Pertussis

Pertussis

1. Essentials for Diagnosis

   • Predominantly in pts. <2 yo
     • adolescents/adults are reservoirs
   • 2 week prodromal catarrhal stage
     • malaise, cough, coryza, and anorexia
   • "Whooping" Cough
     • Paroxysmal cough ending in a high-pitched inspiratory “whoop”
   • Absolute lymphocytosis

2. Pathophysiology

   • Bordetella pertussis
     • Transmitted via respiratory droplets
   • Incubation
     • 7-17 days

3. Risk Factors

   • &lt;2 yo

4. Presentation

   • Time span
     • Time span of 6 weeks with 3 phases
   • 3 Phases
     • Catarrhal stage (1-2 weeks)
       • insidious onset, with lacrimation, sneezing, coryza, anorexia, malaise, and a hacking night cough that becomes diurnal&nbsp; *Most contagious during this stage*
     • Paroxysmal stage (2-4 weeks)
       • bursts of rapid, consecutive coughs, followed by a deep, high-pitched inspiration “whoop,” *may have a post-cough emesis*
     • Convalescent stage (4-6 weeks after onset)
       • 4-6 weeks after onset of illness with a decrease in function and severity of paroxysms of cough
   • Lymphocytosis
     • WBC is usually 15,000-20,000 mcL with 60-80% lymphocytes
   • Cough lasting more than 2 weeks
     • Cough lasting more than 2 weeks in adults is suggestive of illness

5. Diagnostics

   • Isolation of Organisms
     • Isolation of organism from nasopharyngeal PCR or throat culture
     • Bordet-Gengou agar medium
       • Bordet-Gengou agar medium for throat culture: most sensitive during first 2 weeks of illness
   • PCR assays
     • PCR assays for nasopharyngeal swab: sensitive up to 4 weeks of illness

6. Management

   • Supportive
     • oxygenation, nebulizers, mechanical ventilation as needed
   • Macrolide Abx
     • Treatment shortens the duration of carriage and may diminish the severity of coughing paroxysms
     • Erythromycin
       • 500 mg 4x/day orally for 7 days
     • Azithromycin
       • 500 mg orally 1 day and 250 mg for next 4 days
       • Better tolerated, and preferred treatment if pt &lt; 1 month
     • Clarithromycin
       • 500 mg orally 2x/day for 7 days
     • Trimethoprim-sulfamethoazole
       • 160 mg – 800 mg orally 2x/day for 7 days

7. Prevention

   • Acellular pertussis vaccine
     • 5 doses of DTaP at 2 months, 4 months, 6 months, 15-18 months, and 4-6 years
     • - Recommended for all infants
     • &nbsp;- Combined with diphtheria and tetanus (DTaP)&nbsp;
     • - Booster recommended to adolescents and adults (11-18 years)&nbsp;
     • - Booster recommended during each pregnancy (during 27- 36 weeks gestation)
   • Macrolide Abx
     • Same antibiotic regimen recommended for those in contact with an active case of pertussis, where exposure to the active case occurs within 3 weeks of the onset of the active case’s cough

8. Prognosis

   • Mortality increases in infants due to apnea/cerebral hypoxia

9. Complications

   • Pneumonia, encephalopathy, otitis media, sinusitis, and seizures