EVALUATION OF A NEW RAPID DIAGNOSTIC TEST “DETERMINE™ MALARIA PF” AGAINST STANDARD BLOOD FILM, ICT MALARIA P.F™ AND PARASIGHT™ F

A new rapid immunochromatographic test for malaria diagnosis, Determine™ Malaria Pf, was evaluated. This diagnostic kit is an antigen capture assay based on the detection of histidine-rich protein 2 (HRP-2) of Plasmodium falciparum. Positive test results are read visually, with the formation of red bands within 30 min. 438 patient samples were tested from malaria endemic areas in Palawan, Philippines and non-endemic areas, the Research Institute for Tropical Medicine in Metro Manila and the Komagome Hospital and Keio University Hospital in Tokyo. Of 136 malaria samples, 101 was P. falciparum, 33 P. vivax and 2 mixed infection. There were 302 other diseases, 26 of infectious nature, 201 non-infectious, and 75 working normals. Using microscopy as the gold standard, . sensitivity for Determine™ Malaria Pf, ICT Malaria P.f ™ and ParaSight™ F was 100%, 99% and 100%, respectively, and specificity was 96.7%, 99.1%, and 93.4%, respectively. The positive predictive value for Determine™ Malaria Pf was 90.4%, 97.1% for ICT Malaria P.f™ and 82.4% for ParaSight™ F. The negative predictive value was 100% for Determine™ Malaria Pf, 99.7% for ICT Malaria P.f™ and 100% for ParaSight™ F. Determine™ Malaria Pf had an analytical sensitivity for Parasite detection as low as 30-50 Parasites/μl. Antigenemia was seen to persist until about9 days in patients treated with the second line drug sulfadoxine-pyrimethamine (Fansidar ®) despite a negative blood film. It was longer in chloroquine-treated patients, 14-21 days, only to give a strong positive signal on the day some patients recrudesce, also with a positive blood film. Following of HRP-2 antigen clearance might be used to predict early treatment failures or drug resistance. Determine™ Malaria Pf is a very simple 2-step rapid and convenient procedure with excellent sensitivity and specificity. Its marked simplicity and reliability makes it ideal for field use where remote health centers are minimally equipped and staffed, and malaria diagnosis urgently needed.