HIV and Chronic Hepatitis C Co-Infection in Washington State

BACKGROUND: Hepatitis C virus (HCV) is the most common chronic blood-borne disease in the United States and is the leading cause of liver cancer. The Centers for Disease Control and Prevention (CDC) estimate that approximately 25% of HIV-infected persons are co-infected with HCV. Co-infection is associated with higher rates of morbidity, mortality, and an increased risk for an accelerated progression of liver disease as compared to HIV or HCV mono-infection.   

METHODS: Data for hepatitis C and HIV was provided by state surveillance systems. Co-infection was determined using a LinkPlus match between all HIV and HCV cases reported to the state. Analysis was restricted to cases diagnosed from 2004-2013. Descriptive statistics significance was calculated using chi-square and fisher’s exact tests. Logistic regression models were used to compare differences in co-infected cases from mono-infected cases.  

RESULTS: From 2004-2013, 5345 new HIV cases were diagnosed in Washington, of these 373 were also diagnosed with chronic HCV resulting in an overall co-infection percentage of 7% for the time period. Females had an increased odds being diagnosed co-infected as compared to males (OR=1.804, p=<.0001). Among mono-infected and co-infected cases, White race was most common (58%, 60% respectively). Black, non-Hispanic had the highest co-infection rates at 3.67 cases per 100,000 from 2004-2009 and 4.81 cases per 100,000 persons from 2005-2010. The highest percentage of co-infection occurred from 50-59 years for both sexes (9% males, 15% females). Co-infected individuals have 9.15 times the odds of reporting injection drug use (IDU) as compared to HIV mono-infected persons (p<.0001). In the HIV/HCV Co-infection Care Cascade in 2013, 80% (207/258) cases were in HIV care during the last 12 months with 59% (151/258) achieving suppressed viral loads (≤200 copies/mL).   

CONCLUSIONS: While the co-infection percentage reported was 7%, the actual number of HCV infections is most likely higher because it takes many years to develop chronic HCV. This delay in onset is a limitation in reporting the most recent data for co-infections. Local health jurisdictions (LHJ) often do not report new cases due to capacity limitations. One survey found that 26% of LHJs conducted no follow-up on HCV cases. Contrary to current literature, females had a higher percentage of co-infection than males in Washington. Case characteristics that were similar with other studies included increased risk for Black, non-Hispanics and IDU. The high risk for co-infection among IDU is an area of concern and could be used to target future interventions.