Comparing approaches for chemoprevention for school-based malaria control in Malawi: an open label, randomized,...

School-age children in sub-Saharan Africa suffer an underappreciated burden of malaria which threatens their health and education. To address this problem, we compared the efficacy of two school-based chemoprevention approaches: giving all students intermittent preventive treatment (IPT) or screening and treating only students with detected infections (IST).

In a three-arm, open-label, randomized, controlled trial (NCT05244954) in Malawi, 746 primary school students, aged 5-19 years, were individually randomized within each grade-level to IPT (n = 249), IST with a high-sensitivity rapid diagnostic test (hs-RDT, n = 248), or control (n = 249). At six-week intervals three times within the peak malaria transmission season (February-June 2022) treatment with dihydroartemisinin-piperaquine (DP) was administered to girls <10 years and all boys, and chloroquine to older girls. The primary outcome was Plasmodium falciparum (Pf) infection detected by PCR 6-8 weeks after the final intervention. Secondary outcomes included anaemia, clinical malaria, and scores on tests of attention, literacy, and math. Analysis was by modified intention-to-treat.

Outcomes analyses included 727 (97%) participants. At the end of the study, prevalence of Pf infection was 17% (41/243) in the IPT arm, 24% (58/244) in the IST arm, and 53% (127/240) in the control arm. Compared to controls, IPT and IST reduced the odds of Pf infection (IPT adjusted odds ratio [aOR]: 0.18 (95% CI: 0.11, 0.27); p < 0.0001; IST aOR: 0.27 (95% CI: 0.18, 0.40); p < 0.0001). However, only participants receiving IPT had a lower incidence of clinical malaria (0.19 cases per person per six months (95% CI: 0.14, 0.27) vs 0.56 (95% CI: 0.46, 0.68); incidence rate ratio: 0.38 (95% CI: 0.26, 0.55); p < 0.0001)) and prevalence of anaemia (8% [20/243] vs 15% [36/240]; aOR: 0.49 (95% CI: 0.27, 0.91); p = 0.023) compared to controls. Literacy scores were higher in both intervention arms. No between group differences in tests of attention or math or number of serious adverse events were found.

Results support implementation of IST with hs-RDTs or IPT for reduction in the prevalence of infection. Based on reductions in clinical malaria, IPT may provide additional benefits warranting further consideration by school-based malaria chemoprevention programs.

Doris Duke Charitable Foundation Clinical Scientist Development Award 2021191, U.S. NIH K24AI114996 & K23AI135076.