Housing and malaria risk: Evidence across ecological and climatic gradients in sub-Saharan Africa.

Malaria risk in sub-Saharan Africa is patterned not only by ecological suitability but also by unequal access to protective domestic environments. Housing is increasingly recognized as a social determinant of health that can structure exposure to infectious bites, yet evidence remains limited on whether housing-associated differences persist across heterogeneous transmission ecologies. Pooled DHS and MIS data (17 countries, 2006-2022; n=206,723) were analysed using logistic regression to predict positive malaria rapid diagnostic test (RDT), adjusting for child and household characteristics and for ecological (proxied by biomes) and climatic context (elevation, rainfall, and temperature). Effect modification was assessed via housing interactions and summarized using predictive margins. Modern housing was associated with lower odds of RDT positivity in the baseline model (β=-0.543, p<0.001), net of socioeconomic status, WASH conditions, net usage, and ecological-climatic controls. Predicted probabilities of positive RDTs varied substantially by ecological context, but remained lower in modern dwellings. Climatic gradients shifted baseline predicted risk in expected directions for rainfall and elevation, whereas temperature displayed more complex patterning in which the diurnal temperature range gradient differed across mean-temperature strata while maintaining a consistent modern-housing advantage. Findings support a housing-determinants framing in which stratified domestic environments systematically differentiate malaria risk within broader transmission ecologies, highlighting housing quality as a durable, non-insecticidal correlate of child malaria vulnerability across diverse ecological settings.