Temperature-related neonatal deaths attributable to climate change in Kenya

While increasing heat is a direct impact of climate change on health, the contribution of climate change to temperature-related neonatal deaths in Low- and Middle-income Countries (LMICs), including Kenya, is unknown. We aim to estimate the temperature-related burden of neonatal deaths (children less than 28 days of age) in Kenya between 2022 and 2024 that is attributable to climate change. We use daily neonatal mortality counts for the period ranging from January 1, 2022, to December 31, 2024, from the Kenya Health Information System (KHIS) tracker database. For heat exposure, we use daily reanalysis mean temperature data from the third simulation round of the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP3a),  including both the obsclim (factual) and counterclim (counterfactual) scenarios at a 0.5^° x 0.5^°  spatial scale. We perform an extended two-stage design for small geographical areas to estimate temperature-neonatal mortality associations and temperature-related burden of neonatal deaths in Kenya between 2022 and 2024 that is attributable to climate change. The KHIS data includes all hospital-based neonatal deaths (~ 29,000) recorded across all the 47 counties in Kenya between 2022 and 2024. We find that across all counties in Kenya, exposure to extreme heat (99^th percentile temperature) relative to the minimum mortality temperature for a period of seven days increases the relative risk of neonatal mortality by 1.517 (95% C.I 1.129 - 2.037), although with important geographical differences. Moreover, we found a larger effect in regions with a smaller ratio of health workers per 100,000 population than in those with a higher ratio, and in areas with poor access to insurance compared to those with higher access. Overall, climate change was responsible for 3.6% (95% C.I. 0.9% – 6.5%) of heat-related neonatal deaths in Kenya between 2022-2024. This study underscores the negative impacts of extreme temperatures on neonatal health. Future increases in global mean temperature will likely amplify heat-related health risks, highlighting the urgent need for climate-informed neonatal health mitigation and adaptation measures to protect newborns' health in the face of a changing climate.