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Learn about diphtheria, who is at risk, and how it spreads.

About diphtheria

Diphtheria is a nose and throat infection caused by bacteria. It can cause trouble breathing or swallowing, heart failure, and paralysis (not being able to move all or part of your body).

Antibiotics (medicines that fight bacteria) can be used to treat diphtheria infections. Even with treatment, up to 1 out of 10 people who get diphtheria will die.

In children under 5 years and adults older than 40 years, 2 to 4 out of 10 people who get diphtheria can die.

Who is most at risk?

People who travel to countries where there is a risk of diphtheria and have not had all their diphtheria vaccines are at the highest risk.

Diphtheria is particularly serious for unimmunized babies and children. Before vaccines, diphtheria was the most common cause of death in Canadian children ages 1 to 5.

How it spreads

Diphtheria is spread by coughing, sneezing, or having close contact with someone who has diphtheria.



Contact with someone infected

Current as of: June 30, 2023
Author: Provincial Immunization Program, Alberta Health Services
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