Efficiency of the Paracheck - Pf test for rapid diagnosis of Plasmodium falciparum malaria

Abstract

The performance of the Paracheck Pf dipstick method that detects Plasmodium falciparum histidine-rich protein-2 (Pf HRP-2) antigen in whole blood was evaluated in a malaria endemic area. Results were compared with conventional giemsa-stained thick blood films. A total of 14% (20/141) patients were found to be parasitemia; of these 7% (9/121) were Plasmodium falciparum and 8% (10/121) were Plasmodium vivax infections. The Paracheck Pf test was positive in 9/64 with P. falciparum identified on blood smear examination, resulting in a sensitivity of 90% (9/10). Specificity was 99.2 (130/131). Of the 1 false positives and 1 false nagative, 1 patient reported Plasmodium vivax. The Paracheck Pf test missed one patient with high parasite density (32,520 parasites/l). The test is highly sensitive and specific requiring no instrument or trained personnel. It appears to be a very useful tool for rapid diagnosis of malaria, especially in remote areas with limited diagnosis facilities.