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Pertussis, also known as whooping cough, is predominantly a childhood-associated disease accounting for 20-40 million cases worldwide, with over 90% occurring within the developing world (1,3).

A highly contagious disease involving the respiratory tract and accounting for up to 7% of adult cough illnesses reported annually, Pertussis is characterized by prolonged, repetitive coughing spells interrupted by a “whooping” sound as an infected person attempts to catch his/her breath before the onset of another coughing spasm (2,4,6,8). Although adults typically do not present severe symptoms, non-vaccinated individuals of all ages are susceptible to infection, with fever, coughing accompanied by a “whooping” sound, vomiting and exhaustion following coughing spells, difficulty breathing, and potential death are typically associated with infants and young children (2,10).

Cases of Pertussis have been described as early as the 16 th century, and the beginning of the 20 th century in the United States was marked by high childhood incidence and mortality, with more than 200,000 cases reported annually (4). Most recently, great medical advancements have been made since the turn of the century, following the 1906 isolation of Bordella Pertussis , the bacterium causing the disease, and the introduction of a Pertussis vaccine in the 1940s. Subsequent widespread vaccination of children in the US signaled a steady decline in annual infections, with a national low of 1010 cases by 1976 (5). By the 1980s, however, approximately 4400 cases were being reported per year in America , and in 2001, annual incidence had increased to approximately 8000 individuals with outbreaks occurring every three to four years (5,6,8).

Reported Cases In the United States

Vaccine Coverage in Children Under 1 Year Old in the Americas, 1995

Although the disease causes 200,000-400,000 deaths per year worldwide primarily among infants, widespread vaccination within the developed world have fueled common misconceptions that whooping cough no longer exists (1,3). Interestingly, the case fatality rate within the developing world is 1-2%, compared to less than one-half of one percent in developed countries (3). Higher incidence of Pertussis in the US and globally have been linked to worldwide under-vaccination of children, misdiagnosis specifically of mild infection, and an increased understanding and subsequent recognition of whooping cough in adults and older children as a contributor to infection in previously unvaccinated children (4,5,7,8).

In Western countries alone, prevalence among individuals over the age of 15 accounts for 10-12% of total infections reported among those countries (1). In the US between 1997 and 2000, over 20% of reported Pertussis occurred in these individuals compared to only 6.5% in 1978-1981 (9).

Pertussis US Age Demographic

The seeming reemergence of Pertussis infection substantiates the need to evaluate and update current efforts for keeping worldwide whooping cough in check.

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