A new study has found that the Delta variant of the coronavirus that ravaged the country since June last year was the deadliest of Australia’s first three waves.
Patients admitted to the ICU during the third wave were mostly unvaccinated and younger than the previous two waves, Monash University researchers found, and while the length of stays in the ICU and hospital went decrease, the risk of dying in the hospital increased.
People admitted to the hospital during the Delta wave were also more likely to be pregnant or obese, and less likely to suffer from comorbid conditions, according to the study. Australia has had multiple waves of COVID-19 infections since the start of the pandemic in March. 2020, but the third wave of the Delta variant was the deadliest, according to new research. (SMH / Kate Geraghty)
Dr. Aidan Burrell, of Monash School of Public Health and Preventive Medicine, said the data revealed that third-wave patients showed “an increased risk of death” from bacterial pneumonia and pulmonary embolism.
The third wave stood out for increased use of non-invasive respiratory support above mechanical ventilation and patients lying in front during mechanical ventilation, he said.
“There was widespread adoption of new evidence-based practices,” Burrell said.
“However, despite these differences, the risk of dying was higher in the third wave and the results reinforce the need to provide adequate resources to ICUs, especially during peak demand.”
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Although fewer ICU patients received invasive respiratory therapies, changes in hospital mortality risks were observed mainly in people who had received mechanical ventilation.
The research published in the Medical Journal of Australia analyzed the evolution of patient characteristics, treatments and critical patient outcomes in the first, second and third waves.
In those waves, 2493 people were admitted to 59 ICUs: 214 in the first (9 percent), 296 in the second (12 percent) and 1983 (80 percent) in the third.
Thirty patients died in hospital during the first wave, 35 in the second and 281 in the third.
According to the latest government data, 9,599 Australians have died from COVID-19 since the start of the pandemic. (SMH / Kate Geraghty)
In Australia, relatively few infections were experienced in waves one and two, due to a combination of national quarantine and social distancing measures.
The load on the hospital and ICU remained at almost usual levels.
However, the emergence of the Delta strain in mid-2021 reduced the effectiveness of these measures and quickly followed a rapid spread of the community.
During the Delta Wave, New South Wales and Victoria recorded the highest number of infections and deaths, and both states imposed a number of public health measures such as vaccinations, social distancing and blockades.