Diphtheria Fact Sheet

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Diphtheriais an infectious disease caused by the bacterium Corynebacterium diptheriae.

There are two types of diphtheria; one type affects the respiratory tract and the other affects the skin.  The most common type affects the tonsils, throat, or nose.  Diphtheria is a rare disease in the United States primarily due to widespread immunization.  Cases of diphtheria most commonly occur among unvaccinated or under-vaccinated persons.  The last reported case of diphtheria in Maryland occurred in 1973, and fewer than 5 cases have been reported in the United States in recent years.

Diphtheria is spread from person-to-person through contact with infected secretions.

Diphtheria may be spread by contact with the secretions from an infected person’s nose, throat, skin, eyes and lesions.  Rarely, diphtheria may also be spread through contact with articles soiled by the discharge from a lesion.  A person with diphtheria is usually contagious for up to 2 weeks, but rarely more than 4 weeks.  An infected person should remain in isolation until two lab tests taken 24 hours apart are negative 24 hours after antibiotics are stopped.

Symptoms to look for include:

  • Sore throat
  • Low grade fever
  • Neck swelling (“bull neck”)
  • Skin lesions ( specific to cutaneous diphtheria)

Symptoms may occur 2 to 5 days (1-10 days range) after exposure, and may occasionally take longer to appear.

Laboratory testing is needed to confirm a diphtheria infection. 

People who think they have diphtheria should see a doctor or their local health department immediately to be tested.  Doctors can confirm the diagnosis by taking a sample of the tissue from the throat with a swab.  Doctors can also take a sample of tissue from an infected wound and have it tested in a laboratory to check for the type of diphtheria that affects the skin.

See a doctor for treatment.

If a doctor suspects diphtheria, treatment should begin immediately, even before the results of the laboratory tests are available.  The infected person should be given an anti-toxin to stop the diphtheria toxin that is circulating in the body.  Certain antibiotics should also be prescribed to treat the infection.  Check with your doctor or local health department for advice.

A person in close contact with someone who has diphtheria should receive treatment as well. Close contacts should be quickly identified and monitored for symptoms of diphtheria.  Contacts should be tested for diphtheria, given antibiotics, and an age-appropriate dose of diphtheria containing vaccine.  Close contacts may include: 

  • Persons who live in the same house;
  • Persons who have contact with mouth or nose secretions, such as through a cough, sneeze, kissing, or sexual contact.  This also includes people who share food and eating utensils;
  • Persons who have done medical treatments such as mouth-to-mouth resuscitation or intubation; or
  • Close contacts in child and daycare settings or schools.

Diphtheria can be prevented with diphtheria vaccine.

Every child should get diphtheria vaccine at 2, 4, 6, and 15 to 18 months of age, and another dose at 4 to 6 years age before entering school.  A booster dose of diphtheria vaccine is also recommended at 11 to 12 years of age if it has been 5 years since the last dose.  Age-appropriate vaccination against diphtheria is required for entry into Maryland childcare institutions and schools.  For additional information about diphtheria vaccine, please visit: http://www.cdc.gov/vaccines/vpd-vac/diphtheria/default.htm#clinical.