Assessment of vector microfilarial uptake as a comparatively non-invasive technique for monitoring onchocerciasis treatment campaigns in the Americas.
Since 1992, efforts have been made to combat onchocerciasis in Guatemala through mass distribution of ivermectin.
The impact of the campaign is assessed by taking skin-snips from sentinel groups within selected communities.
This method gives an estimate of the prevalence and intensity of infection, and thus the efficacy of the treatment.
In some communities people are becoming reluctant to volunteer for skin-snipping, and so there is a need for an alternative technique that will give quantitative results.
In most hyperendemic communities in Guatemala, biting blackflies are so ubiquitous that few people object to allowing 10 to 20 flies to engorge upon them.
We examined data on the quantitative uptake of microfilariae by Simulium ochraceum before and after ivermectin distribution to see whether results similar to skin-snip data could be obtained.
Counts of microfilariae ingested by S. ochraceum are compared to the numbers found in skin-snips from the same volunteers.
In a group of 31 untreated infected persons, a skin-snip survey detected 64.5% positive, while feeding flies (vector microfilarial uptake, VmfU) detected 96.8%. Post-treatment, in a sample of 58 of whom 52 (89.7%) had a history of infection, both skin-snips and VmfU detected 54.2%. Vector blood meals contained more microfilariae than a mg of skin before treatment, but both recorded about equal numbers after treatment. (...)
Mots-clés Pascal : Onchocercose, Filariose, Nématodose, Helminthiase, Parasitose, Infection, Traitement, Population, Evaluation, Surveillance, Vecteur, Taux parasitisme, Peau pathologie, Oeil pathologie, Simulium ochraceum
Mots-clés Pascal anglais : Onchocerciasis, Filariosis, Nematode disease, Helminthiasis, Parasitosis, Infection, Treatment, Population, Evaluation, Surveillance, Vector, Parasitism rate, Skin disease, Eye disease
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 97-0307070
Code Inist : 002B05E03B4C. Création : 15/07/1997.