Blood-feeding patterns of Culex quinquefasciatus and other culicines and implications for disease transmission in Mwea rice scheme, Kenya

Abstract

Studies were conducted in Mwea Rice Scheme, Kenya during the period April 2005 and January 2007 to determine the host-feeding pattern of culicine mosquitoes. Mosquitoes were collected indoors and outdoors and tested for human, bovine, goat, and donkey blood meals by an Enzyme-Linked Immunosorbent Assay. A total of 1,714 blood-engorged samples comprising Culex quinquefasciatus Say (96.1%), Culex annulioris Theobald (1.8%), Culex poicilipes Theobald (0.9%), Aedes cuminsi Theobald (1.0%), Aedes taylori Edwards (0.1%), and Mansonia africana Theobald (0.1%) were tested. Except for A. taylori, in which the single blood meal tested was of bovine origin, the other species fed mostly on both bovine (range 73.3-100%) and goats (range 50-100%). Donkeys were also common hosts for all species (range 19.4-23.5%) except A. taylori and M. africana. C. quinquefasciatus was the only species containing human blood meals (0.04), and indoor collected populations of this species had significantly higher frequency of human blood meals (9.8%) compared with outdoor-collected populations (3.0%). Mixed blood feeding was dominant among culicine species comprising 50.0%, 73.3%, 73.5%, 80.6%, and 94.1% of the samples for M. africana, C. poicilipes, C. quinquefasciatus, C. annulioris, and A. cuminsi, respectively. Ten mixed blood meal combinations including a mixture of all the four hosts were observed in C. quinquefasciatus, compared to one blood meal combination for M. Africana, and two combinations for C. poicilipes, C. annulioris, and A. cuminsi. Mixed bovine and goat blood meal was the most common combination among the five culicine species followed by a mixture of donkey, bovine, and goat blood meals. We conclude that culicine species in Mwea are least likely to be vectors of lymphatic filariasis due to their high "preference" for livestock over human hosts, but they present an increased risk for arbovirus transmission particularly Rift Valley Fever virus, in which domestic animals serve as amplification hosts.

Beyond Nature and Nurture: Phenotypic Plasticity in Blood-Feeding Behavior of Anopheles gambiae s.s. When Humans Are Not Readily Accessible

“…quinquefasciatus , the most common urban mosquito in tropical Africa and an important vector of lymphatic filariasis, a species for which there is little information on inherent host preferences. On the basis of blood meal identifications, this mosquito is generally classified as anthropophagic, 6,57 (but see Muturi and others 58 for strong zoophagy). Using odor-baited tents, Mboera and Takken 59 showed that Cx.…”

Serologic Evidence of Arboviral Infections among Humans in Kenya

“…7,10,11 Given the vectorial capacity for arboviral transmission in the region and the history of confirmed arboviral outbreaks, serosurveys are an important component for understanding the circulating, but perhaps rarely diagnosed, human arboviral transmission prevalence. Currently, there are no countrywide serosurvey data regarding arbovirus infection across Kenya or the types of human arboviral infections that are most prevalent.…”

Arboviruses: Variations on an Ancient Theme

“…The main RVFV sylvatic vectors (Culex poicilipes, Aedes vexans and Aedes ochraceus) display opportunistic feeding behavior (bovines, sheep and chickens) and more likely to feed on animals than humans, whereas the domestic Culex pipiens, which was implicated as the main vector of RVFV during the outbreak in Egypt in 1977, is highly anthropophilic and highly susceptible to infection after feeding on a viremic host [161,[175][176][177]. Finally, vectors that take mixed blood meals can become coinfected, leading to a higher chance for reassortment of the viral genome [167,175,178].…”