The total number of cases is now 28. The new cases today all relate to overseas travel.
There is still no evidence of community transmission in New Zealand, Bloomfield says.
The Ministry of Health is working to identify any close contacts.
Two of the cases are in Southland, two in Taranaki, one in Rotorua, one in Northland and two in Auckland.
None of the new eight cases are school students.
"We are obviously alert to all the new cases and identifying any close contacts," Bloomfield says.
The Ministry of Health is contacting up to 1000 close contacts of the 28 confirmed cases.
Healthline will be provided with the details for the people considered close contacts from being on the flights with the new eight cases.
Bloomfield said he hasn't heard any official word on a full national lockdown, like in Italy.
"We are planning for a long-term effort here," Bloomfield said.
Bloomfield said he didn't have a timeframe for when New Zealand will experience community spread.
"We are watching very closely as to whether we have any community spread. We also want to act before we see any evidence of widespread community outbreak."
"We've seen a big increase in the number of tests being done, only a few of those cases are testing positive, but it does give us a good idea of whether there's wider community transmission. We're testing people with wider influenza symptoms and it's not at this point been covid-19."
"There's a lot of work going on to confirm our labs have everything they need to conduct the tests, get the results out quickly, identify the positive results and contact trace."
Bloomfield said some of the earlier cases will be recovered now, but they all need to stay self-isolated for 14 days once they've recovered.
Some elective surgery is being postponed so staff can be upskilled on how to care for people who are ventilated.
Get used to keeping your distance
Bloomfield emphasised we need to get used to maintaining physical distance, particularly when visiting older people in the community.
Government agencies are working with businesses to create more distance between employees.
The recommended social distancing is 1.5 metres and the distance for contact tracing is 2 metres.
Bloomfield said people need to be taking care of their mental wellbeing and there's information on the Ministry of Health website.