Extreme rainfall and anaemia among children under five in 46 low- and middle-income countries.

BACKGROUND

Childhood anaemia remains a major public health challenge in low- and middle-income countries (LMICs). While extreme rainfall has been linked to child growth, its impact on childhood anaemia has not been well characterised.

METHODS

Our study used data from the Demographic and Health Survey programme conducted between 2000-2022 across 46 LMICs, comprising 373 901 children aged 6-59 months. Generalised linear models estimated ORs for childhood anaemia associated with extreme rainfall events during maternal pregnancy and the 3 months preceding the survey. We further quantified the burden of childhood anaemia attributable to extreme rainfall.

RESULTS

The overall prevalence of childhood anaemia was 61.9%. Among 373 901 children, 69 481 (18.6%) experienced at least one extreme rainfall event with a 5-year return period during pregnancy, and 28 776 (7.7%) were exposed within the 3 months preceding the survey. Maternal exposure during pregnancy was associated with a modest increase in anaemia risk (OR: 1.025; 95% CI 1.007 to 1.044), whereas exposure during the 3 months prior to the survey showed a greater magnitude of association (OR: 1.137; 95% CI 1.107 to 1.168). Age-stratified analyses indicated that children aged under 2 years were more sensitive to maternal exposure, whereas those aged 2 years and older were more affected by rainfall exposure before the survey. Extreme rainfall was estimated to be responsible for approximately 5 million cases of childhood anaemia, with the highest absolute burden observed in sub-Saharan Africa.

CONCLUSIONS

Childhood anaemia in LMICs is associated with extreme rainfall, with disproportionate impacts observed in sub-Saharan Africa. These findings underscore the need to integrate climate variability into strategies for anaemia prevention and child health protection.