There are nine new cases of Covid-19 in managed isolation.
The total number of active cases in New Zealand is 73. The total number of confirmed cases since the outbreak started is 1920.
Three of today's cases come from the US. One person tested positive for Covid after arriving in the country under the new pre-flight testing regulations.
Other travellers with Covid come from India, Kazakhstan, India, the United Arab Emirates and the United Kingdom.
Two people from the US who arrived on January 7 and tested positive on day 12 were part of the same family bubble, the ministry said.
The third person from the US arrived in New Zealand on January 18 and tested positive on day three.
Four people who arrived in the country from India, Kazakhstan and the United Arab Emirates on January 19 all tested positive for Covid on day zero.
Two travellers from the United Kingdom who arrived on January 9 and 10 both tested positive on the second week in managed isolation.
The ministry said today marked a year since the first Covid-19 PCR test was carried out in New Zealand.
The PCR test, using a nasopharyngeal swab, is considered the gold standard for Covid testing as it detects the virus the most effectively.
The first test was processed by ESR.
Almost 1.5 million tests had been carried out in the community and at the border since that time, the ministry said.
A year into the epidemic, testing remained a key component of New Zealand's elimination strategy, enabling quick identification of cases.
The rapid development of testing capability throughout New Zealand was one of the success stories underpinning the response and the sector now had surge capability to handle testing up to 25,000 samples per day, the ministry said.
Border workers in quarantine facilities would now be offered voluntary daily Covid-19 saliva tests in addition to their regular weekly nasopharyngeal swab.
The ministry said the nasopharyngeal PCR test would continue to be used in the community for people who had symptoms consistent with the infection.
This week the first passengers arrived in Auckland from Rarotonga as part of a one-way travel arrangement with the Cook Islands.
Passengers would only be eligible for the quarantine-free travel if they haven't been outside the Cook Islands in the past 14 days or they had not been in contact with a confirmed case in the past 14 days, among other requirements.
The ministry said work continued on the possibility of quarantine-free travel from New Zealand to the Cook Islands.
The health and safety of New Zealanders and those arriving from the Cook Islands remained a priority, which meant quarantine-free travellers would be kept separate from other travellers in airports and there would be additional screening of these passengers as soon as they landed.
"It's important for passengers not to travel if they're feeling ill or showing any symptoms and to remember to scan QR codes wherever they go by using the NZ Covid Tracer App, or keep a paper record if they don't have the app," the ministry said.
Yesterday the ministry released its latest genomic sequencing results of people who had tested positive for the infection since January 6.
Tests have now detected 36 people arriving in New Zealand with the contagious strains since they emerged late last year - 29 samples of the UK variant and seven of the South African variant.
In the past fortnight, 17 more people were now in quarantine facilities infected with two highly contagious Covid-19 strains.
Whole genome sequencing had identified 11 samples of B.1.1.7 (known as the UK variant) and six samples of B.18.104.22.168 (known as the South Africa variant).
The ministry warned these strains would continue to show up in managed isolation facilities across New Zealand.
"We expect we will continue to see both the UK variant and South Africa variant in positive cases in our managed isolation facilities here in New Zealand as these forms of the virus become increasingly common around the world," the ministry said.
On Wednesday, the ministry announced six new coronavirus cases in managed isolation, including one traveller from South Africa who tested positive on day 24.
The infected travellers came from South Africa, Britain, Zimbabwe, America and Russia.
The case from South Africa was within a travel bubble of a previously confirmed case reported on December 31. The infected person has been in the Auckland quarantine facility since the contact case was detected.
This week, the ministry moved to strengthen the border with day 0/1 test and pre-departure testing for all passengers with the exception of those from Australia, Antarctica and most Pacific Islands.