Bacteria
Yersinia pestis
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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
Temperature
s 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 Bite
s 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 Node
s (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
Lice
nsed, 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]
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