An emergency planning expert has questioned why Havelock North was not locked down following a water contamination that's affected thousands.
An estimated 4100 people in the Hawke's Bay town have been affected by gastric illness as a result of the contamination and 509 cases of campylobacter are suspected, although the source remains unclear.
Hastings District Council rushed to chlorinate the area's water supplies and issued a boil notice after discovering the bug last week.
But Bridgette Sullivan-Taylor, an emergency response specialist and University of Auckland lecturer, says better planning was needed to properly handle the crisis.
"The number one priority should be to stop spread of infection, the second to keep amenities functioning. It's about the benefit of foresight," she said.
She said Havelock North should have gone into temporary lockdown when campylobacter was found.
"Stopping the movement of people and trying to find the source of the problem should have been key priorities. That could have contained the spread of the illness."
Dr Sullivan-Taylor said a lockdown would have also given clarity to businesses about being able to claim insurance for disruption.
"And school principals should have been relieved of the unreasonable expectation to assess the risk to their community without sufficient information or guidance from the DHB and council," she said.
Meanwhile, the Hawke's Bay District Health Board says the situation is coming under control.
Seven people were still in hospital on Sunday - down from 17- and on Saturday it was confirmed the water supply of neighbouring Hastings had also tested positive for E coli - although it is already being chlorinated and poses no danger, according to the district council.
Two new people went to emergency departments overnight.
Pharmacies have also noticed relapses, which the DHB says is expected.
"All the evidence we are seeing, since the water was chlorinated, is that the outbreak is waning and there is no evidence of a second wave," acting medical officer Dr William Rainger said.
The DHB continues to recommend all water in Havelock North be boiled and chlorination of the water supply is continuing.
Campylobacter in very rare cases can cause complications including reactive arthritis or the neurological Guillain-Barre syndrome.
Hastings mayor Lawrence Yule and the DHB will meet with the family of Jean Sparksman, 89, who died a week ago, four days after becoming ill from campylobacter.
Coroner Peter Ryan has said a post-mortem examination showed Mrs Sparksman also had other underlying health problems, which will be assessed in his inquiry into her death.
A government investigation into the contamination in Havelock North and its aftermath will also be formulated next week, according to Health Minister Jonathan Coleman.
On Friday an interim scientific analysis by Institute of Environmental Science and Research indicated contamination from cattle, sheep and deer may have been present in Havelock North's water supply.