Prevalence of elevated ALT values, HBsAg, and anti-HCV in the primary care setting and evaluation of guideline defined hepatitis risk scenarios.

Background & Aims Prevalence data for hepatitis B and C and an evaluation of a guideline based screening in the primary care setting are not yet available. We therefore implemented a hepatitis B surface antigen (HBsAg) and anti-hepatitis C virus (HCV) screening and developed guideline based screening strategies. Methods HBsAg, anti-HCV, and alanine aminotransferase (ALT) were included in a routine check-up together with a questionnaire covering 16 guideline adapted risk scenarios. Significant risk factors were identified by stepwise logistic regression. Results 51 private practices screened 21,008 patients. The HBsAg, anti-HCV, and HCV-RNA prevalence was 0.52%, 0.95%, and 0.43%, respectively. Infections were previously unknown in 85% and 65% of HBsAg and anti-HCV positive individuals, respectively. Sexual risk factors were under-reported, while the following scenarios were significantly associated with viral infections (Odds ratio [95% confidence interval]). HBV: Immigration (4.4 [2.9, 6.7]), infection in household (2.5 [1.2, 4.5]), male gender (1.6 [1.1, 2.4]). Male immigrants had a 2.1% HBsAg prevalence and 80% were unaware of the infection. HCV: IV drug use (384 [233, 644]), blood transfusion before 1992 (5.3 [3.5, 7.9]), immigration (2.4 [1.5, 3.6]). Presence of either one of the HBV related guideline defined risk scenarios or elevated ALT identified 82% of previously undiagnosed patients. Presence of one of the three significant HCV risk factors or elevated ALT levels diagnosed 83% of unknown HCV-RNA positive cases by screening only 26% of the population. Conclusions Undiagnosed hepatitis B and C infections frequently exist in the primary care setting. Easy to apply guideline defined risk scenarios help to diagnose previously unknown infections.