PARASIGHT(R)F TEST COMPARED WITH THE POLYMERASE CHAIN-REACTION AND MICROSCOPY FOR THE DIAGNOSIS OF PLASMODIUM-FALCIPARUM MALARIA IN TRAVELERS

Imported malaria is an increasing problem worldwide. A rapid and accur ate test for Plasmodium falciparum infection would facilitate the diag nosis of malaria in the returned traveler The ParaSight(R)F antigen ca pture assay (dipstick test) is a new diagnostic test for P. falciparum based on detection of circulating histidine-rich protein-2 antigen. W e performed a blinded evaluation of this assay compared with microscop y and the polymerase chain reaction (PCR) for the detection of P. falc iparum infection in 151 febrile travelers. Compared with the PCR, the dipstick test had a sensitivity of 88% and a specificity of 97%. The a bility of the dipstick test to detect P. falciparum was similar with t hat of microscopy (88% versus 83%) since the species of Plasmodium in 14 of 133 malaria-infected patients could not be determined by microsc opy due to low parasite numbers. The dipstick test was 40% sensitive f or infections with < 50 parasites/mu l, 89% with 50-100 parasites/mu l , and greater than or equal to 93% with > 100 parasites/mu l. Circulat ing antigen was detectable in 68% of the patients seven days after ini tiation of treatment and in 27% at day 28. The dipstick test represent s a simple and accurate test for the diagnosis of P. falciparum infect ion in the returned traveler.