Canadians born between 1945 and 1975 should be tested for the potentially liver-destroying virus hepatitis C, a new set of guidelines recommends.

More than 250,000 Canadians are believed to be infected with hepatitis C, but an estimated 40 to 70 per cent are unaware they harbour the blood-borne virus because it can take decades before symptoms become evident. Chronic infection can lead to cirrhosis of the liver or liver cancer.

The Canadian Association for the Study of the Liver, a national group of health-care providers and researchers, published its guidelines on testing and treating hepatitis C in Monday's edition of the CMAJ.

A key recommendation is that people be tested based on their age — not only possible risk factors, said Dr. Jordan Feld, a liver specialist at Toronto's University Health Network and a co-author of the guidelines.

"And the reason we've done this is it just happens that somewhere between two-thirds and three-quarters of people with hepatitis C were born between 1945 and 1975 in Canada," he said.

"So just the way someone gets a blood pressure check or a cholesterol check or a colonoscopy based on their age, we would recommend that they get a hepatitis C test if they're born between those years.

The Canadian Association for the Study of the Liver, a national group of health-care providers and researchers, published its guidelines on testing and treating hepatitis C in Monday's edition of the CMAJ. (Benchamat/Shutterstock)

"And if we do that, we hopefully diagnose the vast majority of people living with hepatitis C."

People at high risk

The recommendations differ from those issued last year by the Canadian Task Force on Preventive Health Care in the same journal.

"We recommended against screening the average Canadian who's not at elevated risk for this chronic infection," said Dr. Roland Grad, a member of the Canadian Task Force for Preventive Health Care and a family doctor in Montreal.

Grad's reasons included:

Absence of direct evidence on the benefits of screening.

The costs of screening and treatment would have a dramatic impact on health-care budgets in the order of $1.5 billion in 2016 dollars.

A concern that many individuals would be identified by screening as chronic infection would not get timely access to treatment.

"We really do not know whether these drugs are a cure," Grad said, given the trials lasted a few years and it typically takes 20 to 30 years for the virus to cause damage.

People at high risk include those who:

Engaged in IV drug use with shared needles.

Had a tattoo or body piercing with unsterile equipment.

Had unprotected sex with multiple partners.

Received a blood transfusion, blood product or organ transplant prior to 1992.

Feld said almost all private and most provincial and territorial drug plans now cover the cost of the drugs.

Screening and treating patients

Screening for the hepatitis C virus, or HCV, involves an inexpensive blood test. Most people exposed to the virus are able to clear the infection.

"As the landscape has evolved such that everyone can access therapy we felt much more strongly that then everyone who is at risk should be tested," said Feld's co-lead author, Dr. Hemant Shah, a liver specialist and clinical practice director of the Francis Family Liver Clinic at Toronto's University Health Network.

Joe Camara learned he contracted hepatitis C in 1993 after using intravenous drugs. The Toronto man was sent to the U.S. for treatment.

"I was throwing up. I would turn all yellow. Just sick," he recalled. Since Camara started receiving direct-acting antiviral medication, he says his energy has returned and he feels great.

Eliminate viral hepatitis C by 2030

Bernadette Lettner, a registered nurse at the Regent Park Community Health Centre in Toronto, where Camara is now treated, points out that Canada has signed on to the WHO commitment to eliminate viral hepatitis C by 2030.

"I think that if you commit to doing something like that, then you're going to have to make sure you're able to test people who previously wouldn't know that they're hep C positive," she said.

Joe Camara says his energy levels have greatly improved after starting direct-acting antiviral pills for hepatitis C. (Craig Chivers/CBC)

According to Lettner, many of those who are unaware are baby boomers. "The majority of new cases are in people who inject drugs or in prison populations," she said.

Those with a chronic infection based on two positive blood tests six months apart are eligible for the oral treatments, Lettner said.

Shah acknowledged the liver specialists all have relationships with the manufacturers of different hepatitis C drugs but said it didn't influence their recommendations.