Testing for Hepatitis C Virus Infection

Editor – I have read the article “Tests of Liver Injury”¹ and found the discussion on hepatitis C testing of great interest. In our Ugandan (East Africa) patients, we have problems obtaining consistent results with hepatitis C ELISA kits (HCV EIA). Different HCV EIA kits give varied results making it difficult to confirm the presence of HCV RNA, as some of the negatives are later confirmed positive by the quantitative HCV RNA test.

Although both of the EIA kits screen for the same HCV antigens (the core, NS3, NS4 and NS5) and claim to cover all the 6 known genotypes, neither give consistent results in our populations. One problem is these kits have not been validated in African populations, and we do not know the prevalence of the HCV genotypes circulating in the population. I plan to genotype our population in order to determine whether our use of these EIA kits will provide valid results for our patients, but until the genotype data is available, I am resorting to using the RIBA test to confirm infection and subsequently genotyping positive samples. However, I have been informed the RIBA test is quite expensive compared to HCV RNA testing.

I am, at the moment, uncertain which tests to choose so patients are not diagnosed falsely as positive or negative for HCV infection. I would appreciate additional discussion from the authors regarding the use and validity of these different tests for HCV infection.