A team of researchers from Columbia University in New York had just published a paper describing their brand-new technique that bypasses the need for all educated guesswork in detecting viral infections, and is capable of identifying every virus known to man in a single blood sample.
The study was published on September 22 in the open-access journal mBio.
In the 120 or so years since viruses were first discovered, our ability to find them, and diagnose the diseases they cause, has improved enormously. But even the most cutting-edge techniques have their limitations.
Nucleic acid sequencing technologies allow scientists to decipher the genetic material of viruses in a sample, but since the DNA of a virus is usually swamped by that of the host, finding out which is which can be tremendously difficult.
Another technique – Polymerase Chain Reaction (or PCR) – can remedy this by making lots and lots of copies of the DNA, but it cannot be performed en masse and requires at least some idea of what‘s being sought after in the first place.
The new method, on the other hand, called the Virome Capture Sequencing Platform for Vertebrate Viruses (VirCapSeq-VERT), acts as a massive set of “hooks” (around 2 million in total), each baited with distinctive DNA markers for every known group of virus that affects humans and vertebrates that the team synthesized specifically for this task.
Once submerged in a blood sample spiked with genes from many infamous viruses, such as those that cause Ebola, dengue, flu, and MERS, the technology successfully pulled out all of the culprits – even when they were present in miniscule amounts.
And since the VirCapSeq-VERT offers up the full genomes of whatever virus it detects, there shouldn’t be any false positives. “If you get a genome, you know what it is. It’s unequivocal,” said study lead author Ian Lipkin. “It also allows you to find mutations that would circumvent traditional diagnostics, or that might affect resistance to drugs or vaccines.”
Unlike the previously mentioned technologies, VirCapSeq-VERT can also process up to 21 individual samples from different individuals by attaching a unique barcode to the viral DNA from each patient. This feature alone could make the technique commercially viable in the near future.
What’s even more fascinating, however, is that it’s remarkably flexible – a fit that’s at least within 60% similarity to something represented in the library will be identified, which could prove highly useful in detecting mutant strains and, perhaps, even previously unknown viruses.
“The results look very promising,” remarked Nick Loman from the University of Birmingham, who was not involved in the study. “Going forward, we can combine techniques like this with portable sequencing and have a diagnostic device which provides incredibly rich data for clinicians and epidemiologists. Ultimately what we would like is an entirely unbiased method that captured all pathogens – known and unknown – with exquisite sensitivity.”