Pregnant women as a sentinel population for genomic surveillance of malaria in the Democratic Republic of Congo

Genomic surveillance is a valuable tool for detecting changes in the drug susceptibility of malaria parasites, allowing early modification of treatment strategies. However, implementation can be costly and problematic to set up in fragile and high-burden countries, especially when targeting cohorts of children. To address these challenges, we investigated whether in the Democratic Republic of Congo pregnant women attending antenatal care (ANC) services could act as a surrogate sentinel population. Between 2021 and 2023, we conducted a study in Kinshasa, targeting 4,001 pregnant women attending ANCs, and 2,794 children living in the same area. Blood samples from malaria-positive cases were genotyped using an amplicon sequencing platform, to allow comparisons of Plasmodium falciparum genomes between the two cohorts and estimations of drug-resistance mutations prevalence. Parasite populations sampled from the two cohorts exhibited highly similar allele frequencies at all tested loci, including drug resistance markers potentially under selection. Pregnant women did not have higher frequencies of sulphadoxine-pyrimethamine resistant haplotypes, which undermine preventive treatments, than children, and we did not find any kelch13 mutation at significant frequency. Although parasite densities were lower in adults, the complexity of infection was similar to that in children. There was no evidence of Plasmodium vivax infections in the study. A cohort of pregnant women produces highly similar results to those from children, allowing the implementation of simple and efficient genomic surveillance systems integrated into routine ANC activities, while benefitting women with diagnosis and treatment. ClinicalTrials.gov Identifier: [NCT05072613][1]. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study was funded by Bill & Melinda Gates Foundation and the Wellcome Trust of England. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Approval was given by the research ethics committee of the University of Oxford (OxTREC, 548-21), the Kinshasa School of Public Health (ESP/CE133/2021) and the Ministry of Health of DRC (025/GPK/CAB/MIN.SPH/LNK/NIP/ski/2021). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT05072613&atom=%2Fmedrxiv%2Fearly%2F2024%2F05%2F27%2F2024.05.27.24307472.atom