Comparison of Parascreen Pan/Pf, Paracheck Pf and light microscopy for detection of malaria among febrile patients, Northwest Ethiopia.

Two malaria rapid diagnostic tests (RDT), Parascreen Pan/Pf and Paracheck Pf, were tested in rural health centres in Ethiopia against independent expert microscopy (the gold standard). Participants (n =1997) presented with presumptive malaria to ten health centers in Amhara Regional State during the 2007 peak malaria season (October to December). By microscopy, 475 (23.8%) suspected malaria cases were positive, of which 57.7% were P. falciparum; 24.6% P. vivax and 17.7% mixed infections. Parascreen and Paracheck were positive for 442 (22.1%) and 277 (13.9%) febrile patients, respectively. For Parascreen, P. falciparum sensitivity was 79.6%, specificity 97.4%, positive predictive value (PPV) 86.9%, and negative predictive value (NPV) 95.6%. For Parascreen, P. vivax sensitivity was 74.4%, specificity 98.6%, PPV 76.3% and NPV 98.4%. For Paracheck, P. falciparum sensitivity was 73.7%, specificity 99.2%, PPV 95.3%, NPV 94.5%. Sensitivity was significantly higher for both tests (P<0.05) when parasite density was >100/microl of blood; in these cases Parascreen was 90.7% and 91.5% sensitive for P. falciparum and P. vivax, respectively, while Paracheck was 87.9% sensitive for P. falciparum. Parascreen thus performed adequately for both P. falciparum and P. vivax compared to expert microscopy and is more useful than Paracheck where microscopy is unavailable. Copyright 2010 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.