New Springston Bore Puts Stop To Illness Outbreak

A Canterbury District Health Board investigation into a cluster of campylobacter cases in the Springston Township during February and March this year has concluded that the outbreak was caused by contamination of the town’s water supply.

Since the commissioning of a replacement bore by Selwyn District Council on 13 March, there have been no further notifications of campylobacter infection from the Springston area, Canterbury Medical Officer of Health Dr Alistair Humphrey said.

While investigating the four campylobacter notifications from Springston township, a team from CDHB’s Community and Public Health division found a further 38  cases of gastrointestinal illness, and two further cases of campylobacter in visitors to Springston.  Peaks in illness in the community coincided with periods when the town’s water had not met New Zealand Drinking Water Standards.

A case control study carried out by the team revealed that the rate of water borne illness among Springston residents was significantly higher than would normally be expected.  People who consumed unboiled Springston water were 16.25 times more likely to develop a gastrointestinal illness than those who did not drink the water.

Dr Humphrey said, “the stories of suffering recounted by local residents at their public meeting last month were a salutary lesson for all those involved in delivering our water supplies.  We are very glad to have been able to identify the source of the outbreak and that the problem has been corrected by the Selwyn District Council.”

“We were concerned to find a case of E.coli 0157 in addition to the campylobacter cases.  Fortunately this was a non toxigenic form of the bacteria, but E.coli 0157 has been associated with deaths in other parts of the world.  This is another powerful reminder of the importance of adhering to the New Zealand Drinking Water Standards.”

Selwyn District Council Asset Manager Ray Anderson said the depth of the new Springston well would provide a much greater level of protection for local residents.

“At 109 metres deep, it is twice as deep as the old well and we think the age of the water should be in the order of 50-100 years old.  The older the water, the greater its level of security,” he said.

“There have been no bacteria recorded in the new well since it was commissioned and initial chlorination was stopped on 19 March. The water is being sampled twice weekly in accordance with the New Zealand Drinking Water Standards.  Residents have been notified that their water is now safe to drink.”

ENDS