Economic evaluation of Wolbachia deployment in Colombia: A modeling study

Background and Aims Wolbachia are bacteria that inhibit dengue virus replication within the mosquito. A cluster-randomized trial found Wolbachia reduced virologically-confirmed dengue cases by 77% and previous models predicted Wolbachia to be highly cost-effective in Indonesia, Vietnam, and Brazil. in Colombia, Wolbachia was introduced in the Aburrá Valley in 2015 and Cali in 2020. To inform decisions about future extensions, we performed economic evaluations of the potential expansion of Wolbachia deployments to 11 target Colombian cities. Methods We assembled quantities and the distribution by severity of reported dengue cases from Colombia’s national disease surveillance system and the health service provision registry (RIPS). An epidemiological panel of three experts estimated the shares of non-medical cases and adjustments for under-reporting and misclassifications. We determined costs (in 2020 US dollars) of treating dengue illness from the benchmark insurance tariff, RIPS data on treatment services per symptomatic dengue case, and the national government database for establishing insurance premiums. A cluster randomized trial quantified the effectiveness of Wolbachia against symptomatic dengue cases. Results Projecting impact over 10 years for Cali, we estimated a net health-sector savings of USD4.95 per person. We also estimated averting 369 disability-adjusted life years (DALYs) per 100,000 population. From a societal perspective, at 10 years Wolbachia deployment is expected to have highly favorable benefit-cost ratios, with benefits per dollar invested of $5.50 in Cali and USD4.68 over all target cities. Conclusions Over 10 years, Wolbachia is highly beneficial on economic grounds, and almost universally cost saving. That is, Wolbachia’s savings in health care costs alone would more than offset deployment costs nationally and in 9 target cities (those with adjusted annual dengue incidence at least 50/100,000 population). In these 9 target cities, Wolbachia would generate at least USD3.00 in benefits per dollar invested, giving substantial confidence that Wolbachia deployment would be cost-beneficial in Colombia.