Climate vulnerability and child morbidity in Bangladesh: evidence from a nationally representative public health survey

The health consequences of climate change are no longer distant threats; they are increasingly reflected in the everyday burden of childhood illness in climate-vulnerable settings. Bangladesh is highly exposed to climate-related hazards, while children under five remain physiologically and socially vulnerable to infection, environmental stress, and disruptions in basic services. Limited national evidence exists on how broader climate vulnerability is associated with childhood morbidity. This study assessed the association between district-level climate vulnerability and recent morbidity among children under five children in Bangladesh. This cross-sectional study analyzed 8,573 under-five children from the 2022 Bangladesh Demographic and Health Survey. Climate Vulnerability Index data, sourced from the Local Government Initiative on Climate Change (LoGIC) project by the United Nations Development Programme (UNDP) Bangladesh, were linked with child-level survey records using district identifiers. Child morbidity was defined as the occurrence of fever, symptoms of acute respiratory infection, or diarrhea within the two weeks preceding the survey. Multivariable logistic regression, utilizing a complex samples module to account for primary sampling unit (PSU) clustering, stratification, and sample weights, was used to estimate adjusted odds ratios (aOR) with 95% confidence intervals (CI). Broader regional characteristics were accounted for by including geographic regions as fixed-effect covariates. Overall, 33.0% of children experienced recent morbidity. In bivariate analysis, the proportion of morbidity was highest among children living in high climate vulnerability areas. Adjusting for child, parental, household, and regional characteristics, children in high climate vulnerability areas had significantly higher odds of morbidity than those in low vulnerability areas (adjusted odds ratio = 1.20, 95% confidence interval: 1.07–1.35). Children aged < 12 and 12–35 months had higher morbidity odds compared to those aged 36–59 months. Parental education, maternal age at first birth, region, and religion were also significantly associated with child morbidity. Recent morbidity affects one in three under-five children in Bangladesh, showing a significant association with district-level climate vulnerability. These findings highlight the need to integrate climate vulnerability evidence into child health planning, primary health care strengthening, and targeted adaptation strategies in highly vulnerable areas.