Pertussis
Background
- “Whooping cough”. The “whoop” is caused on inspiration between coughs.[1]
- Most common in kids < 1yo, because they haven’t completed the whole vaccine series, AND adults, who have waning immunity.
- One of the only vaccine preventable diseases that has increased in prevalence recently
- Up to 20% of adults with cough >2 weeks have serologic evidence of pertussis[2]
- Bordetella pertussis, a gram-negative coccobacillus
Pathophysiology
- Transmitted by aerosolized droplets, extremely contagious
- Infects ciliated respiratory cells (rarely goes hematogenous), creates toxins damaging respiratory epithelium.
Clinical Presentation
- Incubation period several days-3 weeks
- 3 stages:
- Catarrhal phase: lasts 1-2 wks. Clinically indistinguishable from other URIs; dry cough starts near the end. Greatest infectivity phase.
- Paroxysmal phase: lasts 2-4 weeks => fever improves, cough worsens. Staccato cough + whoop (present in 1/3 kids), post-tussive emesis (often in adolescents, adults). Infants can present as apnea. Pts often appear well between coughing episodes.
- Petechiae, epistaxis, pneumothorax, and/or subconjunctival hemorrhage may occur due to high intrathoracic pressures during coughing.
- Convalescent phase: lasts weeks-months; residual cough
Sequelae
- PNA superinfections, rib fractures, PTX, aspiration of gastric contents, CNS complications
Diagnosis
- WBC elevated in infants (20-100), adults may be WNL
- CXR with peribronchial thickening, atelectasis, and/or consolidation
- Nasopharyngeal swab can identify it in 3-7 days; often neg in adults.
- Cough for >2 weeks, post tussive emesis, feeling well otherwise, treat them empirically. Especially if infant or pregnant people at home.
Management[3]
- Supportive
- Suction in infants, hydration. Neonates with apnea should be admitted to the ICU.
- Antibiotics
- Don’t help much with severity or duration. Decreases infectivity.
- Peds: Azithromycin 10mg/kg (max 500mg/day) Qdaily x3 days
- Adults: Azithromycin 500mg Qdaily for 3 days OR clarithromycin 500mg BID x7 days
- Pregnant: Erythromycin 500mg QID x7 days
- Pts are considered infectious for 3 wks after start of paroxysmal phase, or after 5 days of antibiotics (droplet isolation).
Post-Exposure Prophylaxis
- Prophylaxis for all household exposures of known Pertussis
- High risk people exposed to pertussis: infants, women in 3rd trimester of pregnancy, immunocompromised, severe asthma, people with close contact to infants <1year, people who work in neonatal ICUs / maternity wards.
Prevention
- Tdap for adults, regardless of recent tetanus shot.
- DTaP for infants getting their first childhood immunization
- Vaccinate women during each pregnancy
- Immunity wanes 8 y after immunization. Often elderly will get the disease and transmit it to young unimmunized infants.
Tetanus Vaccine Selection Guide
| Age | If No Pertussis Contraindications | If Pertussis Contraindicated | Comments |
| 2mo - 7yrs | DTaP | DT | DT available from pharmacy |
| 7yrs - 10yrs | Td | Td | |
| 10yrs | Tdap(Adacel)^ | Td | ^Off label use, but appears safe and immunogenic |
| 11yrs - 16yrs | Tdap(Adacel) | Td | |
| 16yrs - 65 | Tdap(Adacel)^^ | Td | ^^Use Td if patient is known to have received prior Tdap |
| 65yrs + | Td |
Td |
Consider TIG for tetanus prone wound plus Td(tetanus immune globulin) |
Caveats
- Adolescents who have already gotten a booster dose of Td are encouraged to get a dose of Tdap as well. Waiting 5 years after their last Td is encouraged but not required. A period of at least 2 years between Td and Tdap is recommended in these cases.
- Pregnancy is not a contraindication to Tdap. The only true contraindication to tetanus immunization is a history of neurologic or severe hypersensitivity to a previous dose.
- Stable neurologic disorders and family history of vaccine reactions are not contraindications to receiving these vaccines.
- No vaccine has ever been shown to play any role in the development of autism or autism spectrum disorders.
See Also
Sources
- Herbert, Mel; Takhar, Sukhjit. “Pertussis Update 2013”. Emergency Medicine Reviews and Perspectives. May 2013
- Marx et al. “Pertussis”. Rosen’s Emergency Medicine 8th edition vol 1 pg 1696-1699.
- “ Pertussis Postexposure Antimicrobial Prophylaxis”. Centers for Disease Control and Prevention. http://www.cdc.gov/pertussis/outbreaks/pep.html. Aug 28, 2013
- “Pertussis: Clinical Features”. Centers for Disease Control and Prevention. http://www.cdc.gov/pertussis/clinical/features.html. Sept 4, 2014
- ↑ Frumkin K. Pertussis and persistent cough: practical, clinical and epidemiologic issues. J Emerg Med. 2013 Apr;44(4):889-95.
- ↑ Trends in hospitalizations and resource utilization for pediatric pertussis. Hosp Pediatr. 2014 Sep;4(5):269-75
- ↑ *“Pertussis Treatment Options”. British Medical Journal Best Practice. http://bestpractice.bmj.com/best-practice/monograph/682/treatment.html. Sept 3, 2014.