A new test developed by scientists at Washington University School of Medicine in St. Louis may prove an invaluable aid to doctors who can't figure out what's wrong with their patients. The test, described in a study in the Genome Research journal, is able to detect, all at once, pretty much any virus that afflicts humans and animals, even viruses that are uncommon or barely detectable, UPI reports. The ViroCap test—said by a press release to be "just as sensitive as … gold-standard polymerase chain reaction (PCR)" tests, which cap out at detecting about 20 viruses at a time—registered a 52% improvement over PCR tests, per UPI. "With this test, you don't have to know what you're looking for," says the study's senior author, per the press release. "[The test] casts a broad net and can efficiently detect viruses that are present at very low levels." And the test can be used not only to diagnose more serious viruses such as Ebola, but also for more everyday ones like rotavirus.
How researchers put the test together is a gene-sequencing feat, using a system much like the one used to run a suspect's fingerprints through a criminal database. Scientists pulled out 2 million or so stretches of DNA and RNA from every virus known to plague man or beast, matching those stretches up to patient viruses to make a match. For flummoxed doctors who can't make a definitive diagnosis, the test could prove a godsend. "The test is so sensitive that it also detects variant strains of viruses that are closely related genetically," a pediatrics professor says. "Slight genetic variations among viruses often can't be distinguished by currently available tests." A bit of a damper to the good news: The test still needs to go through the rigors of academic testing, so it may be a few years until it's available for the general population. (A drop of blood can tell you every virus you've ever had.)