Certified Professional Food Safety (CP-FS) Practice Exam

Which virus is rarely associated with shellfish?

1. Hepatitis A

2. Norwalk virus

3. Salmonella

4. Vibrio

The correct answer is: Norwalk virus

Norwalk virus, also known as the Norovirus, is primarily associated with foodborne illnesses and is commonly linked to contaminated water, unwashed produce, and ready-to-eat foods. However, it is less frequently found in association with shellfish compared to other options provided. Hepatitis A is well-documented to be transmitted through shellfish, especially when they are harvested from contaminated waters. Vibrio species, such as Vibrio parahaemolyticus, are also often linked with raw or undercooked shellfish, particularly oysters. Salmonella can be present in a variety of food sources, including poultry and eggs, but it is generally not associated with shellfish to the same extent as Hepatitis A and Vibrio. This context highlights why Norwalk virus is considered less associated with shellfish compared to the other pathogens listed.