Startling new figures in the NSW government's weekly COVID surveillance report have unearthed a frightening fact.

Many of those who have coronavirus, have no idea they've got it.

The public first became aware of the outbreak on Sydney's northern beaches on December 16, and in the following days infections rose sharply before a local lockdown and other public health measures slowed down the spread.

A new breakdown of data collected by NSW contact tracers and virus testers shows nearly everyone who tested positive before December 16 felt sick or were displaying symptoms of COVID-19.

But as scores of venues were added to a list of locations where patrons were urged to get tested "immediately", more and more asymptomatic people were diagnosed with the highly contagious virus, suggesting many could be infected, and infecting others, without knowing.

As the northern beaches cluster grew, more people were diagnosed with COVID-19 without showing any symptoms.
As the northern beaches cluster grew, more people were diagnosed with COVID-19 without showing any symptoms.

A graph included in the latest weekly COVID-19 surveillance report shows a growing proportion of cases were asymptomatic in the days after the outbreak became known.

"The majority of cases reported having symptoms at the time diagnosis at the start of the outbreak," NSW Health officials write in the report.

"Rapid targeting messaging to people in the Northern Beaches area advising them to get tested led to a larger proportion asymptomatic cases at diagnosis in the later stages of the outbreak."

In the seven days up to December 19, there were 19 people who received a positive COVID-19 diagnosis despite not feeling any symptoms.

"(Those people) had sought testing because they were either close contacts or had been in a venue that had been visited by confirmed cases of COVID-19," the report authors wrote.

Identifying COVID-19 infections before symptoms arise has been identified as a key goal in the state's fight against the coronavirus, the report says.

Originally published as Frightening figure in NSW outbreak


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