Reducing mosquito-borne disease transmission to humans: A systematic review of cluster randomised controlled studies that assess interventions other than non-targeted insecticide

Assessment of community support for Wolbachia-mediated population suppression as a control method for Aedes aegypti mosquitoes in a community cohort in Puerto Rico

Arboviral diseases transmitted by Aedes species mosquitoes pose an increasing public health challenge in tropical regions. Wolbachia-mediated population suppression (Wolbachia suppression) is a vector control method used to reduce Aedes mosquito populations by introducing male mosquitoes infected with Wolbachia, a naturally occurring endosymbiotic bacterium. When Wolbachia-infected male mosquitoes mate with female wild mosquitoes, the resulting eggs will not hatch. Public support is vital to the successful implementation and sustainability of vector control interventions. Communities Organized to Prevent Arboviruses (COPA) is a cohort study to determine the incidence of arboviral disease in Ponce, Puerto Rico and evaluate vector control methods. Focus groups were conducted with residents of COPA communities to gather their opinion on vector control methods; during 2018–2019, adult COPA participants were interviewed regarding their views on Wolbachia suppression; and a follow-up questionnaire was conducted among a subset of participants and non-participants residing in COPA communities. We analyzed factors associated with support for this method. Among 1,528 participants in the baseline survey, median age was 37 years and 63% were female. A total of 1,032 (68%) respondents supported Wolbachia suppression. Respondents with an income of $40,000 or more were 1.34 times as likely [95% CI: 1.03, 1.37] to support Wolbachia suppression than those who earned less than $40,000 annually. Respondents who reported repellant use were 1.19 times as likely to support Wolbachia suppression [95% CI: 1.03, 1.37]. A follow-up survey in 2020 showed that most COPA participants (86%) and non-participants living in COPA communities (84%) supported Wolbachia suppression during and after an educational campaign. The most frequent questions regarding this method were related to its impact on human and animal health, and the environment. Continuous community engagement and education efforts before and during the implementation of novel vector control interventions are necessary to increase and maintain community support.

Vector control is key to decrease the incidence of viral infections transmitted by Aedes mosquitoes, like dengue, but traditional control methods like insecticides and breeding sites reduction can be time-consuming, ineffective, and challenged by insecticide resistance. In the method known as Wolbachia suppression, male mosquitoes infected with the bacterium Wolbachia are released to mate with wild female mosquitoes. As the resulting eggs do not hatch, the mosquito population decreases over time. As public support is key to implement and maintain any vector control method, we assessed community support for Wolbachia suppression through focus groups and interviews with residents of Ponce, Puerto Rico, where a community cohort has been implemented. Support for this method in this population was high and increased after an educational campaign. Respondents with higher income and those who used repellent in the last 30 days were more likely to support Wolbachia suppression. Questions regarding the impact of this method on human and animal health, and the environment, were the most reported. Community engagement activities to increase the understanding of the method, including clear and specific information on health risk assessments, should be conducted before and during the implementation of Wolbachia suppression.