Abstract
BACKGROUND: Although the association between malaria and anaemia is widely studied in patient cohorts, the population-representative causal effects of malaria on anaemia remain unknown. This study estimated the malaria-induced decrease in haemoglobin levels among young children in malaria-endemic Burkina Faso. METHODS: The study was based on pooled individual-level nationally representative health survey data (2010-2011, 2014, 2017-2018) from 17 599 children under 5 years of age. This data was used to estimate the effects of malaria on haemoglobin concentration, controlling for household fixed-effects, age, and sex in a series of regression analyses. The fixed-effects controlled for observed and unobserved confounding on the household level and allowed to determine the impact of malaria infection status on haemoglobin levels and anaemia prevalence. Furthermore, the diagnostic results from microscopy and rapid diagnostic tests were leveraged to provide a quasi-longitudinal perspective of acute and prolonged effects after malaria infection. RESULTS: The prevalence of both malaria (survey prevalence ranging from 17.4% to 65.2%) and anaemia (survey prevalence ranging from 74% to 88.2%) was very high in the included surveys. Malaria was estimated to significantly reduce haemoglobin levels, with an overall effect of - 7.5 g/dL (95% CI - 8.5, - 6.5). Acute malaria resulted in a - 7.7 g/dL (95% CI - 8.8, - 6.6) decrease in haemoglobin levels. Recent malaria without current parasitaemia decreased haemoglobin concentration by - 7.1 g/dL (95% CI - 8.3, - 5.9). The in-sample predicted prevalence of severe anaemia was 9.4% among malaria positives, but only 2.2% among children without malaria. CONCLUSION: Malaria infection has a strong detrimental effect on haemoglobin levels among young children in Burkina Faso. This effect seems to carry over even after acute infection, indicating prolonged haemoglobin reductions even after successful parasite-elimination. The quasi-experimental fixed-effect approach adds a population level perspective to existing clinical evidence.