Pion Sébastien, Clarke P., Filipe J.A.N., Kamgno J., Gardon Jacques, Basanez M.G., Boussinesq Michel. (2006). Co-infection with Onchocerca volvulus and Loa loa microfilariae in central Cameroon : are these two species interacting. Parasitology, 132 (6), p. 843-854. ISSN 0031-1820.
Titre du document
Co-infection with Onchocerca volvulus and Loa loa microfilariae in central Cameroon : are these two species interacting
Pion Sébastien, Clarke P., Filipe J.A.N., Kamgno J., Gardon Jacques, Basanez M.G., Boussinesq Michel
Source
Parasitology, 2006,
132 (6), p. 843-854 ISSN 0031-1820
Ivermectin treatment may induce severe adverse reactions in some individuals heavily infected with Loa loa. This hampers the implementation of mass ivermectin treatment against onchocerciasis in areas where Onchocerca volvulus and L. loa are co-endemic. In order to identify factors, including co-infections, which may explain the presence of high L. loa micro-filaraemia in some individuals, we analysed data collected in 19 villages of central Cameroon. Two standardized skin snips and 30 mu l of blood were obtained from each of 3190 participants and the microfilarial (mf) loads of both O. volvulus and L. loa were quantified. The data were analysed using multivariate hierarchical models. Individual-level variables were: age, sex, mf presence, and mf load; village-related variables included the endemicity levels for each infection. The two species show a certain degree of ecological separation in the study area. However, for a given individual host, the presence of microfilariae of one species was positively associated with the presence of microfilariae of the other (OR = 1-79, 95 % CI [1-43-2-24]). Among individuals harbouring Loa microfilariae, there was a slight positive relationship between the L. loa and O. volvulus mf loads which corresponded to an 11% increase in L. loa mf load per 100 O. volvulus microfilariae. Co-infection with O. volvulus is not sufficient to explain the very high L. loa mf loads harboured by some individuals.
