New Zealand Food Safety is reminding consumers to thoroughly cook mussels following an increase in cases of Vibrio parahaemolyticus around the country this summer.
Deputy director-general New Zealand Food Safety Vince Arbuckle said, "Since mid-November 2021, there have been 31 confirmed cases with 10 people hospitalised with the illness from around the country, and evidence suggests a change in water temperature and conditions may make live mussels more susceptible to the bacteria.
"As mussel harvesting is a favourite summer pastime of many New Zealanders and are sold live and raw in many New Zealand supermarkets, we advise consumers to cook mussels thoroughly before consumption to avoid getting sick. We have been working with the major supermarket chains to ensure that point-of-sale signage to cook mussels is available for consumers.
"People with low immunity, pregnant, or elderly should always avoid eating raw or undercooked shellfish as the illness can be more severe," said Mr Arbuckle.
New Zealand Food Safety advises consumers to follow simple food safety guidance to avoid contracting Vibrio parahaemolyticus by following some simple rules.
Keep hands and utensils clean
Always wash your hands and kitchen utensils after handling raw seafood, and before using other utensils or handling other foods. This will prevent the bacteria from spreading in your kitchen.
Cook mussels thoroughly
Cook mussels until steaming hot. Don’t eat them raw or lightly cooked as this won’t kill the Vibrio bacteria. One good way to know mussels are fully cooked is that their shells pop open when boiled or steamed, and the mussel inside is firm to the touch.
Chill mussels immediately
Refrigerate shellfish as soon as possible after harvesting from the beach or purchasing from the supermarket. You can use a chilly bin filled with ice or frozen ice packs to transport live shellfish in your car. Once you get home, you should store mussels in a bowl covered with a cold, wet towel on the bottom shelf in your refrigerator.
"New Zealand Food Safety is working together with public health units and the seafood industry to ensure appropriate public health measures are taken. However, consumers can minimise risks by cooking their shellfish thoroughly," said Mr Arbuckle.
What to do if you get sick:
If you get sick after eating shellfish, phone Healthline for advice on 0800 61 11 16 or seek medical attention immediately. If possible, store and refrigerate any leftover shellfish for testing.
Vibrio parahaemolyticus symptoms may include watery or bloody diarrhoea, abdominal cramps, nausea, vomiting, fever, and/or headache.
For more food safety tips on harvesting and consuming shellfish, you can download advice in the pamphlet Food Safety for Seafood Gatherers on our website.
Safety for Seafood Gatherers [PDF, 688 KB]