Systematic Review on Diversity and Distribution of Anopheles Species in Gabon: A Fresh Look at the Potential Malaria Vectors and Perspectives

Abstract

Gabon is located in the malaria hyper-endemic zone, where data concerning malaria vector distribution remains fragmentary, making it difficult to implement an effective vector control strategy. Thus, it becomes crucial and urgent to undertake entomological surveys that will allow a better mapping of the Anopheles species present in Gabon. In this review, we examined different articles dealing with Anopheles in Gabon from ProQuest, Web of Science, PubMed, and Google scholar databases. After applying the eligibility criteria to 7543 articles collected from four databases, 42 studies were included that covered a 91-year period of study. The review revealed a wide diversity of Anopheles species in Gabon with a heterogeneous distribution. Indeed, our review revealed the presence of 41 Anopheles species, of which the most abundant were members of the Gambiae and Nili complexes and those of the Funestus and Moucheti groups. However, our review also revealed that the major and minor vectors of malaria in Gabon are present in both sylvatic, rural, and urban environments. The observation of human malaria vectors in sylvatic environments raises the question of the role that the sylvatic environment may play in maintaining malaria transmission in rural and urban areas. Ultimately, it appears that knowledge of biodiversity and spatial distribution of Anopheles mosquitoes is fragmentary in Gabon, suggesting that additional studies are necessary to complete and update these entomological data, which are useful for the implementation of vector control strategies.

Urban Green Spaces and Vector-Borne Disease Risk in Africa: Case of the Sibang Forested Park in Libreville (Gabon, Cen-Tral Africa)

“…In conclusion, this study conducted in the urban forested area of Sibang, allowed the recording of a bit more than 12% of the number of the currently known mosquitoes species reported in Gabon [37,[69][70][71][72]. The investigations revealed a variety of larval habitats exploited by the mosquito species recovered from the study area.…”

A review of Gabonese gorillas and their pathogens: Diversity, transfer and One Health approach to avoid future outbreaks?

“…we do not know which the man or the gorillas, transmitted the pathogens to the other. Furthermore, it is not obvious to believe that the exchange of Plasmodium species between gorillas and humans in the Gabon settings may become frequent insofar as among the vectors responsible for the transmission of simian parasites in gorillas, secondary vectors for the transmission of human malaria in urban and rural areas are found (Paupy et al, 2013;Makanga et al, 2016;Longo-Pendy et al, 2022). For instance, P. vivax-like, whose vector species identified are Anopheles moucheti, Anophles vinckei and Anopheles marshallii (Prugnolle et al, 2013;Makanga et al, 2016).…”

A cross-sectional study of malaria transmission in suggests the existence of a potential bridge vector susceptible of ensuring the transfer of simian malaria parasites to humans

“…Moreover, the very low occurrence of Anopheles mosquitoes observed in Mayumba, with only one specimen detected, An. coustani, which is known to be a minor vector of malaria in sub-Saharan Africa and in Gabon in particular (Longo-Pendy et al, 2022) 10.3389/fevo.2023.1176687 Frontiers in Ecology and Evolution 10 frontiersin.org (Imboumy-Limoukou et al, 2020) who showed that there were no cases of malaria in this coastal town of Gabon (Imboumy-Limoukou et al, 2020). The impact of environmental changes on the spatial dynamics of mosquitoes is not only specific to Anopheles species but has also been observed in mosquitoes of the Aedes genus (Albrieu Llinás et al, 2018;Zettle et al, 2022).…”

“…Of the 131 Anopheles species found in tropical Africa, less than 10% are known to transmit Plasmodium (Sinka et al, 2012;Coetzee, 2020). In Gabon, around 41 Anopheles species have been recorded, however, among all species identified in different areas of the country, only some are known for their role in Plasmodium transmission, with Anopheles funestus and Anopheles gambiae known as the main vectors (Longo-Pendy et al, 2022). In addition, recent studies have revealed that some opportunistic anopheline mosquitoes could play the role of bridge vectors (e.g., Anopheles moucheti, Anopheles vinckei) and promote the exchange of Plasmodium between humans and primates (Paupy et al, 2013;Makanga et al, 2016).…”

“…In addition, recent studies have revealed that some opportunistic anopheline mosquitoes could play the role of bridge vectors (e.g., Anopheles moucheti, Anopheles vinckei) and promote the exchange of Plasmodium between humans and primates (Paupy et al, 2013;Makanga et al, 2016). Moreover, the fact that the vectors responsible for the transmission of malaria are found in different ecosystems (forest, rural, and urban) (Longo-Pendy et al, 2022) could be a limitation for all control strategies but it could also enhance the risk of parasites exchange between humans and animals in the rural and forest environment.…”