pertussis /pərtus″is/ [L, per + tussis, cough] , an acute, highly contagious respiratory disease characterized by paroxysmal 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, Bordetella pertussis, is a small, nonmotile gram-negative coccobacillus. A similar organism, B. parapertussis, causes a less severe form of the disease called parapertussis. Also called whooping cough. ▪ OBSERVATIONS: Transmission occurs directly by contact or inhalation of infectious particles, usually spread by coughing and sneezing, and indirectly by contact with freshly contaminated articles. Diagnosis consists of positive identification of the organism in nasopharyngeal secretions. The initial stages of the disease are difficult to distinguish from bronchitis or influenza. A fluorescent antibody staining technique specific for B. pertussis provides an accurate means of early diagnosis. The incubation period averages 7 to 14 days, followed by 6 to 8 weeks of illness divided into three distinct stages: catarrhal, paroxysmal, and convalescent. Onset of the catarrhal stage is gradual, usually beginning with coryza, sneezing, a dry cough, a slight fever, listlessness, irritability, and anorexia. The cough becomes paroxysmal after 10 to 14 days; it occurs as a series of short rapid bursts during expiration followed by the characteristic whoop, caused by a spasm of the epiglottis, a hurried, deep inhalation that has a high-pitched crowing sound. There is usually no fever, and the respiratory rate between paroxysms is normal. During the paroxysm there is marked facial redness or cyanosis and vein distension, the eyes may bulge, the tongue may protrude, and the facial expression usually indicates severe anxiety and distress. Large amounts of a viscid mucus may be expelled during or after paroxysms, which occur from 4 to 5 times a day in mild cases and as many as 40 to 50 times a day in severe cases. Vomiting frequently occurs after the paroxysms as a result of gagging or choking on the mucus. In infants, choking may be more common than the characteristic whoop. This stage lasts from 4 to 6 weeks, with the attacks being most frequent and severe during the first 1 to 2 weeks, then gradually declining and disappearing. During the convalescent stage a simple persistent cough is usual. For a period of up to 2 years after the initial attack, paroxysmal coughing may accompany respiratory infections. ▪ INTERVENTIONS: Routine treatment consists of bed rest, adequate nutrition, and adequate amounts of fluid. Erythromycin or another antibacterial may be prescribed to reduce transmission or to control secondary infection. Hospitalization may be necessary for infants and children with severe or prolonged paroxysms and for those with dehydration or other complications. Oxygen may be needed to relieve dyspnea and cyanosis. IV therapy may be necessary when prolonged vomiting interferes with adequate nutrition. Intubation is rarely necessary but may be lifesaving in infants if the thick mucus cannot be easily suctioned from the air passages. Pertussis immune globulin is available, but its efficacy has not been established and its use is not recommended. Active immunization is recommended with pertussis vaccine, usually in combination with diphtheria and tetanus toxoids in a series of injections at 2, 4, and 6 months of age and boosters at 12 to 18 months and 4 years of age. One attack of the disease usually confers immunity, although some second, usually mild, episodes have occurred. ▪ PATIENT CARE CONSIDERATIONS: Severe paroxysms in an infant may require oxygen, suction, and intubation. The child needs to be kept calm and protected from respiratory irritants such as dirt, smoke, or dust. Overstimulation, noise, or excitement may precipitate paroxysms. Adequate nutrition and adequate fluids are encouraged through frequent small feedings. Common complications of the disease include bronchopneumonia; atelectasis; bronchiectasis; emphysema; otitis media; convulsions; hemorrhage, including subarachnoid and subconjunctival hemorrhage and epistaxis; weight loss; dehydration; hernia; prolapsed rectum; and asphyxia, especially in infants. Paroxysms can be fatal.
