Vital Signs

Newly Reported Acute and Chronic Hepatitis C Cases — United States, 2009–2018

A. Blythe Ryerson, PhD; Sarah Schillie, MD; Laurie K. Barker, MSPH; Benjamin A. Kupronis, MPH; Carolyn Wester, MD

Disclosures

Morbidity and Mortality Weekly Report. 2020;69(14):399-404. 

In This Article

Discussion

Historically, CDC has focused hepatitis C screening efforts among persons born during 1945–1965 and testing among those with identified risk factors regardless of age.[8,14,15] Concurrent with the nation's opioid crisis, however, rapid increases in acute HCV infections among young adults, including reproductive-aged persons, have put multiple U.S. generations at risk for chronic HCV infection. In today's issue of MMWR Recommendations and Reports, CDC recommends a universal testing strategy for hepatitis C among adults, including pregnant women.[11]

CDC first began publishing recommendations for hepatitis C screening in 1991, when the U.S. Public Health Service (USPHS) issued guidelines recommending hepatitis C testing of all blood and organ donations intended for human use.[16] In 1998, CDC expanded the hepatitis C interagency testing guidelines to include a recommendation for testing persons at high risk. These persons were defined as those who had ever injected drugs and shared needles, syringes, or other drug preparation equipment; received clotting factor concentrates produced before 1987; had ever been on maintenance hemodialysis; had persistently abnormal alanine aminotransferase levels; received blood transfusions or organ transplants before July 1992; had a recognized exposure (e.g., a needlestick or other sharps injury); or were born to a mother infected with HCV.[14] In 1999, USPHS added persons with human immunodeficiency virus to the groups recommended for testing.[15] In 2012, because of concern regarding limited effectiveness of risk-based hepatitis C testing and a high prevalence of disease among persons born during 1945–1965, CDC augmented the risk-based testing guidelines with a recommendation for a one-time testing of all baby boomers, even in the absence of a known risk factor.[8]

Ecologic evidence reveals that CDC's 2012 recommendation to screen all baby boomers for HCV infection resulted in increased testing among that birth cohort.[17] However, existing testing strategies have had limited success because >39% of all adults with HCV infection still report being unaware that they are infected. Further, the increase in new acute and newly reported chronic infections among young adults further supports the need for expanded and easier-to-implement hepatitis C testing recommendations. The new CDC recommendations released today include screening of all adults aged ≥18 years once in their lifetime and screening of all pregnant women during each pregnancy.[11] They also include an exception for settings where the prevalence of HCV infection is <0.1%; however, there are few known settings with a hepatitis C prevalence below that threshold.[18,19] The recommendation for testing of persons with risk factors remains in effect, regardless of age or setting prevalence, including continued periodic testing of persons with ongoing risk. The U.S. Preventive Services Task Force (USPSTF) recently published a recommendation statement on screening for hepatitis C virus infection in all adults aged 18–79 years (B recommendation).[20] The USPSTF recommendation differs from CDC's recommendation in that 1) an upper age limit is defined, 2) there is no recommendation for screening during every pregnancy, 3) and a prevalence threshold at which universal screening would remain cost-effective is not identified.

The findings in this report are subject to at least three limitations. First, the number of cases of acute and chronic hepatitis C reported to CDC underestimate the actual incidence of disease, and not all states reported chronic infections to CDC in 2018. For every reported case of acute hepatitis C, CDC estimates that there are 13.9 actual cases;[9,12] however, this estimation methodology is imprecise and might be influenced by testing rates. Second, minor changes to the CSTE case definition, changes to the reporting practices across jurisdictions, and changes to hepatitis C testing practices among providers during 2009–2018 should be considered when examining acute hepatitis C cases temporally. Finally, because NHANES sampling is limited to the noninstitutionalized, civilian population, survey results related to hepatitis C might not be nationally representative because they do not include some populations at highest risk for hepatitis C (e.g., incarcerated persons).

These findings highlight the need for immediate implementation of the new CDC universal hepatitis C screening recommendations for all adults and pregnant women.[11] Following a decade of sharp increases in acute hepatitis C infections, particularly among young adults, the rates of newly reported chronic infections among baby boomers and millennials are now equal, demonstrating that even younger generations are at risk. Diagnosing HCV infection is a necessary first step to linking persons to cure to prevent life-threatening consequences of long-term chronic infections and transmission to others.

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