Victoria records 179 COVID-19 cases, hotel quarantine inquiry continues, Daniel Andrews denies lift on Victoria restrictions, NSW, SA border talks intensify, Australia death toll at 472
The dark blue line shows locally acquired cases where the infection source cannot be traced – the “mystery cases” that Premier Daniel Andrews and Chief Health Officer Brett Sutton often mention in the daily coronavirus updates.
During July, both of these lines were shooting up at a similar pace, but since about the start of this month, the light blue line (cases with a known source) has climbed far higher than the dark blue line (mystery cases).
This divergence suggests that a larger proportion of recent coronavirus cases in Victoria can be traced back to outbreaks rather than the infection source remaining a mystery to the health department.
You might have noticed a red line on the chart too. At one stage it was climbing rapidly but now it’s dipped below 1000.
Those are the cases that are still being investigated by the health department. Back when there were 500-plus new cases a day on average this was creating a backlog, but now the daily infection numbers are lower it means the number of cases still being investigated is being brought under control.
That means there is a bit of a time lag built into this graph, so when the number of cases under investigation comes downs it means that the blue lines go up.
Today the number of new cases tied to community transmission rose by 24.
That in some ways tells us how many investigations the health department was able to cleat in the past day, but given the pool of cases under investigation is declining, it also suggests community transmission rates are slowing down.