Identification of cryptic coinfection with Plasmodium falciparum in patients presenting with vivax malaria

• Main Authors: M. Mayxay, S. Pukrittayakamee, K. Chotivanich, M. Imwong, S. Looareesuwan, N. J. White
• Other Authors: Mahidol University
• Format: Article
• Published: 2018
• Subjects: Immunology and Microbiology; Medicine
• Online Access: https://repository.li.mahidol.ac.th/handle/123456789/26576

In Thailand, ∼ 8% of patients treated for vivax malaria are found subsequently to have coinfection with Plasimodium 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.