Housing and household characteristics associated with malaria vectors abundance and clinical malaria incidence in a semi-urban and a rural area of Burkina Faso.

Background: The risk of malaria transmission varies between rural and urban areas. Environmental characteristics and habitat structure can explain this variation. Understanding these factors is crucial for the informed selection of existing and new vector control tools. This study investigated how housing and household characteristics affect vector abundance and malaria incidence in a semi-urban and rural setting of Burkina Faso.

Methods: CDC light traps were used to sample indoor mosquitoes from July to October 2021 in 355 randomly selected houses in semi-urban and rural areas of the Nouna health district. A digital data collection application was used to record information on occupants, housing structure, and household characteristics. Indoor temperature was monitored with a wall thermometer during the night of mosquito collection. Mosquitoes were morphologically sorted and identified by Polymerase Chain Reaction. Poisson and logistic linear models were used to assess the effects of house structure and household characteristics on indoor mosquito abundance, mosquito infection, and human malaria cases.

Results: A total of 22,863 mosquitoes were collected, the most abundant of which were Anopheles including Anopheles coluzzii, Anopheles gambiae sensu stricto, Anopheles arabiensis. In the rural site, minor vectors such as Anopheles nili, Anopheles funestus, and Anopheles pharoensis were found. Mosquito abundance, the number of infected mosquitoes, and the presence of human malaria cases didn't vary significantly according to wall type, roof type, the presence of breeding sites, and the use of LLINs. However, the vegetation around the houses was positively associated with mosquito abundance [RR: 2.5; CI (1.43-4.15); p < 0.001], vector infection [RR = 2.5; CI (1.74-3.33); p < 0.001], and the presence of malaria cases [RR: 1.4; CI (1.03-2.0); p = 0.048]. The presence of children under five years of age [RR: 1.52; CI (1.25-1.84); p < 0.001], female householder [RR: 1.23; CI (1.02-2.78); p < 0.001] were also significantly associated with the human malaria cases.

Conclusion: The household environment, such as vegetation around houses, appears to increase the risk of malaria transmission, while building materials have a smaller effect, in semi urban and rural areas of Burkina Faso. In addition to prophylaxis and medication, malaria control strategies must strengthen environmental management to keep vector populations away from human dwellings.