292 - Invasive Anopheles stephensi and Aedes aegypti Larval Mosquito Surveillance Using the Environmental DNA

Anopheles stephensi is a major malaria vector species in South Asia, the Middle East and the Arabian Peninsula. This vector species has been expanded to several African countries during the past decade since its first detection in Djibouti in 2012. Anopheles stephensi invasion to Africa has posed a significant health risk to the fast-growing urban Africa as its population thrives very well in urban environment. In parallel, the recent infiltration of Aedes aegypti into California and other western U.S. states has sparked substantial public health concerns. To effectively control the spread of invasive mosquito vectors, sensitive surveillance methods enabling early detection are very valuable. Environment DNA (eDNA) method that detects genetic material in aquatic habitats and has found useful in identifying invasive species across various aquatic organisms, including mosquitoes using qPCR. The goal of this study was to determine the sensitivity of the novel eDNA technique for detecting An. stephensi and Ae. Aegypti in aquatic habitats in laboratory conditions. Additionally, we evaluated the utility of eDNA for mosquito surveillance under field conditions.  Several experiments were conducted to ascertain the sensitivity and persistence of mosquito eDNAs under varying larval densities, water volumes and rearing conditions, including the presence of other Anopheline and Culicidae larvae. Furthermore, the eDNA technique was applied to two field sites in Ethiopia, which had recently experienced an invasion of An. stephensi. We are currently analyzing the data to determine whether the novel eDNA technique is a valuable tool for monitoring the distribution and spread of invasive mosquito vector species.