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What Is Diphtheria?

Diphtheria is a bacterial infection. It spreads easily and happens quickly, and mainly affects the nose and throat. Children under 5 and adults over 60 years old are particularly at risk for getting it. People living in crowded or unclean conditions, those who aren’t well nourished, and children and adults who don’t have up-to-date immunizations are also at risk.

Diphtheria (dif-THEER-ee-uh) is very rare in the United States and Europe, where children routinely get vaccinated against it. But it’s still common in developing countries where immunizations aren’t given routinely.

What Are the Signs & Symptoms of Diphtheria?

In its early stages, diphtheria can be mistaken for a bad sore throat. A low-grade fever and swollen neck glands are the other early symptoms.

The toxin, or poison, caused by the bacteria can lead to a thick coating (or membrane) in the nose, throat, or airway. This makes a diphtheria infection different from other more common infections that cause sore throat (such as strep throat). This coating is usually fuzzy gray or black, and can cause breathing problems and trouble swallowing.

As the infection continues, someone may:

  • have trouble breathing or swallowing
  • complain of double vision
  • have slurred speech
  • show signs of going into shock (skin that’s pale and cold, rapid heartbeat, sweating, and an anxious appearance)

What Problems Can Happen?

In diphtheria cases that progress beyond a throat infection, the toxin spreads through the bloodstream. This can lead to potentially life-threatening problems that affect other organs, such as the heart and kidneys. The toxin can:

  • damage the heart and affect its ability to pump blood
  • make the kidneys have trouble clearing wastes from the body
  • cause nerve damage, eventually leading to paralysis

Up to 50% of people whose diphtheria isn’t treated may die.

Can Diphtheria Be Prevented?

Preventing diphtheria depends almost completely on giving the diphtheria/tetanus/pertussis vaccine to children (DTaP) and non-immunized adolescents and adults (Tdap). After a single dose of Tdap, teens and adults should get a booster shot with the Tdap or the diphtheria/tetanus vaccine (Td) every 10 years. Most cases of diphtheria happen in people who aren’t vaccinated at all or who didn’t get all their shots.

The Tdap vaccine is also recommended for all pregnant women during the second half of each pregnancy, even if they’ve had the vaccine before.

The immunization schedule calls for:

  • DTaP vaccines at 2, 4, and 6 months of age
  • a booster dose given at 12–18 months
  • a booster dose given again at 4–6 years
  • Tdap vaccine given at 11–12 years
  • booster shots of Tdap or Td every 10 years after that to maintain protection
  • Tdap vaccine during the second half of each pregnant woman’s pregnancy

Most children tolerate the vaccine well. Sometimes it causes mild side effects, such as redness or tenderness at the injection site, a low-grade fever, or general fussiness or crankiness. Severe complications, such as an allergic reaction, are rare.

Is Diphtheria Contagious?

Diphtheria is highly contagious. It passes easily from an infected person to others through sneezing, coughing, or even laughing. It also can spread to someone who picks up tissues or drinking glasses that were used by an infected person.

People infected with the diphtheria bacteria, even if they don’t have any symptoms, can infect others for up to 4 weeks. The incubation period (the time it takes for a person to become infected after being exposed) for diphtheria is 2 to 4 days, although it can range from 1 to 6 days.

How Is Diphtheria Treated?

Children and adults with diphtheria are treated in a hospital. After a doctor confirms the diagnosis through a throat culture, the infected person gets a special anti-toxin, given through injections or an IV, to neutralize the diphtheria toxin already circulating in the body, plus antibiotics to kill the remaining diphtheria bacteria.

People with an advanced infection may need a ventilator to help them breathe. If the toxin may have spread to the heart, kidneys, or central nervous system, patients may need IV fluids, oxygen, or heart medicines.

A person with diphtheria must be isolated. Family members and other close contacts who haven’t been immunized, or who are very young or elderly, must be protected from contact with the patient.

When someone is diagnosed with diphtheria, the doctor will notify the local health department and treat everyone in the household who may have been exposed to the bacteria. Treatment includes throat cultures and booster doses of the diphtheria vaccine. They will also get antibiotics as a precaution.

With prompt care in a hospital, most patients recover from diphtheria. After the antibiotics and anti-toxin take effect, they will need bed rest for a while (4 to 6 weeks, or until full recovery). Bed rest is particularly important if someone develops myocarditis (inflammation of the heart muscle), which can be a complication of diphtheria.

After recovery, people who had diphtheria should still get all the diphtheria vaccine shots to protect them from another infection. Having had the disease doesn’t guarantee lifetime immunity.

When Should I Call the Doctor?

Call your doctor right away if anyone in your family has symptoms of diphtheria, you see symptoms in someone else, if anyone in your family is exposed to diphtheria, or if you think that you or a family member is at risk. Remember, though, that most throat infections are not diphtheria, especially in countries that immunize against it.

If you’re not sure if your kids have been vaccinated against diphtheria, call your doctor. Also make sure your own booster immunizations are current. Studies show that many adults over 40 years old aren’t fully protected against diphtheria and tetanus.