Final answer:
The CDC is the federal agency responsible for tracking foodborne illness outbreaks and works with state and local health departments to monitor and manage these outbreaks.
Step-by-step explanation:
The federal agency charged with tracking outbreaks of foodborne illness is the Centers for Disease Control and Prevention (CDC). The CDC plays a critical role in protecting the public from diseases including foodborne illnesses by overseeing the National Notifiable Disease Surveillance System (NNDSS). They collaborate with state and local health departments to monitor diseases and outbreaks, provide data to the public, and help trace the source of outbreaks to prevent their spread, like the example of the Salmonella outbreak associated with onions traced back to California.