Hawke's Bay has reported no new cases of Covid-19 on Thursday, with the regional total remaining at 35.
Medical Officer of Health Dr Nick Jones said the district health board's public health team was actively investigating the contacts of a case confirmed on Wednesday.
This woman in her 20s had been at Eastern Institute of Technology (EIT), Taradale, on March 23 and 24, before becoming aware of her illness.
Dr Jones said all but one of the known contacts of this person had been contacted.
"While we still don't know where this person acquired the illness from we are following up a number of leads and should know more in the next few days.
"While it is unlikely that anyone who hasn't already developed illness will do, I urge everyone to be vigilant.
"Contacts should be aware that although they may have had a very mild illness, and now be fully recovered, they may have passed the virus to other people within their bubble over the last two weeks.
Any contact or family member of a contact who has become unwell with a cough, sore throat, shortness of breath, a runny nose or loss of smell should contact their GP or Healthline on 0800 358 5453 Jones said.
There remains six recovered cases in Hawke's Bay.
Hastings has 11 current cases and one recovered, Wairoa has 3 cases, Central Hawke's Bay none and Napier has 21 current cases and 5 recovered.
There are no cases in Hawke's Bay in hospital.
There are 29 new cases of Covid-19 nationally since yesterday and Prime Minister Jacinda Ardern says New Zealanders have saved lives by staying at home over the past fortnight.
The new cases are made up of 23 new confirmed cases and six new probable cases.
There are no additional deaths to report, but there are 14 people in hospital and four people in ICU.
There are now 317 recovered cases across NZ – an increase of 35 on yesterday, higher than the number of new cases.
The combined total of confirmed and probable cases in New Zealand is 1239, Director General of Health Ashley Bloomfield says.
On day 15 of the lockdown, Ardern told Kiwis that it was working.
"And at the halfway mark I have no hesitation in saying, that what New Zealanders have done over the last two weeks is huge. In the face of the greatest threat to human health we have seen in over a century, Kiwis have quietly and collectively implemented a nationwide wall of defence," she said.
"You have saved lives."
"We are on track to meet their most optimistic scenario. We are turning a corner. But to succeed, we need it to keep working."
She said to expect roadblocks this Easter weekend.