The New Zealand Food Safety Authority (NZFSA) has warned people against consuming uncooked oysters imported from Korea. Frozen Korean oysters bags are clearly labelled as requiring to be cooked before consuming. The warning is mainly because the product is known to sometimes carry norovirus, which causes a gastrointestinal illness.
In New Zealand these Korean oysters are packed frozen in 1kg bags and labeled according to the current import health standard, with a statement that the product must be cooked or must not be eaten raw.
These oysters are to be cooked in such a way that the centre of the oyster reaches 90šC and is held at that temperature for 90 seconds. NZFSA has also reminded chefs and consumers of the product to encure proper hand and kitchen hygiene especially during defrosting, to ensure that cross-contamination of other foods with raw oyster juice does not take place.
The typical symptoms of norovirus infection include headache, vomiting, nausea, abdominal pain and diarrhea which often occur within 10 to 50 hours after consumption. Although the symptoms usually resolve in two days those affected should avoid preparing food of any sort for at least 48, and preferably 72, hours after the last symptoms have ended. This is because norovirus is very contagious, and food handlers who have been infected can be a major source of infection.
The recent outbreaks appear to have been caused because the label instructions appear not to have been followed. NZFSA is reviewing the import health standard to determine if the current provisions are sufficient and is considering if further risk mitigation steps are needed. NZFSA is also approaching the Korean government agencies responsible for the certification of these products to discuss what assurances New Zealand will need to have confidence that product arriving in New Zealand is as stated.