Positive blood culture with Plasmodium falciparum: case report

An adult traveler presented with fever and malaise after returning from Sierra Leone. Young trophozoites of Plasmodium falciparum were seen in a blood smear, with parasitemia being 10%. Moreover, blood cultures drawn on admission signaled as "positive" after 1 day of incubation, but no bacteria were seen in the Gram stain or were subcultured. A Giemsa-stained smear from the positive bottle contents yielded numerous pigmented, mature trophozoites of P. falciparum. This case indicates that, in patients with malaria, the growth of P. falciparum in blood cultures can result in "false"-positive blood cultures.