What disease is mandated to be reported under RIDDOR?

Legionella is the correct answer because it is specifically listed as a notifiable disease under RIDDOR (Reporting of Injuries, Diseases and Dangerous Occurrences Regulations). This regulation requires employers to report certain work-related diseases and incidents to ensure health and safety in the workplace. Legionella, which can cause Legionnaires' disease, primarily arises in environments like water systems where the bacteria can proliferate. Due to its severity and potential to cause outbreaks, it’s essential for healthcare providers and employers to monitor and report cases to prevent public health risks.

In contrast, while tuberculosis is a significant disease that affects public health, it typically falls under different reporting guidelines rather than RIDDOR-specific mandates for work-related causes. Diabetes and common flu do not generally pose the same immediate risk or concern in a workplace reporting context as Legionella, making them less relevant in the context of mandatory reporting under RIDDOR.