Comparison of Two Rapid Immunochromatographic Assays (ICT Malaria P.f. /P.v. Test and OptiMAL Test) with Microscopy for Detection of Malaria Parasites.

ABSTRACT

This study was done to compare the ability of newly developed immunochromatographic assays (ICT), i.e., ICT malaria P.f. / P.v. test and optiMAL test with standard microscopy for the diagnosis of malaria. ICT P.f. / P.v. test detects Plasmodium falciparum specific histidine rich protein-2 (HRP2) antigen and a pan-malarial common specific antigen, where as optiMAL test detects P. falciparum specific parasite Lactate Dehydrogenase (pLDH) enzyme and a common specific pLDH enzyme. Material and Methods: Blood samples were obtained from 150 patients clinically diagnosed as malaria between July 2011 to December 2011.The venous blood were tested for malaria by microscopy and simultaneously ICT P.f./P.v.and optiMAL tests. Results: From total 150 samples, 59 (39.3%) were positive by blood films while 64 (42.7%) were positive by ICT p.f. / p.v. and 52 (34.7%) by optiMAL tests. The blood film indicated that 32.2% (19 of 59) of patients were positive for P. vivax and 67.8% (40 of 59) were infected with P. falciparum. ICT P.f./P.v. test showed 23.4% (15 of 64) were positive for P. vivax and 76.6% (49 of 64) were infected with P. falciparum. Similarly, optiMAL test detected 30.8% (16 of 52) were positive for P. vivax and 69.2% (36 of 52) were infected with P. falciparum. ICT P.f./P.v. test had sensitivities 78.9%, 87.5% and specificities 100%, 87.3% for P. vivax and P. falciparum respectively. optiMAL test showed sensitivities 84.2%, 80% and specificities 100%, 96.4% for P. vivax and P. falciparum respectively. Conclusion: These rapid immunoassays (ICT P.f./P.v. and optiMAL) tests can be used as supplementary to traditional light microscopy for the diagnosis of malarial parasites.