Towards the invasion of wild and rural forested areas in Gabon (Central Africa) by the Asian tiger mosquito Aedes albopictus: Potential risks from the one health perspective

BACKGROUND: Since its first record in urban areas of Central-Africa in the 2000s, the invasive mosquito, Aedes albopictus, has spread throughout the region, including in remote villages in forested areas, causing outbreaks of Aedes-borne diseases, such as dengue and chikungunya. Such invasion might enhance Ae. albopictus interactions with wild animals in forest ecosystems and favor the spillover of zoonotic arboviruses to humans. The aim of this study was to monitor Ae. albopictus spread in the wildlife reserve of La Lopé National Park (Gabon), and evaluate the magnitude of the rainforest ecosystem colonization. METHODOLOGY: From 2014 to 2018, we used ovitraps, larval surveys, BG-Sentinel traps, and human landing catches along an anthropization gradient from La Lopé village to the natural forest in the Park. CONCLUSIONS: We detected Ae. albopictus in gallery forest up to 15 km away from La Lopé village. However, Ae. albopictus was significantly more abundant at anthropogenic sites than in less anthropized areas. The number of eggs laid by Ae. albopictus decreased progressively with the distance from the forest fringe up to 200m inside the forest. Our results suggested that in forest ecosystems, high Ae. albopictus density is mainly observed at interfaces between anthropized and natural forested environments. Additionally, our data suggested that Ae. albopictus may act as a bridge vector of zoonotic pathogens between wild and anthropogenic compartments.