Gibson, a sergeant in the Canadian Armed Forces based at CFB Borden, north of Toronto, has hepatitis C.
He was completely unaware of the chronic infection for years, probably decades. Tests done during a military physical in late 2008 noted Gibson had an abnormal blood platelets reading and further testing led to an early 2009 diagnosis. By the time Gibson realized he was carrying the virus, he was already on a potentially fatal track — he had stage 5 liver failure.
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"It just came right out of the blue," says Gibson, 49, who has served in the military for 30 years.
Feld and Sherman are hepatologists — liver specialists — who have seen too many cases like Gibson's. And they fear they will soon face many more people who are completely unaware that they are on the verge of irreversible liver damage due to a virus most contracted years earlier. They believe a silent epidemic of hepatitis C infections will soon reach the point where it bursts into view, placing a huge strain on the health-care system.
Attempts to puzzle out how they became infected sometimes arrive at a conclusion. Some may have tried injection drugs in the freewheeling late 1960s, or had a blood transfusion before blood products were screened for hepatitis C (that began in 1992 in Canada). Some had medical procedures in parts of the world where needle reuse was or remains a common practice. Some got a tattoo in the wrong place at the wrong time.
But in about 30 per cent of cases no answer can be found, says Feld. That's why, he argues, efforts aimed at finding people infected with hepatitis C cannot focus solely on people who fall into high-risk groups such as injection drug users (present and past), immigrants from countries with high rates of hepatitis C and people who had blood transfusions before screening went into effect.
"It is true that if you really dug deep, obviously everyone (with hepatitis C) has some risk factor. They got the infection somehow. But finding the risk factor is so difficult that risk factor-based screening for almost any infection that it's been studied in is ineffective," says Feld, who practises at Toronto Western Hospital.
Gibson had blood transfusions in 1981, when he was a teenager. That's how, he believes, he became infected.
In the world of hepatitis C, he's one of the lucky ones. Gibson's sister gave him a piece of her liver in May 2012. But he remains infected and will continue to be monitored by his doctors.
In the same month Gibson had his liver transplant, the U.S. Centers for Disease Control took the unusual step of recommending that all baby boomers be screened once for hepatitis C. That's because the evidence suggests rates of the disease are higher among this age cohort in the U.S. than groups born before or since.
The goal is to find those who are infected — estimated at between one per cent and 1.5 per cent of the U.S. population — before the virus causes cirrhosis or liver cancer.
In Canada, liver experts are worrying the country could also be facing an avalanche of cases of liver failure and liver cancer. Led by the Canadian Liver Foundation, they have been calling on the Public Health Agency of Canada to also recommend one-time screening for people born between 1945 and 1975 — the baby boom plus 10 extra years on either end — to capture immigrants at high risk.
When the CDC came out with its recommendation, public health agency officials said they wanted time to study the issue, arguing the scope of the problem in Canada isn't as great as it is in the United States. For instance, the agency believes less than one per cent of Canadians — 0.8 per cent — are infected with hepatitis C.
The agency is still working on its position on hepatitis C screening, aided by experts from across the country.
Dr. Howard Njoo, director general for the agency's centre for communicable diseases and infection control, says he hopes the working group will present him with its suggestions by the end of the year, or early in 2014. And he acknowledges that the federal government's assessment is evolving somewhat.
While earlier modelling studies suggested only about 21 per cent of the people in Canada who are infected don't know it — or roughly 60,000 people — work from other countries with similar problems would indicate that figure is optimistic.
In France, where officials have had a program aimed at trying to identify infected people, they have discovered about half of people who were hepatitis C-positive were unaware of their status, says Sherman, a hepatologist at Toronto General Hospital and chairman of the Canadian Liver Foundation.
Njoo admits the Canadian figure may rise to about 30 to 40 per cent — a significant jump in the number of people who will need assessment and eventually treatment. And he says he expects the working group's efforts will lead to broader recommendations on who should be screened for hepatitis C — though perhaps not as broad as the U.S. guidance.
"I anticipate maybe based on the newer evidence that comes to light that we may need to modify slightly," says Njoo.
"I can't say that we'd end up being in sort of the same place as the U.S. with the exact same guidance. But I imagine that certainly based on the evidence that ... we may need to maybe update our guidance."
Society can find these people now — before they become gravely ill — or it can find them later, hepatitis C experts say.
Finding them sooner carries a steep price tag; many people can be cleared of the infection, with drugs, but the treatment costs tens of thousands of dollars. Finding them later will be even more expensive, doctors argue, when you factor in the costs of liver transplants (where organs are available), treatments for liver cancer and years of productive lives lost.
Feld says until Canada actually starts screening, there isn't a good way to get a handle on how big the problem is here.
"One of the reasons we need to start screening is to find out if we need to start screening," he says.
"It sounds silly, but right now the problem in Canada is we actually don't have the data. ... We may screen for a year or two and find out actually the prevalence in our baby boomers is not what it is in the U.S. and this isn't a good strategy."
He says, though, that right now data from B.C. — the best Canadian data — suggests screening of baby boomers does make sense.