Comparison of Thick Films, in Vitro Culture and DNA Hybridization Probes for Detecting Plasmodium falciparum Malaria

Abstract

Using blood from volunteers with sporozoite induced malaria, a comparison was made of the sensitivity and specificity of Giemsa stained thick film examination, in vitro culture, and 4 different DNA probes for detecting parasitemia. Between 9 and 13 days after sporozoite inoculation, patent parasitemia (4–550 parasites/µl) was detected by thick film examination of 0.5 µl blood in 7 volunteers. Cultures of 1 ml blood obtained 7 days after sporozoite inoculation were positive in all volunteers who eventually developed patent parasitemia. The DNA hybridization probes detected parasites in only 5–28% of smear- or culture-positive samples.