Pertussis

Basics

  • Highly contagious respiratory illness among close contacts
  • Synonyms: whooping cough, “the cough of 100 days”

Description

  • Host: humans
  • Most common reservoir: adults
  • Ages: all
  • Distribution: worldwide
  • Pattern: endemic or epidemic with outbreaks every 3 to 5 years
  • Seasonality: peaks late summer–autumn; can occur year-round
  • Transmission: person to person via aerosolized droplets
  • Effective vaccine: available
  • Immunity: neither 100% nor lifelong immunity with either infection or vaccine
  • System(s) affected: respiratory
  • Classic clinical manifestations include paroxysmal cough, inspiratory whoop and posttussive emesis.

Epidemiology

  • Caused by Bordetella pertussis
  • Typical incubation period: 7 to 10 days

Incidence

  • United States (2012 most recent peak year): 48,277 cases reported
  • Worldwide: 24.1 million cases and about 160,700 deaths per year

Etiology and Pathophysiology

  • Toxin mediated
  • Infectious process with predilection for ciliated respiratory epithelium
  • Common organisms:
    • B. pertussis
    • Bordetella parapertussis

Genetics
No known genetic predisposition

Risk Factors

  • Exposure to a confirmed case
  • Non- or underimmunized infants and children
  • Premature birth
  • Chronic lung disease
  • Immunodeficiency (e.g., AIDS)
  • Obesity and pre-existing asthma
  • Age <6 months (accounts for ~90% pediatric pertussis hospitalizations) (1)

General Prevention

  • Public health measures
    • Surveillance
    • Outbreak management
    • Care of exposed individuals
  • Prevention programs
  • Immunizations
    • Primary childhood immunization series against pertussis followed by boosters
    • Maternal immunization during each pregnancy
    • Adults, including health care providers in close contact with infants <1 year of age, should be immunized.

Pediatric Considerations
Strategies to reduce neonatal pertussis:

  • Tdap with each pregnancy, ideally between 27 and 36 weeks’ gestation
  • Cocooning
  • Tdap recommended for all persons in close contact with infants <1 year of age

Geriatric Considerations
Older adults are at increased risk for pertussis complications due to (2):

  • Age-related changes in immunity
  • Comorbid medical conditions

Commonly Associated Conditions

  • Apnea in infants
  • Secondary bacterial pneumonia
  • Sinusitis
  • Seizures
  • Encephalopathy
  • Urinary incontinence
  • Death

There's more to see -- the rest of this topic is available only to subscribers.