the filarial parasite Onchocerca volvulus, which differ in their ability to induce ocular disease.
Transmission studies have suggested that six sibling species of the parasite vector, the black fly Simulium damnosum sensu lato, allow development of the two strains of O volvulus with varying efficiency.
We aimed to test the hypothesis of parasite-vector complexes, whereby the two parasite strains, known as forest and savanna, are preferentially transmitted by distinct groups of the species of S damnosum s l. Methods During 1993 and 1994, wild black flies were collected from 11 river basins within the area covered by the Onchocerciasis Control Programme (OCP).
The flies were dissected and filarial larvae, ovaries, and malpighian tubules removed.
Genomic DNA was extracted from larvae, and PCR amplification was used to classify O volvulus parasites as forest or savanna strains.
PCR-amplified DNA from ovaries and malpighian tubules was used to distinguish sibling species of S damnosum s I. S yahense and S squamosum were distinguished by body colour.
Findings 214 of 105 105 flies dissected were infected with filarial larvae ; 84 of these were infected with mature O volvulus parasites.
Of the 35 savanna-dwelling infected flies, 17 carried forest-strain parasites and 18 savanna-strain parasites. (...)
Mots-clés Pascal : Onchocercose, Filariose, Nématodose, Helminthiase, Parasitose, Infection, Facteur transmission, Vecteur, Parasite, Mécanisme action, Etude expérimentale, Arbre forestier, Souche, Rivière, Onchocerca volvulus, Nematoda, Nemathelminthia, Helmintha, Invertebrata, Facteur risque, Afrique Ouest, Afrique, Peau pathologie, Oeil pathologie
Mots-clés Pascal anglais : Onchocerciasis, Filariosis, Nematode disease, Helminthiasis, Parasitosis, Infection, Transmittance, Vector, Parasite, Mechanism of action, Experimental study, Forest tree, Strain, Rivers, Onchocerca volvulus, Nematoda, Nemathelminthia, Helmintha, Invertebrata, Risk factor, West Africa, Africa, Skin disease, Eye disease
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 97-0137520
Code Inist : 002B05E03B4C. Création : 21/05/1997.