NSW Health has revealed one in 10 people who tested positive to coronavirus last week had no symptoms.
Of the 53 people who tested positive from August 30 to September 5, nine of those exhibited no sign that they might be sick.
Infectious disease expert Dr Peter Collignon told NCA NewsWire the number served as a strong reminder to take the daily health alerts seriously.
“It shows if you’re a high risk individual or a close contact (to a positive case) that you do need to get tested and quarantine yourself for 14 days, because you may well have the infection even if you have no symptoms,” he said.
“It also means those around you who may be asymptomatic get tested, because if you test positive, they’ll be a close contact.”
Dr Collignon said asymptomatic patients were also a good sign for the all important “R number”, which rates how much the virus spreads.
“What’s a bit reassuring about this, is in general I think you expect people who have minimal or no symptoms will transmit the disease less efficiently than people who are coughing and spluttering,” he said.
“If 10 people give it 14 people who give it to 16 people, there’s an epidemic,” he said.
“If they give it to six who give it to four, it starts to go away.”
Despite this, the man at the centre of the Crossroads cluster, which was responsible for more than 50 cases, told health authorities he didn’t feel unwell despite having one of the highest infection rates experts had seen.
In a daily virus briefing with media last month, Premier Gladys Berejiklian said the idea you could have the virus and not know should serve as a point of fear for those who insist on continuing to live life as normal.
“It’s so contagious that if you don’t know you have it and you are still socialising you have the potential to give it to so many people,” she said.
While the results may cause concern to some people, Dr Collignon said it matched the number of asymptomatic patients some experts had predicted there would be.
“My view is about 20 per cent of cases are asymptomatic or have minimal symptoms,” he said.
“Have we missed some asymptomatics? We may have, but they’re doing pretty intense follow-up, including now testing people who were in close contact but don’t have symptoms.
“I think about 20 per cent is what you’d expect.”