P R O T O C O L S U M M A R Y  Title: Field evaluation of the performance of HCV Serological Rapid Diagnostic Tests among HCV/HIV co-infected patients.  Aim: To evaluate the performance of serological HCV Rapid Diagnostic Tests (RDTs) to identify tests adapted to resource-limited settings, reliable for HIV-infected patients.  Study design: Prospective evaluation of the performance of serological RDTs for HCV screening.  Primary objective: o To evaluate the performance of serological HCV RDTs under field conditions using as reference standard a combination of enzyme immunoassay (EIA) and recombinant immunoblot assay (RIBA) for the detection of antibodies anti-HCV in HIV infected patients.  Secondary objectives: o To describe the accuracy (sensitivity, specificity) of the RDTs as screening tests o To describe the performance of the RDTs according to the HCV genotype and HCV VL o To describe the performance of the RDTs according to the CD4 counts and HIV VL o To describe the performance of the RDTs in presence of HBV co-infection (presence of antigen anti-HBs (HBsAg)) o To describe the operational characteristics of the tests including ease of use, technical complexity and inter-reader variability. o To evaluate predictive values of each HCV RDT based on the prevalence of the testing center.