Bordetella pertussis

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Bordetella pertussis / (Redirected from Pertussis)



  • Small, Gram-negative coccobacillus
  • Fastidious, slow-growing, and strictly aerobic
  • Catalase positive non-fermentative
  • Pertussis toxin helps it to evade the host defenses


  • Four steps to infection: attachment, evasion of host defenses, local damage, and systemic manifestations
  • Virulence determined by filamentous hemagglutinin (FHA) and fimbriae (FIM) adhesins
    • Required for tracheal colonization
    • Pertussis toxin (PT) also plays a role
  • Adenylate cyclase toxin (ACT) and PT allow it to evade host defenses
    • ACT inhibits macrophages by catalysing ATP to cAMP
    • PT delays neutrophil recruitment by suppressing G protein signaling pathways
  • Tracheal cytotoxin (TCT) produces NO and damages the tracheal epitheleal cells
  • Few systemic manifestations because it doesn't enter circulation

Clinical Manifestations

  • Presents with cough lasting 14 days or more, with paroxysms of coughing, an inspiratory whoop, and post-tussive vomiting
  • Incubation period of 7 to 10 days on average (range 5 to 21 days)

Young Children

  • Three stages:
    1. Catarrhal stage, with rhinorrhea, nonpurulent conjuctivitis, occasional cough, and a low-grade fever; lasts 1 to 2 weeks.
    2. Paroxysmal stage, with fits of coughing and an inspiratory whoop; lasts 1 to 6 weeks. May have post-tussive emesis. Occasionally associated with hyperinsulinemia and hypoglycemia in infants.
    3. Convalescent stage, with the cough slowly resolving over 1 to 6 weeks, occasionally up to 8 weeks.


  • Can present atypically, with less whooping and less post-tussive vomiting
  • Coughing is seen in most patients, lasting longer than 21 days
    • Mean duration 36 to 48 days
  • Post-tussive vomiting is suggestive of pertussis

Carrier State

  • Transient nasopharyngeal carriage in immunized children


  • Case-fatality rate of 1% in children under 6 months
  • Pnuemonia is the most common complication, either caused by the disease itself for by coinfection (especially RSV)
  • Encephalopathy is a rare complication, usually in unimmunized children
    • Begins weeks 2 to 4 after cough, with seizures and focal neurologic deficits
  • Pulmonary hypertension
  • Pneumonia and urinary incontinence are common in older patients
  • The paroxysms of coughing can also cause subconjunctival hemorrhages, syncope, and rib fractures


  • Nasopharyngeal swab/aspirate culture
    • Sensitivity 15 to 80%
  • PCR
  • Serology
    • Antibodies (IgG and IgA) against GHA, agglutinogen, or PT
      • IgG rises 2 to 3 weeks after infection or immunization (1 week after booster)
      • Look for a two-fold increase in IgG to diagnose acute infection
    • Antigens including PT


  • Treat within 21 days of symptom onset (except if <1 mo. old, treat regardless of duration)
  • In children
  • In infants <1 mo, azithromycin 10 mg/kg/d for 5 days
  • In adults


Infection Control

  • Droplet precautions
  • Duration
    • Treated: after 5 days of effective treatment
    • Untreated: after 3 weeks from onset of paroxysms
  • Communicable from onset of catarrhal stage to 3 weeks after onset of coughing or paroxysms

Post-Exposure Prophylaxis

  • Consider prophylaxis of close contacts (face-to-face within 3 feet), third-trimester pregnancy, infants, and healthcare workers
  • Should be considered up to 21 days following last contact
  • Options include:


  • Options include whole-cell (DTP) and acellular (DTaP or Tdap)
    • Acellular removed lipopolysaccharide so is less reactive, but is as or more effective than whole cell
      • There was a fear of encephalopathy and SIDS with DTP
      • Acellular has PT, the two hemagluttinins, and protectin
    • DTaP (diphtheria toxoid, tetanus toxoid, and acellular pertussis, pediatric formula)
      • Given at 2, 4, 6, and 18 months, with booster at 4-6 years
    • Tdap booster once in adulthood, and with every pregnancy for women (third trimester)
  • None of the vaccines carry life-long immunity; even the immunity from the acellular pertussis vaccine wanes after 4-5 years