Shellfish poisoning outbreak

Following detection by the FSA of unusually high levels of toxins, various shellfish harvesting sites in Scotland have been closed. These toxins, which occur naturally, especially during the summer months, can cause acute food poisoning.

In addition, the FSA has been informed that approximately 70 people in south east England have reported symptoms consistent with diarrhetic shellfish poisoning (see ‘Science behind the story’ below). The vast majority of cases occurred between 13 and 15 July.

The cases have been linked to the consumption of mussels originating from a particular harvesting area in Shetland, Scotland. After these mussels were harvested, an unusually high toxin level was detected by the FSA’s weekly monitoring programme. The area has been closed, and as a precautionary measure the industry has voluntarily suspended all commercial harvesting from the waters around Shetland until toxin levels subside.

The business that supplied the shellfish, Shetland Mussels, has contacted its customers and advised the FSA that all of the mussels from this batch have either been consumed or disposed of. The local authority is investigating and liaising closely with the FSA.

The mussels had been supplied to a number of restaurants, some through a number of intermediary suppliers. Customers reported illness after eating at: Belgo in Covent Garden, Holborn, Clapham and Bromley; Zero Degrees in Blackheath and Reading; The Phoenix near Hook, Hampshire; Boulevard Brasserie in Covent Garden; and Pig’s Ears in Richmond. These premises acted appropriately by notifying the relevant authorities when the cases of illness were identified.

Business responsibilities

It is the legal responsibility of all food businesses to put in place appropriate controls to ensure that only food safe for consumption is placed on the market. The FSA is reminding all UK companies involved in the sale of shellfish to ensure that biotoxin risks are taken into account in their food safety management systems.

Science behind the story

Shellfish toxins are produced by naturally occurring marine phytoplankton, and detected levels are higher in summer months. The FSA has a sampling programme that regularly monitors shellfish harvesting waters regularly and closes areas where biotoxins are detected at levels which exceed the legal limit.

Diarrhetic shellfish poisoning can result in nausea, vomiting, diarrhoea, and abdominal pain accompanied by chills, headache, and fever. Symptoms generally present themselves between 30 minutes and two or three hours after eating affected shellfish, and can last for two or three days.

Advice on shellfish safety can be found on the NHS Choices website >>