Pertussis

Definition

Pertussis is a highly contagious bacterial disease that causes uncontrollable, violent coughing. The coughing can make it hard to breathe.  A deep "whooping" sound is often heard when the patient tries to take a breath.

Alternative Names

Whooping cough

Causes, incidence, and risk factors

Pertussis, or whooping cough, is an upper respiratory infection caused by the Bordetella pertussis or Bordetella parapertussis bacteria. It is a serious disease that can cause permanent disability in infants, and even death.

When an infected person sneezes or coughs, tiny droplets containing the bacteria move through the air, and the disease is easily spread from person to person.

The infection usually lasts 6 weeks.

Whooping cough can affect people of any age. Before vaccines were widely available, the disease was most common in infants and young children. Now that most children are immunized before entering school, the higher percentage of cases is seen among adolescents and adults.

Symptoms

Initial symptoms, similar to the common cold, usually develop about a week after exposure to the bacteria.

Severe episodes of coughing start about 10 to 12 days later. In children, the coughing often ends with a "whoop" noise. The sound is produced when the patient tries to take a breath. The whoop noise is rare in patients under 6 months of age and in adults.

Coughing spells may lead to vomiting or a short loss of consciousness. Pertussis should always be considered when vomiting occurs with coughing. In infants, choking spells are common.

Other pertussis symptoms include:

• Runny nose
• Slight fever (102 °F or lower)
• Diarrhea

Signs and tests

The initial diagnosis is usually based on the symptoms. However, when the symptoms are not obvious, pertussis may be difficult to diagnose. In very young infants, the symptoms may be caused by pneumonia instead.

To know for sure, the health care provider may take a sample of mucus from the nasal secretions and send it to a lab, which tests it for pertussis. While this can offer an accurate diagnosis, the test takes some time, and treatment is usually started before the results are ready.

Some patients may have a complete blood count that shows large numbers of lymphocytes.

Treatment

If started early enough, antibiotics such as erythromycin can make the symptoms go away more quickly. Unfortunately, most patients are diagnosed too late, when antibiotics aren't very effective. However, the medicines can help reduce the patient's ability to spread the disease to others.

Infants younger than 18 months need constant supervision because their breathing may temporarily stop during coughing spells. Infants with severe cases should be hospitalized.

An oxygen tent with high humidity may be used.

Fluids may be given through a vein if coughing spells are severe enough to prevent the person from drinking enough fluids.

Sedatives (medicines to make you sleepy) may be prescribed for young children.

Cough mixtures, expectorants, and suppressants are usually not helpful and should NOT be used.

Expectations (prognosis)

In older children, the outlook is generally very good. Infants have the highest risk of death, and need careful monitoring.

Complications

• Pneumonia
• Convulsions
• Seizure disorder (permanent)
• Nose bleeds
• Ear infections
• Brain damage from lack of oxygen
• Bleeding in the brain (cerebral hemorrhage)
• Mental retardation
• Slowed or stopped breathing (apnea)
• Death

Calling your health care provider

Call your health care provider if you or your child develops symptoms of pertussis.

Call 911 or get to an emergency room if the person has any of the following symptoms:

• Bluish skin color, which indicates a lack of oxygen
• Periods of stopped breathing (apnea)
• Seizures or convulsions
• High fever
• Persistent vomiting
• Dehydration

Prevention

DTaP vaccination, one of the recommended childhood immunizations, protects children against pertussis infection. DTaP vaccine can be safely given to infants. Five DTaP vaccines are recommended. They are usually given to children at ages 2 months, 4 months, 6 months, 15-18 months, and 4-6 years.

The Tdap vaccine should be given around age 11 or 12, and every 10 years thereafter.

During a pertussis outbreak, unimmunized children under age 7 should not attend school or public gatherings, and should be isolated from anyone known or suspected to be infected. This should last until 14 days after the last reported case.

Some health care organizations strongly recommend that adults up to the age of 65 years receive the adult form of the vaccine against pertussis.

References

Braman SS. Postinfectious cough: ACCP evidence-based clinical practice guidelines. Chest. 2006;129(1):138S-146S.

US Food and Drug Administration. First Combination Vaccine Approved to Help Protect Adolescents Against Whooping Cough. Rockville, MD: National Press Office; May 3, 2005. Talk Paper T05-17.

Cohn AC, et al. Immunizations in the United States: a rite of passage.Pediatr Clin North Am. 2005;52(3):669-693.