Clinical trials of a new immunochromatographic test for diagnosis of Plasmodium falciparum malaria in Goa.

Plasmodium falciparum histidine rich protein-2 (PfHRP-2) based immunochromatographic test kit (ICT Malaria Pf) for the rapid diagnosis of P. falciparum malaria was evaluated at the clinic of Malaria Research Centre (Field Station), Goa. Of the 98 febrile patients screened, 22 were ICT positive for P. falciparum. Simultaneous microscopic examination of the blood smears of these ICT positive patients showed that 20 were positive for P. falciparum alone, whereas one had mix infection of both P. vivax and P. falciparum suggesting 100% sensitivity. Only one slide negative patient who had taken 600 mg chloroquine the previous day was positive in the ICT. Out of the remaining 76 blood smears, 41 showed P. vivax infection and none cross-reacted with P. falciparum HRP-2 antigen and were ICT negative except one mix infection case in which P. vivax and P. falciparum infections occurred concomitantly suggesting species specificity of 98.7%. The positive predictive value, negative predictive value and efficacy of the ICT were 95.4, 100 and 98.9% respectively. The band intensity of the ICT positive cases significantly correlated with P. falciparum parasitaemia (p < 0.01). The usefulness and the disadvantages of this diagnostic kit have been discussed in context of prevailing malaria situation in the country.