Hepatitis C screening and detection program in a large population: Epidemiological transition and characterization of the disease.

Introduction: Chronic hepatitis C (CHC) is considered an important public health challenge. Traditionally identified risk factors have undergone an epidemiological transition where other risk factors have become the main cause of new infections.

Objective: To describe risk factors associated to hepatitis C positivity through the evaluation of the epidemiological profile in hepatitis-C high-risk populations.

Methods: Cross-sectional study was conducted as part of an HCV screening program in Mexican population. All participants answered an HCV risk-factor questionnaire and took a rapid test (RT). All patients reactive to the test were subject to HCV PCR (polymerase chain reaction) confirmation. A logistic regression model was used to examine associations between HCV infection and risk factors.

Results: The study included 297 631 participants that completed a risk factor questionnaire and underwent an HCV rapid test (RT). In total, 12 840 (4.5%) were reactive to RT and 9257 (3.2% of participants) were confirmed as positives by PCR test. Of these, 72.9% had at least one risk factor and 10.8% were in prison. Most common risk factors were history of acupuncture/tattooing/piercing (21%), intravenous drug use (15%) and high-risk sexual practices (12%). Logistic regressions found that having at least one risk factor increased the probability of having an HCV-positive result by 20% (OR = 1.20, 95% CI: 1.15-1.26), compared to the population without risk factors.

Conclusions: We identified 3.2% of HCV-viremic subjects, all associated with risk factors and older age. Screening and diagnosis of HCV in high-risk populations (including underserved populations) should be more efficient.