One of HCSP's top 11 hepatitis C news stories of 2005 was the announcement that a team of Israeli researchers had developed a saliva-based test for hepatitis C. The research team reported results of an initial study of their test in dialysis patients in the Journal of Virological Methods (see abstract).
But the bigger news is that OraSure Technologies, a U.S.-based company that markets saliva-based HIV tests, is planning to launch a rapid hepatitis C test. In an August press release, they announced reaching a licensing agreement that
...will permit OraSure to manufacture, distribute and sell a rapid, point-of-care diagnostic product to detect antibodies to HCV in both oral fluid and blood. There currently is no U.S. Food and Drug Administration ("FDA") approved rapid HCV test in the United States, and there is no rapid HCV test available anywhere in the world that can be used on oral fluid.
"Securing this HCV license gives us the opportunity to pursue and develop a rapid test for hepatitis C, one of the most common chronic bloodborne viral infections in the U.S. and abroad, and one that is seen frequently in patients who also have HIV," said Douglas A. Michels, President and CEO of OraSure Technologies. "Our goal has always been to create the most versatile and comprehensive point-of-care rapid tests in the world, and this license will enable us to expand our product offerings to include HCV diagnostics."
Most people in the U.S. with hepatitis C have never been diagnosed and don't know that they're infected. A rapid test -- especially an oral test -- could have a dramatic impact on expanding access to hepatitis C testing.
One caveat -- these tests, like the standard blood test used for initial hepatitis C screening, detect hepatitis C antibodies, and not the virus itself. Some people -- about one in four -- clear the virus spontaneously, thanks to strong immune responses in the early weeks following infection. These people will still have antibodies to hepatitis C, and thus come up positive on the hepatitis C antibody test. Antibody tests can tell you that at some point, you were infected with hepatitis C -- but they can't determine whether you're still chronnically infected. For that, you need a confirmatory test (called a qualitative HCV RNA test) that looks directly for the presence of the hepatitis C virus itself. These qualitative HCV RNA tests generally aren't available outside of doctor's offices.
Many people who get an initial positive result from their hepatitis C antibody test through a health department testing site (or a needle exchange program, or hep C organization) don't make it to the doctor's for the HCV RNA test, and often assume they're still infected. About 25% of these people will turn out to have cleared hepatitis C in the past -- but could still get infected again if they remain at risk. This complicates prevention messages, and underscores the importance of connecting people who test hepatitis C antibody positive to medical care.