Efficiency of Simulium sanctipauli as a vector of Onchocerca volvulus in the forest zone of Ghana.
The role of Simulium sanctipauli Vajime & Dunbar (Diptera: Simuliidae) as a vector of Onchocerca volvulus (Leuckart) (Spirurida: Onchocercidae) in the forest zone of central Ghana was studied in the Upper Denkyira district, where onchocerciasis is hyperendemic. Simulium sanctipauli was found to be a highly efficient vector, with a mean of 377 infective (L3) larvae in the heads of 1000 parous and 122 in the heads of 1000 biting flies. The overall infection rate of 44% of the parous flies with L1, L2 and L3 stages of O. volvulus (identity confirmed by polymerase chain reaction) demonstrates marked anthropophily. Female flies dispersed over a wide area and can transmit onchocerciasis up to at least 10 km away from their breeding sites. Annual community-directed treatments with ivermectin did not have a noticeable effect on the infection rates and parasitic loads of fly populations, which were as high 2 months after as 3 months before the distribution of ivermectin. This failure can be attributed to poor coverage, with treatment taken by only 24.4% of the population of the six study villages.
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Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
Kruppa
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TF
Brenya
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Garms
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D000818:Animals; D000871:Anthelmintics / Q000494:pharmacology; D018509:DNA, Helminth / Q000737:chemistry / Q000235:genetics; D005260:Female; D005869:Ghana; D006801:Humans; D007303:Insect Vectors / Q000469:parasitology*; D007559:Ivermectin / Q000494:pharmacology; D009693:Nucleic Acid Hybridization; D017181:Onchocerca volvulus / Q000235:genetics / Q000254:growth & development*; D009855:Onchocerciasis / Q000517:prevention & control / Q000635:transmission*; D016133:Polymerase Chain Reaction; D012424:Rural Population; D012843:Simuliidae / Q000469:parasitology*; D018709:Statistics, Nonparametric
D000871:Anthelmintics; D018509:DNA, Helminth; D007559:Ivermectin