Wednesday, July 30, 2014

Definition

Whooping cough (pertussis) is a respiratory disease caused by the bacteria Bordetella pertussis.

Description

Pertussis is an acute, highly contagious respiratory disease characterized by coughing that ends in a loud whooping inspiration. It occurs primarily in infants and in children less than 4 years of age who have not been immunized. The causative organism is Bordetella pertussis, and a similar organism, B. parapertussis, causes a less severe form of the disease called parapertussis.

Pertussis is now a rare disease in the U.S., thanks to widespread immunization during infancy. Still, several thousand cases are reported in the U.S. each year. Worldwide there are over 60 million cases of pertussis a year with more than half a million deaths.

It most commonly attacks very young children, with a high mortality rate. The disease, however, is rarely serious once the child has passed his first birthday.

Causes

Pertussis is highly contagious and is transmitted by aerosol droplets at close range. Coughing adolescents and adults (usually not recognized as having pertussis) are the major reservoir for Bordetella pertussis and are the usual sources for the initial case in infants and children.

Symptoms

Pertussis is from the Latin for "intensive cough" and this is the most striking characteristic of the disease. At first, there may only be a runny nose, mild cough, and low-grade fever. But as the disease progresses, the nasal discharge becomes thicker and more profuse, leading to severe upper respiratory congestion in a young baby. This stage usually lasts 1 to 2 weeks before progressing to the next (paroxysmal) stage.

Typically, the child will cough forcefully 5 to 10 times during a single expiration. This is followed by a sudden intake of air and a whooping sound as it is inhaled against the narrowed glottis.

During these coughing spells, the face may turn red or blue, the eyes bulge, the tongue protrude, and there may be drooling. Vomiting may accompany the coughing. Understandably, these attacks leave the child exhausted. This stage may last 2 to 4 weeks or even longer; weight loss is common. The coughing attacks gradually become less frequent and disappear, but a cough may persist for several months after recovery.

Pneumonia is one of the most serious potential complications of whooping cough, causing more than 90 percent of the deaths from the disease in children under the age of 3.

Diagnosis

Diagnosis is based on symptoms, physical examination, and culture or DFA (direct fluorescent antibody) testing of nasopharyngeal secretions.

Treatment

Erythromycin is the drug of choice for the treatment of Bordetella pertussis infection. Administration of erythromycin during the early stage of the disease may prevent it progressing to the paroxysmal or coughing stage. But once the cough begins, antibiotics do not seem to shorten its duration. Hospitalization may be required, almost uniformly for infants less than 3 months and often for infants between 3 and 6 months.

Suction to remove the secretions from the upper nose and upper respiratory tract may be necessary in very young children, and oxygen also may be required. Fluids should be given to prevent dehydration, and even though the disease is exhausting and a child may not feel like eating, maintaining nutrition is important, especially in an infant.

Questions

What causes whooping cough? Can it be prevented?

What is the schedule of immunizations for my child?

What are the risks and benefits of each type of immunization?

If the other family members have been immunized, should they stay away from the infected person?

(Infant) Will whooping cough permanently affect the developing lungs?

Is hospitalization necessary?

How do you tell if the whooping cough has progressed to pneumonia?

What are the side effects of erythromycin?

Prevention

Universal immunization of children with pertussis vaccine, beginning in infancy, is central to the control of pertussis. The FDA approved in 1992 a new diphtheria, tetanus, and acellular pertussis (DTaP) vaccine. The new vaccine differs from the one previously available in that the pertussis component is acellular rather than whole-cell. The whole-cell vaccine contains the entire inactivated pertussis organism while acellular contains elements of the pertussis organism thought to provide protection against the disease.

The American Academy of Pediatrics states that all children should receive 5 doses of pertussis (and diphtheria and tetanus) vaccine by their seventh birthday. This includes 3 doses of the primary series at 2, 4, and 6 months of age and 2 doses of booster vaccine at 15 to 18 months and 4 to 6 years of age.