title: Identification of cryptic coinfection with Plasmodium falciparum in patients presenting with vivax malaria.
abstract: In Thailand, approximately 8% of patients treated for vivax malaria are found subsequently to have coinfection with Plasmodium falciparum. A P. falciparum histidine rich protein 2 (PfHRP-2) dipstick test was evaluated as a predictor of mixed infections with subpatent P. falciparum in a prospective study of 238 patients admitted to the hospital with acute vivax malaria. Of these, 23 (10%) had subsequent development of falciparum malaria without reexposure. Patients with cryptic P. falciparum infection had a significantly lower mean (standard deviation) hematocrit than those with P. vivax alone: 29.6 (7.6%) versus 37.2 (6.4%) (P < 0.0001). Using microscopic appearance of P. falciparum after the start of treatment as the reference standard, the PfHRP-2 test was 74% sensitive and 99% specific in predicting mixed infections with subpatent P. falciparum parasitemia at presentation. The PfHRP-2 dipstick test may be a useful adjunct to microscopy in areas where mixed infections are common.
authors.affiliation: Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
authors.forename: M
authors.initials: M
authors.lastname: Mayxay
authors.forename: S
authors.initials: S
authors.lastname: Pukritrayakamee
authors.forename: K
authors.initials: K
authors.lastname: Chotivanich
authors.forename: M
authors.initials: M
authors.lastname: Imwong
authors.forename: S
authors.initials: S
authors.lastname: Looareesuwan
authors.forename: N J
authors.initials: NJ
authors.lastname: White
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D016778:Malaria, Falciparum / Q000175:diagnosis*; D016780:Malaria, Vivax / Q000150:complications / Q000469:parasitology*; D008297:Male; D016133:Polymerase Chain Reaction; D011506:Proteins / Q000032:analysis; D012680:Sensitivity and Specificity; D000099053:Histidine-Rich Glycoprotein
chemical_list: D011506:Proteins; D000099053:Histidine-Rich Glycoprotein