Covid 19 coronavirus: Is it luck? Top health boss Caroline McElnay's theory on lack of community cases

One of New Zealand's top public health bosses has admitted officials are "scratching our heads a little", in relation to the recent string of Covid-19 positive people coming out of the Pullman.

Director of public health Caroline McElnay has also revealed "we don't know if [it's] luck" when it comes to why there has not been any further community spreading of the virus.

This comes after a fifth person, who had been released from the Pullman MIQ facility, tested positive for Covid-19.

The Ministry of Health today revealed a person self-isolating in Hamilton had tested positive seven days after leaving their MIQ isolation.

But McElnay said the public health risk was low and that people in Hamilton "should not be alarmed".

"We are acting out of an abundance of caution. We are not advising any restrictions or cancellation of events."

Earlier in the morning, a Hamilton Waitangi Day event was cancelled as, according to the hosts, a "credible health source" said there was a new positive case of Covid-19 in the community.

McElnay said health officials were "very confident" the new Hamilton Covid case had been self-isolating since they returned from the Pullman.

Director of public health Dr Caroline McElnay speaks to media during a press conference at Parliament. Photo / Hagen Hopkins/Getty Images

She said she had a "high degree of assurance" the case is well contained.

The new Hamilton case from the Pullman follows four others who were released from the MIQ, but later tested positive.

So far there has been no evidence of any community transmission.

"We don't know if that's luck," McElnay said, "but we certainly have very strong systems to be able to rapidly respond.

"I think we are scratching our heads a little," she said, in response to a question as to why there has not been more community transmission.

"[What] we are seeing is slightly different from what we might expect – certainly if you look at what's been happening in Australia," she said.

"What we've seen from overseas is these new variants could lead to an increased number of community cases. We are seeing with this very small numbers have been infected in the facilities."

The new Hamilton case – who has now been moved to the Jet Park quarantine facility in Auckland – tested positive on the fifth and final day of their post-Pullman self-isolation. They were asymptomatic.

The person's only close contacts were two people who lived with them, who have both since tested negative.

McElnay said officials will be carrying out more tests to determine the strain of the variant, which would help provide clues as to how it was transmitted.

The person had recently returned from overseas and was in the Pullman between January 16 and 30

In light of this fifth post-Pullman person being infected with Covid-19, McElnay said the Government was looking at a range of issues in an "in-depth review".

She revealed the Government has looked at removing common areas from MIQ facilities, as well as looking into extending the length of time people will be required to self-isolate after leaving managed isolation.

"There is an in-depth review, both of the Pullman but also of our quarantine and isolation facilities," McElnay said, adding this is work which has been under way for a "number of weeks".

National's Covid-19 Response spokesman Chris Bishop said he welcomed the "in-depth" review – a review his party had recently called for.

But he said Prime Minister Jacinda Ardern dismissed these calls on January 28.

"Did Jacinda Ardern and Chris Hipkins know this review was under way or is this another example of ministers being at odds with their officials about what work is actually being done?"

The new Covid-19 case would also be used in the Pullman Hotel investigation into how the virus was spreading at the facility.

There are 60 people left at the Pullman – they are all due to leave today.

After that, the facility will receive a "deep clean" and more investigation work will be done.