Assessment of a Low-Cost Mosquito-Borne Disease Early Warning System Integrating Molecular Mosquito and Arbovirus Surveillance.

Introduction: Arboviruses can be transmitted by Anophelinae (Anopheles genus) or Culicinae (Aedes and Culex genera) mosquitoes. Ecological and sociodemographic factors such as urbanisation, poverty, access to health systems and social inequality determine vector density and risk of disease transmission. Effective surveillance of vectors and arboviruses is crucial for guiding public health strategies.

Methods: We developed a low-cost molecular approach integrating mosquito and arbovirus surveillance and assessed its performance during 2021 in San Luis Potosí, Mexico. Our approach incorporates an innovative mosquito trap (Yoy trap), an ITS2-based mosquito molecular taxonomy assay and the use of FTA card preservation of arboviral RNA.

Results: A total of 16,319 mosquitoes were collected, Culex spp. genus being the most abundant (63.3%) followed by Aedes spp. (26.6%) and Anopheles spp. (4.7%). Our approach allowed us to characterise mosquito population dynamics including the centripetal expansion of mosquito range from city outskirts to urban areas. Viral RNA screening of 124 FTA cards identified the presence of four arboviruses in mosquitoes of the city of San Luis Potosi: DENV (6.5%), ZIKV (5.6%), CHIKV (1.6%) and WNV (3.2%).

Conclusions: This surveillance system detected DENV in mosquitoes 7 weeks prior to the first reported human case, further supporting the public health benefits deriving from the adoption of similar innovative, low-cost and robust surveillance systems.