Harbour oysters off limits after virus found

Eleven people have fallen ill after eating oysters from the harbour, near Warkworth, prompting a recall of the frozen seafood.

Norovirus has been found in chilled oysters harvested from the Mahurangi Harbour, north of Auckland.

The Ministry for Primary Industries is warning people not to eat the oysters, and to discard them immediately, to avoid becoming seriously ill.

Matakana Oysters, Orata Marine Ltd, Seafood Harbour, and Hutchings and Addison Ltd are recalling all oysters harvested from the harbour from mid-january.

The ministry said batch numbers and brand names were not fully confirmed, but further information would be posted on its website as it became available.

The affected products were not exported, and most were sold in the local area in pottles or in the half shell.

Melinda Sando, the ministry’s manager of food compliance service group, said the amount of affected product still in people’s kitchens would likely be very small as the oysters have a very short shelf life.

‘‘Our main concern, however, is that people may have frozen the oysters and still have them in their freezer. It is very important that they are discarded.’’

The health risk was discovered after 11 people became ill after eating oysters from the harbour.

The Institute of Environmental Science and Research tested samples of the oysters and norovirus was found.

‘‘The type of virus is the same as that found in the affected people,’’ Sando said.

The problem appeared limited to a small area of the harbour, around Dyers Creek.

‘‘It is likely to be the result of a localised contamination – for example discharge from a boat or a leaking septic tank.’’

Norovirus gastroenteritis generally presents with vomiting followed by diarrhoea.

The ministry was advising people who believed they had eaten affected oysters and had severe or persistent symptoms to see their GP, or call Healthline. – Fairfax NZ