Study compares different strategies to prevent malaria among pregnant women in sub Saharan Africa

Screen and treat strategy for pregnant women in sub Saharan African does not reduce adverse outcomes compared with standard preventative treatment for malaria

A novel strategy to screen pregnant women for malaria with rapid diagnostic tests and treat the test-positive women with effective antimalarials does not lower the risk of adverse pregnancy outcomes compared with treating all pregnant women with the malaria preventive sulfadoxine-pyrimethamine (SP) in sub-Saharan Africa, according to an open label randomized trial published this week in PLOS Medicine by Feiko ter Kuile, of the Liverpool School of Tropical Medicine, and colleagues.

During pregnancy, infections with Plasmodium malaria parasites can be asymptomatic but still lead to maternal anemia, low birthweight, and foetal loss.. In areas where malaria is endemic, the World Health Organization currently recommends treating women with SP three or four times during pregnancy. But in some areas, more than 90 percent of Plasmodium parasites are now resistant to SP. In the new study, the researchers compared this standard of care to a screening approach where women are tested approximately monthly for malaria using rapid diagnostic tests and treated with a different drug, dihydroartemisinin-piperaquine (DP) only if positive for the parasite. The study involved 1873 HIV-negative women at three sites in Malawi who were randomly assigned to receive either strategy.

The prevalence of adverse birth outcomes and maternal deaths was similar in the two groups. However, there were eight percent more cases of malaria at delivery in women assigned to the rapid screening and DP treatment group, meaning an additional eight out of every 100 pregnancies would be affected by malaria using this approach compared to broad prevention using SP. Moreover, the rate of foetal loss was 2.6 percent, double the rate of 1.3 percent seen among women who took intermittent doses of SP. The current results, however, may not hold true in all areas since malaria transmission varies and parasites also vary in their resistance mutations. In addition, the researchers were not able to test the efficacy of using monthly DP for prevention, rather than only coupling it with screening, but this will be studied in the future.

Professor Feiko ter Kuile said: "These results suggest that intermittent screening and treatment with DP may not be a suitable alternative strategy to replace intermittent preventive therapy with SP in settings similar to those studied and may even predispose to unfavorable pregnancy outcomes in these settings."

Source: Liverpool School of Tropical Medicine