A test that combines the ability to detect both coronavirus (commonly called SARS) and influenza, as well as one that finds new pathogens faster, has been developed by a team at the University of Pittsburgh. They have successfully tested this combination on a mouse model and expect to soon test on people as well.
The animal trial suggests that the new test can detect a number of different coronaviruses, including two that cause severe respiratory disease in humans, known as viruses A/SARS1 and A/SARS2. Given that both viruses have the potential to cause very severe disease, the fact that the new test discovered one virus that wasn’t previously known to be linked to SARS is important.
“This is a pathway that allows us to look for these viruses in human populations,” said Anthony Swerdlow, an immunologist who led the research team. “Previous studies have shown that this particular pathway is excellent at detecting very long non-human ancestor sequences that are very similar to the viruses we see as existing.”
Flu kills tens of thousands of people worldwide each year. Scientists are also not always sure why one strain causes a very mild infection, while another can cause severe symptoms, although the two strains are more or less genetically identical. The presence of coronaviruses in humans has been linked to the 1918 flu, which is probably the most severe human pandemic in recorded history. Although none of the three viruses that have caused SARS (including SARS-H1N1) have made a comeback to create a second wave of infection, the coronavirus component is thought to be the biggest reason. The ability to quickly identify a new strain is especially important as SARS evolved rapidly as it spread through the hospital system, returning about every four months to infect new people who had not been previously infected.
Unlike those cases, humans are much less resistant to flu. The new test is particularly useful in that its ability to spot emerging strains could help us anticipate what new virus will emerge, and determine which type will cause the worst of the next new world pandemic.
One rather serious limitation, though, is that this technique doesn’t work for new noroviruses, the virus type that, until recently, had caused the vast majority of bird flu infections, mostly in non-human mammals.
“Not having the ability to detect noroviruses in this assay is a limitation in preventing novel NDM-1 strains from escaping into the human population,” Swerdlow said. “In order to be able to spot new noroviruses, we need to get a new or higher-quality assay in the clinic.”