Cooking temperatures for mussels should be above 65C to ensure any traces of the bug present in the mussels are destroyed, he said.
The mussels that made people ill were all bought in their raw state, in the shell.
They were not the mussels that were sold in plastic pottles, Dansted said.
People severely ill with food poisoning required hospital care after eating raw or undercooked mussels, but most of those that fell ill recovered without hospital treatment, he said.
"The symptoms are predominantly stomach cramps and watery diarrhoea and sometimes nausea, vomiting and fever."
The government body was undertaking testing to confirm the type of Vibrio parahaemolyticus that had caused the illness, with an ongoing survey programme to test mussels and growing waters.
"Until we have more information, New Zealand Food Safety is reminding consumers to take care when handling, preparing and consuming mussels," Dansted said.
"Our advice to consumers who are pregnant or have low immunity is to avoid eating raw shellfish. Make sure you cook shellfish thoroughly before consuming."
Anyone who has eaten raw mussels and feels unwell should contact your doctor immediately, he said.
An outbreak of the same bug was traced to a "single growing area in the Coromandel" in June last year.
The growing area, linked to cases of food poisoning over a six-week period, was closed as the New Zealand Food Safety investigated the outbreak.
Mussel warning:
• 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.
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