The rapid and spontaneous post-partum clearance of Plasmodium falciparum is related to expulsion of the placenta.

Parasitemia among pregnant women with protective immunity to P. falciparum malaria is often dominated by VAR2CSA-positive infected erythrocytes (IEs). VAR2CSA mediates sequestration of IEs in the placenta. We hypothesized that the previously observed spontaneous post-partum clearance of parasitemia in such women is related to the expulsion of the placenta, which removes the sequestration focus of VAR2CSA-positive IEs. We assessed parasitemias and gene transcription before and shortly after delivery in 17 Ghanaian women. The precipitous decline in parasitemia post-partum was accompanied by selective reduction in transcription of the gene encoding VAR2CSA. Our findings provide a mechanistic explanation for the earlier observation.