Horizon 1 1 17 ACLN : Articles dans des revues avec comité de lecture non répertoriées par l'AERES Transactions of the Royal Society of Tropical Medicine and Hygiene 454-458 LOASE ENDEMIE TRAITEMENT MEDICAL VECTEUR DYNAMIQUE DE POPULATION INFECTION PREVALENCE IVERMECTINE CHIMIOTHERAPIE DE MASSE CAMEROUN CENTRE NGAT 1998 fdi:010014873 ENG Transactions of the Royal Society of Tropical Medicine and Hygiene 0035-9203 4 10.1016/S0035-9203(98)91091-4 https://www.documentation.ird.fr/hor/fdi:010014873 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/pleins_textes_7/b_fdi_51-52/010014873.pdf 92 Horizon (IRD) We have studied the impact of large-scale treatment with ivermectin on the transmission of loiasis in a forest village in south Cameroon where loiasis was highly endemic, with a prevalence of 30%. After one year of parasitological and entomological surveillance without treatment, all consenting residents aged > 5 years received ivermectin 200 microg/kg every 3 months. For ethical reasons, treatment was interrupted after 2 years, but parasitological and entomological surveillance continued for 18 months after the end of treatment. The prevalence of loiasis was reduced to < 10% and the mean microfilaraemia decreased by 90% in 2 years. The prevalence and average intensity of infection remained stable during the 18 months after treatment ended. Two vector species were identified, #Chrysops dimidiata$ (representing about 90% of the fly population) and #C. silacea$. The infection rate (all stages) in #Chrysops$ decreased by 75% and the infective rate (percentage of #Chrysops$ harbouring third-stage larvae of #Loa loa$ in the head) decreased by 85% in #C. dimidiata$ and became zero in #C. silacea$. After the end of treatment, the infection and infective rates increased gradually. Large-scale treatment seemed an efficient method for the control of #L. loa$ transmission provided high drug coverage was achieved. Nevertheless, because of the high risk of adverse effects when using the current microfilaricidal drugs, such a strategy remains unacceptable. (Résumé d'auteur) 052MALTRA05