Blood Test Could Reveal Your Viral History | WPN World People News

A single drop of blood may reveal a range of viruses a person has contracted recently, or possibly years ago, a new study suggests.

The researchers describe a new technology that can test for more than 1,000 viral strains at the same time -- using one drop of blood.

Experts said the achievement could represent an advance over existing tests, which look for just one virus at a time. But for now, they see the one-stop, $25 test as useful for research purposes, rather than real-world diagnostics.

"It's hard to say how far off any clinical application could be," said expert.

More immediately, the test -- called VirScan -- could aid research.

"One example would be studies that look for correlations between people's viral exposures and their risk of developing various diseases," expert said.

The Epstein-Barr virus, one of the most common viruses in humans, has been linked to increased risks of certain cancers. But studying such virus-disease connections has been challenging, expert said, partly because current tests look for one virus at a time.

With VirScan, expert explained, it might be possible to test a large group of people with a given disease and another group without the condition. Researchers could then see whether certain viral exposures were more common in people with the disease.

The VirScan test works by detecting antibodies to viruses known to infect humans; antibodies are evidence of a past immune system response to a particular virus.

To test the technology, the researchers used blood samples from almost 600 people from the United States, Peru, South Africa and Thailand -- all of whom were known to carry certain viruses, including HIV and hepatitis C.

Overall, the test accurately picked up more than 90 percent of those known infections, the researchers said. Plus, it rarely gave a positive result for someone who did not carry one of the viruses.

The test also detected antibodies against viruses that study participants were not known to harbor. On average, people had antibodies to 10 viruses, though a few had antibodies to at least 84.

Cold and flu viruses, along with various herpes viruses -- including Epstein-Barr -- were among the most common bugs detected.

According to expert, it's not clear how far back in time the test can dig. Over the years, antibodies to infection wane, he explained.

"This test gives a snapshot of the antibodies in your blood right now," expert said.

Plus, the typical adult has been exposed to far more than 10 viruses -- the average in this study group, said expert, an infectious disease specialist who was not involved in the research.

"This is an interesting technology," said expert, a spokesperson for the Infectious Diseases Society of America. "But I'm not sure how this would be used clinically."

For one thing, expert explained, it takes time for the immune system to form antibodies to a particular virus. "It's not clear how evidence of a past exposure would say anything about the acute symptoms a patient is having now".

"If you think a patient has HIV," expert added, "you order an HIV test."

Expert agreed, though, that the test might prove useful in the research setting.

The research team did come across one unexpected finding, Kula said. Overall, study participants had very similar immune responses to specific viruses: That is, each person's antibodies were directed against the same amino acids within a given virus.

"That was surprising because the immune response is thought to be very personal," expert said.

Going forward, that finding could have implications for understanding the immune response to infection.

Source: U.S. Dept. of Health & Human Services