His message came after four people escaped from managed isolation in separate incidents within the past week, one of whom went to a supermarket and another to a liquor store.
New Zealand's 25 active cases are all people in managed isolation.
But Bloomfield says it's as important as ever to keep downloading and using the contract tracing app so if anyone does get sick in the community the Government can easily trace people who might have been in contact with them.
Despite the Government's push to use the app, a top public health expert has described it as "doomed", with just 0.2 per cent of the population using it.
Part of the reason for that is the feeling it isn't really needed anymore.
"It's a tough ask to get Kiwis to download an app when the risk is so low," Otago University professor Nick Wilson said.
"At this point they're more likely to die from a lightning strike."
Health Minister Chris Hipkins has asked officials for advice as to how to encourage better uptake as he also yesterday urged Kiwis to keep using it.
An update to the app to allow for people to manually enter their movements is expected by the end of the month.
The plea comes as New Zealand recorded its lowest daily community testing rate since March 16.
Just over 1000 tests were performed, but 672 of those were in managed isolation and quarantine.
A week ago, Health Minister Chris Hipkins was concerned about how far testing levels had fallen and told health officials to get seven-day averages back up to about 4000 a day.
Hipkins had received advice from Bloomfield that that level of testing would give New Zealanders and the Government "sufficient confidence" that community transmission of the virus wasn't happening.
On Sunday, New Zealand had its lowest testing day since March 16 - with just 371 tests processed outside of border facilities.
Hipkins said he wanted to see the overall community testing go up.
"And I've made that clear."
Bloomfield said "the important thing" was that the right people were being tested and those were in isolation or worked in connection to the border.
This week asymptomatic border staff and air crew would start being tested for surveillance purposes, he said.
"We also want to have enough testing in the community as part of the surveillance to ensure that if there are any cases out there, we are detecting them and the spread of testing is good by region and ethnic group."
Wilson, a public health researcher, said the numbers "seem pretty low" but says he doesn't think New Zealand has become complacent.
He believed the case definition should be changed so community testing was focused in the cities with international airports - Auckland and Christchurch - and centres with border facilities.
With "almost no chance" that Covid-19 is in the community, the only way it would get through was a border failure and so those centres were the most at risk, Wilson said.
Wilson is about to do more analysis about how many tests should be processed a day with this "more targeted" approach.
Meanwhile, the Government has given more details about the group of 30 deportees set to arrive from Australia this week.
Hipkins said they would be arriving on one chartered flight, paid for by the Australian government, and will stay at an undisclosed hotel in Auckland with enhanced security.
He said a rigorous psychiatric assessment would be completed before people entered the facilities.
He reiterated the Government's stance on Australia's policy.
"Obviously New Zealand is disappointed with the policy overall ... we don't agree with the approach they're taking."
