GSTM1 and malaria: Of those, 823 women had a blood smear collected, and in 141 (17%) of them malaria infection was confirmed by microscopy; 68 cases were due to P. vivax, 72 cases were due to P. falciparum, and one case was due to P. malariae. In 85% (117/137) malaria episodes women were found to be anemic (Hb<11g/dL) and 14% (19/137) severely anemic (Hb<7g/dL).