Economic evaluations of onchocerciasis interventions: a systematic review and research needs.

OBJECTIVE: To provide a systematic review of economic evaluations that has been conducted for onchocerciasis interventions, to summarise current key knowledge and to identify research gaps. METHOD: A systematic review of the literature was conducted on the 8th of August 2018 using the PubMed (MEDLINE) and ISI Web of Science electronic databases. No date or language stipulations were applied to the searches. RESULTS: We identified 14 primary studies reporting the results of economic evaluations of onchocerciasis interventions, seven of which were cost-effectiveness analyses. The studies identified used a variety of different approaches to estimate the costs of the investigated interventions/programmes. Originally, the studies only quantified the benefits associated with preventing blindness. Gradually, methods improved and also captured onchocerciasis-associated skin disease. Studies found that eliminating onchocerciasis would generate billions in economic benefits. The majority of the cost-effectiveness analyses evaluated annual mass drug administration (MDA). The estimated cost per disability-adjusted life year (DALY) averted of annual MDA varies between US$3 and US$30 (cost year variable). CONCLUSIONS: The cost benefit and cost effectiveness of onchocerciasis interventions have consistently been found to be very favourable. This finding provides strong evidential support for the ongoing efforts to eliminate onchocerciasis from endemic areas. Although these results are very promising, there are several important research gaps that need to be addressed as we move towards the 2020 milestones and beyond.