Final answer:
Facilities must report cases of communicable diseases to the local health authority as they are part of the broader system of disease surveillance and control coordinated by agencies like the CDC.
Step-by-step explanation:
When a resident has a communicable disease, the facility must report to the local health authority. This is mandated to ensure prompt public health intervention to prevent and control the spread of diseases. The local health authority will typically forward the report to more centralized agencies as necessary, such as the state health department or the Centers for Disease Control and Prevention (CDC), which oversees the National Notifiable Diseases Surveillance System (NNDSS). The NNDSS tracks diseases of public health importance on a national level, which helps in the formulation and evaluation of public health practice and policy.