For those in the baby boom generation, their annual physical in the New Year is more likely than ever to include a new blood test for a disease that may have been silently lurking in their bodies for decades.

“You don’t want to find out you have hepatitis C when you have symptoms, because it can do liver damage,” Rhonda Susman, director of infection prevention at Lawrence + Memorial Hospital in New London, said last week. “The blood test is something that should be part of your physical. It’s better to know and get it treated before you have symptoms.”

Since 2012, the federal Centers for Disease Control and Prevention has been recommending that everyone born between 1945 and 1965 get a blood test for hepatitis C, a virus that can lie dormant for 20 years or more before causing symptoms that lead to liver damage, cirrhosis and liver cancer. Over the past few months, the CDC’s public education campaign has expanded to include television commercials that are prompting more people to start asking their doctors about getting the test.

“A lot of people are now calling to ask about it,” said Dr. Robert Sidman, vice president of medical affairs for the east region of Hartford HealthCare, including The William W. Backus Hospital in Norwich.

The CDC calls hepatitis C “an unrecognized health crisis,” infecting as many as 3.2 million Americans without their knowledge. An increase in the death rate from hepatitis C since 1999 prompted the CDC to recommend all baby boomers get tested. Previously, it had only recommended the test for those with known risk for the infection, such illegal drug use or blood transfusions before 1992, when enhanced screening of donated blood was instituted.

Sidman said more doctors are now routinely recommending the hepatitis C test to patients ages 51 to 71, who are five times more likely than the rest of the population to have the virus. The reason for the higher prevalence among this group isn’t clear, although this generation was likely to have become infected in the 1960s through the 1980s when transmission of the virus was highest, according to the CDC. The virus is primarily spread through contact with blood from an infected person. According to the CDC, baby boomers could have gotten infected from medical equipment and procedures used in the decades when the virus was most prevalent but infection control procedures were not as strict as the ones used currently. Sharing needles or equipment used to inject drugs could also transmit the virus, the CDC said.

“Fifteen to 20 percent of those with the virus will have no effects, but 70 to 80 percent will develop some form of liver disease,” Sidman said. “About 10 to 15 percent will get cirrhosis,” a serious condition that can result in the need for a liver transplant.

Left untreated, hepatitis C interferes with the liver’s ability to perform its vital functions, including filtering and processing blood, nutrient storage and proper digestion.

“Long term, hepatitis C can lead to liver failure and death,” said Dr. Mary Cummings Satti, a primary care physician.

That’s why Satti, who practices at the Hartford HealthCare Medical Group, Primary Care for Women in Old Lyme, began advising her baby boomer patients about 1 1/2 years ago to have their blood tested for the hepatitis C antibodies. Most had never heard of the disease, she said, so “they needed a little education about it.” Now that the television commercials are airing, she said, more are initiating the conversation.

“Most are very receptive to getting the test,” she said.

A few patients have tested positive, though they did not have symptoms, she said. They were referred to a gastroenterologist, who usually prescribes the antiviral medication Harvoni to combat the infection.

In Connecticut, about 23,000 people have or have had hepatitis C in the past, according to the state Department of Public Health.

j.benson@theday.com