A Canadian task force is recommending against screening adults for chronic hepatitis C virus (HCV) unless certain health conditions indicate they’re at increased risk.
A guideline published in the Canadian Medical Association Journal by the Canadian Task Force on Preventive Health Care (CTFPHC) cited low HCV prevalence among adults in Canada and insufficient evidence of the harms and benefits of screening as the main reasons for issuing this recommendation. Even if patients are identified as positive by screening, symptoms may not develop for decades or never appear at all, the guideline’s authors indicated.
“Not screening for HCV [in the general population] will help focus our limited healthcare resources to test (and treat) individuals at elevated risk for HCV and to provide other medical interventions that are of proven … benefit,” the task force concluded.
Adults at low risk in Canada are unlikely to contract HCV through sexual or household transmission, or through blood products, due to the country’s regular screening of blood and organs, according to CTFPHC.
Screening low-risk adults also comes with potential risks, the authors cautioned. These include insurance snafus, labeling, social stigma, and the possibility of diagnosing and treating patients who yield a positive test but wouldn’t have otherwise developed HCV symptoms. Additionally, those identified with the disease through screening might not have the opportunity to get antiviral treatments in a timely manner.
The task force in a literature review was also unable to find sufficient evidence that validated the use of anti-HCV antibody and HCV-antigen tests for predicting active HCV infection.
“The proportion of confirmed active infections among positive screening test results varies widely across studies and test types. The proportion of RNA-positive, active HCV infection cases ranged from 0% to 89.7% among positive antibody-based assays and from 0% to 100% among antigen-based assays,” the task force wrote.
The new guideline only applies to low-risk populations. Individuals at increased risk may include: hemodialysis patients or those with needlestick injuries; those with a history of incarceration, homelessness, high-risk sexual behavior, or drug use; people who traveled to or lived in countries with endemic HCV or who received healthcare that failed to protect against HCV; anyone who received a blood transfusion, blood product, or organ transplant before 1992; and those who engaged in high-risk activities such as body piercing, tattooing, or shared personal hygiene materials with any HCV-positive individuals.
CTFPHC’s recommendation contrasts sharply with U.S. policy. The Centers for Disease Control and Prevention recommends that all individuals born between 1945 and 1964 have a one-time HCV test, regardless of whether they have other risk factors.
Not everyone in Canada is on board with the task force’s recommendation. The Canadian Liver Foundation (CLF), which called for an even more expanded age bracket on testing than the CDC, argues that the new approach will miss people infected with HCV, ultimately raising healthcare costs.
Late diagnosis and poor treatment protocols in Canada are largely contributing to rising liver cancer rates, said foundation chairperson and practicing hepatologist Morris Sherman, PhD, MB, FRCPC, in statement. “We are disappointed that, despite widespread support among medical experts and advocacy groups, the CTFPHC failed to establish new guidelines which would encourage widespread screening not just based on risk factors but also by age,” he said.
CLF has recommended screening adults born between 1945 and 1975, a measure that studies suggest could uncover nearly 80% of all undiagnosed HCV infections. While CTFPHC’s efforts are commendable, “the truth is that risk-based testing, which was first recommended in 2009, has only been effective in identifying a small proportion of adults with recognized risk factors,” Sherman continued. The drawback is patients without any known risk factors won’t get tested and won’t know if they have HCV or not.
The task force recommended against testing all adults on the premise that it would cost too much, cause stress to people diagnosed with HCV, and raise the potential for false positive results, Sherman said. “But don’t we have an obligation to inform people if they have a potentially fatal but curable disease?”