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Test Using Drop of Blood Can Reveal Person's Viral Infection History

  • Jessica Berman

FILE - A patient's finger is pricked for a blood test.

FILE - A patient's finger is pricked for a blood test.

Every virus that has ever made people sick can now be detected in a drop of blood. A new test can tell doctors about a person's history of prior viral infections, something that may head off more serious diseases in the future.

The new blood test, called VirScan, has the potential to detect more than 1,000 different viral strains in the virome, the vast array of viruses that can infect humans.

Principal investigator Stephen Elledge of Brigham and Women’s Hospital and Harvard Medical School in Boston says the genetics test, which requires only a single drop of blood, can tell doctors whether a patient was exposed to harmful viruses

For example, people can be infected for years with hepatitis C that can destroy the liver, leading to cancer.

“These sorts of viral infections — HIV is another one — can get going for a long time before you start seeing problems," Elledge said. "And by the time you see problems, it is much more dangerous.”

There are now treatments that cure hepatitis and lifesaving therapies for HIV. By knowing whether someone was infected with a harmful virus years before, Elledge said, doctors can begin treatments early.

Researchers used blood samples from 600 donors in the United States, Peru, South Africa and Thailand to develop VirScan. They found people in each country had been infected with a unique set of about 10 viruses.

Right now, doctors can order a single test to detect a single virus, and that is only if the physician is astute enough to suspect a particular infection.

More broadly, Elledge said, VirScan might make it possible to look at the health impact of combinations of viruses. "So we do not really know where this is going to go,” he said.

Elledge said VirScan could also be used to determine the root of more vexing conditions, such as which viruses trigger autoimmune diseases like diabetes and lupus.