09/29/26 Public Health Education Topic: Diphtheria

Per CDC

Key points

• Diphtheria is a serious disease caused by a toxin produced by some strains of bacteria called Corynebacterium diphtheriae.

• Keeping up to date with recommended vaccines is the best protection against diphtheria.

• Talk to a vaccine provider if you have questions about diphtheria vaccines.

Risk factors

Close contact

Close contact with someone with diphtheria increases the risk of getting infected. Close contact with someone with diphtheria includes

• Living with them

• Being close together often

• Sharing respiratory secretions (saliva, spit)

• Being exposed to wound secretions (open sores or ulcers)

International travel

Nearly all diphtheria cases in the United States are associated with international travel to an affected area.

Vaccination status

People who aren't up to date with their diphtheria vaccines are at increased risk of severe disease with respiratory diphtheria.

How it spreads

People most commonly spread C. diphtheriae by coughing or sneezing, which creates small respiratory droplets that contain the bacteria. Other people can get infected if they breathe in those droplets.

People can also get infected from touching open sores or ulcers caused by C. diphtheriae.

To learn more please visit: About Diphtheria | Diphtheria | CDC