[Prevalence of hepatitis C virus infection in Morocco and serological tests assessment of detection for the viremia prediction]

Abstract

This study aims at assessing the prevalence of hepatitis C virus infection (HCV) in Moroccan general population and the efficacy of different virological tests in detection of the viral RNA in order to promote its screening.

Methods: From December 1st 2005 to April 30th 2007, the prevalence of the anti-HCV antibodies was determined for 8326 people. The mean age was 42.3+/-11.2 years (18 to 87 years) and sex ratio man/woman: 1.6. The determination of the anti-HCV antibodies in our sample has been achieved by the third generation ELISA. Among the detected cases as anti-HCV negative, 100 have been assessed by two other methods: AxSYM HCV and (Acon HCV): a fast test using immune chromatography on the membrane. Furthermore, the ELISA positive cases, 158 have been tested by the two previous techniques and submitted to viral RNA research by RT-PCR. The detection threshold has been fixed at 50 Ul/ml.

Results: The anti-HCV prevalence determined by ELISA was estimated at 1.93%. The mean age of the positive cases was 50.4 years. The viremia prevalence for positive anti HVC was 39%. The assessment of the methods AxSYM HCV, Acon and PCR compared to ELISA showed that the 100 anti negative VHC cases were also negative for the two other tests. For the 158 anti-VHC positive cases by ELlSA, 100 were also positive by AxSYM HCV, 78 by Acon HCV and 61 were RNA positives. The comparison of the anti-VHC positive results achieved by AxSYM HCV and Acon HCV methods with those related to the presence of viral RNA, showed that the AxSYM HCV method has a sensitivity=100%, a specificity=60%, a positive predictive value=61% and a negative predictive value of 100%. Whereas for the Acon HCV, the sensitivity was 99%, the specificity 87%, the positive predictive value 82% and the predictive negative=100%.

Conclusion: The prevalence of anti-HCV obtained by ELISA has been overestimated. It is necessary to use more specific tests to reduce the risk to announce a false positive result to the patient and to reduce the expenses due to the realization of PCR in case of false positives.