Climate change may increase bacteria-infected seafood and water, NZ researchers warn

Embargoed until: Publicly released: 2026-06-12 00:01

New Zealand

Photo by Gil Ndjouwou on Unsplash

Eating seafood, particularly when it’s raw, and swimming in the sea are the main ways NZers get infected with a group of bacteria (Vibrio) that can cause stomach bugs, ear or cut infections, and sometimes more serious illness. Combining several NZ databases, researchers have found that infections are more common in Māori and Pacific people, and happen most in summer. These bacteria thrive in warm seas, and the study authors say climate change will likely increase their numbers around Aotearoa. They say the country needs a more organised reporting system for such infections, to help direct public health measures to prevent and treat them.

News release

From: Pasifika Medical Association Group

Vibrio infections in Aotearoa New Zealand (1998–2024) and the effect of current disease reporting structures

Vibrio bacteria are natural inhabitants of aquatic environments, including coastal areas where people swim and collect shellfish, and thrive in warmer conditions. In humans, these bacteria can cause intestinal illness, wound or ear infections, and sometimes progress to severe illness or death. In Aotearoa New Zealand, only some vibrio-associated illnesses are nationally reported (cholera or acute gastroenteritis from one species, Vibrio parahaemolyticus), but this study has shown illnesses (some very serious) are being caused by a range of vibrio, including four internationally important vibrio species. There are likely to be people groups more at risk for infection or severe health outcomes due to their daily activities and health status. Improved reporting of all vibrio infections will support public health activities to prevent illness both now and in the future as the warming effects of climate change increase the risk of vibrio infections.

Journal/
conference: New Zealand Medical Journal

Organisation/s: PHF Science

Funder: This work was funded by Te Niwha and the Ministry of Business, Innovation and Employment Strategic Science Investment Fund provided to the New Zealand Institute for Public Health and Forensic Science (PHF Science; known as the Institute of Environmental Science and Research [ESR] up until July 2025).

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