New Zealand is trying to figure out how someone in hotel quarantine, who tested negative twice to the virus, seemingly caught the more virulent South African strain of COVID-19 in the last days before being released.
Contact tracing is underway for approximately 30 venues the woman visited after leaving hotel quarantine in Auckland, before she tested positive 10 days later.
New Zealand authorities are trying to determine how the woman caught the virus but are fairly sure it happened within hotel quarantine, according to physicist Shaun Hendy, who has provided modelling throughout the pandemic for the New Zealand Government.
"We got back the genomic testing about midday yesterday and that's indicating that there was another case actually staying on the same floor and the same hotel, with the same genomic signature," Professor Hendy told RN Breakfast.
The Australian Government has temporarily suspended quarantine-free travel for New Zealanders arriving in Australia amid fears of potential community spread.
Professor Hendy said that the positive result should be a warning to Australia and New Zealand to redouble their efforts in their hotel quarantine systems, particularly after the emergence of more virulent strains.
"We do need to be upping our game and the way that we manage people when they come back through the border," he said.
He said it was also essential that New Zealand and Australia shared contact tracing information, if the two countries were going to achieve a sustainable travel bubble.
"Our governments have to get really good at sharing and exchanging information," he said.
"We're not normally sharing that kind of information across borders, so we've got to build those systems and have them in place if we're going to confidently move towards a travel bubble."
Authorities looking at ways virus could have spread in quarantine
Authorities are still not sure how the virus could have spread in quarantine but there are several possibilities, Professor Hendy said.
"We've had several breaches like this in the past, as I know you have in Australia," he said.
One possibility was that the two people the virus was transmitted between used the same facility in the hotel not long after one another.
"We found in a case last year, two people were in an elevator separated by about 10 minutes and an infection was passed on," he said.
"The fact that they were staying on the same floor, I mean, that's sort of circumstantial evidence."
Professor Hendy believed another possibility, of airborne transmission, meant the New Zealand Government was moving to make changes to quarantine hotels.
"I believe that that the Government's actually moving to change the filters that are used in hotels and that's up for quarantine," he said.
No positive tests in early contact tracing efforts
Professor Hendy said the husband of the woman who has tested positive had already tested negative once after the discovery of the case.
"Basically the husband picked her up from the hotel and they went on a short mini-break over the next week," he said.
"Her husband has tested negative. He'll obviously get another twist again and if that comes back negative, then that possibly suggests that she hasn't gone on to many other people.
"There's been there's been a lot of testing done in the region where she went on holiday over the last couple of days and as yet we've not had any positive steps on that."
Contract tracing is continuing in New Zealand.