Epidemiology of Acute HCV
The estimated number of acute hepatitis C cases yearly in the United States is based on Centers for Disease Control and Prevention (CDC) viral hepatitis surveillance data (Figure 1).[1] In 2021, there were an estimated 69,800 new hepatitis C infections in the United States.[1] From 2013 through 2021, the number of cases of acute hepatitis C increased approximately 2-fold.[1] Key epidemiologic features include:[1]
- Case numbers and rates were much higher in men than in women,
- By age, the highest number of rates were seen in persons 20 to 39 years of age,
- By race and ethnicity, the highest rates were in American Indian/Alaskan Native people and White people, and
- There was major state-by-state variation in rates of acute HCV.
The epidemics of opioid and stimulant use in the United States are the predominant force driving the increase in new HCV infections, particularly in young adults.[2,3] In addition, an increase in acute HCV infections has been recognized among men who have sex with men, particularly men living with HIV infection who engage in condomless anal sex and use methamphetamine associated with sex.[4]
Definition of Acute HCV Infection
Most experts define acute HCV infection as the 6-month time period following the acquisition of HCV.[5,6,7] The definition of acute HCV infection does not depend on the presence or absence of symptoms associated with the acute HCV infection because most infections are subclinical. The preferred accepted laboratory diagnosis of acute HCV infection includes documentation of either of the two following criteria:
- A positive (detectable) HCV RNA in conjunction with a negative HCV antibody, or
- Positive HCV antibody with documentation of a negative HCV antibody in the past 12 months