Why Sydney has been worst hit with virus
As the coronavirus continues to spread across the nation, NSW or more specifically Sydney, has been hit harder than anywhere else.
NSW COVID-19 cases jumped to almost 270 yesterday as a fifth person in the state was revealed to have died, taking the national toll to six.
That's almost double the amount of cases Victoria has (147) and it has updated its figures this morning.
Elsewhere the numbers have been substantially smaller, with 94 in Queensland, 37 in South Australia, 35 in Western Australia, 10 in Tasmania, three in the Australian Capital Territory and one in the Northern Territory.
What makes the situation worse in NSW is that the number of coronavirus cases with no known transmission source continues to increase with every passing day.
When asked why Sydney has so many more cases than elsewhere the state chief health officer, Dr Kerry Chant, said it was partly due to the "incredibly high rates of testing in NSW".
She argued NSW has the "liberal testing policies" so they are seeing far greater numbers coming forward to get checked out.
"We have done well in excess of 25,000 tests and continue to test a large number of people each day," she said.
She said the state has been hit with an influx of returning travellers from a "range of countries" in recent days.
Dr Chant said the outbreak had "changed and evolved", citing high amounts of travellers from the United Kingdom, United States and Europe.
"What we have seen is increasing cases in returning travellers from Europe and also America, adding to the previous countries that we have had ... Iran, South Korea and Hong Kong," she said.
However, within Sydney there has been a spate of cases linked to "clusters" in the city's northwest for almost two weeks.
That means that some of the new cases are directly linked back to these locations like the Dorothy Henderson Lodge aged care facility, Ryde Hospital, St Patrick's Marist College and Epping Boys High School. These emerged as transmission hotspots at the beginning March.
Since then, NSW Health found another cluster of at least six confirmed cases from people who attended a wedding in Stanwell Tops, on March 6, which is more than 60km south of Epping.
Investigators believe these cases are potentially linked to travel from the US and close contacts are being followed up for further investigation.
While other states and territories have been able to pinpoint or at least make an educated guess as to where their confirmed cases have come from, the geographical spread of clusters in NSW over several weeks has now made tracing incredibly difficult.
Now the state's health authorities scrambling to trace the people who had been in contact with COVID-19 patients and instruct those people to self-isolate and monitor for symptoms of the virus.
However, Dr Chant said this was increasingly difficult as numbers continued to rise.
"We have also observed an increase in the number of cases where we haven't been able to find a source of that infection," she said.
In an effort to keep the situation under control, NSW Health Minister Brad Hazzard signed an emergency order banning non-essential indoor gatherings of 100 or more people under new national measures to curb the spread of the virus.
The state's schools will remain open but there'll be no assemblies, with strict bans on sick students and teachers. Regular hand washing will be enforced.
Ms Berejiklian says there was "no rationale" for closing schools, with health experts advising they should remain open.
"We would hope any school considering acting alone on this reconsider," the Premier told reporters.
The City of Sydney has also cancelled or postponed all non-essential events and closed gyms and aquatic centres.
Splendour in the Grass, Groovin the Moo and the Sydney Film Festival are among events cancelled or postponed this week.
Universities are suspending face-to-face classes as businesses urge staff to avoid the office. A number of church and mosque services have also been suspended
NSW Police, meanwhile, is halting major roadside drug and alcohol testing operations over hygiene concerns.
Officers will continue to conduct mobile breath testing and there will be an increased police presence around hospitals and shopping centres.
- with AAP