Jean Sparksman, who died after contracting campylobacter. Coroner Peter Ryan will determine what effect campylobacter had on her death.

The woman who died after contracting campylobacter in the Havelock North outbreak had plenty of life left in her, says her son.

Jean Sparksman, 89, died on Saturday. She was one of an estimated 4100 in the town to have contracted the illness from the town's contaminated water supply.

Coroner Peter Ryan has opened an investigation into her death to ascertain, as far as possible, whether the campylobacter infection contributed to her death.

SIMON HENDERY/FAIRFAX NZ The site of a Havelock North water bore that was closed after three instances of bacterial contamination.

Test results on Thursday night confirmed she had contracted campylobacter, but the coroner's office said a post-mortem revealed she had other significant underlying health issues.

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Further tests would determine the specific cause of death, what particular strain of campylobacter had been contracted, and what effect, if any, it had on Sparksman's death.

Istock Tests have shown that an 89-year-old Havelock North woman who died on the weekend had a campylobacter infection

Sparksman's son, Keith, said on Friday his mother had been living in Hastings until about four months ago, when she moved into a serviced apartment at Mary Doyle Lifecare Complex in Havelock North.

She was born and raised in Havelock North, and she and her late husband Jack, who died in 2000, raised four children in the town. She had "quite a few" grandchildren and great-grandchildren, Keith said.

"She was pretty well. I don't think she had been very sick before this, to be fair. She was quite lively, but because her eyesight wasn't the best she figured it was better to be in the rest home," Keith said.

"Under the circumstances, and the way she was, I would have picked her to have had another five years, easy," he said. "She was still very mentally alert and could remember everybody's birthdays, including all the grandchildren.

"She had all their names off pat. Complete opposite to me. I can barely remember my own birthday," he said.

The first Keith knew of her latest illness was when his brother rang him on Saturday to say she had died. "There had been no sign of illness, apart from what people at her funeral told me about in her last four or five days," he said.

"She was a good mum. She didn't work. She stayed at home and concentrated on raising the kids. Dad worked as a postie," Keith said.

He added he didn't want to pre-judge what effect the campylobacter might have had on her death, and he would wait until the coroner had determined that.

Hastings Mayor Lawrence Yule said he planned to speak to the family, but was yet to decide when the best time to do that would be.

"Whether it was the cause of death or not, this lady did have campylobacter and I feel an obligation to speak to her family."

"I just want to share their sadness, in some ways apologise that the situation has ended up like this," Yule said.

A TOWN FALLS ILL

The outbreak was first noticed on Friday last week. An estimated 4100 people in the town of 13,000 are believed to have fallen ill.

Hundreds have gone to their doctors, but the vast majority have not.

People began falling ill in the middle of last week. Hastings District Council became aware of an issue on Friday when a water test result from one of the bores that feed the town returned a positive result for E.Coli.

The presence of E.Coli indicates there has been some sort of contamination, and that the water may contain pathogens that make people ill.

By Friday it became clear to the council and the Hawke's Bay District Health Board that there was a potential link to the contamination and the level of illness being seen at doctors and the hospital.

Town supply water in Havelock North is not chlorinated. On Friday the council and board decided to chlorinate the water to and a boil water notice was issued to residents at 6.40pm.

By the weekend the scale of the outbreak becomes more clear. Two people were admitted to hospital in a critical condition. Another elderly person dies from a gastro like illness. Tests are yet to confirm type of bug was involved.

On Monday several schools opened but later announced they had been advised by the Ministry of Education to remain closed on Tuesday and Wednesday.

On Tuesday it was announced that the bug was campylobacter, and that it somehow made its way into the Te Mata aquifer, a confined aquifer beneath the town.

Given that campylobacter symptoms usually appear 2-5 days after someone has been infected, there are questions over how a test of the bore water on Tuesday last week came back as clear.

MUSHROOM FARM UNLIKELY SOURCE OF CONTAMINATION

Investigations are underway as to how the bug could have entered the aquifer and where it could have come from.

Test results provided to Hastings District Council on Friday afternoon suggested a mushroom farm located near Havelock North's water bores was not responsible for the campylobacter contamination of the town's water supply.

Concerns had been raised that campylobacter in chicken manure used by Te Mata Mushroom Company may have got into the water supply.

But testing by the Institute of Environmental Science and Research had found the contamination appears to have come from a ruminant (cattle or sheep) campylobacter source rather than from chicken.

Yule said while the results did not completely exclude any possible source of the contamination, it made the mushroom farm appear to be an unlikely contributor to the contamination.

Te Mata Mushroom Company owner Michael Whittaker said he welcomed the initial test results but said further scientific assessment needed to be done to determine what had happened.

The speculation involving the mushroom farm had been damaging for the business he said.