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Organism
- Gram negative coccobacillus
- Special media = NAD and charcoal
- Slow growing, 3-5 days
- Survives briefly outside of RT
- FHA = strang adherance qualities
- Pili and pertactin (PRN)
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Toxins
- Pertussis toxin: A-B toxin, ADP-R Gi protein, which inhibitis it, increase cAMP
- Adenylate cyclase (ACT): catalyzes conversion of ATP to cAMP; hemolytic and interferes with cell signalling and microbicidal function of PMNs and Monos
- Tracheal cytotoxin: fragments of cell wall peptidoglycan; cause death of ciliated tracheal cells
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Epidemiology
- Airborne droplets in early stages of disease
- highly contagious
- Strict human disease
- Previously immunized adults are revervoirs
- Mortality high in infants
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Pathogenesis
- Tropism for ciliated epithelium cells
- Adherance mediated bu FHA< pili, pertactin and PT
- Adherance leads to destruction of ciliated cells, cause by tracheal toxin
- Loss of mucus escalator -> cough
- Non-invasive
- PT and ACT causes PMN, Mac and lymphocyte paralysis and death
- PT=lymphocytosis, histamin secretion, insulin secretion
- Immunity: IgG against PT, pili, Pertactin, wanes with age
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Manifestations
- 7-10 days
- Catarrhal: profuse mucoid rhinorrhea for 1-2 weeks with non-specific findings; most communicable at this stage
- Paroxysmal stage: starts with cough, up to 50x a day for 2-4 weeks; whoop and vomiting may cause apnea; marked lymphocytosis (up to 40,000)
- Convalescent stage: coughing, other features fade
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Diagnosis
- Clinical
- Confirmed by isolation from nasal secretions
- Special media - 3-7 days
- DFA for rapid diagnosis
- PCR
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Treatment
- Supportive
- Antmicrobial at early stages
- Prevention: active immunization
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