LAS VEGAS – Between 2010 and 2017, the proportion of newly diagnosed cases of acute hepatitis C virus infection rose threefold, driven largely by the concomitant opioid epidemic.
That makes efforts to screen, diagnose, and cure high-risk populations more important than ever, Stevan A. Gonzalez, MD, said at an annual psychopharmacology update held by the Nevada Psychiatric Association.
About 70% of HCV cases are related to injection drug use,” said Dr. Gonzalez, medical director of liver transplantation at the Baylor Simmons Transplant Institute at the Baylor Scott & White All Saints Medical Center in Fort Worth, Tex. “This is affecting whites as much as blacks and Hispanics, females as much as males, and in nonurban areas as much as in urban areas.”
Data from the Centers for Disease Control and Prevention and the Substance Abuse and Mental Health Services Administration indicate that during 2004-2014, the number of acute HCV cases among those aged 18-29 years increased 400%, and the use of injection opioids rose 600%.
At the same time, the number of HCV cases among those aged 30-39 years increased 325%, and the use of injection opioids rose 83%.
“We’re starting to see a pattern overlapping between HCV exposure and opioid injection,” Dr. Gonzalez said. Other high-risk populations include homeless and incarcerated individuals.
More than 70 million people worldwide have chronic HCV infection, Dr. Gonzalez noted, with possibly as many as 5 million cases in the United States. It remains the nation’s most common blood-borne infection.
Chronic disease develops in up to 85% of people who are exposed, infection is asymptomatic, and HCV remains one of the leading indications for liver transplantation and causes of liver cancer.
From a geographic standpoint, the prevalence of HCV in young adults is eclipsing that of Baby Boomers in several states in the Appalachian region and in Northeast, which have long been trouble spots for opioid use disorder (Gastroenterol. 2018 May;154:1850-1).
Surprising exposure risk
The primary risk of transmission is through contaminated blood and the exposure through needles.
“It really doesn’t matter whether it’s a needle that has a small amount of dead space where a little bit of blood can remain or needles that have a larger amount of blood,” Dr. Gonzalez said.
“I’ve had patients who come to me and say, ‘I can’t believe I have HCV. It’s impossible. I always use my own needles. They’re always brand new; I’ve never shared with anybody,’” he continued.
“This is where education and awareness is so critical, because it’s not just the needles,” Dr. Gonzalez explained. “HCV can survive on inanimate objects. For example, on a tabletop surface or a water container, HCV can remain viable up to 3 weeks. In a syringe, 2 months. For that reason, HCV can also be transmitted through crack pipes and nasal drug use, where the prevalence can be up to 35%.”
The duration of a person’s HCV infection drives the transmission.
“That’s important to think about, because people who have chronic hepatitis C are infectious until they’re treated,” Dr. Gonzalez said. “If they don’t know that they have hepatitis C, they continue to transmit the virus to others.”
One study found that half of people living with HCV are unaware of their infection (PLoS One. 2014 Jul 2;9:e101554). According to Dr. Gonzalez, forthcoming guidelines from the U.S. Preventive Services Task Force are expected to recommend a one-time screening for HCV infection in all adults aged 18-79 years, a Grade B recommendation. “That’s a big deal,” he said. (The draft recommendations are available here.)
HCV infection disproportionately affects individuals in correctional institutions. In fact, an estimated one in three inmates in the United States has chronic HCV.
“This is sort of a forgotten population with a lot of substance use and mental illness,” Dr. Gonzalez said. “Injection drug use in that setting is the most common risk factor: It’s about 60% in terms of the risk of transmission within correctional settings. HCV-associated liver disease has now surpassed HIV as a cause of death within correctional settings.”