Distribution of Aedes mosquito species along the rural–urban gradient in Lambaréné and its surroundings

Parasites & Vectors

Research

Ange Gatien Doumba Ndalembouly¹  Mahmoudou Saidou¹  Barclaye Ngossanga¹  Ynous Djida¹  Romuald Beh Mba¹  Bertrand Lell²  Stravensky Terence Boussougou-Sambe³  Steffen Borrmann³  Rodrigue Bikangui⁴  Ayola Akim Adegnika⁵  Yuri Ushijima⁶  Haruka Abe⁶  Jiro Yasuda⁷ 

[1] Centre de Recherches Médicales de Lambaréné (CERMEL), BP 242, Lambaréné, Gabon;Centre de Recherches Médicales de Lambaréné (CERMEL), BP 242, Lambaréné, Gabon;Division of Infectious Diseases and Tropical Medicine, Department of Medicine 1, Medical University of Vienna, Vienna, Austria;Centre de Recherches Médicales de Lambaréné (CERMEL), BP 242, Lambaréné, Gabon;Institut Für Tropenmedizin, German Center for Infection Research (DZIF), Universität Tübingen, Tübingen, Germany;Centre de Recherches Médicales de Lambaréné (CERMEL), BP 242, Lambaréné, Gabon;École Doctorale Régionale d’Afrique Centrale de Franceville en Infectiologie Tropicale, Franceville, Gabon;Centre de Recherches Médicales de Lambaréné (CERMEL), BP 242, Lambaréné, Gabon;École Doctorale Régionale d’Afrique Centrale de Franceville en Infectiologie Tropicale, Franceville, Gabon;Institut Für Tropenmedizin, German Center for Infection Research (DZIF), Universität Tübingen, Tübingen, Germany;Department of Parasitology, Leiden University Medical Center, 2333 ZA, Leiden, The Netherlands;Fondation Pour La Recherche Scientifique (FORS), BP 045, Cotonou, Benin;Department of Emerging Infectious Diseases, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan;Department of Emerging Infectious Diseases, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan;National Research Center for the Control and Prevention of Infectious Diseases (CCPID), Nagasaki University, Nagasaki, Japan;Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan;

关键词: Aedes. albopictus;    Aedes. aegypti;    Hevea brasiliensis;    Rural area;    Urban area;    Lambaréné;    Gabon;   

DOI  :  10.1186/s13071-023-05901-2

 received in 2023-03-15, accepted in 2023-07-27,  发布年份 2023

来源: Springer

【 摘 要 】

BackgroundAedes albopictus and Aedes aegypti are known for their potential as vectors of dengue (DENV) and chikungunya (CHIKV) viruses. However, entomological surveys are mostly carried out during epidemics. In Gabon where outbreaks of both viruses have occurred, there is no vector control program targeting these arboviruses. Therefore, we assessed the presence of Aedes species along a rural–urban gradient in Lambaréné (Gabon) and its surroundings and determined ecological factors associated to their presence.MethodsAn entomological survey was conducted in Lambaréné and its surrounding rural areas. Mosquitoes were collected with aspirators around human dwellings, and ecological and environmental data were collected from each study area. Morphological identification keys were used to identify Aedes species. RNA was extracted from pools of female mosquitoes and amplified by RT-qPCR to detect the presence of DENV and CHIKV.ResultsOverall, the most common vector collected was Aedes albopictus (97%, 4236/4367 specimens), followed by Aedes aegypti (3%, 131/4367). Albopictus vectors was more abundant in the rural area (Wilcoxon signed-rank test, Z = 627, P = 0.043) than in the urban area. In the urban area, a higher number of mosquitoes (45%) were recorded in the economic zone (zone 3) than in the historical and administrative zones (zone 1 and 2). In the rural area, the proportions of species numbers were significantly higher along the south rural transect (92%) compared to the north rural transect (Wilcoxon signed-rank test, Z = 43, P ˂ 0.016). We also noted a high abundance of vectors in environments characterized by monocultures of Hevea brasiliensis (Hevea) and Manihot esculenta (cassava) (Kruskal–Wallis H-test, H = 25.7, df = 2, P < 0.001). Finally, no mosquito pools were positive for either DENV or CHIKV.ConclusionAedes albopictus was the dominant vector across the study sites due to its high invasiveness capacity. This presence re-affirms the potential for local transmission of both DENV and CHIKV, as indicated previously by serological surveys conducted in our study area, even though no transmission was detected during the current study. These findings underscore the need for regular arbovirus surveillance in the study region, with the aim of supporting vector control efforts in the event of outbreaks.Graphical Abstract

【 授权许可】

CC BY   
© The Author(s) 2023

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