USEFULNESS OF PARASIGHT(TM)F FOR DIAGNOSI S OF PLASMODIUM-FALCIPARUM MALARIA

The ParaSight(TM)F is a new diagnostic test for Plasmodium falciparum infections and is based on the detection of a trophozoite-derived anti gen, the histidine rich protein LI (HRP-II). To assess the usefulness of this test, we conducted a prospective study and analyzed 62 blood s pecimens from 38 patients, using thin blood films, thick blood films a nd the ParaSight(TM)F test. Compared to thick blood film, on samples t aken before and during treatment, the ParaSight(TM)F test had 86.4% se nsitivity and 100% specificity. In 31.5% of P. falciparum infected pat ients, parasitemia was lower than 1 parasite/1000 red blood cells, wit h all specimens being positive by the ParaSight(TM)F test. In 15 cases , specimens were negative by thin blood film, but were positive by thi ck blood film and by the ParaSight(TM)F test. Two patients had, after their treatment was started, positive results by ParaSight(TM)F and ne gative results by thick blood film. Cross-reactivity occurred neither with other Plasmodium species, nor in cases of severe inflammatory syn drom. Persistence of antigenemia was monitored in 14 patients receivin g quinine. At day five of treatment, antigenemia persisted in seven pa tients. In conclusion, the ParaSight(TM)F test does not allow followin g up the efficacy of treatment, identifying other Plasmodium species, or assessing parasitemia. However, because this test is easy to perfor m and has good sensitivity and specificity, it is a useful tool in eme rgent context, in cases of parasitemia lower than the thin blood film threshold, and in cases morphologically difficult to decipher.