Diagnostic Efficiacy of Immunochromatography Technique for Detection of Viral Hepatitisinfection in Suspected Serum Specimens

A prospective study was conducted in order to evaluate the diagnostic efficacy of immunochromatography assays for qualitative detection of hepatitis B surface antigen and hepatitis C virus antibodies, using commercially available rapid test devices. Rural population of district Chakwal visiting primary care hospitals for screening of hepatitis B and hepatitis C virus infections was selected as study population. Coagulated blood specimens were collected from a total of 500 individuals; serum was separated and stored at -20 C till analysis. Necessary demographic information with previous exposure and screening history of each individual was also recorded in pre designed performa. The stored serum specimens were analyzed for detection of hepatitis B surface antigen and hepatitis C virus antibodies through immunochromatography technique (ICT) and enzyme linked immunosorbant assay (ELISA) using commercially available ICT rapid test devices and ELISA kits. Out of total 500 specimens analyzed through ICT for HBs Ag detection, 15 exhibited positive outcome for the infection whereas analysis of the same specimens through standard ELIS test revealed 16 true positives. One of the ICT tested specimens was therefore recorded as false negative. The sensitivity of rapid test device for HBs Ag detection was therefore 93.75% with 100% specificity, 100% positive predictive value and 99.8% diagnostic accuracy. Similarly 34 of the 500 ICT tested specimens exhibited positive outcome for hepatitis C virus infection whereas 37 true positives were recorded when same specimens were analyzed through standard ELISA test. The sensitivity of ICT rapid test device for HCV Ab detection was therefore 91.89% with 99.57% specificity, 94.44% positive predictive value, 99.35% negative predictive value and 99% diagnostic accuracy. The findings indicate that the rapid diagnostic immunoassays, in spite of requiring minimum time and equipment, are not comparable with standard ELISA for screening of hepatitis B and hepatitis C virus infections.