This is the classic story of pertussis, an infectious disease that had been very much in eclipse until the last decade. Many community practitioners are slow to consider it, believing it to be nearly extinct despite the nearly 28,000 cases reported per year. It is a serious respiratory illness that is extremely contagious by both respiratory droplets and hand-to-mouth transmission from contaminated surfaces.

Pertussis evolves through three phases. The catarrhal stage is a 1- to 2-week period of mild cough, upper respiratory symptoms, and low-grade fever. It is rapidly followed by the paroxysmal stage, when thick respiratory secretions cause bursts of coughing. A paroxysm describes many coughs in a single expiration, often followed by a gasping stridorous inspiration from which the “whooping cough” gets its name. (There is a recording of this cough at www.doitforyourbaby.com/mediaplayer.html.)

This phase includes post-tussive vomiting and occasionally diarrhea. Fever is typical, along with high white blood cell counts, with absolute lymphocytosis reaching as high as 20,000. This stage can progress for 1-2 weeks and usually lasts for 2 or 3 weeks. Not infrequently, it can last for 9 weeks. During the latter part of this phase, the patient does not appear ill but has 15-24 paroxysms per day, especially at night. Older patients may fracture ribs. Young infants who are too weak to mount an effective gasp may experience significant episodes of hypoxemia. The dehydration, malnutrition, and exhaustion often require inpatient intervention. At this point, patients have been ill for a month or longer.

The final stage of pertussis demonstrates a decline in the severity of the cough, but patients have a lingering cough and enervation for weeks and often months, with an increased susceptibility to subsequent infections, bronchospasm, and exacerbations of their chronic conditions.

Most pertussis occurs among adolescents and adults, whose immune status has declined over time. However, family members younger than 6 months old will not have had a complete series of immunizations. They are far more likely to have serious sequelae and death. In fact, 63% of infants younger than 12 months with pertussis require hospitalization, and 90 of the roughly 100 deaths in the United States each year are in children younger than 4 months. Primary (Bordetella) and secondary pneumonia, seizures and persistent seizure disorder, asthma, subdural hematoma from cough, encephalopathy, hypoxemia, and possible subsequent intellectual impairment are all well-documented complications. Dehydration and malnutrition are also short term risks during the acute illness.