The Asian tiger mosquito Aedes albopictus (Diptera: Culicidae) in Northern and Central Tunisia: Seasonal activity, spatial distribution modelling and dengue virus surveillance.

Despite the growing public health relevance of Aedes (Stegomyia) albopictus (Skuse), there is a significant gap in our knowledge of its ecology and the prevalence of dengue virus in Tunisia. To address this information gap, between October 2022 and July 2024, we conducted larval and adult mosquito surveillance in nine Tunisian governorates, from each belonging to different bioclimatic areas. The phenology of Ae. albopictus is bimodal with a small population peak in June and a second larger one in September-October. A total of 99 field-collected Ae. albopictus females were pooled and examined for the presence of the four closely related viral strains of dengue virus by PCR multiplex. No dengue virus RNA was detected in the 25 pools of Ae. albopictus examined. Species Distribution Models were used to predict the current potential suitable habitats across Tunisia. The model predicts that the most suitable habitats for Ae. albopictus are located in the northern and northeastern regions of Tunisia, as well as in small patches in the eastern areas, with a continuous distribution extending along the northwestern coastal zones. According to the model, the factors contributing to the distribution of Ae. albopictus in Tunisia include seasonal temperature, elevation, mean temperature of wettest quarter, precipitation of warmest quarter and minimum temperature of coldest month. Our findings provide evidence that Tunisia is at risk for Aedes-borne disease such as dengue fever. Therefore, the establishment of an integrated vector management plan is highly needed to strengthen Aedes surveillance and control programmes in Tunisia.