Abstract
Dengue is among the world’s fastest growing vector-borne diseases, costing US$18 billion globally in 2016. Releasing mosquitoes infected with Wolbachia is a promising strategy to control dengue, chikungunya and Zika. As Wolbachia are passed on to the next generation of mosquitoes, the process is self-sustaining and generally entails minimal ongoing costs. A 24-cluster randomized trial and observational studies with Wolbachia are underway in Yogyakarta, Indonesia. Here we assess the cost-effectiveness over a 10-year present-value horizon of extensions to two potential sites: (1) the current control clusters of Yogyakarta (population 225,313); (2) densely populated parts of Indonesia’s top 7 cities in number of predicted dengue cases (Jakarta, Surabaya, Bandung, Medan, Semarang, Palembang, and Makassar, population 37 million). We based costs (in 2018 US$) on budgets from Yogyakarta and disease impact on a dengue
transmission model calibrated to entomologic data. We projected that the first site would cost US$4.4 million (with a 95% uncertainty interval of $2.9-$6.7 million) and avert 534 (138-1,213) DALYs per year, a 97.4% reduction. The incremental cost-effectiveness ratio (ICER) was $1,123 per DALY averted on a gross basis (counting only program costs), but -$82 on a net basis (i.e., showing a net savings due to medical costs averted). The second site would cost $480 ($306-$746) million, or $13.1 ($8.4-$20.3) per person protected, and avert 48,454 (12,582-110,074) DALYs annually. Its gross and net ICERs were $1,335 and -$4 per DALY, respectively. These results suggest Wolbachia’s ICER is lower (i.e., even more cost-effective) than other widely-accepted public health interventions in Indonesia. For example, Didik Setiawan et al. estimated the ICER for visual inspection with acetic acid and human papillomavirus vaccination for girls at $1,863 per DALY averted. Because Wolbachia costs depend primarily on the area covered, this strategy is most cost-effective for large urban areas. If epidemiologic results confirm entomologic data, the extension of Wolbachia to major cities appears highly cost-effective, and perhaps cost saving.