Delta spreads 'like wildfire' as doctors study whether it makes patients sicker
With a new wave of COVID-19 infections fuelled by the Delta variant striking countries worldwide, disease experts are scrambling to learn whether the latest version of coronavirus is making people - mainly the unvaccinated - sicker than before.
The U.S. Centers for Disease Control and Prevention warned that Delta, first identified in India and now dominant worldwide, is "likely more severe" than earlier versions of the virus, according to an internal report made public on Friday.
The agency cited research in Canada, Singapore and Scotland showing that people infected with the Delta variant were more likely to be hospitalized than patients earlier in the pandemic.
In interviews with Reuters, disease experts said the three papers suggest a greater risk from the variant, but the study populations are limited and the findings have not yet been reviewed by outside experts. Doctors treating patients infected with Delta described a more rapid onset of COVID-19 symptoms, and in many regions an overall increase serious cases.
But the experts said more work is needed to compare outcomes among larger numbers of individuals in epidemiologic studies to sort out whether one variant causes more severe disease than another.
"It's difficult to pin down increase in severity and population bias," said Lawrence Young, a virologist at the UK's Warwick Medical School.
In addition, it is likely that the extraordinary rate of Delta transmission is also contributing to a greater number of severe cases arriving at hospitals, the experts said.
Delta is as contagious as chickenpox and far more contagious than the common cold or flu, according to the CDC report.
-- with files from CTV News --