Modelling the incremental benefit of introducing malaria screening strategies to antenatal care in Africa

30 Jul 2020
Patrick G T Walker, Matt Cairns, Hannah Slater, Julie Gutman, Kassoum Kayentao, John E Williams, Sheick O Coulibaly, Carole Khairallah, Steve Taylor, Steven R Meshnick, Jenny Hill, Victor Mwapasa, Linda Kalilani-Phiri, Kalifa Bojang, Simon Kariuki, Harry Tagbor, Jamie T Griffin, Mwayi Madanitsa, Azra C H Ghani, Meghna Desai, Feiko O Ter Kuile

Plasmodium falciparum in pregnancy is a major cause of adverse pregnancy outcomes. We combine performance estimates of standard rapid diagnostic tests (RDT) from trials of intermittent screening and treatment in pregnancy (ISTp) with modelling to assess whether screening at antenatal visits improves upon current intermittent preventative therapy with sulphadoxine-pyrimethamine (IPTp-SP). We estimate that RDTs in primigravidae at first antenatal visit are substantially more sensitive than in non-pregnant adults (OR = 17.2, 95% Cr.I. 13.8-21.6), and that sensitivity declines in subsequent visits and with gravidity, likely driven by declining susceptibility to placental infection. Monthly ISTp with standard RDTs, even with highly effective drugs, is not superior to monthly IPTp-SP. However, a hybrid strategy, recently adopted in Tanzania, combining testing and treatment at first visit with IPTp-SP may offer benefit, especially in areas with high-grade SP resistance. Screening and treatment in the first trimester, when IPTp-SP is contraindicated, could substantially improve pregnancy outcomes.