A METHOD FOR THE DETECTION AND CONFIRMATION OF ANTIBODIES TO HEPATITIS-C VIRUS IN DRIED BLOOD SPOTS

This study describes the development and evaluation of a cost effectiv e test rationale for the detection of anti-HCV in dried blood spots. S amples were screened using an 'in house' IgG ELISA that incorporated t he recombinant proteins c22-3, c200 and NS5. Confirmation of specific antibody to HCV was by a modification of the immunoblot RIBA 3.0. An e xtensive panel of well evaluated anti-HCV positive and negative sample s from the UK and South Africa were used to assess the sensitivity and specificity of the two tests. One third of the anti-HCV positive samp les had been typed. All anti-HCV positive samples were detected by the 'in house' screening EIA. Test/negative optical density ratios showed that more than 95% of reactive samples produced values greater than 5 .0. Antibodies to HCV could be detected in a wide range of samples der ived from asymptomatic and symptomatic patients and of different genot ypes, with similar sensitivity. The presence of anti-HCV could be conf irmed by RIBA 3.0 in samples with low reactivity but not in anti-HCV n egative samples. Furthermore the immunoblot assay successfully increas ed specificity by screening out false reactive EIA samples that might occur in an epidemiological survey of a multi-ethnic population. (C) 1 997 Elsevier Science B.V.