The Washington State Department of Health announced Wednesday that several Washington state shellfish companies are recalling molluscan shellfish harvested from a portion of the southern shoreline of Hammersley Inlet near Shelton, WA, from Nov. 10 to Dec. 5, 2014, because they may be contaminated with Norovirus. These products were shipped to multiple retail locations nationwide. The recalling companies are notifying those who have received the recalled shellfish, the department stated. Since only shellfish harvested from a portion of the growing area are being recalled, food establishments will have to work closely with their shellfish suppliers to know if they have recalled product. Local health jurisdiction staff are being advised to make sure that any food establishment with shellfish tags from Hammersley Inlet during this time period is aware of the recall and that they have confirmed the status of the shellfish, the department stated. If it is not clear that the shellfish are part of the recall, the food establishment should not sell the products until their status can be confirmed. Norovirus causes a highly contagious illness commonly referred to as viral gastroenteritis, stomach flu, and food poisoning. The virus can survive in marine water for months or even years, although it does not multiply in that environment. Shellfish such as oysters, clams and mussels are filter feeders and ingest Norovirus if it is present in the water. Once ingested, Norovirus can quickly multiply in shellfish, especially when the weather is warm or if the shellfish are not kept cold after harvesting. Check here for other recent food recalls affecting Washington state.