Knowledge and Risk Communication for Undercooked Oyster Preparation in Restaurants

Introduction: Restaurants serving oysters often communicate risks associated with consuming raw shellfish, although there may be a lack of communication about the risks of consuming steamed oysters. In 2009, over 400 patrons of a North Carolina restaurant acquired norovirus from lightly steamed oysters. Oysters must be cooked to an internal temperature of 145°F for 15 seconds to ensure the kill of Vibrio spp. However, oysters must be cooked to an internal temperature of 194°F for 1.5 minutes to inactivate norovirus.

Purpose: It is necessary to determine the level of food safety knowledge and communication within restaurants to ensure that customers are provided enough information to make educated decisions about consuming undercooked oysters. 

Methods: Twenty-six restaurants serving oysters in an urban center were interviewed in person or by phone call. The interviewers visited or called each restaurant location unannounced with the hope of receiving unbiased survey answers. Individuals that were interviewed at the restaurant locations included chefs, managers, owners, greeters, and wait staff.

Results: Of the 26 restaurants serving oysters, 27% served only raw oysters, 4% served only steamed oysters, 69% served both raw and steamed oysters. Restaurant personnel at 47% (n=19) said that if a customer asked whether steamed oysters are fully cooked, (defined as free of all foodborne pathogens) they would respond, “yes,” while 52% said “no” or that it depended on certain parameters. Of the 26 restaurants that served raw and/or steamed oysters, only three restaurant personnel identified a foodborne pathogen associated with oysters.

Significance: This study demonstrates that there is a disconnect between restaurant employee food safety knowledge specific to the safety of steam oysters. This information provides the foundation for an educational intervention for managers, servers, and patrons as it relates to risk management practices.