New Hepatitis C Cases in the United States, 2009–2018, and Universal Screening

Hepatitis C is a leading cause of illness and death from liver disease in the United States and costs the health care system billions of dollars a year. The hepatitis C virus (HCV) spreads mainly through blood, most often by injection drug use, but also sexually and from mother to baby during pregnancy or birth. Acute infection is usually silent or mild and sometimes clears on its own, but more than half of infections become chronic, which also usually has no symptoms until the liver is badly damaged and can be life-threatening. Hepatitis C can be diagnosed with a blood test and cured, yet new cases are rising.

About 2.4 million U.S. adults — approximately 1.0% — were living with hepatitis C in 2013–2016, and only 55.6% of them had ever been told. In 2018 at least 15,713 death certificates listed hepatitis C as an underlying or contributing cause. Historically, chronic infection was most common among baby boomers, born 1945–1965, but alongside the opioid crisis, new infections have come mainly among young adults, including people of childbearing age: maternal infection at delivery rose from 0.8 to 4.1 per 1,000 live births between 2000 and 2015, most among women with opioid use disorder.

Acute hepatitis C, 2009–2018

In 2018, 3,621 acute cases were reported, representing an estimated 50,300 (95% confidence interval 39,800–171,600) after adjusting for cases missed or unreported. The reported rate rose from 0.3 per 100,000 in 2009 to 1.2 in 2018.

Reported acute hepatitis C by year and age group, 2009–2018. CDC.

Newly reported chronic hepatitis C, 2018

137,713 new chronic cases were reported in 2018 (54.1 per 100,000) — 63.1% among males and 36.9% among females. The age pattern had two peaks, at 20–39 and at 50–69.

The number of new chronic cases among younger and older adults was about equal.

Newly reported chronic hepatitis C by sex and age, 2018. CDC.

Most people don't know

In national survey data from 2015–2018, only 60.6% of adults with hepatitis C said they had ever been told they were infected — so more than 39% did not know, which endangers their health and risks spreading the virus.

Why screen everyone

CDC's testing advice has widened over time: testing of donated blood and organs from 1991, people at high risk from 1998 (such as those who ever injected drugs, had certain early transfusions, clotting factor or organ transplants, long-term dialysis, a needlestick exposure or an infected mother), people with HIV from 1999, and a one-time test for all baby boomers from 2012. The boomer recommendation increased testing in that generation, but with so many infected adults still unaware and infections climbing among the young, CDC now recommends:

• testing all adults 18 and older at least once;
• testing all pregnant women during every pregnancy;
• continued, periodic testing for people with ongoing risk, whatever their age.

There is an exception for settings where infection prevalence is below 0.1%, but few such settings are known. The U.S. Preventive Services Task Force separately recommends screening adults aged 18–79; unlike CDC, it sets an upper age limit, does not call for screening in every pregnancy, and names no prevalence threshold.

Diagnosis is the first step toward cure, which prevents the long-term damage of chronic infection and further spread.

Limits

Reported cases undercount true disease — CDC estimates 13.9 actual acute cases for every one reported, an imprecise figure — and not every state reported chronic cases in 2018. Case definitions, reporting and testing practices changed over the period, and the national survey leaves out groups at high risk, such as people who are incarcerated.

Sources

Based on Ryerson AB, Schillie S, Barker LK, et al., "Vital Signs: Newly Reported Acute and Chronic Hepatitis C Cases — United States, 2009–2018," MMWR Vol. 69, No. 14, CDC; a work of the United States government in the public domain. The report's discussion says rates of new chronic infection among baby boomers and millennials are now equal, while its table gives 79.8 and 89.7 per 100,000; the page gives the table.