TITLE:
First Comprehensive Assessment of Aedes aegypti, Bio-Ecology, Spatial Distribution and Arbovirus Transmission in Niger
AUTHORS:
M.S.O. Ramatoulaye, Iro Souleymane, Mamane Salé Noura, Ibrahim Issa Arzika, Olivier Manigart, Lagaré Adamou, Diallo Mawlouth, Ibrahim Maman Laminou, Athanase Badolo
KEYWORDS:
Assessment, Bioecology, Spatial, Distribution, Aedes aegypti, Arbovirus, Niger
JOURNAL NAME:
Advances in Infectious Diseases,
Vol.16 No.4,
November
4,
2026
ABSTRACT: Introduction: Arboviruses, transmitted mainly by the Aedes aegypti (Ae. aegypti) mosquitoes, represent a major global public health issue. The scale of the problem has been amplified by climate change, urbanization and human mobility. In Niger, 308 cases of Yellow Fever, Zika and Chikungunya have been reported since 1960, and the recent detection of Dengue virus in Niamey highlights the need for rigorous surveillance. Objectives: The objectives of this study were to describe the bio-ecology of Ae. aegypti, assess stegomyian indices and to monitor the potential circulation of dengue virus (DENV), Zika virus (ZIKV), yellow fever virus (YFV) and chikungunya virus (CHIKV) in Niger. Methodology: A descriptive and analytical longitudinal study was conducted in ten localities of Niger between January and December 2023 to investigate the spatial and temporal dynamics of Aedes mosquitoes and arbovirus circulation. Various devices (Ovitraps, BG Sentinel, prokopack, domestic larval surveys) were used to capture mosquitoes. Larvae were collected for estimation of stegomyian Indices (Container, Habitats and Breteau Indices) through WHO guideline. After morphological identification, some adults were randomly selected and tested by RT-PCR for DENV, ZIKV, YFV and CHIKV viruses. Results: Aedes spp eggs were detected in all 7/10 sites. The Stegomyian indices were above the WHO thresholds in Niamey and Gaya. A total of 7308 mosquitoes were collected dominated by Culex 73.1% (5344/7308), followed by Aedes 12.35% (903/7308), using BG traps and prokopack. Of these, only Ae. aegypti were recorded, and no Aedes albopictus were observed. Specifically, regarding the Aedes species, Niamey recorded the highest abundance 46.2% (417/903), followed by Tessaoua 19.3% (174/903). Host-seeking activity assessed using BG traps showed higher outdoor activity in Niamey and Gaya. However, no arboviral infection was detected in any of the mosquitoes tested. Conclusion: Aedes aegypti is widely established in Niger, with Niamey and Gaya representing priority areas for surveillance and vector control. The findings from Tessaoua suggest that reliance on domestic larval surveys alone may underestimate arbovirus transmission risk emphasizing the importance of incorporating public and peri-domestic habitats into surveillance programs.