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

Since its first record in urban areas of Central Africa in the 2000s, the anthropophilic and invasive mosquito, Aedes albopictus, has continued to spread across remote rural areas and has promoted outbreaks of Aedes-borne diseases, such as dengue, chikungunya and Zika. Such invasion might enhance Ae. albopictus interactions with wild animals in forests neighboring villages and favor the spillover of zoonotic arboviruses to humans. In this study, we reported the sustained spread of the Ae. albopictus in the wildlife reserve of La Lopé National Park (LNP, Gabon), and we evaluated the magnitude of its colonization of this rainforest ecosystem. Using various sampling methods between 2014 and 2018, we detected Ae. albopictus presence in wild forest galleries up to 15km away from La Lopé, the main inhabited village within the park limits. We demonstrated that Ae. albopictus can invade forest ecosystems where the human presence is low or absent, suggesting that Ae. albopictus may interact with wild animals and act as bridge vector of zoonotic pathogens between the wild and anthropogenic compartments. However, our results showed that Ae. albopictus population density is higher at interfaces between the village and the forest. This suggests that this species might be present at the interface between anthropized and wild environments where the probability of contact with wild animals is increased, and consequently the likelihood of contributing to sylvatic and bridge transmission of pathogens. Our results also suggested that the presence or humans facilitates the colonization of natural forested habitat by this invasive species.