Adherence to ivermectin is more associated with perceptions of community directed treatment with ivermectin organization than with onchocerciasis beliefs

Abstract

Background

The fight against onchocerciasis in Africa has boomed thanks to the Community Directed Treatment with Ivermectin (CDTI) program. However, in Cameroon, after more than 15 years of mass treatment, onchocerciasis prevalence is still above the non-transmission threshold. This study aimed to explore a possible association between people’s beliefs/perceptions of onchocerciasis and of CDTI program, and their adherence to ivermectin in three regions of Cameroon.

Methodology/Principal findings

A cross sectional survey was carried out in three health districts with persistent high onchocerciasis prevalence. Participants were randomly selected in 30 clusters per district. Adherence to ivermectin was comparable between Bafang and Bafia (55.0% and 48.8%, respectively, p>0.05) and lower in Yabassi (40.7%). Among all factors related to program perceptions and disease representations that were studied, perceptions of the program are the ones that were most determinant in adherence to ivermectin. People who had a “not positive” opinion of ivermectin distribution campaigns were less compliant than those who had a positive opinion about the campaigns (40% vs 55% in Bafang, and 48% vs 62% in Bafia, p<0.01), as well as those who had a negative appreciation of community drug distributors’ commitment (22% vs 53% in Bafang, 33% vs 59% in Bafia, 27% vs 47% in Yabassi; p<0.01). The most common misconception about onchocerciasis transmission was the lack of hygiene, especially in Bafia and Yabassi. In Bafang, high proportions of people believed that onchocerciasis was due to high consumption of sugar (31% vs less than 5% in Bafia and Yabassi, p<0.001).

Conclusion/Significance

There are still frequent misconceptions about onchocerciasis transmission in Cameroon. Perceptions of ivermectin distribution campaigns are more strongly associated to adherence. In addition to education/sensitisation on onchocerciasis during the implementation of the CDTI program, local health authorities should strive to better involve communities and more encourage community distributors’ work.

Author summary

Onchocerciasis control in Africa has boomed with the ‘Community Directed Treatment with Ivermectin’ program. Successes of this program over many African countries prompted the international community to set it as main strategy for elimination of onchocerciasis and lymphatic filariasis. In Cameroon, onchocerciasis prevalence in some areas is still higher than what was predicted, despite more than 15 years of mass treatment. Therefore, in the frame of enlargement of the treatment zones, there is a need for enriching local literature on changeable factors that influence adherence to ivermectin. In this study, we assessed possible association between systematic ivermectin intake and people’s beliefs/perceptions of the disease and the program in three neighbouring regions of the country. Beliefs on onchocerciasis and their associations with adherence may differ from one community to another within the same area of the country. Furthermore, among all the factors related to disease and program representations that were studied, perceptions of ivermectin campaign’s organization and of community drug distributor’s commitment are the ones that were most determinant in adherence to ivermectin. Efforts should be done by health authorities in the program implementation inside the communities, with better population ownership and ensuring of good community drug distributors’ work.