Distribution of Hepatitis C Testing in Philadelphia, 2012-2014

Abstract

Background: Hepatitis C virus (HCV) is a widespread problem in the United States, but the disease's low screening rates mean that reported cases account for only a fraction of the population's antibody prevalence. In reality, chronic HCV is the most common chronic blood-borne infection in the country. While newer infections may be completely asymptomatic, the virus can lead to serious complications in the liver down the line, including hepatic fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). Because HCV is a reportable disease, the Philadelphia Department of Public Health (PDPH) hepatitis surveillance registry has records of all of the positive tests performed in the city. Negative test results are not readily available, however, making it difficult to create an accurate picture of who is being tested for HCV. Our study used negative results collected from reference laboratories throughout the city to fill in many of the gaps and determine which neighborhoods were not sufficiently screening at-risk populations. Methods: Our dataset included approximately 100,000 individuals, a little over 90% of whom were HCV negative. Negative test results were obtained from Quest and Lab Corp, two of the major reference laboratories in the area that account for approximately 80% of all of the results of tests performed in Philadelphia. The screening data were then combined with records from the PDPH hepatitis surveillance registry. ArcGIS geographic information software was used to create maps out of neighborhood and census tract data, providing a visual representation of HCV screening distribution in Philadelphia. We also explored differences in demographic characteristics and testing facility information by test result. The data included anyone in the past 2 years who had undergone an antibody (Ab) or RNA test for HCV. Results: We found that census tract poverty rate was positively associated with HCV screening rate. Also, the majority of testing occurred in either hospital networks or private practices. There were significantly more males testing positive for HCV, despite the fact that many more females were tested overall. Similarly, the "baby boomer" age range (50-69) had the highest proportion of HCV positive test results, yet those aged 30-49 had the highest HCV testing rates. Conclusions: Negative test results for reportable diseases are rarely utilized, but can be extremely useful in identifying problem areas and focusing testing resources. Because so many people with HCV go undiagnosed, it is especially important that populations requiring additional attention be recognized and screened.