Submicroscopic malaria infections and inadequate IPTp-SP coverage among pregnant women in rural Burkina Faso: An observational study

---

Résumé

Background: Malaria in pregnancy is a major cause of maternal and neonatal morbidity in sub-Saharan Africa. Intermittent preventive treatment with sulfadoxine-pyrimethamine (IPTp-SP), reduces malaria-associated adverse outcomes but routine diagnostics miss low-density infections, and coverage remains suboptimal in many endemic settings.

Methods: We conducted an observational study (June 2023-June 2024) at a health centre in Koubri, central Burkina Faso, combining a cross-sectional assessment at the first antenatal care (ANC) visit with retrospective abstraction of routine ANC and delivery records. At enrolment, pregnant women were tested by real-time PCR; microscopy and rapid diagnostic test (RDT) were performed when available. IPTp-SP doses, follow-up testing, and birth outcomes were extracted from facility registers. Modified Poisson regression with robust variance was used to identify predictors of PCR-confirmed infection, factors associated with low birthweight (LBW, < 2500 g) and the association between cumulative IPTp-SP doses and PCR positivity.

Results: At first ANC, PCR detected Plasmodium infection in 30.1% (155/515) of women. Among 183 women tested by all three methods, PCR prevalence was 23.5% versus 8.2% by microscopy and 8.7% by RDT, with approximately two-thirds of infections missed by routine diagnostics. Primigravidae had twice the infection risk of multigravidae (aPR 2.14, 95% CI 1.21–3.79),). Each additional IPTp-SP dose was associated with lower infection prevalence (aPR 0.89, 95% CI 0.80–0.99). Most women (78.6%) received ≥ 3 doses, but only 18.9% reached ≥ 5 doses, Among 225 deliveries, LBW prevalence was 14.7% ( PCR-confirmed infection at first ANC was associated with increased LBW risk (aPR 1.52, 95% CI 1.01–2.28).

Conclusion: Routine ANC diagnostics substantially underestimated malaria prevalence among pregnant women Higher IPTp-SP dosing was associated with reduced infection during pregnancy. but few women achieved five or more doses. Primigravidae and women living far from facilities had both lower coverage

Mots-clés

Malaria in pregnancy, Plasmodium falciparum, Intermittent preventive treatment (IPTp-SP), Sulfadoxine-pyrimethaminen, Real-time PCR, Burkina Faso