There are 40 new cases of coronavirus confirmed in New Zealand today.
Director-General of Health Ashley Bloomfield told reporters there were also three new probable cases.
There were 155 cases of confirmed and probable cases, and he said the daily tally would now include probable cases.
The probable cases had returned a negative result, but their history and symptoms showed they had Covid-19, and they were treated the same as if they had returned a positive result.
Details of the cases would be updated on the Ministry of Health website.
Six cases were in hospital, and they were all stable, and none of them required ICU treatment.
Bloomfield said there was a community transmission case in Orewa, who had been on a tour to Milford and presumably came into contact with an overseas traveller.
Both he and his partner had tested positive, Bloomfield said.
Meanwhile 12 patients had recovered.
Asked if losing the sense of smell was a symptom of Covid-19, Bloomfield said it was an incidental finding and researchers were following that up now.
Health workers might need to self-isolate from their own family if they were caring for someone who had Covid-19.
"I'm sure everyone would be looking to minimise the risk to their household members, including health workers."
"Anyone who has been tested is expected to be in strict self-isolation until they are advised of the result."
Six people at the Hereford Conference in Queenstown had now tested positive, Bloomfield said.
All new cases that he had information on, about a third of the 40 new cases, had a link to overseas travel or to close contacts of an already confirmed case.
Most cases in New Zealand were still related to overseas travel, he said.
"At this point we are classifying four cases as 'community transmission' - three in Auckland and one in the Wairarapa."
Contact tracing was underway for all of those cases.
He said he was not aware of any confirmed cases among health workers, and there was one confirmed case in an Auckland rest home.
People in the rest home, including staff who may have been exposed, were being looked after in a "bubble".
Aged care residential facilities were told to put in place strict protocols for visiting weeks ago.
More than 900 tests were carried out yesterday, bringing the total to over 8300 tests.
Bloomfield said there was a clear consensus among public health professionals and scientists that moving to alert level 4 sooner rather than later gave New Zealand the best chance to break community transmission.
An increase in testing capacity meant that testing could now take place in a school, for example.
There would be strict rules on visiting people in hospital during the lockdown period, he said.
He said millions more masks were being produced, so he was confident about the personal protection equipment (PPE) stocks in New Zealand.
Education update: 'Difficult task' getting devices to pupils' home
Secretary for Education Iona Holsted told reporters it may be ideal to limit connections to immediate family, while others may need more help.
A child of an essential worker who can't stay home could have an identified buddy in their self-isolated group to take care of the child.
Another example could be carers of a disabled child when the carers need rest. Those designated helpers, though, cannot socialise with others, nor can they be people with compromised immunity.
Holsted said the Ministry of Education was working through the logistics of distance learning, including access to internet and getting devices to learners who do not have them.
She said getting devices to the right homes was a difficult task at the moment because they had to be delivered to homes, not schools.
Where devices couldn't work, hard copies of schoolwork would be delivered, she said.
Some areas had no internet coverage at all, so the ministry was working with television and radio services to beam into children's homes.
Holsted expected schools to provide online learning, and she said students should use lockdown time to study.
If the lockdown was prolonged, the year of study would be more disrupted and NZQA would decide how that would affect the year of learning.
She said options were being looked at for childcare, but older people - including grandparents - and those with compromised immunity were not suitable people to look after kids.
She said police vetting would help ensure childcare services would be appropriate, and there were many ECE workers who could step into nanny roles.
Supermarkets will stay open
Ministry of Business, Innovation and Employment deputy chief executive Paul Stocks said
"essential" services under alert level 4 were there to provide for the necessities of life, not to bring normalcy to everyday life.
Those services had to limit the risk of spreading Covid-19.
There were 15 sectors considered to be such services, and they can be viewed at covid19.govt.nz.
"We will continue to update that website, and from 5pm today, there will be an 0800 number for firms to call in if they are unclear about their essential services status."
He said if a business was unclear about whether they were essential, then they probably were not.
"This is an evolving situation."
The essentials of life, including supermarkets, will remain open, Stocks said.
Service stations will also be open, as will the supply chains that sit behind those services.
People without a car would be able to travel in a taxi, for example, by sitting in the back seat to maintain physical distancing.
Stocks said the Government had not decided that The Warehouse, which said today it would stay open during the lockdown, was an essential service.
He cautioned businesses from claiming they were an essential service prematurely.
"We don't want a bunch of people showing up to retail stores."
Stocks said all communities needed access to food, so dairies and corner stores could stay open if they were the only provision in more isolated communities.
Supermarket workers who came into contact with a lot of people should take care and maintain physical distancing, and should self-isolate when they returned home.
Stocks said clarification would be provided about whether liquor stores were an essential service.
Further work was being done and more clarity will be added to the website tonight. "It won't be perfect ... we are in unchartered territory."
'Everyone must stay home'
The Government's coronavirus taskforce is providing an update on the number of confirmed cases and the logistics of New Zealand preparing for the lockdown.
All of Government Controller John Ombler said that the response to Covid-19 is "unprecedented" and staff across the private and public sectors were working on delivering essential services to New Zealanders.
From 11.59pm on Wednesday "everyone must stay at home unless they are working in essential services".
Ombler said that meant no socialising with people outside their households.
He said people could go outside and exercise, but keep 2m away from other people at all times.
"Physical separation, but maintain social connection."
Ombler said maintaining distance was still important while going to the supermarket or pharmacy.
Everyone needed to follow these requirements, and enforcement action would be taken if that did not happen.
He said New Zealanders overseas should make plans in case they couldn't find flights home.
He added that they should not rely solely on Government assistance.
There is a heavy police presence at some supermarkets today as Kiwis stock up on food and alcohol before the lockdown begins at 11.59pm on Wednesday.
Yesterday, the number of confirmed cases in the country rose to 102, with 36 new cases since Sunday.
Almost all of the cases are related to overseas travel or other confirmed Covid-19 cases.
But two are being treated as community transmission which is why the alert level will be raised to 4 in an attempt to try stamp out the spread of the virus.
At 11.59pm on Wednesday, New Zealand will go into an extreme and unprecedented nationwide lockdown for four weeks.