Individuals living in an onchocerciasis focus and treated three-monthly with ivermectin develop fewer new onchocercal nodules than individuals treated annually

Parasites & Vectors

Joseph Kamgno¹  Jacques Gardon²  Sébastien D. S. Pion³  Jérémy T. Campillo³  Cédric B. Chesnais³  Michel Boussinesq³ 

[1] Centre for Research on Filariasis and other Tropical Diseases (CRFilMT);Hydrosciences Montpellier, Institut de Recherche pour le Développement (IRD);UMI 233, Institut de Recherche pour le Développement (IRD) and University of Montpellier 1;

关键词: Onchocerciasis;    Onchocerca volvulus;    Nodules;    Onchocercoma;    Ivermectin;    Cameroon;   

DOI  :  10.1186/s13071-020-04126-x

来源: DOAJ

【 摘 要 】

Abstract Background Little information is available on the effect of ivermectin on the third- and fourth-stage larvae of Onchocerca volvulus. To assess a possible prophylactic effect of ivermectin on this parasite, we compared the effects of different ivermectin regimens on the acquisition of onchocercal nodules. Methods We analyzed data from a controlled randomized clinical trial of ivermectin conducted in the Mbam Valley (Cameroon) between 1994 and 1998 in a cohort of onchocerciasis infected individuals. The number of nodules that appeared between the start and the end of the clinical trial was analyzed, using ANOVA and multivariable Poisson regressions, between four treatment arms: 150 µg/kg annually, 800 µg/kg annually, 150 µg/kg 3-monthly, and 800 µg/kg 3-monthly. Results The mean number of nodules that appeared during the trial was reduced by 17.7% in subjects treated 3-monthly compared to those treated annually (regardless of the dose). Poisson regression model, adjusting on subject’s age and weight, initial number of nodules and intensity of O. volvulus infection in his village of residence, confirmed that the incidence of new nodules was reduced in 3-monthly treatment arms compared to annually treatment arms, and that the dosage of ivermectin does not seem to influence this effect. Furthermore, the number of newly acquired nodules was positively associated with the initial number of nodules. Analysis of disappearance of nodules did not show any significant difference between the treatment groups. Conclusions To our knowledge, these results suggest for the first time in humans, that ivermectin has a partial prophylactic effect on O. volvulus. Three-monthly treatment seems more effective than annual treatment to prevent the appearance of nodules.

【 授权许可】

Unknown