"A cheap new lab test can use just a drop of blood to reveal the different kinds of viruses you've been exposed to over your lifetime."

"The test suggests that, on average, people have been infected with about ten different types of known virus families, including influenzas, and rhinoviruses that cause the common cold, according to a report published Thursday in Science."

"'Usually if you go to the doctor, the doctor might suspect that you have a particular virus, and then he or she will order a test to test that one virus,' says Stephen Elledge at Harvard Medical School and Brigham and Women's Hospital. 'But if you want to know about all viruses, there was really no way to do it.'"

"He and his colleagues developed this test by turning to vast databases of information about known human viruses. Their test checks to see if a person's blood has antibodies that recognize bits of viruses. 'And in that way, you can look back into the history of your viral infections,' says Elledge."