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Yersinia pestis
Aka: Yersinia pestis, Pneumonic Plague, Bubonic Plague, Plague
- See Also
- Bioterrorism
- Lymphadenitis
- Epidemiology
- Madagascar (fall 2017)
- Cases: 1800 as of November 2017
- Deaths: 127 as of November 2017
- http://www.who.int/csr/disease/plague/en
- U.S. (2015)
- Cases: 11 with 3 deaths
- Desert Southwest (Arizona, New Mexico) and Yosemite National Park
- Kwit (2015) MMWR Morb Mortal Wkly 64(33): 618-9 [PubMed]
- Pathophysiology
- Bacteria: Yersinia pestis
- Gram Negative Rod
- Bipolar staining
- Facultative anaerobic bacterium
- Incubation
- Pneumonic Plague: 2-3 days
- Bubonic Plague: 2-10 days
- Organism survival
- Viability
- Water, moist meal, grain for weeks
- Near freezing Temperatures from months to years
- Dry Sputum, flea feces, buried bodies
- Killed by
- Heated for 15 minutes at 72 C
- Several hours in direct sunlight
- Transmission
- Reservoir: Rodents (rats, mice, ground squirrels)
- Flea Bites transmit bubonic form
- Aerosolized organisms transmit pneumonic form (e.g. Bioterrorism, person-to-person transmission)
- Types: Plague
- Bubonic Plague (80-95% of cases)
- Non-fluctuant inguinal Lymphadenitis
- Follows bite of an infected flea
- Primary septicemic Plague (10-20% of cases)
- May occur in combination with Bubonic Plague
- Gastrointestinal symptoms predominate early
- Multiorgan failure, DIC, Sepsis occur later
- Pneumonic Plague (rare)
- Hematogenous seeding or droplet inhalation (highly contagious)
- Occurs from person-to-person transmission (or aeroslized Biological Weapon)
- Mortality >60% with treatment (approaches 100% without treatment)
- Findings: Symptoms and signs
- Pneumonic Plague
- High fever
- Chills
- Headache
- Productive cough with Hemoptysis
- Toxic appearance
- Rapidly fulminant Pneumonia within 2-3 days of exposure
- Disseminated Intravascular Coagulation (DIC) or Shock may ensue
- Bubonic Plague
- Malaise
- High fever
- Tender, swollen Lymph Nodes (buboes)
- Primarily inguinal (legs most commonly flea bitten)
- Labs
- Fluid Gram Stain and culture (from Sputum, tracheal aspirates, blood or aspirated buboe)
- Yersinia pestis Antigen detection or PCR
- Gram Negative Bacilli with "safety pin" appearance
- Organism grows on standard culture medium
- Imaging: Pneumonic Plague
- Chest XRay with consolidative Pneumonia, bilateral and multilobar
- Management
- Treat for 10-14 days
- Contact Isolation
- Droplet Isolation for plague Pneumonia patients for first 48 hours
- Preferred Regimens (choose one)
- Streptomycin
- Adults and Children: 15 mg/kg (up to 2 g) IV/IM every 12 hours
- Gentamicin
- Adult: 5 mg/kg IM or IV every 24 hours
- Child: 2.5 mg/kg IM or IV every 8 hours
- Other Regimens (choose one)
- Doxycycline (over age 8 years)
- Convert to oral dosing when clinically improved
- Adult: 200 mg IV, then 100 mg IV every 12 hours
- Child: 2.2 mg/kg IV (max: 100 mg) every 12 hours
- Dose as adult for children over 45 kg
- Ciprofloxacin
- Adult: 400 mg IV every 12 hours
- When improved convert to 750 mg oral twice daily
- Child: 15 mg/kg (max: 400 mg) IV every 12 hours
- Chloramphenicol
- Adult: 1 g IV every 6 hours
- Child: 25 mg/kg (max: 1 g) IV every 6 hours
- Prevention
- Licensed, killed Vaccine (no longer available)
- Doses at 0, 1-3 months, and 5-6 months
- Booster at 6 month intervals x3, then every 1-2 years
- Effective against bubonic, but not pulmonic Plague
- Post-exposure Prophylaxis (adult dosing below)
- Continue for 7 days or length of exposure
- Doxycycline 100 mg PO bid
- Ciprofloxacin 500 mg PO bid
- Tetracycline 500 mg PO qid
- Prognosis
- Mortality 100% if untreated (or treatment delayed >48 hours)
- References
- Gilbert (2019) Sanford Guide, accessed 1/27/2020 on IOS version
- Seeyave (2015) Crit Dec Emerg Med 29(5): 13-21
- Inglesby (2000) JAMA 283:2281-90 [PubMed]
- Rathjen (2021) Am Fam Physician 104(4): 376-85 [PubMed]