Covid 19 coronavirus: Jacinda Ardern's big call tomorrow - ready for alert level 2?

VIRUS LATEST
* Global cases set to hit 4 million today - with more than 275,000 deaths. NZ has just 103 active cases
* Swamped: Police fear mayhem on streets, crowded bars in level 2
* Liam Dann - one of the biggest weeks in NZ economic history
* Level 2 comes early? Aucklanders flock to waterfront, beach suburbs packed
* Latest developments and essential information

D-Day on alert level 2 is looming and the number of new cases are flat-lining, but academics are cautioning that people without symptoms could still be spreading Covid-19 in the community.

And as Cabinet prepares to decide on moving alert levels tomorrow, there remains a lack of consensus over mask-wearing and contact-tracing capacity needed for level 2, when restrictions on movement will be far looser.

Good weather at the weekend had Aucklanders flocking to Tamaki Drive and surfers crowded Lyall Bay in Wellington - prompting concerns about the public's willingness for physical distancing, even while still at level 3.

But barring a spike in numbers today and tomorrow, a move to level 2 this week looks increasingly likely as New Zealand is still on course on its path to eliminate Covid-19.

The New Zealand situation - we have now just 103 cases - contrasts with those in the US and UK. The number of global cases is set to hit 4 million today, and there have been 276,000 deaths.

In the UK, there have been 31,500 deaths, with lockdown continuing, and over-60s warned they might not be able to travel overseas for a year.

Police are warning Kiwis not to flout the law after hordes took to beaches on Saturday despite the country still being at alert level 3.

The day started with a "mass" of surfers converging on Wellington's Lyall Bay, and as the weather heated up in Auckland many took to the city's inner bays, not just for their allowed dose of exercise, but to sunbathe and even a children's birthday party.

Scores of people were seen along the shared path on Tāmaki Drive, appearing to show little regard for social distancing measures.

At level 3, people are allowed to head outside for exercise and hit the beach for a swim, but are not supposed to treat it as a social gathering.

A woman at an Auckland bay told TVNZ she was there with a group of 12-year-old boys for her son's birthday, despite knowing it was against the rules.

"We do know we probably are a little borderline with the rules, but are still going ahead anyway," she said.

Images showed people out sunbathing and swimming at the city's inner bays. "Maybe people are getting complacent. It almost seems like it is over," a man told One News.

But it is not over yet, and police are encouraging people to report those flouting the rules.

Police recorded about 300 level 3 breaches - about half recorded last Saturday.

Meanwhile, there were only two new cases of Covid-19 yesterday, both linked to the St Margaret's Hospital and Rest Home in Auckland.

One was a Waitematā DHB nurse who had been looking after St Margaret's patients at Waitākere Hospital, and was among the close contacts of other positive cases announced previously.

There are now 1492 confirmed and probable cases, but 92 per cent of people have recovered. Only 103 cases remain active - including only two in hospital.

The number of daily tests in the past three days has also been the highest in New Zealand so far, and is expected to continue to grow as DHBs roll out their updated surveillance testing plans from next week; 3.5 per cent of the population have now been tested.

No recent cases of community transmission have led to any outbreaks.

It has now been three weeks since the number of new daily cases was above single digits, and with today being the 13th day at alert level 3, the latest numbers seem to indicate the lighter level 3 restrictions have not led to any new outbreaks.

But that couldn't be known with any certainty, according to University of Auckland Professor Shaun Hendy, who has been providing the Government with modelling on the prevalence of Covid-19.

"We knew the numbers would start coming down to days where we didn't detect any cases, but that doesn't mean there isn't a possibility of some undetected cases out there," he told the Herald.

"The chains of transmission can persist for some time, and there seem to be a small percentage of people who don't seem to develop symptoms at all and can still be infectious."

Hendy said the long tail of the virus also meant a new outbreak from the level 3 period might still emerge.

For example, an asymptomatic but infectious person could have passed the virus to another person clustered in the queue at BurgerFuel last week, who could have then passed it on further without feeling any symptoms for several days.

"It's extremely hard to find those cases until they go on to infect someone who develops symptoms."

Auckland University Professor Shaun Hendy says while the trends are looking good, there remained a possibility of undetected transmission of Covid-19 in New Zealand. Photo / Supplied

Hendy said the persistently low number of cases was undoubtedly a good sign, but a clearer sign would be a couple of weeks - one incubation period - of no new cases.

"There's not a strong signal telling us to prolong level 3, but if you want to be conservative and have a lower risk of a second wave, you'd stay a bit longer while you ramped up contact-tracing resources."

University of Otago epidemiologist Professor Michael Baker said moving to level 2 was a tough call because a lot depended on how New Zealanders would act.

As well as hand hygiene, staying at home if sick and physical distancing, he said that a "strategic policy" on wearing masks - such as on public transport - and strong contact tracing would mitigate level 2 risks.

The Health Ministry's stance on masks was for people to use them if they knew how, but the evidence around potential benefits - as well as harms - was inconclusive.

Contact tracing has been considered an area that has needed significant improvement; the release of Cabinet papers yesterday revealed the system could only trace 10 active cases in mid-March at a time when there were 12 cases in New Zealand.

That has now been vastly improved, and yesterday the Government released a report from University of Otago infectious diseases physician Ayesha Verrall into progress since her system audit last month.

Five of her eight recommendations had been completed, including a daily check on close contacts of confirmed cases to monitor compliance.

Recommendations still being worked on included a record of the number of close contacts who have been infected by the time they are contacted, which reflects timeliness, and the proportion of contacts who became infected, which measures secondary transmission.

Verrall has recommended the capacity to trace the contacts of 1000 cases a day was needed before moving to level 2.

But Bloomfield has called into question the basis for this number. The capacity of the public health units is to trace the contacts for 185 cases a day, while the national centre was being built up to boost overall capacity to 300 cases a day.

Otago University Professor Michael Baker says a policy of wearing masks on public transport would make him more comfortable with moving to level 2 next week. Photo / Supplied

Hendy said another way to mitigate the risks, as flagged as a possibility by Prime Minister Jacinda Ardern, was to phase in aspects of level 2.

Reducing people-to-people transmission meant that social gatherings of up to 100 people were higher risk, with Hendy citing the stag parties and weddings that had led to some of the 16 significant clusters.

"The nightmare scenario is a big cluster breaking out again, and moving faster than our contract tracers can stay ahead of it."

Cabinet's decision was a complex judgement call, he said.

"It's about that risk. When we go to level 2, will we have a second wave outbreak that overwhelms our public health system?

"That's hard for us to say from our modelling."