Extra staff had been brought on at Healthline due to the surge in calls about coronavirus.
Those quarantined at Whangaparaoa - now for five days - are still receiving daily health checks, as are staff. A number of people had swabs taken due to very mild symptoms, even though these did not fit the case definition of coronavirus.
"As you might imagine there is a low bar for us to do testing on those who are at the centre."
Planning had also started for how to repatriate the 59 people who had been evacuated from Wuhan but were not New Zealanders.
Bloomfield said there was an "emerging story" regarding "aerosol spread" of coronavirus - meaning fine particles could be sneezed, coughed or breathed out into the air and transmitted a reasonable distance such as across a room.
This differed from two other ways respiratory illness could be spread - by droplets in the air, or droplets that had settled on surfaces.
To manage this, people who are unwell need to self-isolate, he said.
Yesterday alone over 400 people had registered to self-isolate, Bloomfield said.
The deadly disease has infected more than 40,000 people worldwide but it is not thought to have reached New Zealand's shores yet.
More to come.