20 Jul 2025

Increase in cases of vomiting, diarrhoea since Nelson-Marlborough flooding

11:03 am on 20 July 2025
Two people are guided across dangerous floodwaters in Tasman on Friday 11 July, 2025, by members from Fire and Emergency NZ's specialist water response teams from Christchurch and Nelson, using long poles to test what lies under the water.

People cleaning flood-affected areas have been advised to cover cuts and wounds, wear a mask, and wash hands thoroughly before eating and drinking. Photo: Supplied/ Fire and Emergency NZ

Health New Zealand has reported a spike in reported cases of vomiting and diarrhoea at the top of South Island, after recent flooding.

The health agency said floodwater and silt could be contaminated with faeces, and agricultural or industrial waste, and often carried bugs that could cause gastrointestinal illnesses.

It said the overall number of cases reported to the public health service in Nelson-Marlborough was small, but investigations showed many had been exposed to the flooding.

However, it was unable to directly link the outbreak to contaminated drinking water or food caused by the flooding, or contact with flood-contaminated land and water.

A spokesperson was unable to confirm the number of cases.

The agency said, while the Tasman District Council had tested its water supply and had no concerns about water quality, it had advised bore-water owners and those who had been issued with a notice to boil their water as a precaution.

"People should treat all surface water as contaminated, and keep children and pets away from contaminated areas, until they have been cleaned up."

Health NZ said people cleaning flood-affected areas should cover cuts and wounds, wear a mask, and wash hands thoroughly before eating and drinking.

It encouraged anyone with symptoms of gastrointestinal illness - including diarrhoea or vomiting - following the floods to call Healthline or contact their general practitioner.

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