House modifications show promising results in reducing indoor malaria vectors in western Kenya
Updated: Feb 20
Malaria remains a significant health burden in sub-Saharan Africa, with over 200 million cases and nearly half a million deaths each year. One of the primary methods of malaria transmission is through the bites of infected mosquitoes, which can be particularly prevalent in rural areas.
However, a recent study has shown that simple modifications to typical rural house design can be an effective and relatively inexpensive method of reducing indoor mosquito vector densities and consequently decreasing malaria transmission.
The study, conducted in a rice irrigation scheme area of western Kenya, involved modifying ten houses with ceilings made of locally available papyrus mats and insecticide-treated netting, while leaving ten other houses unmodified as controls. The researchers used the pyrethrum spray method to collect indoor resting malaria vectors in both the intervention and control houses over a four-month period.
The results of the study were promising. The house modifications reduced house entry by Anopheles gambiae s.l and Anopheles funestus densities by between 78–80% and 86% respectively, compared to unmodified houses. The geometric mean density of Anopheles gambiae s.l. and Anopheles funestus in modified houses were significantly lower compared to controls.
In addition, the modifications were associated with a 84% and 87% reduction in the odds of Anopheles gambiae s.l. and Anopheles funestus presence in modified houses, respectively, compared with unmodified houses. Residents responded favorably to this mode of vector control, indicating that it may be acceptable to implement on a larger scale.
These results are significant because simple house modifications have the potential to reduce human exposure to malaria vectors and hence parasite infection in areas where malaria transmission is high. Furthermore, the use of locally available materials makes this intervention affordable and easily scalable, making it a viable option for malaria control programs in sub-Saharan Africa.
In conclusion, this study demonstrates that house modifications involving insect screen ceilings made from locally available materials and small insecticide-treated nets incorporated into house construction can significantly reduce indoor malaria vectors in a rice irrigation scheme area of western Kenya. These findings suggest that ceiling modification could be of great benefit when used in combination with other malaria control strategies. The study is published in the journal Malaria Journal, and the full text is available here.