Evaluation of FTA cards for pathogen and Aedes vector detection through environmental nucleic acid 'shedding'

Aedes-borne arboviral diseases are a growing global health concern, driven by climate change and land use alterations that create new mosquito breeding sites and expand their geographic range. Interactions between mosquito species and various hosts, including migratory birds and mammals, increase the risk of outbreaks in previously unaffected regions. The invasive mosquito Anopheles stephensi, a major malaria vector in Asia, now threatens Africa. With international trade and travel rising, concerns grow about its potential spread to South Africa. South Africa, a regional hub, faces public health risks from arboviruses and malaria due to cross-border disease transmission and global travel. Limited knowledge in the ecology and epidemiology of Aedes-borne arboviruses and Anopheles malaria vectors in South Africa hampers effective interventions. To address this gap, this project, using a One Health approach, incorporates environmental mosquito surveillance to identify high-risk areas. Traditional mosquito surveillance methods are logistically challenging and often miss certain species. This project aims to develop a cost-effective passive surveillance method using environmental nucleic acids and Flinders Technology Associates (FTA) cards, which preserve nucleic acids at ambient temperatures. FTA cards have shown promise in preserving mosquito saliva for virus detection and identifying triatomine species from eDNA shedding. However, their use for preserving nucleic acids shed by mosquitoes for vector identification remains unexplored. This project will assess FTA cards' effectiveness in detecting invasive Aedes and Anopheles species, along with the pathogens they transmit in South Africa. The study includes a systematic review of Aedes aegypti, Aedes albopictus, and Anopheles stephensi distribution, geostatistical modelling of environmental risk factors, and the development of DNA metabarcoding methods to differentiate mosquito species in laboratory and field conditions.