For Public Health Professionals

Phil image on antiretroviral drug resistance testing on patient specimens

The highly contagious measles virus is often brought into the United States by travelers or people from other countries. Each imported measles case could start an outbreak, especially if undervaccinated groups are exposed. Surveillance and prompt investigation of cases and contacts help to stop the spread of disease. Listed below are key resources that are especially relevant to public health professionals.

Case definition

Measles cases are reported by states to CDC through the National Notifiable Diseases Surveillance System (NNDSS). Both probable and confirmed cases should be reported nationally. Read more about the measles case definition.

Measles cases and outbreaks

Measles is nationally-notifiable and cases should be reported to the appropriate health department. Measles cases are reported by states to CDC through NNDSS. Read more about measles cases and outbreaks.

Surveillance manual

The Manual for the Surveillance of Vaccine-Preventable Diseases provides current guidelines for those directly involved in surveillance of and response to vaccine-preventable diseases, especially personnel at state and local health departments. View the measles chapter.

Responding to measles outbreaks

Prompt recognition, reporting, and investigation of measles is important because the spread of the disease can be limited with early case identification and public health response including vaccination and quarantine of susceptible contacts without presumptive evidence of immunity. Laboratory confirmation is essential for all measles outbreaks.

State and local health departments have the lead in investigating measles cases and outbreaks when they occur

Resources