Evaluation of two rapid screening assays for detecting hepatitis C antibodies in resource-constrained settings.

OBJECTIVE

To evaluate the diagnostic accuracy of the OraQuick HCV rapid antibody test from OraSure and the Multisure HCV antibody assay from MP Biomedicals.

METHODS

Five seropanels from patients, intravenous drug users and blood donors with and without HCV infection were used on the two rapid immunochromatographic tests. Sensitivity, specificity and predictive values were calculated. In addition, seropanels from 10 seroconverters were used to assess early identification of HCV infection. The study was undertaken in a laboratory at Paul Ehrlich Institute in Germany.

RESULTS

Panel 1 contained of 55 positive and 25 negative samples. The OraQuick HCV test had a sensitivity of 100% (95% CI: 93.5-100) and a specificity of 100% (95% CI: 86.3-100). The Multisure HCV test had a sensitivity of 100% (95% CI: 93.5-100) and a specificity of 96% (95% CI: 79.6-99.9). Panel 2 consisted of 193 pre-characterised anti-HCV-positive patient samples. The OraQuick HCV test identified 191 samples correctly and the Multisure HCV 192. The sensitivity was 99.0% (95% CI: 96.3-99.9) for the OraQuick HCV test and 99.5% (95% CI: 97.1-100) for the Multisure HCV test. Panel 3 was composed of seroconversion samples of 10 patients. The OraQuick HCV test detected all of these 10 infections while the Multisure HCV test detected six and was indeterminate on 2. Panel 4 included 53 anti-HCV negative blood samples from blood donors. Both tests correctly identified all 53. Panel 5 consisted of 26 samples of HCV/HIV co-infected patients. The sensitivity of the OraQuick HCV test was 65.2% (95% CI: 42.8-82.8) after 20 min and 73.9% (95% CI: 51.3-88.9) after 40 min of incubation. The Multisure HCV test had a sensitivity of 96.2% (95% CI: 80.4-99.9).

CONCLUSION

This evaluation revealed good sensitivity for both rapid screening assays. The detection of seroconverters, however, was lower in the MutiSure HCV test. Therefore the MultiSure test should be used with hesitation in high incidence settings. The OraQuick gave HCV false-negative results in almost 25% of the HIV-positive sera. Therefore may the OraQuick be less suited in HIV prevalent areas.