Characteristics of Aedes aegypti adult mosquitoes in rural and urban areas of western and coastal Kenya

Abstract

Aedes aegypti is the main vector for yellow fever, dengue, chikungunya and Zika viruses. Recent outbreaks of dengue and chikungunya have been reported in Kenya. Presence and abundance of this vector is associated with the risk for the occurrence and transmission of these diseases. This study aimed to characterize the presence and abundance of Ae. aegypti adult mosquitoes from rural and urban sites in western and coastal regions of Kenya. Presence and abundance of Ae. aegypti adult mosquitoes were determined indoors and outdoors in two western (urban Kisumu and rural Chulaimbo) and two coastal (urban Ukunda and rural Msambweni) sites in Kenya. Sampling was performed using quarterly human landing catches, monthly Prokopack automated aspirators and monthly Biogents-sentinel traps. A total of 2,229 adult Ae. aegypti mosquitoes were collected: 785 (35.2%) by human landing catches, 459 (20.6%) by Prokopack aspiration and 985 (44.2%) by Biogents-sentinel traps. About three times as many Ae. aegypti mosquitoes were collected in urban than rural sites (1,650 versus 579). Comparable numbers were collected in western (1,196) and coastal (1,033) sites. Over 80% were collected outdoors through human landing catches and Prokopack aspiration. The probability of collecting Ae. aegypti mosquitoes by human landing catches was significantly higher in the afternoon than morning hours (P<0.001), outdoors than indoors (P<0.001) and in urban than rural sites (P = 0.008). Significantly more Ae. aegypti mosquitoes were collected using Prokopack aspiration outdoors than indoors (P<0.001) and in urban than rural areas (P<0.001). Significantly more mosquitoes were collected using Biogents-sentinel traps in urban than rural areas (P = 0.008) and in western than coastal sites (P = 0.006). The probability of exposure to Ae. aegypti bites was highest in urban areas, outdoors and in the afternoon hours. These characteristics have major implications for the possible transmission of arboviral diseases and for the planning of surveillance and control programs.

Seroprevalence of yellow fever, dengue, West Nile and chikungunya viruses in children in Teso South Sub-County, Western Kenya

“…The differences seen in these studies may be attributed to the different detection methods used at the time (Geser et al, 1970;Vu et al, 2017), different time periods (Geser et al,1970;Vu et al, 2017), different climatic conditions or geographic regions (Kwallah et al, 2015;Mease et al, 2011;Vu et al, 2017), or different environmental, vector, andhost dynamics (Grossi-Soyster et al, 2017;Ngugi et al, 2017;Ndenga et al, 2017;Mwongula et al, 2013;Awando et al, 2013;Kwallah et al, 2015;Ochieng et al, 2015;Vu et al, 2017).…”

The level of knowledge and attitude towards dengue fever among medical students of Udayana University, Bali, Indonesia in 2018

“…The highest prevalence of Aedes aegypti will be on March and April. 10 In a recent discussion, some of the publications stated their concern about the possibility of dengue virus could be transferred by blood transfusion.…”

The evolution of dengue-2 viruses in Malindi, Kenya and greater East Africa: epidemiological and immunological implications

“…Taken together, our findings indicate that the 25 2017 Malindi DENV-2 outbreak arose from a strain which had circulated for several years in Kenya 26 before recent detection, has experienced diversifying selection pressure, and may contain new 27 putative immunogens relevant to vaccine design. These findings prompt further genomic 28 epidemiology studies in this and other Kenyan locations to further elucidate the transmission dynamics 29 of DENV in this region. 30 Author summary (non-technical): 31 Kenya experiences a substantial burden of dengue, yet the patterns of dengue spread in this region are 32 unclear.…”