Whooping cough has returned

Pertussis, or whooping cough, is an endemic infectious disease in the United States, with tens of thousands of cases annually. Classically thought of as a childhood infectious disease of the past, whooping cough not only has made a comeback over recent years, but over half the time presents as an illness in adolescents and adults.  Importantly, pertussis booster vaccination is now recommended as part of the adult health maintenance.

Whooping cough is a highly contagious illness caused by the bacteria Bordetella pertussis.  It is traditionally characterized by a three phased illness; the catarrhal phase, the paroxysmal phase and the convalescent phase. The catarrhal phase consists of non-specific symptoms such as malaise, runny nose and cough.  Often the patient may also have excessive tearing and redness of the eyes.  The paroxysmal phase is when the classic whooping cough-a series of severe, vigorous coughs that occur during a single expiration, separated by a quick, intense inspiration and a distinctive “whooping” sound. The cough may be triggered by almost anything-yawning, stretching, laughing, etc.  The convalescent phase exhibits gradual resolution of symptoms.  This three phased illness, however, is much less common in adolescents and adults, likely because of prior vaccination. Prolonged cough, without the “whoop”, is the most common presentation. One study reported that as many as 20% of patients with new onset cough of more than one week duration may have pertussis.

The diagnosis of whooping cough is surprisingly difficult. In patients who have two weeks of a new cough the possibility of infection must be entertained. If there is a known community outbreak, a clinical diagnosis may be made. However, if there is no such outbreak, multiple diagnostic tests of nasal and pharyngeal fluid and/or blood tests must be considered.

Once a diagnosis has been made, there are antibiotic options available. However, although treatment most likely affects contagion and disease spread, its impact on patient symptoms is not clear. Azithromycin and clarithromycin are the most commonly prescribed medications.

Vaccination against pertussis has been standard for decades. Administered to children in a preparation with preventive activity against diphtheria and tetanus as well, the vaccine (DTaP) is 70-90 percent protective.  However, the effectiveness of the vaccine wanes with time, which has led to the increase in the incidence of pertussis over the past years. In response to this, the Advisory Council on Immunization Practices now recommends that adolescents aged 11 to 18 years should receive a single booster immunization (Tdap). In addition, adults aged 19 to 64 should also follow this guideline if they have not ever received booster immunization. In 2012, recommendations were broadened to include adults 65 years or older who have never received Tdap immunization.

If you have not received this vaccination, or are unsure about your status, please speak with your primary care physician.