# Investigating the dynamics of Plasmodium falciparum gametocyte carriage in expectant women under intermittent preventive treatment with sulfadoxine-pyrimethamine in Kilifi, study protocol

## TL;DR

This study investigates how sulfadoxine-pyrimethamine treatment affects malaria gametocyte levels in pregnant women in Kilifi, Kenya, to improve malaria prevention strategies.

## Contribution

The study introduces a cross-sectional investigation into gametocyte carriage dynamics in pregnant women receiving IPTp-SP in a high malaria transmission area.

## Key findings

- The study will assess the prevalence of Plasmodium falciparum gametocytes in pregnant women receiving IPTp-SP.
- Findings may inform new interventions to improve malaria prevention during pregnancy.
- The research will evaluate factors influencing IPTp-SP uptake and its efficacy in reducing parasite prevalence.

## Abstract

Malaria in pregnancy remains a public health problem. The World Health Organization (WHO) recommends intermittent preventive treatment with sulfadoxine-pyrimethamine (IPTp-SP) to all pregnant women in moderate to high malaria transmission areas. Kenya's Ministry of Health recommends at least three doses of IPTp-SP (IPTp-SP3 +) to pregnant women in regions where malaria is endemic. Although SP remains cost-effective and effective for IPTp, there are two main challenges with the use of SP: i) widespread use of SP can lead to an increase in the prevalence of drug resistance molecular markers, including those encoding for
Plasmodium falciparum dihydrofolate reductase (
dhfr) and P
f dihydropteroate synthase (
dhps) and ii) SP, used either for curative or preventive treatment, is associated with microscopic and sub microscopic gametocytaemia, both of which contribute to sustained malaria transmission. Our study aims to investigate the dynamics of
Plasmodium falciparum gametocyte carriage in pregnant women under intermittent preventive treatment with sulfadoxine-pyrimethamine in Kilifi.

This will be a cross-sectional study and will recruit (N=462) expectant women attending antenatal care (ANC) clinics in four health facilities within the Kilifi Health and Demographic Surveillance Sites: Njunju, Pingilikani, Ngerenya, and Kilifi County Teaching and Referral Hospital (KCTRH). To be recruited into our study, women will need to be in their first or second pregnancy when they are more likely to have malaria and should have had at least one dose of sulfadoxine-pyrimethamine.

Our study will provide information on the current status of malaria during pregnancy in Kilifi and the prevalence of gametocytes among expectant mothers on IPT-SP. The results of this study may help inform new interventions to prevent malaria during pregnancy, including adding a third drug to SP with probable gametocytocidal effects.

Malaria during pregnancy poses significant risks to both maternal and fetal health, increasing the likelihood of maternal anemia, low birth weight, and premature delivery. In regions with high malaria transmission, such as Kilifi, Kenya, intermittent preventive treatment with sulfadoxine- pyrimethamine (IPTp-SP) is used to prevent malaria in pregnant women. Although IPTp-SP is generally regarded as safe and effective, recent evidence indicates that its performance may be suboptimal. This study aims to determine the prevalence of malaria parasitemia among pregnant women attending antenatal care (ANC) clinics in Kilifi. It will evaluate the IPTp-SP efficacy by determining parasite prevalence and gametocyte carriage in pregnant women. Additionally, the study will identify factors that influence IPTp-SP uptake by analyzing data from a previous larger study, the Kilifi Perinatal and Maternal (KIPMAT) study, which investigated the impact of various risk factors—such as HIV infection, maternal nutrition, malaria, and anemia—on maternal and infant morbidity and mortality. The findings from this research will help inform strategies to optimize malaria prevention and treatment during pregnancy, ultimately improving maternal and child health outcomes.