Prevalence and Risk Factors of Occult HCV Infection in the Adult Population of Mexico City

Occult HCV infection (OCI) is defined by the presence of HCV RNA in hepatocytes and/or peripheral blood mononuclear cells (PBMCs) without detectable HCV RNA or anti-HCV antibodies in plasma. OCI is underrecognized and may contribute to HCV transmission. This study estimated OCI prevalence and associated risk factors in adults from Mexico City. Methods: A retrospective cross-sectional study was conducted, analyzing 507 general population volunteers. Demographic data and potential risk factors were collected via questionnaire. Anti-HCV detection was performed using two techniques: immunochromatographic rapid test and chemiluminescent microparticle immunoassay (CMIA). Nested PCR was employed to detect HCV RNA in plasma and PBMCs. Positive samples were genotyped through sequencing and phylogenetic analysis of the Core/E1 region. Results: Of 507 participants, four were anti-HCV positive. HCV RNA was found in PBMCs of 27 individuals, while plasma samples tested negative, indicating a 5.3% OCI prevalence. OCI was significantly associated with blood donation (p = 0.015), drug use (p = 0.019), particularly cocaine (p = 0.001), and endoscopy (p = 0.043). Genotypes 1b, 1a, 2b, 3a, and 2j were detected in OCI cases. Conclusions: OCI prevalence in Mexico City's general population is notable, with significant links to blood donation, cocaine use, and endoscopy. Enhanced diagnostic strategies are crucial to detect OCI and mitigate HCV transmission.