New test detects hepatitis B in 1 hour with a finger prick: Study
Accuracy of rapid testing on par with traditional methods taking weeks
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A new test that uses a tiny drop of blood collected from a finger prick and returns results in about an hour can detect hepatitis B with accuracy on par with traditional testing methods that usually take days or weeks to return results.
That’s the main finding of a new study whose results, according to the researchers, suggest that fingerstick testing could remove a key barrier to global efforts to eliminate hepatitis B worldwide by 2030.
“The results of our trial found that the fingerstick point-of-care test is highly accurate, closely matching the accuracy of traditional tests,” Gail Matthews, PhD, the study’s senior author at the Kirby Institute in Australia, said in an institute news story that noted that “the majority of people with chronic hepatitis B live in low- and middle-income countries.”
“This is a very important finding because it has the potential to expand access to testing and treatment globally, and especially in resource limited settings or remote areas, where current testing access is poor,” Matthews said.
The study, “Evaluation of fingerstick blood point-of-care testing of hepatitis B DNA for enhanced hepatitis B treatment decision making: a diagnostic accuracy study,” was published in the Journal of Clinical Microbiology.
The hepatitis B virus (HBV) is spread by contact with bodily fluids and infects the liver, leading to liver inflammation or hepatitis. In some patients, especially those infected during childhood, the virus causes a long-lasting or chronic infection that can set the stage for fatal complications such as liver cancer.
Hepatitis B “is responsible for over 1 million deaths per year, but is preventable by vaccination, and effective treatment is available for chronic infection,” the release stated.
Over 250 million thought to have hepatitis B, but most not diagnosed
The World Health Organization estimates that more than 250 million people worldwide are living with chronic hepatitis B, but nearly all of them have not been diagnosed. This is in large part because most people with this infection live in poorer regions of the world where it can be difficult to access appropriate diagnostic tests.
This includes tests to measure blood levels of HBV DNA, which are sometimes used to help diagnose hepatitis B and are also key for guiding treatment decisions.
“Not everyone who has hep B needs treatment,” said Behzad Hajarizadeh, MD, PhD, the study’s first author at the Kirby Institute. “People with higher levels of the virus are more likely to benefit from treatment, so DNA tests are required to determine the levels of virus in the system. DNA testing is also used once a patient starts treatment, to help understand if the treatment is working.”
Traditionally, tests to measure HBV DNA involve collecting a blood draw from a vein, then shipping it to a lab for analysis. That means patients have to travel to a facility that can perform blood draws — which can be far for people in remote or rural areas, even in wealthy nations — and then wait to get the results. At minimum, such testing typically takes at least several days.
The idea behind point-of-care testing is for clinicians to provide results at the same clinical visit where the test is administered. This would not only remove diagnostic delays, but also allow patients to start care as soon as possible.
A point-of-care test device called the GeneXpert system, sold by Cepheid, has been found to detect viral genetic material from many infections, including hepatitis C, which is caused by the hepatitis C virus.
GeneXpert system found to have accuracy of at least 90%
Now, researchers in Australia sought to determine whether this system could also be used to test for HBV DNA levels.
To find out, the team analyzed HBV DNA levels in 246 adults with chronic hepatitis B using both the traditional blood draw methods and the point-of-care test. The patients’ median age was 45, and 46% were women.
The results showed that the point-of-care test accurately identified 97% of patients with HBV DNA levels above 100 international units (IU) per mL of blood, and correctly ruled out 90.3% of those with levels below this cutoff. The test also discriminated between people with levels above the cutoff of 2,000 IU/mL and those with lower levels with an accuracy of at least 95%.
Levels of HBV DNA detected with the point-of-care test tended to be slightly higher than those detected with the standard blood draw test, which “may lead to overtreatment in some patients who would not otherwise be eligible,” the researchers wrote. However, the team noted that this “is unlikely to compromise patients’ health, given the minimal side effects of HBV antiviral therapies.”
Moreover, the scientists said that overall differences between the point-of-care and standard tests for people with non-concordant results were small enough that they would “not usually change clinical decision-making in real-world practice, given expected fluctuations in HBV DNA levels over time.”
We are hopeful that this research will support the roll-out of point-of-care testing for hepatitis B, enhancing access and ultimately, improving health and saving lives.
Overall, the data suggest that this point-of-care test can rapidly and accurately detect HBV DNA, supporting its potential use, especially in settings where standard blood draw testing is hard to access.
Thomas Tu, PhD, a cofounder of Hepatitis B Voices Australia, noted that “access to testing is a major barrier to progress on hepatitis B elimination.”
Tu is a hepatitis B researcher and associate professor at the Westmead Institute for Medical Research in Australia, but was not involved in the study. Still, he was optimistic about its findings.
“We are hopeful that this research will support the roll-out of point-of-care testing for hepatitis B, enhancing access and ultimately, improving health and saving lives,” Tu said.
