Preventive malaria treatment among school-aged children in sub-Saharan Africa: a systematic review and meta-analyses

Abstract

Summary Background The burden of malaria infection in sub-Saharan Africa among school-aged children aged 5–15 years is underappreciated and represents an important source of human-to-mosquito transmission of Plasmodium falciparum . Additional interventions are needed to control and eliminate malaria. We aimed to assess whether preventive treatment of malaria might be an effective means of reducing P falciparum infection and anaemia in school-aged children and lowering parasite transmission. Methods In this systematic review and two meta-analyses, we searched the online databases PubMed, Embase, Cochrane CENTRAL, and Clinicaltrials.gov for intervention studies published between Jan 1, 1990, and Dec 14, 2018. We included randomised studies that assessed the effect of antimalarial treatment among asymptomatic school-aged children aged 5–15 years in sub-Saharan Africa on prevalence of P falciparum infection and anaemia, clinical malaria, and cognitive function. We first extracted data for a study-level meta-analysis, then contacted research groups to request data for an individual participant data meta-analysis. Outcomes of interest included prevalence of P falciparum infection detected by microscopy, anaemia (study defined values or haemoglobin less than age-adjusted and sex-adjusted values), clinical malaria (infection and symptoms on the basis of study-specific definitions) during follow-up, and code transmission test scores. We assessed effects by treatment type and duration of time protected, and explored effect modification by transmission setting. For study-level meta-analysis, we calculated risk ratios for binary outcomes and standardised mean differences for continuous outcomes and pooled outcomes using fixed-effect and random-effects models. We used a hierarchical generalised linear model for meta-analysis of individual participant data. This study is registered with PROSPERO, CRD42016030197. Findings Of 628 studies identified, 13 were eligible for the study-level meta-analysis (n=16 309). Researchers from 11 studies contributed data on at least one outcome (n=15 658) for an individual participant data meta-analysis. Interventions and study designs were highly heterogeneous; overall risk of bias was low. In the study-level meta-analysis, treatment was associated with reductions in P falciparum prevalence (risk ratio [RR] 0·27, 95% CI 0·17–0·44), anaemia (0·77, 0·65–0·91), and clinical malaria (0·40, 0·28–0·56); results for cognitive outcomes are not presented because data were only available for three trials. In our individual participant data meta-analysis, we found treatment significantly decreased P falciparum prevalence (adjusted RR [ARR] 0·46, 95% CI 0·40–0·53; p<0·0001; 15 648 individuals; 11 studies), anaemia (ARR 0·85, 0·77–0·9...

School-based screening and treatment may reduce P. falciparum transmission

“…While this concern is important, it should be weighed against the direct student health and potential indirect community benefits when evaluating the approach. 20 Our results join previous studies in supporting the need for implementation studies to measure the indirect impact of school-based treatment on community-level malaria transmission. Although RDTs will fail to detect some low-density infections, such as those observed in the dry season and in our lowest prevalence school, a screen-and-treat approach may substantially reduce the population of gametocytes in the community.…”

“…While this concern is important, it should be weighed against the direct student health and potential indirect community benefits when evaluating the approach. 20…”

“…Treatment options include “intermittent preventive treatment” where all students regularly receive antimalarial drugs for parasite clearance and transient prophylaxis, and “screening-and-treatment” where asymptomatic students are screened and only those testing positive receive treatment. Preventive treatment directly decreases infection and gametocyte prevalence, clinical disease, and anemia among students 20,21 , but potential indirect effects on the surrounding community have not been established. While dynamic modeling data suggests the utility of this intervention, only one study has reported the impact of school-based preventive treatment on community-level infection, finding a small but significant decrease in community infection prevalence surrounding intervention schools despite low intervention coverage.…”

“…Third, our results are based on a single treatment intervention; the impact of repeated school-based treatment is likely to be even larger. In clinical trials that have evaluated the impact of school-based malaria preventive treatment on health outcomes, the most successful interventions were repeated either monthly during the high transmission season or quarterly throughout the year 20. Reinfection rates, seasonal variation in transmission, and duration of the prophylactic effect of the treatment drugs should be used to guide the frequency of intervention required.…”

Malaria Parasite Species Composition of Plasmodium Infections Among Asymptomatic and Symptomatic School-Age Children in Rural and Urban Areas of Kinshasa, Democratic Republic of Congo

“…It has been shown that continuous systematic malaria screening and treatment of asymptomatic individuals, such as school-aged children, in high-transmission settings may reinforce malaria intervention measures (7,71,72). Moreover, school-based malaria prevalence surveys (are easier to conduct and are cost-effective for more de ned assessments at the local level, including routine longitudinal malaria surveillance as it is a reliable indicator of malaria burden and transmission intensity in a de ned community (30,73).…”