A new, inexpensive diagnostic test could help doctors better identify the exact source of viral infections.
A paper published Tuesday in the journal mBio details the test, Virome-Capture-Sequencing platform for Vertebrate viruses, or VirCapSeq-VERT for short.
Researchers at the Center for Infection and Immunity at Columbia University's Mailman School of Public Health developed the test, saying it’s as sensitive as the best out there.
But, unlike current diagnostic tests, VirCapSeq-VERT can simultaneously test for hundreds of different viruses at once, providing near complete sequences of their genetic makeup.
Thomas Briese, Ph.D., associate professor of epidemiology at Columbia and first author of the new paper, said VirCapSeq-VERT's most important contribution will be in the hands of clinicians.
“If you have patients you suspect have a viral disease, you can now for a very reasonable amount of money, definitively characterize all the viruses present in those individuals in order to figure out how they should be treated,” Briese said in a press release.
VirCapSeq-VERT costs approximately $40 when testing for 20 viruses, where other procedures like rRNA depletion cost approximately $65 per sample, researchers said.
The new study was funded by the National Institutes of Health and the Department of Homeland Security.
Identifying a Virus’s DNA
When your doctor is looking for the source of what ails you, there are many variables.
First, are your symptoms caused by a virus, bacteria, parasite, or something else?
Second, if it is a virus, which one is it?
As viruses are living organisms that can evolve defenses around treatments — known as drug resistance — it’s vital that clinicians use the right antiviral medicine to make you well and prevent the virus from becoming stronger.
Rapid diagnostics, or those that can identify the source of infections quickly, can help doctors find the source of an infection and provide the correct treatment faster.
The scientists behind VirCapSeq-VERT say their test is a breakthrough in this field, as it results in 100 to 10,000-fold increases in viral matches compared with current test methods.
To test VirCapSeq-VERT, scientists selected pieces of DNA from among nearly 2 million known viruses, representing all viral taxonomy known to infect vertebrates. This includes common viruses like influenza and herpes virus but also more worrisome ones like Ebola, West Nile, and dengue viruses.
These pieces of DNA work like a probe to pull out segments of a blood, feces, or tissue sample to identify the virus.
Dr. Ian Lipkin, director of Columbia’s Center for Infection and Immunity and senior author of the paper, said other screening methods lack the the necessary sensitivity for detecting viruses or the ability to detect multiple viruses at once.
This makes them slower and more costly, he said.
“VirCapSeq-VERT is a specific, sensitive, powerful way of characterizing all of the viruses in a sample,” Lipkin said in a press release. “This will be an important tool for precision medicine as well as basic and clinical research.”
Researchers were not available to answer questions from Healthline, according to a media spokesman from Columbia.
Catching Their Cousins, Too
As previously mentioned, viruses can mutate quickly, which poses a problem for both detection and treatment.
As VirCapSeq-VERT uses genetic sequencing to identify a virus, it can detect a virus even if it isn’t an exact genetic match. It’s like the way you and a sibling aren’t genetically identical, but you’re a pretty close match.
The Columbia scientists say VirCapSeq-VERT can detect a virus when as much as 60 percent of its DNA doesn't match the probe, meaning when a virus mutates, the test can still identify it.
The researchers say their new testing will help not only individual infections but is also valuable during outbreaks.
Columbia’s infectious disease experts are currently using the technology and are talking with other labs interested in using it.
When it will be widely available, however, isn’t yet clear.