Distribution of Aedes mosquitoes in the Kilimanjaro Region of northern Tanzania

Abstract

Little is known about the presence and distribution of Aedes mosquitoes in northern Tanzania despite the occurence of viruses transmitted by these mosquitoes such as Chikungunya virus (CHIKV) and Dengue virus (DENV) in the region. Adult and larval mosquitoes were collected from rural and urban settings across a wide range of altitudes in the Kilimanjaro Region using the Mosquito Magnet CO₂ Trap for collection of adults and old tires for breeding of larvae. Polymerase chain reaction assays were performed on captured adult mosquitoes to detect the presence of CHIKV and DENV. A total of 2609 Aedes aegypti adult mosquitoes were collected; no other Aedes species larvae were found. Mosquito yields were significantly higher in urban settings than rural settings (26.5 vs. 1.9 mosquitoes per day, p = 0.037). A total of 6570 Ae. aegypti larvae were collected from old tires; no other Aedes species larvae were found. Of the 2609 adult mosquitoes collected, none tested positive for CHIKV or DENV. As far as we are aware, this paper reports for the first time the presence of Ae. aegypti in the Kilimanjaro Region of northern Tanzania. Although CHIKV and DENV were not isolated from any of the collected mosquitoes in this study, the apparent absence of other Aedes species in the area suggests that Ae. aegypti is the primary local vector of these infections.

Keywords:

• Aedes aegypti
• Aedes albopictus
• Chikungunya
• Dengue
• Sub-Saharan Africa

Acknowledgments

The authors wish to thank the KCMC, the KCMC-Duke collaboration for the support of mosquito collections and storage, and KCMU College insectary staff for their support in rearing mosquitoes. The authors further thank Charles Masenga, Augustine Mtui, Godfrey Kweka, and Levynson Lewis who served as field assistants.