A norovirus outbreak occurs at an assisted-living facility. Which immediate public-health action best prioritizes protection of the highest-risk residents?

• A. Close the facility permanently and immediately transfer all residents to different long-term care centers regardless of symptom status, without waiting for case confirmation.
• B. Recommend residents drink more fluids and continue communal dining because the outbreak will stop on its own; focus only on symptomatic residents receiving supportive care in place without altering food service practices.
• C. Isolate symptomatic residents, exclude symptomatic staff from food handling, intensify hand hygiene and surface disinfection, and notify public health authorities.
• D. Provide prophylactic antibiotics to all residents and staff because antibiotics will prevent viral spread and are the fastest way to stop gastrointestinal outbreaks in institutional settings.

Answer: (C)