Every Drop Of Blood Can Identify Every Virus You've Ever Hosted, Study

The human blood acts like a documentation centre of every virus that has ever infected it. Just one drop of blood can help you to find out your history, according to rt.

The VirScan test screens the blood for antibodies against 206 species of viruses that infect humans, according to a research study published in the journal Science on Thursday. The test was made and developed by Stephen Elledge, a professor of genetics and medicine at Brigham and Women's Hospital and Harvard Medical School, and colleagues at the Howard Hughes Medical Institute.

"We've developed a screening methodology to basically look back in time in people's [blood] sera and see what viruses they have experienced," Elledge said. "Instead of testing for one individual virus at a time, which is labor intensive, we can assay all of these at once. It's one-stop shopping."

As the test can be performed for just $25, it could become an important research tool to identify disease patterns among diverse populations, and also enable researchers to compare the old and the young, or people in diverse parts of the world, according to nytimes.

The immune system boosts its production of pathogen-specific antibodies when it encounters a virus for the first time, and can continue to produce them for years - even decades - after the infection subsides.

This allows VirScan to not only detect viruses that the body is fighting, but also acts like a document of infections. Elledge as well as his team of researchers took blood samples from 569 people from the United States, South Africa, Thailand and Peru.

The team also analysed samples from people who were infected with particular diseases. "It turns out that it works really well," Elledge said. "We were in the sensitivity range of 95 to 100 percent for those, and the specificity was good - we didn't falsely identify people who were negative. That gave us confidence that we could detect other viruses, and when we did see them we would know they were real."

The average person is said to have been exposed to 10 out of 206 viruses. Yet a few viruses showed some exposure to more than twice the amount.

"Many of those [people] have probably been infected with many different strains of the same virus," said Elledge. "You could be infected with many strains of rhinovirus over the course of your life, for instance, and it would show up as one hit."

The scientists found that the herpes viruses leading to cold, enteroviruses leading to upset stomachs, influenza, and rhinoviruses causing the common cold were most commonly found.

US citizens were infected with less viruses than people in other countries, while elders were affected more than younger people.

The breakthrough could be beneficial for vaccine design, as well as for new viruses, explain the scientists. They will also enable scientists to "look at viruses and how they differ between populations of people, or people who have different diseases," Elledge said.

The classic ELISA test is able to identify just one pathogen at a time and hasn't been developed to fight viruses, which limits the value of these tests, according to bostonmagazine.

However, VirScan, when tested for chicken pox, could pick out just 25-30 percent of people. "That's much lower than you'd expect," Tomasz Kula, a graduate student working in Elledge's lab, told Wired. "Oftentimes people are vaccinated for it or had it when they were very young, and it wanes over time. So we know we're not the best when it comes to this," he added.