Prevalence and clinical implications of occult hepatitis C infection: a meta-analysis of studies conducted in Egypt

Abstract Background Egypt had the highest prevalence of hepatitis C virus (HCV) infection. However, the underlying mechanisms of occult HCV infection (OCI) remain unclear. OCI is defined by the presence of HCV RNA in hepatocytes or peripheral blood mononuclear cells (PBMCs) despite undetectable levels in serum. This hidden viral reservoir may contribute to late relapse in antiviral-treated patients. This study aims to quantify OCI prevalence across different subgroups in Egypt, evaluate its association with liver enzyme levels, and examine the recurrence rate of viremia among OCI cases. Methods A comprehensive literature search was conducted from inception to January 29, 2025, across PubMed, Scopus, Cochrane Library, Virtual Health Library, Google Scholar, and Web of Science. Results were reported as prevalence (%) or standardized mean differences (SMD) with a 95% confidence interval (CI), using a random-effects model. All statistical analyses were performed using Comprehensive Meta-Analysis software, with a p -value of less than 0.05 considered statistically significant. Results This study included 36 articles with study durations spanning from 2010 to 2022. OCI prevalence was lowest in healthy individuals (5.2%) and highest in patients with blood-related malignancies (32%) and liver disease (21.9%). Among other groups, prevalence was 9.5% in hemodialysis patients, 11.4% in HCV patients who achieved SVR, and 13.6% in individuals who spontaneously recovered from HCV. Genotype 4 was the most frequently reported genotype in OCI cases. Viremia recurrence among OCI-positive patients who achieved SVR ranged from 5 to 50%. ALT and AST levels were significantly higher in the OCI group, with an SMD of 1.56 (95% CI: 0.86–2.26, p < 0.001) for ALT and 1.70 (95% CI: 0.86–2.60, p < 0.001) for AST. Conclusions The prevalence of OCI is significantly high among patients with blood-related malignancies and liver disease. Of particular concern is its presence in blood donors and apparently healthy individuals, underscoring potential public health implications. Moreover, follow-up studies have documented a high rate of viremia in HCV patients who achieved SVR, suggesting a potential mechanism for late relapse. These findings underscore the necessity for continued surveillance and longitudinal studies to elucidate OCI’s role in viremia persistence, its infectious potential, and its association with both hepatic and extrahepatic complications.