What is the most common cause of milkborne disease, particularly associated with raw milk?

• A. Staphylococcus aureus
• B. Listeria monocytogenes
• C. Norovirus
• D. Campylobacter

Answer: (D)

Raw milk can carry several pathogens, but the strongest association with illness from unpasteurized milk is Campylobacter. This bacterium is commonly shed in cattle feces and can contaminate milk during the milking process, making raw milk a direct route of exposure. Campylobacter jejuni causes gastroenteritis and is frequently implicated in milkborne outbreaks linked to unpasteurized dairy products, which is why it’s the leading answer in this context. Pasteurization is highly effective at killing Campylobacter, along with other pathogens, which is why pasteurized milk markedly lowers this risk. While Staphylococcus aureus, Norovirus, and Listeria monocytogenes can cause dairy-related illness, they are not as commonly tied to raw-milk–associated outbreaks as Campylobacter.