• The first cluster involved three males and one female, aged 26 and 40.
• The second cluster involved eight males, aged 17 and 20.

Consumption of raw oystersand sashimi

• Consumption of raw food
• Foods were contaminated with Vibrio parahaemolyticus and Norovirus

• Raw oysters and sashimi are high-risk food, as there is no heat treatment to kill foodborne pathogens or "superbugs" before eating.

• Purchase oysters and sashimi intended for raw consumption (either live inshell oysters or frozen oysters)from reputable and hygienic suppliers. Maintain a purchase log and look out for the condition and expiry date for prepackaged products.

• It must ensure that staff maintain good personal hygiene and wash hands thoroughly between handling raw oyster and sashimi. Utensils, equipment and working area are cleaned and disinfected regularly as needed.

• Use clean and sterile towels for oyster and sashimi preparation Use only designated tools and equipment for handling them separately. The equipment should be labelled "oysters eaten raw only", "sashimi only" and kept separately from other equipment.

• Raw oysters and sashimi should be stored in a designated refrigerator to avoid cross-contamination with other foods.

• Oysters and sashimifrom the same batch and source should be put into the same container, they should be used on a first-in, first-out basis.

• Keep oysters between 2°C and 4°C for at most two days. If keeping the oysters for longer than two days is expected, freeze them. Defrost oysters and sashimi separately in a designated refrigerator and separate them from other food items.

• Oyster handlings when occurring at room temperature, should not exceed one hour.

• Display live oysters on crushed edible ice, replace ice in a timely manner and drain melted ice-water as needed.

• It is necessary to strengthen the training on food safety, environment and personal hygiene of management personnel and food handlers.