– An acute, highly communicable bacterial infection of the mucous membranes of the bronchus characterized by a spasmodic cough.
Causes and Incidence
Whooping cough is caused by Bordetella pertussis, a nonmotile, gram-negative cocco-bacillus. It is usually transmitted through aspiration of droplet spray produced by an infected individual during paroxysms. Pertussis is endemic throughout the world and becomes epidemic in 2- to 4-year cycles. It occurs in all age groups, but infants and toddlers are the most susceptible. The incidence had been greatly reduced in the United States since the 1940s, when a pertussis vaccine was introduced, but an upsurge in reported cases began in the late 1980s and continues currently.
When inhaled, B. pertussis attaches itself to the cilia of the respiratory epithelial cells and incubates for about 7 to 10 days before producing symptoms. The pertussis toxin is absorbed from the respiratory tract into the lymph system, causing a lymphocytosis. The pathogenesis of the paroxysmal cough is unknown.
Pertussis has three stages, each lasting about 2 weeks. The individual is contagious from the onset of the first symptom until the end of the second stage or until the patient is treated with antibiotics.
Drippy nose, sneezing, tearing, and low-grade fever; listlessness; hacking nocturnal cough
Exhausting paroxysms of prolonged coughing two to three times an hour that often end with an inspiratory whooping sound or choking and vomiting accompanied by production of copious, viscid, tenacious mucus with cyanosis and apnea
Diminished coughing and production of mucus
Complications most commonly occur in infants and very young children; they include bronchopneumonia, asphyxiation, convulsions, and cerebral hemorrhage, with resultant spastic paralysis and mental retardation.
The diagnosis is often missed in the catarrhal phase, since the disease mimics flu or bronchitis at this point. Lymphocytosis in an afebrile individual is suggestive and should lead to culture of nasal secretions. A definitive diagnosis is made by a positive culture of nasal secretions in the catarrhal or early paroxysmal stage. Direct fluorescent antibody staining of secretions may also isolate the pathogen but is less sensitive than a culture.
Tracheostomy if needed.
Antiinfective drugs to treat bronchopneumonia or otitis media; erythromycin in incubation or catarrhal stage to arrest pathogen; prevention through immunization; prophylactic treatment of contacts with antiinfective drugs.
Hospitalization of infants, with IV fluids, oxygen, possible ventilatory support, and suctioning; close monitoring of fluids, electrolytes, and nutritional needs; respiratory isolation during catarrhal and paroxysmal stages; home treatment for older children and adults with bed rest; minimal stimulation; small, frequent feedings; adequate hydration; and respiratory isolation.