Variation of plasma plasmodium density among women receiving sulfadoxine – pyrimethamine for intermittent preventive treatment of malaria during pregnancy

Malaria prophylaxis during pregnancy is gradually being replaced with intermittent preventive treatment (IPT) using sulfadoxine - pyrimethamine (SP). This change in approach has been deemed necessary because of the high resistance to chloroquine by Plasmodium falciparum observed in malaria endemic zones. Chloroquine has been widely used for malaria prophylaxis. The objectives of this study was to evaluate the changes in plasmodium density among women receiving SP for IPT. The second objective was to determine the proportion of women who develop clinical malaria despite IPT. It was a descriptive analytic study that lasted two years (2003 – 2004 inclusive) at the Yaounde Central Maternity and at the University Biotechnological Centre in Nkolbison, Yaounde. 210 pregnant women who accepted freely to participate in the study were recruited between the 18 th and 20 th week of gestation. Parasite densities were determined initially (To) before the first dose of SP and two weeks after at T1, also at T2 (before the second dose of SP) and at T3 (two weeks after the second dose). The final parasite density estimations were at birth (T4). The women were followed up closely for evidence of clinical malaria. Ten out of 210 pregnant women recruited defaulted. Consequently only 200 women were followed up to term and received two doses of SP. 35.5% of them were infected at To with an average parasite density of 1415.9+155/mm3. At T1, the proportion of infected women and the average parasite density decreased to 6% and 755.62 + 205/mm 3 respectively. The proportion of infected women rose to 10.0% at T2 but the parasite density dropped to 385.44+ 331/mm 3 . At T3, only 1.4% of the women were infected and the average parasite density was 100/mm 3 . At T4, no woman had a positive blood smear. 6.25% of the women developed clinical malaria. Clinics in Mother and Child Health Vol. 2(2) 2005: 351-353