Long-lasting insecticidal net ownership and malaria infection by socio-economic status: a cross-sectional household study in an area along Lake Victoria, Kenya.

backgroundThis study focused on the importance of long-lasting insecticide treated nets (LLINs) in malaria control in a study area where socio-economic disparities are widening. The objective was to assess the effectiveness of LLIN ownership when nets were available for no more than two people, controlling for differences in socio-economic status (SES). It was hypothesized that LLIN effectiveness would differ by SES and that LLIN effectiveness should be analysed with adjustment for differences in SES.

methodsA household level survey was conducted in an area in the Lake Victoria region in Suba North Sub-County, Homa Bay County, Western Kenya between June and September 2021. Through the household survey, the number of people living in the home, the number of LLINs, and demographic data were recorded. The ratio of the number of people reporting sleeping in the house to the total number of LLINs in the home was calculated. Through a school-based malaria survey, researchers administered blood-spot, PCR tests for Plasmodium infection. Community workers linked individual malaria tests to homes that were involved in the household survey through names and geographic identifiers. A generalized linear model (GLM) tested the associations between household parasitaemia risk in children and the ratio of people to LLINs, stratifying on asset-based household level SES measures.

resultsThe association between sufficient LLIN ownership and household malaria infection status was analysed across SES groups. In middle SES households, sufficient LLIN ownership was significantly associated with lower malaria infection status compared with insufficient LLIN ownership (OR 0.32, 95% CI 0.12-0.92). In the low SES group, a similar trend was observed, although it was not statistically significant (OR 0.59, 95% CI 0.15-2.91). When middle and low SES groups were combined, sufficient LLIN ownership remained significantly associated with lower incidence (OR 0.37, 95% CI 0.17-0.87).

conclusionsThe results suggest that promoting the use of one LLIN by no more than two people, as recommended by WHO, can reduce the risk of malaria. Efforts to promote LLINs as an effective means of preventing malaria in children might encourage LLIN compliance and maintain community level control targets. If households have been excluded from LLIN distribution, LLINs should be distributed immediately along with information about their effectiveness. The effectiveness of LLINs varies by region, but strategies to sustain LLIN use should be recognized as contributing to benefits for the entire community.