A task force of national health experts recommends clinicians screen all adults 18 to 79 for the hepatitis C virus (HCV), noting that the viral infection is now associated with more deaths in the United States than the top 60 reportable infectious diseases combined.

Many people are unaware they are carrying the viral infection.

“People with hepatitis C do not always feel sick and may not know they have it,” says chair of the U.S. Preventive Services Task Force Douglas K. Owens, M.D, M.S. “Screening is key to finding this infection early, when it’s easier to treat and cure, helping reduce illnesses and deaths.”

Screening involves testing a blood sample to see whether it contains antibodies (disease-fighting proteins) that react specifically to the hepatitis C virus. This test is followed by a second test that determines the level of virus in the blood. When used together, these two tests accurately identify whether a person has hepatitis C infection, according to the Task Force.

An estimated 4.1 million people in the United States are carrying HCV antibodies; about 2.4 million are living with the virus, according to the Task Force. The HCV infection becomes chronic in 75% to 85% of cases and some of those people develop symptoms such as chronic fatigue and depression, and liver diseases that can range from cirrhosis to liver cancer.

Approximately one-third of people ages 18 to 30 who inject drugs are infected with the virus; 70% to 90% of older injection-drug users are infected.

Owens, who is the director of Stanford Health Policy and the Henry J. Kaiser, Jr., Professor of Medicine, said the opioid epidemic now plays an important role in the prevalence of HCV. There are more than three times the number of acute HCV cases than a decade ago, particularly among young, white, injection drug users who live in rural areas. Women aged 15 to 44 have also been hit hard by the virus that is spread through contaminated blood.

“The opioid epidemic has added fuel to the HCV fire, substantially increasing transmission,” said Owens. “HCV is now an enormous public health problem, affecting a much broader age range of people than before. Fortunately, we have the tools to identify people and treatment is now successful in the vast majority of patients, so screening can prevent the mortality and morbidity from HCV.”

The U.S. Preventive Services Task Force is an independent panel of national experts in prevention and evidence-based medicine whose recommendations are followed by primary care clinicians nationwide. It has recommended people who are at high risk be tested for hepatitis C, as well as “baby boomers” born between 1945 and 1965, but now recommends screening all adults age 18 to 79, and younger or older patients if they are at high risk of acquiring HCV.

Hepatitis C is primarily spread when blood from an infected person enters the body of someone who is not infected. There currently is no vaccine for hepatitis C although research in the development of a vaccine is underway. But there are effective oral direct-acting antiviral (DAA) medications that can clear the virus from the body, particularly if caught early.

“Hepatitis C affects millions of people across the country,” says Task Force member Michael J. Barry, M.D. “We recommend screening all adults regardless of their risk because new evidence shows that more people can benefit from this service than even before.”

The Task Force’s final recommendation statement and corresponding evidence summary have been published online in the Journal of the American Medical Association, as well as on the Task Force website at http://www.uspreventiveservicestaskforce.org.