Diphtheria Surveillance and Trends

For Public Health

Key points

  • CDC tracks diphtheria cases using a national surveillance system.
  • CDC also identifies cases by requests for diphtheria antitoxin (DAT).
  • Diphtheria is now an uncommon disease in the United States.
  • Speak to a healthcare provider if you suspect you or a loved one may have diphtheria.
An illustration of generic data

Data systems

Diphtheria outbreaks in other countries

In addition to areas with endemic diphtheria, there are diphtheria outbreaks in Australia and multiple countries in sub-Saharan Africa. Travelers to these countries should talk with their doctor about being up to date with their diphtheria vaccines.

National Notifiable Diseases Surveillance System

Diphtheria is a nationally notifiable disease.

CDC collects national information about diphtheria cases through the National Notifiable Diseases Surveillance System (NNDSS). CDC receives NNDSS data each week.

For Everyone About National Notifiable Diseases Surveillance System

Report suspected diphtheria cases promptly

Healthcare providers should promptly report suspected diphtheria cases to their respective health department. Health departments shouldn't delay reporting because of incomplete information or lack of laboratory confirmation.

Tracking DAT requests

CDC also identifies cases by DAT requests. Since 1997, DAT is available for U.S. healthcare providers only through CDC.

For Health Care Providers Diphtheria Antitoxin

How the data are interpreted

Disease trends

Diphtheria used to be one of the most common causes of illness and death among children. In the United States, diphtheria antitoxin was introduced in the 1920s and 1930s. Universal childhood vaccination began in the 1940s.

Now diphtheria is well controlled. The last U.S. case of confirmed respiratory diphtheria was in 1997. A small number of cutaneous cases associated with international travel have been reported since then.

Explore the data

Use the figure below to see reported U.S. diphtheria case counts from NNDSS since 1920. To zoom in on a select range of years, slide the bar beneath the figure. The case counts for years highlighted in the grey vertical bar are provisional. You can also view the data in table format by clicking on "Data Table" beneath the figure.


Data reporting

View NNDSS infectious disease data tables.

Data definitions

The Council of State and Territorial Epidemiologists (CSTE) released the most recent case definition for diphtheria in 2019.

Resources

Diphtheria chapter of the Manual for the Surveillance of Vaccine-Preventable Diseases

Information to Collect on Close Contacts of Diphtheria Cases

Diphtheria Surveillance Worksheet

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Content Source:
National Center for Immunization and Respiratory Diseases (NCIRD); Division of Bacterial Diseases