Characterization and productivity profiles of Aedes aegypti (L.) breeding habitats across rural and urban landscapes in western and coastal Kenya

Abstract

Background Aedes aegypti, the principal vector for dengue and other emerging arboviruses, breeds preferentially in various man-made and natural container habitats. In the absence of vaccine, epidemiological surveillance and vector control remain the best practices for preventing dengue outbreaks. Effective vector control depends on a good understanding of larval and adult vector ecology of which little is known in Kenya. In the current study, we sought to characterize breeding habitats and establish container productivity profiles of Ae. aegypti in rural and urban sites in western and coastal Kenya.MethodsTwenty sentinel houses in each of four study sites (in western and coastal Kenya) were assessed for immature mosquito infestation once a month for a period of 24 months (June 2014 to May 2016). All water-holding containers in and around the households were inspected for Ae. aegypti larvae and pupae.ResultsCollections were made from a total of 22,144 container visits: Chulaimbo (7575) and Kisumu (8003) in the west, and from Msambweni (3199) and Ukunda (3367) on the coast. Of these, only 4–5.6% were positive for Ae. aegypti immatures. In all four sites, significantly more positive containers were located outdoors than indoors. A total of 17,537 Ae. aegypti immatures were sampled from 10 container types. The most important habitat types were buckets, drums, tires, and pots, which produced over 75% of all the pupae. Key outdoor containers in the coast were buckets, drums and tires, which accounted for 82% of the pupae, while pots and tires were the only key containers in the western region producing 70% of the pupae. Drums, buckets and pots were the key indoor containers, producing nearly all of the pupae in the coastal sites. No pupae were collected indoors in the western region. The coastal region produced significantly more Ae. aegypti immatures than the western region both inside and outside the sentinel houses.ConclusionsThese results indicate that productive Ae. aegypti larval habitats are abundant outdoors and that only a few containers produce a majority of the pupae. Although the numbers were lower, productive habitats were detected within households. Targeting source reduction efforts towards these productive containers both inside and outside homes is likely to be a cost-effective way to reduce arboviral transmission in these regions.

Habitat characteristics and insecticide susceptibility of Aedes aegypti in the Ifakara area, south-eastern Tanzania

“…As already highlighted by several previous studies, tires in particular serve as important breeding sites for Ae. aegypti because they can hold water for long periods even in the dry season [11,19,42]. The multiple applications of used tires in the area will, however, complicate efforts to effectively dispose of the tires.…”

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).…”

Solid Wastes Provide Breeding Sites, Burrows, and Food for Biological Disease Vectors, and Urban Zoonotic Reservoirs: A Call to Action for Solutions-Based Research

“…Aedes albopictus is reported to preferentially breed in solid waste (91), and tires (92), open coconut shells (92,93) and small plastic containers (92,93). Aedes aegypti prefers to breed in discarded tires (95,98) and artificial water containers (95); plastic containers (96), solid waste (96,98), buckets (97), drums (97), tires (97), pots (97), and garbage dumps (98). Both Aedes albopictus and Aedes aegypti breed in plastic teacups (100,101), plastic containers (79-82, 102, 103, 128), tires (79,82,101), trash (96,101), bottles (103), and cans (103).…”