Hundreds of Covid tests have so far returned negative results in the Whanganui region after places of interest were identified in Bulls and Waiouru.
Whanganui DHB CEO Russell Simpson is optimistic but residents must stay vigilant.
"As each day goes by, there's an increasing level of confidence there hasn't been transmission from that case," he said.
"It is still the unknown period. There are lots of people who reside in our district who are close contacts that we are following up."
Simpson is calling for common sense from the community as it heads into the next period determining whether or not Covid has spread across the district.