New Zealand Food Safety is urging people to ensure they cook raw mussels thoroughly, after an increase in cases of food poisoning associated with commercially grown mussels from the Coromandel area.

New Zealand Food Safety director of food regulation Paul Dansted says people got sick as the mussels were eaten raw or they did not thoroughly cook them.

'Cooking kills the marine microorganism Vibrio parahaemolyticus, which occurs naturally throughout the world. Not all strains of this microorganism cause illness in humans.

'Generally people who are sick recover without hospital treatment however, in severe cases, hospitalisation is required. The symptoms are predominantly stomach cramps and watery diarrhoea and sometimes nausea, vomiting and fever.

"If you have eaten raw mussels and feel unwell, contact your doctor immediately," says Paul.

'Testing is being done to confirm the type of Vibrio parahaemolyticus that has caused this illness. New Zealand Food Safety has an ongoing survey programme to test mussels and growing waters to help us understand why this occurred.

'Until we have more information, New Zealand Food Safety is reminding consumers to take care when handling, preparing and consuming mussels. Our advice to consumers who are pregnant or have low immunity is to avoid eating raw shellfish."

General advice for consumers includes:

• Don't eat raw or undercooked mussels or other shellfish. Cook them thoroughly before eating.
• Always wash your hands with soap and water after handing raw shellfish.
• Avoid contaminating cooked shellfish with raw shellfish and its juices.

'Eating raw shellfish always carries risk for foodborne illness,” says Paul.

Make sure you cook shellfish thoroughly before consuming.

Learn more about Vibrio parahaemolyticus on the Ministry for Primary Industries website at https://www.mpi.govt.nz/dmsdocument/11033-vibrio-parahaemolyticus-microbial-pathogen-data-sheet.

The mussels were all bought in their raw state, in the shell.

They are not the mussels that are sold in plastic pottles.