Impacts of Deforestation on Childhood Malaria Depend on Wealth and Vector Biology

Ecosystem change can profoundly affect human well-being and health, including through changes in exposure to vector-borne diseases. Deforestation has increased human exposure to mosquito vectors and malaria risk in Africa, but there is little understanding of how socioeconomic and ecological factors influence the relationship between deforestation and malaria risk. We examined these interrelationships in six sub-Saharan African countries using demographic and health survey data linked to remotely sensed environmental variables for 11,746 children under 5 years old. We found that the relationship between deforestation and malaria prevalence varies by wealth levels. Deforestation is associated with increased malaria prevalence in the poorest households, but there was not significantly increased malaria prevalence in the richest households, suggesting that deforestation has disproportionate negative health impacts on the poor. In poorer households, malaria prevalence was 27%-33% larger for one standard deviation increase in deforestation across urban and rural populations. Deforestation is also associated with increased malaria prevalence in regions where Anopheles gambiae and Anopheles funestus are dominant vectors, but not in areas of Anopheles arabiensis. These findings indicate that deforestation is an important driver of malaria risk among the world's most vulnerable children, and its impact depends critically on often-overlooked social and biological factors. An in-depth understanding of the links between ecosystems and human health is crucial in designing conservation policies that benefit people and the environment. This study analyzes the relationship between deforestation and malaria risk in children using a unique and large data set in six sub-Saharan African countries. We found that deforestation is associated with increased malaria risk. However, the effect of deforestation varied among household wealth levels and locally dominant vector species. The prevalence of malaria was higher among poor households, but deforestation had no impact on malaria among wealthier households. Furthermore, deforestation was associated with higher malaria in clusters dominated by Anopheles gambiae and Anopheles funestus. Forest cover can provide human health benefits, especially for the least wealthy households and in areas where dominant mosquitoes occur. Although deforestation has been linked with malaria risk, little is known about whether socioeconomics or vector ecology moderate this effect Across six sub-Saharan African countries, deforestation increased malaria risk in poorer communities more than in wealthier communities Understanding ecosystems-human health-poverty linkage is crucial in designing conservation policies that provide equitable health outcomes