Scientists at the Washington University School of Medicine in St. Louis have just developed a new test that detects virtually every single virus known to infect human and nonhuman animals. That's huge, because diagnosing viruses has typically been a much more cumbersome process. 

When you feel sick, and go to the doctor's office, it usually goes like this: Your doctor looks at your symptoms, makes you say "ahh," takes a stab at what kind of virus or bacteria you might have, and then sends a sample of your bodily juices to a lab to be tested for a few things (usually around 20) she thinks it might be. If she guesses wrong, and the lab shows up negative, she has to order more and more tests until she hits on the right one. It's about the same process when your dog or cat visits the vet.

Making things even more complicated, treating a virus with antibiotics does zip, and is pretty bad for humankind, because it can help create bacterial superbugs. Tests can distinguish between a bacteria and a virus, but until now, couldn't tell you which dang virus you actually had. 

And then there are the only-sort-of-right diagnoses. Some tests can tell you that you have a flu virus, but might not be able to pinpoint exactly which one. This study showed that standard testing identified a particular virus as Influenza A (which causes the seasonal flu), but didn't catch that it was actually a pretty deadly subtype of Influenza A, which kills 36,000 Americans every year. That's something your doctor may want to know, so she can give you the proper treatment. The new test correctly identifies these subtypes.

By current estimates, there are at least 320,000 viruses that affect mammals alone – a class that includes your cat, your dog, your rabbit, your horse, your pig, your cow, and you. A test that can distinguish between such a wide variety of viruses is a huge jump ahead in diagnostic science. The test can even spot viruses that are only there in very small amounts, which is especially promising for communities with outbreaks of deadly diseases like Ebola.

So, how did they do it? The researchers took DNA and RNA from every single virus known to infect humans and animals, and performed genetic sequencing on them. All in all, they collected 2 million sections of DNA and RNA. And that number will grow as more viruses are identified.

"We think the test will be especially useful in situations where a diagnosis remains elusive after standard testing or in situations in which the cause of a disease outbreak is unknown," said the study's senior author, Gregory Storch, M.D., the Ruth L. Siteman Professor of Pediatrics at Washington University.

The researchers, who received funding from the NIH, just published their findings online in the journal Genome Research.

Source: PubMed

Photo: Maj. Guy Hayes of Army Medicine | Flickr