Pion Sébastien, Filipe J.A.N., Kamgno J., Gardon Jacques, Basanez M.G., Boussinesq Michel. (2006). Microfilarial distribution of Loa loa in the human host : population dynamics and epidemiological implications. Parasitology, 133 (1), p. 101-109. ISSN 0031-1820.
Titre du document
Microfilarial distribution of Loa loa in the human host : population dynamics and epidemiological implications
Pion Sébastien, Filipe J.A.N., Kamgno J., Gardon Jacques, Basanez M.G., Boussinesq Michel
Source
Parasitology, 2006,
133 (1), p. 101-109 ISSN 0031-1820
Severe adverse events (SAEs) following ivermectin treatment may occur in people harbouring high Loa loa microfilarial (mf) densities. In the context of mass ivermectin distribution for onchocerciasis control in Africa, it is crucial to define precisely the geographical distribution of L. too in relation to that of Onchocerca volvulus and predict the prevalence of heavy infections. To this end, we analysed the distribution of mf loads in 4183 individuals living in 36 villages of central Cameroon. Mf loads were assessed quantitatively by calibrated blood smears, collected prior to ivermectin distribution. We explored the pattern of L. loa mf aggregation by fitting the (zero-truricated) negative binomial distribution and estimating its overdispersion parameter k by maximum likelihood. The value Of k varied around 0.3 independently of mf intensity, host age, village and endemicity level. Based on these result, we developed a semi-empirical model to predict the prevalence of heavy L. loa mf loads in a community given its overall mf prevalence. If validated at the continental scale and linked to predictive spatial models of loiasis distribution, this approach would be particularly useful for optimizing the identification of areas at risk of SAEs and providing estimates Of Populations at risk in localities where L. loa and O. volvulus are co-endemic.
