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Immunizations: Diphtheria

Diphtheria is a serious infection caused by bacteria. The strain of bacteria is called Corynebacterium diphtheriae. The bacteria can enter your body if you eat food with a live germ. The bacteria create a toxin, or poison, in your body.

Diphtheria is an acute disease. That means it can make you very sick for a short period of time.

Close up image of Diphtheria bacteria

A vaccine can prevent diphtheria

The best way to prevent diphtheria is to get the vaccine.

Learn more about the diphtheria vaccines

Diphtheria 101

Diphtheria is contagious and can spread from person to person. An infected person may cough or sneeze. Another person can inhale the droplets. Touching open sores or an ulcer also causes the infection to spread.

Diphtheria can infect the skin or the respiratory tract system, which is parts of the body involved in breathing. Symptoms of diphtheria depend on which part of the body is infected.

Respiratory diphtheria

Diphtheria bacteria most commonly infect the respiratory system. When the bacteria get into and attach to your throat and lungs, it can cause:

  • Weakness.
  • Sore throat.
  • Mild fever.
  • Swollen glands in the neck.

The bacteria make a toxin, or poison, that kills healthy tissues in the respiratory system. Within two to three days, the dead tissue forms a thick, gray coating that can build up in the throat or nose. This gray coating can cover tissues in the nose, tonsils, voice box, and throat, making it hard to breathe and swallow.

If the toxin gets into your blood stream, it can damage your heart, nerves, and kidneys.

Diphtheria skin infection

Diphtheria bacteria also can infect the skin. This infection causes open sores or ulcers. However, diphtheria skin infections rarely result in any other severe disease.

Getting treatment right away is important. Treatment for diphtheria includes using:

  • Diphtheria antitoxin to stop the toxin made by the bacteria from damaging your body. This treatment is critical for respiratory infections. It is rarely used for skin infections.
  • Antibiotics to kill and get rid of the bacteria. Antibiotics are important for both diphtheria infections in the respiratory system and on the skin.

Even with treatment, respiratory diphtheria is deadly for about 1 in 10 people who have the infection.

Vaccines prevent diphtheria. DTaP and Tdap are two of the vaccines for diphtheria. Before vaccines, diphtheria was a leading cause of death for children. Thanks to the vaccine, diphtheria cases are rare in the United States.

The Centers for Disease Control and Prevention (CDC) recommends diphtheria vaccines for:

  • Infants
  • Children .
  • Teens
  • Adults

Find out if you and your children are protected against diphtheria. Check our Department of Health Services (DHS) Wisconsin Immunization Registry.

If you’re worried about cost, your family may be eligible for free vaccines. Read about our Vaccines For Children and Vaccines For Adults programs.

Just for health care providers

Diphtheria is a communicable disease. Health care providers must report cases of diphtheria.

Diphtheria is a Wisconsin Disease Surveillance Category I disease.

Report it right away to the patient’s local public health department. Call as soon as you identify a confirmed or suspected case. The health department then notifies the state epidemiologist.

Within 24 hours, submit a case report through one of the following:

Read more about required disease reporting in Wisconsin.

Case reporting and public health guidelines

Contact us


Last revised January 3, 2023