Prevalence and significance of anaemia in childhood bacterial meningitis: a secondary analysis of prospectively collected data from clinical trials in Finland, Latin America and Angola

OBJECTIVES: To describe the prevalence and severity of anaemia and to examine its associations with outcome in children with bacterial meningitis (BM). DESIGN: Secondary analysis of descriptive data from five randomised BM treatment trials. SETTING: Hospitals in Finland, Latin America and Angola. PARTICIPANTS: Consecutive children from 2 months to 15 years of age admitted with BM and who had haemoglobin (Hb) measured on admission. OUTCOME MEASURES: Prevalence and degree of anaemia using the WHO criteria, and their associations with recovery with sequelae or death. RESULTS: The median Hb was 11.8 g/dL in Finland (N=341), 9.2 g/dL in Latin America (N=597) and 7.6 g/dL in Angola (N=1085). Of the children, 79% had anaemia, which was severe in 29%, moderate in 58% and mild in 13% of cases. Besides study area, having anaemia was independently associated with age <1 year, treatment delay >3 days, weight-for-age z-score <−3 and other than meningococcal aetiology. Irrespective of the study area, anaemia correlated with the markers of disease severity. In children with severe to moderate anaemia (vs mild or no anaemia), the risk ratio for death was 3.38 and for death or severe sequelae was 3.07. CONCLUSION: Anaemia, mostly moderate, was common in children with BM, especially in Angola, in underweight children, among those with treatment delay, and in pneumococcal meningitis. Poor outcome was associated with anaemia in all three continents. TRIAL REGISTRATION NUMBER: The registration numbers of Angolan trials were ISRCTN62824827 and NCT01540838.