CDC Report: New Hepatitis C Infections Nearly Tripled in Five Years

Agency attributes increase mainly to rising rates of injection-drug use

Between 2010 and 2015, the number of new hepatitis C virus (HCV) infections reported to the Centers for Disease Control and Prevention (CDC) nearly tripled, reaching a 15-year high, according to new surveillance data released by the agency.

Because HCV infections have few symptoms, nearly half of people living with the virus don’t know they are infected, and most new infections go undiagnosed, the CDC says. Further, limited surveillance resources have led to underreporting, meaning the annual number of HCV cases reported to the CDC (850 in 2010 and 2,436 in 2015) does not reflect the true scale of the epidemic. The CDC estimates that approximately 34,000 new HCV infections actually occurred in the United States in 2015.

According to the agency’s new surveillance data, reported cases of acute HCV infection increased more than 2.9-fold from 2010 through 2015, rising annually throughout this period. Examining annual trends beginning in 2011, reported cases of acute HCV infection increased 44.3% from 2011 to 2012 (1,232 and 1,778 cases, respectively); increased 20.3% to 2,138 cases in 2013; increased 2.6% to 2,194 cases in 2014; and increased 11% to 2,436 cases in 2015.

The increase in acute HCV case reports reflects new infections associated with rising rates of injection-drug use, and, to a much lesser extent, improved case detection, according to the CDC. Several early investigations of newly acquired HCV infections showed that most occur among young, white persons who live in nonurban areas (particularly in states within the Appalachian, Midwestern, and New England regions of the country); trends in these states likely indicate an overall increase in HCV incidence throughout the country, the CDC noted. States with the highest rate of new HCV infections––West Virginia, Kentucky, and Tennessee––did not receive CDC support for case finding during the reporting years (2011–2015). After adjusting for under-ascertainment and under-reporting, an estimated 33,900 new HCV infections occurred in 2015.

Overall, mortality among HCV-infected persons—primarily adults 55 to 64 years of age—increased between 2006 and 2010. In 2013, HCV-associated deaths exceeded the combined number of deaths with 60 other infectious diseases as underlying causes. CDC data indicate that the number of HCV-associated deaths increased 10.9% from 2011 through 2014 and decreased 0.2% to 19,629 in 2015. Approximately one-half of all deaths in 2015 occurred among persons 55 to 64 years of age. However, deaths associated with HCV were largely underestimated, according to the agency; the only large U.S. study of deaths among persons with confirmed HCV infection indicated that only 19% had HCV listed on the death certificates despite 75% having evidence of substantial liver disease.

Comprehensive approaches are needed to combat the dual epidemics of opioid addiction and injection-related infectious diseases, according to the CDC. The Department of Health and Human Services has developed five strategies to combat the current opioid epidemic. These strategies include improving access to treatment and recovery services; promoting the use of overdose-reversing drugs; strengthening current understanding of the opioid epidemic through better public-health surveillance; providing support for cutting-edge research on pain and addiction; and advancing better practices for pain management.

Sources: CDC; May 11, 2017; and CDC Surveillance Data; May 11, 2017.