Delta spreads ‘like wildfire’ as variant’s severity baffles disease experts

Published August 3, 2021
People wear masks while riding on the subway as cases of the infectious coronavirus Delta variant continue to rise in New York City, on August 2. — Reuters
People wear masks while riding on the subway as cases of the infectious coronavirus Delta variant continue to rise in New York City, on August 2. — Reuters

LOS ANGELES: With a new wave of Covid-19 infections fueled 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 US Centres 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 hospitalised than patients earlier in the pandemic.

In interviews, 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.

Shane Crotty, a virologist at the La Jolla Institute for Immunology in San Diego, said the clearest indication that the variant may cause more severe disease comes from the Scotland study, which found that Delta roughly doubled the risk of hospitalisation compared to an earlier version.

The majority of hospitalisations and deaths from coronavirus in the United States are occurring in people who have not been vaccinated. But there is evidence that the shots are less effective in people with compromised immune systems, including the elderly.

For vaccinated, otherwise healthy individuals, the odds are that if they contract Covid-19 they will only experience asymptomatic or mild disease, said Dr Gregory Poland, infectious disease expert at the Mayo Clinic.

“But they can pass it on to family members and others who may not be so lucky,” Poland said. “We have to be vaccinated and masked or we will, for the fourth time now, endure another surge and out of that will come worse variants.”

The rate of severe illness, especially in regions where vaccination rates are low, is again straining healthcare workers on the front lines of the pandemic.

“This is like a wildfire, this is not a smoldering campfire. It is full-on flames right now,” said Dr. Michelle Barron, senior medical director of infection prevention and control at Colorado’s UCHealth.

Published in Dawn, August 3rd, 2021

Opinion

Editorial

Afghan puzzle
Updated 28 May, 2024

Afghan puzzle

Unless these elements are neutralised, it will not be possible to have the upper hand over terrorist groups.
Attacking minorities
28 May, 2024

Attacking minorities

WHILE Pakistan has watched many perish in the cauldron of sacrilege, the state has done little to turn down the...
Persistent scourge
28 May, 2024

Persistent scourge

THE challenge of polio in Pakistan has reached a new nadir, drawing grave concerns from the Technical Advisory Group...
Mercury rising
Updated 27 May, 2024

Mercury rising

Each of the country's leaders is equally responsible for the deep pit Pakistan seems to have fallen into.
Antibiotic overuse
27 May, 2024

Antibiotic overuse

ANTIMICROBIAL resistance is an escalating crisis claiming some 700,000 lives annually in Pakistan. It is the third...
World Cup team
27 May, 2024

World Cup team

PAKISTAN waited until the very end to name their T20 World Cup squad. Even then, there was last-minute drama. Four...