Diphtheria: Causes

What causes diphtheria? How is it spread?

Diphtheria is caused by bacteria that infect a person's throat, upper airways and skin. The bacteria also produce a toxin that can affect other organs.

Diphtheria is usually spread from person to person. It can be passed through:

• coughing and sneezing
• touching objects that were recently exposed to the bacteria (such as shared utensils, cups and toys) then rubbing your eyes, nose or mouth

Infected people can spread diphtheria to others until the bacteria have completely disappeared from their own bodies. This usually takes 2 to 4 weeks if the infection is not treated. If you get treatment, you are no longer infectious after 48 hours.