Opioid Crisis Shifts Hepatitis C Virus to Millennial Generation

Hepatitis C virus (HCV) infection has skipped a generation and become a predominantly millennial disease, according to a poster presented during IDWeek 2019.

Investigators from the University of Louisville screened 82,243 individuals for HCV infection in 2016-2018 in Norton Healthcare in order to assess trends in a large health care system in an area with a high prevalence of opioid use and HCV infection. The investigators defined millennials as individuals born between 1980 and 1995, and baby boomers were those born between 1945 and 1965.

Traditionally, baby boomers were the largest drivers of HCV, though millennials have been shown in previous research to be the fastest-growing population of those infected with the virus. However, those studies were performed at single institutions with small sample sizes.

Importantly, millennials are also a key driver of the opioid crisis, the study authors noted, especially in the Appalachian region including Kentucky, where the study was conducted.

From the screened populations, the investigators identified 2615 (3%) individuals that screened positive for HCV. They said this was the largest population of individuals screened for HCV. Then, cases were classified based on the patient’s year of birth.

Millennials represented nearly half of those infected with HCV at 49% in 2018, compared to 40.5% in 2017 and 32.2% in 2016. The study authors underlined that that represents a 53% increase over the 3-year study period.

On the opposite end of the spectrum, the population of HCV-positive individuals among baby boomers has decreased by 32% (from 46.2% in 2016 to 31.2% by 2018).

The average age of the HCV-positive individuals significantly decreased by an average of 3.7 years annually, the study authors noted. For example, the average age of those infected was 47.3 years in 2016, to 39.9 years in 2018.

“We conclude that the opioid crisis has led to a drastic demographic shift in those infected with HCV,” study author John Myers, PhD, MSPH, a professor of pediatrics at the University of Louisville, told Contagion®. “Currently the typical HCV-infected individual is a younger male, compared to the traditional thinking that the typical HCV-infected individual is a baby boomer male.”

The study authors predict that over time, HCV-positive individuals are more likely to be male and more likely to be Hispanic. Likelihood of being male increased among this population from 49.6% to 54.4% through the 2016-18 range of the study period, while the likelihood of being Hispanic increased from 1.6% to 17.7% over the same period.

Similarly, the study authors also predict a plateau around age 28 years will be observed in about 7 years without any intervention. They additionally hypothesize that the population of HCV-positive millennials will increase over time — because the infected population reached 33.6% in 2016, 42.4% in 2017, and 51.4% in 2018 – while baby boomers will significantly decrease over time. HCV-positive baby boomers populations have decreased from 44.0% in 2016, 38.8% in 2017, and 29.3% in 2018.

“These results correlate with trends seen with the opioid epidemic, which is driven by millennials,” the study authors concluded. “The opioid crisis has led to a drastic demographic shift, and currently the typical HCV-infected individual is a younger male. Without interventions, this trend will continue for over 7 years, plateauing near the demarcation of millennials and generation Z.”

The poster, titled “Hepatitis C is now a Millennial Disease in Response to the Opioid Crisis: A Demographic Shift in Hepatitis C Infection,” was presented at IDWeek 2019 in a poster presentation on October 3, 2019, in Washington DC.