By Reuters Staff
(Reuters) - A gene called IFI27 that becomes activated early in COVID-19, even when symptoms are absent, might help identify people most likely to have contracted the virus after coming in contact with an infected person, researchers say.
Every week for six months, 400 UK healthcare workers completed questionnaires about COVID-19 symptoms and provided blood samples and nasal swabs for PCR testing. In 41 workers diagnosed with COVID-19, IFI27 genes were "switched on" at the time of their first positive PCR test, even in asymptomatic individuals, according to a report in The Lancet Microbe.
In some cases, IFI27 could predict infection one week before a positive PCR test, coauthor Joshua Rosenheim of University College London told Reuters.
Overall, testing for IFI27 correctly identified 84% of COVID-19 cases and correctly ruled it out in 95% of uninfected participants.
Blood biomarkers like IFI27 can signal other viruses as well, so PCR is still the gold standard for diagnosing COVID-19.
"However, testing for blood biomarkers is still valuable," Rosenheim said. "IFI27 predicted infection despite the person not having any symptoms and often before a positive PCR test, so it could be used during contact tracing."
IFI27 tests in people who recently came in contact with a confirmed COVID-19 patient could allow for earlier diagnosis and treatment and "might even permit us to recommend self-isolation in a more targeted manner," he said.
SOURCE: https://bit.ly/3kMTcaf The Lancet Microbe, online July 6, 2021.