Which symptom should prevent a food handler from working while preparing meals for elderly cancer care patients?

The symptom that should prevent a food handler from working while preparing meals for elderly cancer care patients is a sore throat with fever. This is particularly significant because both a sore throat and fever can indicate a more serious illness, potentially contagious, that could be harmful to vulnerable populations, such as elderly patients undergoing cancer treatment.

Elderly individuals, especially those with compromised immune systems due to cancer, are at a higher risk for severe complications from foodborne pathogens or communicable diseases. The combination of a sore throat and fever signals that the food handler may be suffering from a respiratory infection or other illness that could be transmitted through food handling or close contact.

In food safety regulations, individuals exhibiting any symptoms that could lead to food contamination or illness in others are advised to refrain from food handling duties. Thus, ensuring that food handlers do not work while exhibiting these symptoms is crucial to maintain food safety and protect the health of those receiving care.