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. ### Competing Interest Statement All authors received funding from the Wellcome Trust under a grant (224459/Z/21/Z) to the World Mosquito Program (WMP), Monash University (Clayton, VIC, Australia), which had no role in review nor the decision to submit. The direct sponsor (WMP) had the right to review but authorized submission with no required changes. Donald S. Shepard has received financial support from Abbott, Inc, Sanofi, and Takeda Vaccines, Inc. in the past 36 months unrelated to the present study. All other authors declare no other conflicts of interest. ### Funding Statement Yes ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: This modeling study did not involve any human studies data as it was based entirely on aggregate or publicly available anonymous data. These data could not allow any individual to be identified nor linked with any individual. The research team did not prospectively nor retrospectively recruit human participants nor did the team obtain tissues, data, or samples for the purposes of this study. The research team did not review existing medical records nor archived samples. Therefore, this study was outside the purview of the Committee for Protection of Human Studies in Research so ethical approval was not applicable. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Data access may be requested from the respective Colombian government agencies. For RIPS, see https://www.minsalud.gov.co/proteccionsocial/Paginas/rips.aspx. For population, see https://www.dane.gov.co/index.php/estadisticas-por-tema/demografia-y-poblacion/proyecciones-de-poblacion.