Objective: The objective of this study was to assess the impact of universal versus risk-based hepatitis C (HCV) testing of source patients' (SPs) postexposure to blood and body fluids on the HCV exposure rates among healthcare workers.
Methods: Exposure and test result information between 1993 and 2004 was abstracted from the Johns Hopkins Bloodborne Pathogen Database. A Poisson regression model estimating HCV infection among underlying SPs based on partial testing was developed and applied.
Results: After adjusting for the effect of partial testing of SPs, the estimated underlying prevalence of HCV-positive SPs increased slightly during the study period, from 11.9% to 15.1%, but the trend was not statistically significant. Yield curve of HCV-positive SPs rose quickly when SPs' testing rates were low but became flat when SPs' testing rates were high.
Conclusion: Reliance on HCV risk factors to screen SPs resulted in an underestimation of the prevalence of HCV in SPs before 1997 when the testing rates were between 15.4% and 25.6%. When SPs' testing rates were above 65%, our model predicted no additional yield of HCV-positive SPs.