Pertussis can occur in any age group, but is most severe in infants <4 to 6 months.
Consider pertussis in patients of any age with a persistent cough.
Consider pertussis even in vaccinated individuals, since immunity wanes within a few years after immunization.
Initiate antibiotic therapy with a macrolide (azithromycin is preferred) prior to obtaining test results, especially in infants, pregnant women, and those in close contact with them.
The classic presentation has three stages: catarrhal with nonspecific upper respiratory tract symptoms, paroxysmal phase with a severe “whooping” cough, and convalescent phase with less severe coughing, but the presentation may be atypical.
Lymphocytosis is typical, but is not always present, and fever is usually absent unless there is secondary bacterial infection.
Indications for hospital admission include infants <4 to 6 months, dehydration, and those with respiratory, neurologic, or cardiac complications.
Pertussis is an acute bacterial, highly contagious respiratory infection with a significant morbidity and mortality, especially in infants.1 In the United States, prior to the advent of vaccines, pertussis was the number one cause of communicable disease death in children <14 years old, accounting for 10,000 deaths annually. It was responsible for more deaths in the first year of life than measles, meningitis, scarlet fever, diphtheria, and poliomyelitis combined.2,3 With the widespread use of the pertussis vaccine, there was a >90% drop in the number of cases, reaching a nadir in 1976, with an increase in the incidence since then. Epidemic pertussis has occurred every 2 to 5 years since 1989.1–3
Worldwide, it was estimated by the World Health Organization (WHO) that in 2008 there were about 16 million cases of pertussis with 195,000 deaths.4 The incidence is highin developing countries and nations with low vaccination rates. In the developing world, disease rates are greatest in young children, while in the developed world, disease rates are highest in infants who are too young to be fully vaccinated.5–7 Although pertussis can occur all year long, it is most frequent in the late summer and fall.1,8
In the United States and Europe, in spite of widespread vaccination, the incidence has been increasing.1–3 For adolescents and adults, the approximate number of cases per year in the United States is 600,000.2 Moreover, it is underreported, particularly in adults and adolescents, with reported cases only 15% to 25% of the actual number.1
In the United States, epidemics occur every 2 to 5 years.7 Recent epidemics occurred in 2005, 2010, 2012, and 2014, with 2012 being the largest outbreak in 60 years, when >48,000 cases were reported.5
The resurgence of this vaccine-preventable disease has been attributed to several factors: (1) increased awareness of the disease, (2) availability of better laboratory tests for detection of Bordetella pertussis, (3) genetically modified changes in B. pertussis, (4) waning immunity—either infection, acquired (after 4–20 years) or vaccination (after 4–12 years),9 (5) vaccine failures secondary to decreased potency of the vaccines or not effective against all strains of Bordetella, and (6) individuals unimmunized for religious or other reasons.
CLINICAL PRESENTATION: CLASSIC ...