ABSTRACT
BACKGROUND: Malaria affects 24 million children globally, resulting in nearly 500,000 child deaths annually in low- and middle-income countries (LMICs). Recent studies have provided evidence that severe malaria infection results in sustained impairment in cognition and behaviour among young children; however, a formal meta-analysis has not been published. The objective was to assess the association between severe malaria infection with cognitive and behavioural outcomes among children living in LMICs. METHODS: Six online bibliographic databases were searched and reviewed in November 2022. Studies included involved children < 18 years of age living in LMICs with active or past severe malaria infection and measured cognitive and/or behaviour outcomes. The quality of studies was assessed. Definitions of severe malaria included cerebral malaria, severe malarial anaemia, and author-defined severe malaria. Results from all studies were qualitatively summarized. For studies with relevant data on attention, learning, memory, language, internalizing behaviour and externalizing behaviour, results were pooled and a meta-analysis was performed. A random-effects model was used across included cohorts, yielding a standardized mean difference between the severe malaria group and control group. RESULTS: Out of 3,803 initial records meeting the search criteria, 24 studies were included in the review, with data from 14 studies eligible for meta-analysis inclusion. Studies across sub-Saharan Africa assessed 11 cohorts of children from pre-school to school age. Of all the studies, composite measures of cognition were the most affected areas of development. Overall, attention, memory, and behavioural problems were domains most commonly found to have lower scores in children with severe malaria. Meta-analysis revealed that children with severe malaria had worse scores compared to children without malaria in attention (standardized mean difference (SMD) -0.68, 95% CI -1.26 to -0.10), memory (SMD -0.52, 95% CI -0.99 to -0.06), and externalizing behavioural problems (SMD 0.45, 95% CI 0.13-0.78). CONCLUSION: Severe malaria is associated with worse neuropsychological outcomes for children living in LMICs, specifically in attention, memory, and externalizing behaviours. More research is needed to identify the long-term implications of these findings. Further interventions are needed to prevent cognitive and behavioural problems after severe malaria infection. TRIAL REGISTRATION: This systematic review was registered under PROSPERO: CRD42020154777.
Subject(s)
Developing Countries , Malaria, Cerebral , Child , Child, Preschool , Humans , Cognition , Malaria, Cerebral/complications , Malaria, Cerebral/epidemiology , Africa South of the SaharaABSTRACT
BACKGROUND: Cerebral malaria (CM) and severe malarial anemia (SMA) are associated with neurocognitive impairment in childhood but their effects on long-term academic achievement are not known. METHODS: Ugandan children 5 to 12 years old who participated in a previous study evaluating cognitive outcomes after CM (n = 73) or SMA (n = 56), along with community children (CC, n = 100) from the same household or neighborhood, were on average enrolled 67.1 months (range, 19-101 months) after the severe malaria episode or previous study enrollment. Academic achievement in word reading, sentence comprehension, spelling, and math computation was evaluated using the Wide Range Achievement Test, Fourth Edition. Age-adjusted z-scores for academic achievement outcomes were calculated from CC scores. RESULTS: After adjustment for age and time from enrollment, reading scores were lower (mean difference from CC [95% confidence interval]) in children with CM (-0.15 [-0.27 to -0.03], P = .02) or SMA (-0.15 [-0.28 to -0.02], P = .02) than CC. Postdischarge malaria episodes were associated with worse spelling and reading scores in CM and worse spelling scores only in SMA. Pathway analysis showed that incidence of postdischarge uncomplicated malaria contributed significantly to the association of CM or SMA with poorer reading scores. CONCLUSION: Children with CM or SMA have poorer long-term reading skills. Postdischarge malaria episodes contribute significantly to this association. Postdischarge malaria chemoprevention should be assessed as an intervention to improve long-term academic achievement in children with severe malaria.
