The Effectiveness of Inpatient Reflex Hepatitis C PCR Testing in Tertiary Medical Centers

Abstract

Introduction: While hepatitis C (HCV) antibody (Ab) testing is the standard of choice widely available for screening, confirmation of active infection requires evidence of viremia with RNA PCR testing. In general, after a positive Ab test, a clinician has to make a conscious effort and manually order HCV PCR. This is to confirm the diagnosis and rule out past infection or false positive results. While automatic reflex PCR testing of positive Ab serum samples is available in some institutions, it is unclear how well implementation of reflex PCR testing affects HCV confirmation and subsequent linkage to care. Methods: Reflex PCR testing on HCV Ab positive samples was started in June of 2015 at the Northwell Health system in New York. A retrospective reviewof inpatientswith a positive HCV Ab test performed at 2 of our tertiary care hospitals, North Shore University Hospital (NS) and Long Island Jewish Medical Center (LIJ). Data encompassing before and after starting reflex testing between 2014 to May 2018 was reviewed (Table 1). The rates of HCV PCR performed after positive Ab testing, missed PCR testing, as well as rates of positive HCV PCR were calculated and compared throughout the study period. Results: A total of 947 positive HCV Ab tests were performed during the study time period. Prior to the start of reflex testing, the rates of missed HCV PCR testing ranged from 25.9% to 36.4% between the 2 hospitals in 2014, and26.9% to 27.8% in the first half of 2015. After the implementation of reflex testing, the rate of subsequent missed HCV PCR confirmatory testing dropped over time to 0% at NS, and 4.2% at LIJ in the first half of 2018 (Table 2, Figure 1). The HCV PCR positive rate slowly declined over time, beginning with 63.6%-65.1% in 2014, down to 31.8%-47.8% for NS and LIJ respectively.933_A Figure 1. Summary of positive HCV antibody tests, confirmatory PCR testing, and positive PCR tests.Conclusion: The dramatic improvement and effectiveness ofreflex testing in PCR confirmation of HCV infection are clearly demonstrated in our study. While it tooktime for this practice to be implemented, 100% compliance with PCR testing was achieved at one hospital, and96% in the other. It is interesting to note that the rate of positive PCR declined over time, suggesting that some patients were treated and achieved sustained virologic response. Reflex HCV PCR testing should be consideredto be standard of care in all institutions that perform HCV screening.933_B Figure 2. Percentage of missed HCV PCR testing after positive HCV antibody results.933_C Figure 3. Rate of missed HCV PCR despite positive HCV antibody testing