A cost-effective algorithm for the diagnosis of Hepatitis C virus infection and prediction of HCV viremia in Cameroon

Conventional tests for antibody to Hepatitis C virus (HCV) and HCV RNA require considerable time before results are available, remain very expensive and are not adapted to many sub-Saharan African countries where HCV is endemic. The aim of this study was to evaluate the accuracy of an algorithm consisting of two HCV rapid tests to diagnose and predict HCV viremia in patients in Cameroon.Three hundred and twenty nine plasma samples were screened by two HCV rapid tests (ImmunoComb® II HCV, PBS Orgenics and Hexagon® HCV, Human). Previous evaluation of these samples for HCV antibodies (anti-HCV) by conventional third generation ELISA, considered as a reference test, indicated that 168 were anti-HCV negative and 161 positive. Among the 161 anti-HCV positive plasma, 114 (71%) were HCV RNA-positive by RT-PCR assay.The ImmunoComb® II HCV test provided the more sensitive detection of anti-HCV (sensitivity: 99.4% with a 95% CI = 96–100%). Surprisingly, the second HCV rapid test, Hexagon® HCV, showed a high capacity to identify non-viremic subjects amongst anti-HCV positive cases (93.6% [95% CI: 82–99%]). These results suggest an algorithm using ImmunoComb® II HCV as a first test to screen anti-HCV positive subjects, and Hexagon® HCV as a second test to discriminate between viremic and non-viremic HCV seropositive subjects.