Senior epidemiologist Kate Ward and her team at NSW Health’s public health emergency operations centre have been making thousands of calls to people three weeks after they were initially diagnosed to find out how long it takes them to recover.
Their preliminary analysis of the first 2000 cases found 50 per cent of those patients recovered after 16 days, 75 per cent recovered after three weeks, and 95 per cent reported they had recovered by week six.
For all who still had symptoms at the initial three-week phone call, they would be followed up every two weeks to find out when they recovered.
Ms Ward said they were basically asking people whether they felt better or not, and when they first felt free of symptoms – not an exact science, she said, but it was the best way to collect data.
“It is subjective, but I don’t know if there is a more objective way of doing it,” she said, adding the task was made more challenging by the fact her team cannot ask if people have gone back to their normal routine as daily life has been disrupted.
Ms Ward said the data had also found older patients were taking longer to recover than younger ones.
While NSW Health hasn’t released data about how many patients experience particular symptoms, the severity of their disease and age and gender breakdowns, Ms Ward said they will release the information once they have more robust figures.
University of Sydney Emeritus Professor of Public Health Stephen Leeder said it’s important to know how long it will take people to recover, but there is more critical data needed on how long people can transmit the virus for after becoming infected, and how long immunity lasts.
“We’re still a bit uncertain about how long someone is [infectious] after an episode,” he said.
“There’s a question mark over whether the immunity coronavirus infers is lasting, most common colds don’t give you immunity for very long, so the notion that once you’ve had it and can’t get it again remains to be confirmed.”
NSW Health is treating 249 COVID-19 cases, with 194 of those being treated in out-of-hospital care. Twenty-one people are being treated in intensive care, and 17 of those patients are on ventilators. There have been 30 deaths in NSW.
Rachel Clun is a journalist at The Sydney Morning Herald.