The rate of U.S. residents who inject opioids has risen in recent years in tandem with the rate of new cases of hepatitis C virus (HCV), suggesting the former factor is driving the latter, MD Magazine reports. The warning signs are particularly concerning among young people.

Injection drug use is also associated with HIV transmission, although HCV transmits much more readily through this route.

Publishing their findings in the American Journal of Public Health, researchers analyzed data from the Centers for Disease Control and Prevention’s (CDC) National Notifiable Disease Surveillance System, looking at diagnoses of acute cases of hep C (indicating a recent infection). They also relied on the Substance Abuse and Mental Health Services Administration’s (SAMHSA) data on national admissions to substance use disorder treatment facilities.

The researchers looked at data from 2004 to 2014, a period during which a total of 12,953 people were diagnosed with acute hep C. This meant that the annual rate of acute hep C diagnoses increased from 3 to 7 cases per 1 million people.

That said, there was a 5.29-fold increase in such admissions during the study period, compared with just a 1.85-fold rise for admissions of people who inject heroin.

Young people between 18 and 29 years old saw the highest increases in both the rate of heroin injection use and abuse of prescription opioids as well as the rate of acute HCV: a 5-fold increase in the rate of acute hep C, a 7.03-fold increase in the rate of admissions to substance abuse facilities for heroin injection, and a 9.17-fold spike in admissions of the injection of prescription opioids.

During the study period, the rate of acute hep C increased nearly 4-fold among women and more than 2-fold among men.

The study authors concluded: “These findings strongly suggest that the national increase in acute HCV infection is related to the country’s opioid epidemic and associated increases in [injection drug use].”

To read the MD Magazine article, click here.

To read the study, click here.

Editor’s note: A previous version of this article incorrectly stated that during the study period there was a 5.29-fold increase in admissions to drug treatment programs for prescription opioids and a 4 percent increase in admissions for heroin use; the correct figures were 3.58-fold and 1.85-fold, respectively. The 5.29-fold and 4 percent respective increases applied to Latinos only.