Abstract:
This study evaluated the impact of combining house screens with long-lasting insecticidal
nets (LLINs) on mosquito host-seeking, resting, and biting behavior. Intervention houses received
house screens and LLINs, while control houses received only LLINs. Centre for Disease Control light
traps, pyrethrum spray collections and human landing catches were used to assess the densities of
indoor and outdoor host-seeking, indoor resting, and biting behavior of malaria vectors in 15 sentinel
houses per study arm per sampling method. The protective efficacy of screens and LLINs was
estimated through entomological inoculation rates (EIRs). There were 68% fewer indoor host-seeking
Anopheles funestus (RR = 0.32, 95% CI 0.20–0.51, p < 0.05) and 63% fewer An. arabiensis (RR = 0.37,
95% CI 0.22–0.61, p < 0.05) in screened houses than unscreened houses. There was a significantly
higher indoor biting rate for unscreened houses (6.75 bites/person/h [b/p/h]) than for screened
houses (0 b/p/h) (χ2 = 6.67, df = 1, p < 0.05). The estimated indoor EIR in unscreened houses
was 2.91 infectious bites/person/six months, higher than that in screened houses (1.88 infectious
bites/person/six months). Closing eaves and screening doors and windows has the potential to
reduce indoor densities of malaria vectors and malaria transmission.
