Discussion
malaria
MALARIA
Our field study revealed a very high malaria vector density in rural communities within the well-established Ahero rice irrigation scheme in western Kenya. Notably the sampling tools employed, highlighted a nearly balanced vector host-seeking density outdoors and indoors, with a mean of 29–35 estimated bites per person per night in either location, during the short rainy season. The outdoor malaria vector population was dominated by Our findings also corroborate the need for vector control interventions targeting the outdoor peri-domestic space. However, none of the three tested interventions, transfluthrin-treated eave strips (‘push’), odour-baited trap (‘pull’) and the combined ‘push–pull’ system, reduced outdoor biting by either of the two abundant malaria vectors, There was, however, a strong protective efficacy of the ‘push’ and ‘push–pull’ intervention for the indoor environment. Indoor vector densities were significantly reduced to a similar extent by both interventions. There was no benefit to combining the ‘push’ with the ‘pull’ as seen by either an increased protective efficacy or an increase in the mosquito population removed by the ‘pull’. These findings from the field stand in contrast to preceding semi-field evaluations in large field cages from western KenyaThe increase of The odour-baited Suna trap neither reduced mosquito bites and house entry, nor did it catch mosquitoes in any biologically relevant numbers to support a vector control effort by reducing vector densities through mass-trapping. Given the high mosquito densities overall, the powered traps only coincidentally caught In our study site, the mean nightly indoor collections of Whilst not the focus of our study, it is important to highlight that outdoor densities of Our hierarchical Bayesian modelling framework provides easily interpretable interval estimates for both the control and the intervention effect across different houses and weeks. Despite the selection of relatively uniform households along a transect with all houses facing the flooded rice fields, mosquito densities were highly variable across houses and weeks. This might have been associated with a range of biotic and abiotic factors out of our control, such as distance to productive larval microhabitats