Health Encyclopedia

Diphtheria

Definition

Diphtheria is an acute infectious disease caused by the bacteria Corynebacterium diphtheriae.

Causes, incidence, and risk factors

Diphtheria spreads through respiratory droplets (such as those produced by a cough or sneeze) of an infected person or someone who carries the bacteria but has no symptoms. Diphtheria can also be spread by contaminated objects or foods (such as contaminated milk). Symptoms usually occur 2 to 5 days after you have come in contact with the bacteria.

The bacteria most commonly infects the nose and throat. The throat infection causes a gray-to-black, tough, fiber-like covering, which can block the airways. In some cases, diphtheria may first infect the skin, producing skin lesions.

Once infected, dangerous substances produced by the bacteria can spread through your bloodstream to other organs, such as the heart, and cause significant damage. The most common complication is inflammation of the heart muscle (myocarditis). The nervous system is also frequently and severely affected, and may result in temporary paralysis.

Diphtheria may be mild or severe. Some people may not have symptoms. In others, the disease can slowly get worse.

Because of widespread and routine childhood DPT immunizations, diphtheria it is now rare in many parts of the world. There are fewer than 5 cases of diphtheria a year in the United States.

Risk factors include crowded environments, poor hygiene, and lack of immunization.

Symptoms

Sore throat (may range from mild to severe)
Painful swallowing
Hoarseness
Drooling (suggests airway blockage is about to occur)
Fever
Chills
Bloody, watery drainage from nose
Croup-like (barking) cough
Stridor, difficulty breathing, or rapid breathing
No breathing
Bluish coloration of the skin
Skin lesions (usually seen in tropical areas)

Note: There may be no symptoms.

Signs and tests

The health care provider will perform a physical exam and look inside your mouth. This may reveal a gray-to-black covering (pseudomembrane) in the throat, enlarged lymph glands, and swelling of the neck or larynx.

Tests used may include:

Gram stain or throat culture to identify Corynebacterium diphtheriae
Electrocardiogram (ECG)

Treatment

If the health care provider thinks you have diphtheria, treatment should be started immediately, even before test results are available.

Diphtheria anti-toxin is given as a shot into a muscle or through an IV (intravenous line). The infection is then treated with antibiotics, such as penicillin or erythromycin.

People with diphtheria may need to stay in the hospital while the anti-toxin is being received. Other treatment may include:

Fluids by IV
Oxygen
Bed rest
Heart monitoring
Insertion of a breathing tube
Correction of airway blockages

Anyone who has come into contact with the infected person should be immunization or booster shots against diphtheria. Protective immunity lasts only 10 years from the time of vaccination, so it is important for adults to get a booster of tetanus-diphtheria (Td) vaccine every 10 years.

Those without symptoms but who carry diphtheria should be treated with antibiotics.

Expectations (prognosis)

The death rate is 10%. Recovery from the illness is slow.

Complications

The diphtheria toxin can damage the heart, nervous system, kidneys, or other organs. This may lead to:

Myocarditis, which can lead to heart failure
Nerve problems such as peripheral neuritis, which can cause uncoordinated movements and paralysis
Kidney damage
Inflammation of the kidneys (nephritis)

Calling your health care provider

Contact your health care provider if you have come in contact with diphtheria.

Remember that diphtheria is a rare disease. Diphtheria is also a reportable disease, and any cases are often publicized in the newspaper or on television. This helps you to know if diphtheria is present in your area.

Prevention

Routine childhood immunizations and adult boosters prevent the disease. See diphtheria immunization (vaccine).

Review Date:9/25/2006
Reviewed By:Charlotte Grayson, MD, Private Practice specializing in Internal Medicine and Infectious Disease, Smyrna, GA. Review provided by VeriMed Healthcare Network.

ADAM Quality A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial process. A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The Agency for Health Care Administration (Agency) and this website do not claim the information on, or referred to by, this site is error free. This site may include links to websites of other government agencies or private groups. Our Agency and this website do not control such sites and are not responsible for their content. Reference to or links to any other group, product, service, or information does not mean our Agency or this website approves of that group, product, service, or information.

Additionally, while health information provided through this website may be a valuable resource for the public, it is not designed to offer medical advice. Talk with your doctor about medical care questions you may have.