Covid 19 coronavirus: Auckland still has 'low risk' of outbreak – experts

Experts are confident Auckland still faces a low risk of community outbreak, despite today’s latest Covid-19 case being a “casual plus” contact.

One epidemiologist however warns it’s possible the current cluster could keep bubbling away for days, or even weeks, given the virus’ long incubation period.

The newly-announced case, identified this morning, is a Papatoetoe High School student who was tested for the first time yesterday.

The schoolgirl was identified as a casual plus contact of the community cases linked to the February outbreak but had not returned to the school and had been isolating at home.

The student lives in a house with six people, including one family member who also goes to Papatoetoe High School, and that sibling has not been back to school either.

Director General of Health Ashley Bloomfield said all of the family members of the new case were being tested but only the confirmed case is symptomatic at the moment.

There are 27 locations of interest connected to the latest outbreak in the Papatoetoe area and 1416 casual plus contacts identified.

Officials were still following up with another 10 students considered “casual plus” – which was a person who’d visited a location of interest at the same time as a person who has since tested positive for Covid-19, but did not meet the criteria for a close contact.

Experts approached by the Herald today were confident the flare-up would be kept contained.

“The good news is that the new case and her sibling have not been back to school since this outbreak started, so the risk to the community is still fairly low,” Covid-19 modeller Professor Michael Plank said.

“The important thing now will be for contact tracers to track down any close and casual contacts the student and her household bubble may have had over the last few days, and for them to get tested.”

Otago University epidemiologist Michael Baker was similarly optimistic.

“This [latest case] was someone they were intending to check out anyway, and they just missed them,” he said.

“It shows the system is working – and how hard it is to track down every last contact, when you have over 1000 of them.”

Asked whether the involvement of the more-transmissible UK variant could partly explain why the case was only a casual-plus contact, Baker said it was difficult to speculate.

Even with the strain, he added, how the virus spread was dependent on individual factors.

“And it’s worth remembering that it took a great deal of observational data to conclude that these variants were more transmissible,” he said.

“Overall, I think this pattern is still manageable, because, while this is what happens with a larger cluster than usual, it is still consistent with the idea that contact tracing, and looking at concentric circles of contacts, is effective.

“Obviously, there’s now going to be more contact tracing, given this new family group was exposed, so this may go on for some time.

“We can’t guarantee that this is the end of this cluster, and it could extend for days or even potentially some weeks, because of the incubation period.

“But that doesn’t mean that we’re necessarily looking at a serious outbreak at this stage.

“The ominous thing would be if we had cases that appeared in the community that were linked to no cases – and we’ve still not seen that.”