Factors associated with ivermectin non-compliance and its potential role in sustaining Onchocerca volvulus transmission in the West Region of Cameroon

Summary

Community directed treatment with ivermectin is the cornerstone of current efforts to eliminate onchocerciasis. Ivermectin distribution alone has been shown to be able to interrupt transmission, but there are foci where long-term distribution of the drug alone has failed to ensure elimination thresholds are reached. Two health districts in the West Region of Cameroon remain with high prevalence of infection despite annual distribution of ivermectin since 1996.

The study aims to explore factors related to non-compliance in two health districts in the West Region of Cameroon. Nearly 30% of the population did not take ivermectin during the most recent round of mass drug administration and there was a significant proportion of the population that had reportedly never taken the drug. The key factors related to drug compliance in the most recent round, related to either programmatic and delivery issues, primarily absenteeism at the time of the campaign, or alternatively individual determinants, such as side effects associated with the drug, ethnicity, age and years lived in the village. Efforts to reduce the number of systematic non-compliers and non-compliance in certain groups are likely to be important in ensuring the interruption of transmission in the study area.