Australia is racing the clock to find out where a mystery community Covid-19 case has come from; with no obvious links between the infected Sydney man in his 50s and others with the virus.
Genome sequencing shows his infection is similar to that of person who arrived in Australia via the US, but it's likely there are other cases between the pair.
That means restrictions for the Greater Sydney area.
Sydney Morning Herald health reporter Mary Ward talks to Lisa Owen.
