1. Bordatella Pertussis
Adaobi Okobi, M.D.

2. Learning Objectives Epidemiology
Review the clinical features and natural history of pertussis
Discuss differential diagnosis
Treatment, Complications

3. Introduction
Pertussis is a respiratory tract infection caused by Bordatella pertussis transmitted by aerosolized droplets from coughing
B. Pertussis is a small, gram negative pleomorphic coccobacillus

4. Epidemiology 30-50 million cases/year worldwide
300,000 deaths/year worldwide
84% of children in the US who died of the disease from were under 6 months
Periodic epidemics occur every 3-5 years despite vaccination efforts
Increasing incidence of the disease because of waning immunity in the adolescent and adult population as well as fewer people vaccinating their children

5. Epidemiology
Data from: the Centers for Disease Control and Prevention

6. Epidemiology
Data from: the Centers for Disease Control and Prevention

7. Natural History Incubation period: 7-10 days Three phases Catarrhal
Paroxsymal
Convalescent

8. Phase 1: Catarrahal Similar to the “common cold”
Mild cough and runny nose
Duration: 1-2 weeks
If fever is present it is low-grade
Cough worsens instead of improves, unlike typical URIs
May be short or absent in infants

9. Phase 2: Paroxsymal Cough is persistent and severe
Long series of coughs which may result in gagging, cyanosis or post-tussive emesis
May also be associated with apnea or bradycardia in young infants
Coughing may be spontaneous or induced
Whooping (noise associated with force inspiration) is uncommon in children
Duration: 2-6 weeks
*Complications are most likely to occur during this stage

10. Phase 3: Convalescent
Cough gradually decreases over several weeks to months
Cough may recur with subsequent URIs for months after the disease has resolved

11. Differential Diagnosis
Mycoplasma pneumoniae
Chlamydia spp.
Tuberculosis
Viral
RSV
Adenovirus
Parainfluenza
Influenza
Rhinovirus
Foreign body aspiration
Asthma/Reactive Airway Disease
Reflux
Aspiration pneumonia
Croup
Sinusitis
TE fistula
Congestive heart failure

12. Diagnosis Clinical Case Definition Laboratory Criteria
A cough illness lasting at least 2 weeks with one of the following: paroxysms of coughing, inspiratory "whoop," or posttussive vomiting, without other apparent cause (as reported by a health professional).
Clinical case definition is appropriate for endemic or sporadic cases.
In outbreak settings, a case may be defined as a cough illness lasting at least 2 weeks (as reported by a health professional).
Nasopharyngeal culture
Polymerase chain reaction (PCR)
Direct fluorescent antibody testing of nasopharyngeal secretions has been shown to have low sensitivity and variable specificity.
Serologic testing for pertussis is not widely available nor is it standardized

13. Specimen Collection

14. Diagnosis Laboratory findings: CXR:
Lymphocytosis >10,000 lymphocytes/microL
CXR:
May be normal or have peribronchial cuffing, perihilar infiltrates or atelectasis
*Confirmed cases should be reported to the Department of Health

15. Complications Vomiting Seizures (1-2%) Encephalopathy (0.3%) Death
Apnea (50%)
Infants < 6 months; likely related to vagal stimulation
Pneumonia (20%)
May be primary or from bacterial superinfection
Associated with extreme leukocytosis (>60,000 cells/microL)
May have associated pulmonary hypertension
Increased risk of mortality
Vomiting
Seizures (1-2%)
Encephalopathy (0.3%)
Likely from hypoxia related to coughing
Death
Most occur in infants < 6 months (1% case fatality rate) with the majority under 2 months

16. Hospitalization Indications for admission: Indications for discharge:
Respiratory distress
Evidence of pneumonia
Inability to feed
Cyanosis or apnea
Seizures
Indications for discharge:
Tolerate coughing without bradycardia or hypoxia
Adequate PO intake
Caregivers are comfortable with the child
Close outpatient follow up can be obtained

17. Treatment Treat anyone with symptoms and lab evidence of infection
Droplet precautions (mask within 3 feet) x 5 days after treatment
Supportive-
Cardiopulmonary monitoring
Pulse oximetry
Monitor PO intake
Antimicrobials-
Azithromycin x 5 days
Erythromycin x 14 days
Clarithromycin x 7 days
Bactrim x 14 days
Early treament (within 1 week) may decrease severity of symptoms
Treatment within 2 weeks of cough decreases spread of infection

19. Prophylaxis Antibiotic prophylaxis recommended for all close contacts:
Face to face contact (within 3 feet)
Direct contact with respiratory, oral or nasal secretions
Sharing the same confined space for > 1 hr

20. Take Home Points Pertussis is a very contagious respiratory pathogen
There are 3 phases: catarrhal, paroxsymal, and convalescent
Infants under 6 months have the highest mortality rate
Complications include apnea, pneumonia, seizures, encephalopathy, and death
Treat with macrolides as soon as the diagnosis is suspected and give prophylaxis to any close contacts