A novel respiratory virus is detected in multiple bordering countries and a cluster of cases appears in several U.S. states. Which division of responsibilities between CDC and WHO best reflects their typical roles?

The WHO directly manages clinical care in every affected country, dispatching clinical teams to treat patients, whereas the CDC only provides laboratory confirmation for cases within the U.S.

The CDC and WHO perform identical functions at all levels, with no distinction between national and international roles, and they alternate responsibility by alphabetical order of affected country names.

The WHO coordinates international surveillance, issues global guidance and travel recommendations; the CDC leads national surveillance, outbreak investigation and implementation of control measures within the United States.

The CDC is responsible for all international responses and issues travel bans worldwide, while the WHO solely advises local hospitals within countries without coordinating cross-border efforts.