Gatherings of more than 500 people should be cancelled to help stop the spread of coronavirus, Prime Minister Jacinda Ardern says.
Doctors have more freedom to test for Covid-19 and no longer have to call the local Medical Officer of Health before ordering a test.
And in a letter to GPs, the Director-General of Health Ashley Bloomfield stresses people who are asymptomatic shouldn't be tested to ensure the availability of supplies in the future.
"For this reason, there may be regional variation in testing protocols," he said.
But the Opposition has criticised the Government for "nickel-and-diming" tests even if someone has come in contact with a confirmed case.
In a letter to GPs on Sunday, Bloomfield announced the Ministry of Health changed the case definition for Covid-19 which is how doctors decide if a case is likely.
Now anyone with a fever, shortness of breath, a cough or a sore throat who's travelled to a coronavirus hotspot or come in contact with a confirmed case should be tested.
But doctors should use their clinical judgement to assess whether someone who doesn't quite meet the case definition should be tested anyway, Ministry of Health advice says.
Any patient who meets the threshold for testing will have the cost of their consultation covered.
But Bloomfield urged prudence with testing in the letter.
"While the volume of testing is going to increase, I ask you to continue to apply the case definition when considering who you should test, and to use testing supplies and personal protective equipment with prudence.
"There is no indication for the testing of asymptomatic people.
"Covid-19 is likely to be with us for some months, and it is important that we ensure the availability of supplies for the coming stages."
The Director-General of Health, Dr Ashley Bloomfield, briefing media on on Covid-10 coronavirus. Photo / Mark Mitchell
The Ministry of Health is also working with other agencies to establish how they'll cope with higher testing volumes, though what that looks like exactly is yet to be established.
It could be designated practices, mobile services or community-centres, Bloomfield said.
But Opposition health spokesman Michael Woodhouse said the testing regime needed to be more liberal to ensure there wasn't a community outbreak.
Only testing people with symptoms isn't consistent with putting everyone who's come from overseas into self-isolation whether or not they've come into contact with the virus or are ill, Woodhouse said.
He referred to Minister Tracey Martin who sat next a now-infected Australian politician, Peter Dutton, for at least an hour one week ago.
She said her doctor said she didn't need to be tested as she didn't have symptoms.
Martin is self-isolating as a precaution.
"We appear to be nickel-and-diming a testing regime, even for people who've been in close contact with people who've had the virus," Woodhouse said.
Minister Tracey Martin is in self-isolation as a precaution. Photo / Mark Mitchell
The president of the Royal New Zealand College of General Practitioners, Dr Samantha Murton, said she believes the current testing regime is wide enough as there's "no point testing people who has no symptoms".
"If someone only has mild symptoms, then they're less likely to be shedding droplets and the risk of passing it around to other people is a lot lower."
Murton said the vital part in the response and testing regime is contact-tracing to ensure anyone who's been in contact with a confirmed case and has symptoms is tested.
"So as long as we're doing the tracing around those people, then this is good enough testing."
Murton rejected the idea that people who are asymptomatic are "carriers" who could transmit to other more vulnerable people.
International evidence shows people who are asymptomatic and transmit the virus is very low, she said.
Instead it's people who have symptoms and are spreading the disease through coughing.
"If someone only has mild symptoms, then they're less likely to be shedding droplets and passing it around to other people is a lot lower."
Murton urged anyone who had any symptom - no matter how small - and met the criteria of international travel or contact with a confirmed case to call their GP or Healthline for advice.
Woodhouse also said more liberal testing regime could shortcut having so many people in self-isolation if their tests came back negative.
"If they've had two or three tests and they've come back negative, let them out of self-isolation.
"Maybe the costs of those tests is much lower than the cost of self-isolation.
"This is where I think the Government is taking a very narrow view of the strategies taken - they're all interconnected."
Woodhouse said he was aware of a woman who went to the doctor because she felt unwell and her employer told her she couldn't go back to work until testing negative.
But she was told she didn't meet the criteria to be tested, so is now forced to stay home for two weeks without enough sick leave to cover the absence.
