Field Effectiveness of Drones to Identify Potential Aedes aegypti Breeding Sites in Household Environments from Tapachula, a Dengue-Endemic City in Southern Mexico

Abstract

Simple Summary Mexico’s mosquito control program requires better tools for effective mosquito surveillance in dengue-endemic areas. Additionally, technology must be more available in order to gain a better understanding of the factors that condition the presence of mosquitoes in residential settings. This study is the first to report on the use of drones for mosquito breeding surveillance in Mexico and aims to evaluate the effectiveness of low-cost drone images in order to identify Aedes aegypti mosquito breeding sites on the roofs of buildings and backyards. The results were compared to the current government Aedes vector surveillance program, which is based on on-ground activities in Tapachula city, Chiapas, southern Mexico. Through drone surveillance, we identified a total of 983 containers that were distributed in 10 types; approximately one-third (2752) of the containers were inspected by ground surveillance systems that were distributed in 26 container types. The concordance between drone and ground surveillance was 64.9% in detecting at least one container using both methods. Drones can identify the most common roof containers and should be used in dengue-endemic areas that have many possible breeding sites and are in accessible housing areas. Drones can be useful in complementing mosquito surveillance and control programs. Abstract Aedes aegypti control programs require more sensitive tools in order to survey domestic and peridomestic larval habitats for dengue and other arbovirus prevention areas. As a consequence of the COVID-19 pandemic, field technicians have faced a new occupational hazard during their work activities in dengue surveillance and control. Safer strategies to monitor larval populations, in addition to minimum householder contact, are undoubtedly urgently needed. Drones can be part of the solution in urban and rural areas that are dengue-endemic. Throughout this study, the proportion of larvae breeding sites found in the roofs and backyards of houses were assessed using drone images. Concurrently, the traditional ground field technician’s surveillance was utilized to sample the same house groups. The results were analyzed in order to compare the effectiveness of both field surveillance approaches. Aerial images of 216 houses from El Vergel village in Tapachula, Chiapas, Mexico, at a height of 30 m, were obtained using a drone. Each household was sampled indoors and outdoors by vector control personnel targeting all the containers that potentially served as Aedes aegypti breeding sites. The main results were that the drone could find 1 container per 2.8 found by ground surveillance; however, containers that were inaccessible by technicians in roofs and backyards, such as plastic buckets and tubs, disposable plastic containers and flowerpots were more often detected by drones than traditional ground surveillance. This new technological approach would undoubtedly improve the surveillance of Aedes aegypti in household environments, and better vector control activities would therefore be achieved in dengue-endemic countries.