Point-of-care (POC) tests for hepatitis C expand testing beyond clinical settings where a blood draw is not readily available. They are an important tool in the effort to eliminate hepatitis C as an endemic disease by 2030. The only Health Canada-approved POC test is the OraQuick hepatitis C antibody test, which requires a 20-minute wait before the results can be read.
Frontline workers familiar with the OraQuick test will likely have noticed that positive results often appear far more quickly than 20 minutes, if they appear at all. And yet testers are constrained to make people wait the entire duration. In practice, people being tested may not be willing or able to wait 20 minutes to return for results, increasing the likelihood that individuals drop out of care. If our primary concern is to identify and cure currently infected individuals, we have found that this delay is an unnecessary barrier to care.
Introducing the five-minute rule
Our research at the Viral Hepatitis Care Network (VIRCAN), part of the Toronto Centre for Liver Disease at the University Health Network (UHN), shows that a five-minute wait is all that is needed to link potentially infected patients to care. In that five minutes, all those currently infected with hepatitis C test positive using the OraQuick test.
To help reach this conclusion, we recruited patients with past or present hepatitis C infection and found that all participants with present infection (227/227) tested positive before five minutes, as did many participants who were recently cured. The only participants whose tests became positive after five minutes were those with past infection who had cleared the virus many years before. These findings, part of a peer-reviewed process, form the basis of the VIRCAN 5-Minute Rule for the OraQuick test: individuals testing positive before five minutes need a follow-up RNA test to confirm infection. But, individuals testing negative at five minutes do not need an RNA test, even if results subsequently become positive after five minutes.
How it works
The reason the test activates faster for infected individuals—why the five-minute rule works—is because individuals with an existing infection continue to produce high levels of antibodies. The OraQuick test detects the presence of these antibodies against hepatitis C; when they are abundant, the test is activated more quickly.
The test works slower for many people with resolved infections because of the gradual drop in hepatitis C antibodies years after getting rid of the virus, either spontaneously or from being cured by treatment. These individuals have fewer antibodies which often requires more than five minutes to activate the test. This leads to an important aspect of the five-minute rule: a positive result appearing only after five minutes indicates a past infection, probably resolved many years ago.
What it means
Every stage of hepatitis C care needs to be streamlined to help achieve the 2030 goal of elimination. Shortening testing time makes the first stage in care that much easier. And as anyone who has used the test in a busy setting knows, making people wait 20 minutes means that some will walk away and never come back for their results. Thanks to our five-minute rule for the OraQuick test, that need never happen again.
David Smookler PhD, is a research analyst at the Viral Hepatitis Care Network (VIRCAN) and the lead for education and outreach to First Nation communities. He previously presented a CATIE webinar on the simplicity of using dried blood spots for community-wide testing for hepatitis C.
Aaron Vanderhoff is the community outreach and engagement lead at the Viral Hepatitis Care Network (VIRCAN) in Toronto. His work involves hepatitis C POC testing in community settings, as well as training and supporting programming for POC testing and linkage to care in Ontario.