Diphtheria in the United States: How CDC Tracks a Disease That Has Nearly Vanished

Diphtheria used to be one of the most common causes of illness and death among children. Today it is uncommon in the United States.

From killer to rarity

How CDC keeps watch

• National reporting. Diphtheria is a nationally notifiable disease. CDC gathers case information every week through the National Notifiable Diseases Surveillance System (NNDSS), whose records of U.S. cases go back to 1920 (data tables).
• Antitoxin requests. Since 1997, U.S. health care providers can get diphtheria antitoxin (DAT) only through CDC — so each request also flags a possible case.
• Prompt reporting. Providers should report suspected cases to their health department right away; health departments shouldn't wait for complete information or lab confirmation.
• Case definition. The Council of State and Territorial Epidemiologists issued the latest case definition in 2019.

Outbreaks abroad

Beyond places where diphtheria is always present, outbreaks have been reported in Australia, Haiti and several countries in sub-Saharan Africa. Travelers should check with their doctor that their diphtheria vaccines are up to date — and anyone who suspects diphtheria should see a health care provider.

For public health staff: the diphtheria chapter of the Manual for the Surveillance of Vaccine-Preventable Diseases, a close-contact form and a surveillance worksheet.

Sources

Based on "Diphtheria Surveillance and Trends," Centers for Disease Control and Prevention; a work of the United States government in the public domain.