Abstract:
Background and Aims: To enhance screening and diagnosis in those at-risk of hepatitis
C virus (HCV), efficient and improved sampling and testing is required. We investigated
the performance of point-of-care (POC) tests and dried blood spots (DBS) for
HCV antibody and HCV RNA quantification in individuals at higher risk for HCV (people
who use and inject drugs, sex workers and men who have sex with men) in seven
South African cities.
Methods: Samples were screened on the OraQuick HCV POC test (471 whole blood
and 218 oral fluid); 218 whole blood and DBS paired samples were evaluated on the
ARCHITECT HCV antibody (Abbott) and HCV viral load (COBAS Ampliprep/COBAS
TaqMan version 2) assays. For HCV RNA quantification, 107 dB were analyzed with
and without normalization coefficients.
Results: POC on either whole blood or oral fluid showed an overall sensitivity of
98.5% (95% CI 97.4-99.5), specificity of 98.2% (95% CI 98.8-100) and accuracy of
98.4% (95% CI 96.5-99.3). On the antibody immunoassay, DBS showed a sensitivity
of 96.0% (95% CI 93.4-98.6), specificity of 97% (95% CI 94.8-99.3) and accuracy of
96.3% (95% CI 93.8-98.8). A strong correlation (R2 = 0.90) between viral load measurements
for DBS and plasma samples was observed. After normalization, DBS viral
load results showed an improved bias from 0.5 to 0.16 log10 IU/mL.
Conclusion: The POC test performed sufficiently well to be used for HCV screening in at-risk populations. DBS for diagnosis and quantification was accurate and should
be considered as an alternative sample to test. POC and DBS can help scale up hepatitis
services in the country, in light of our elimination goals.
