View source for Plague

==Background==
*The plague is a severe, acute infection caused by [[Gram Negative]] bacillus, ''Yersinia pestis.''
**''Y. pestis'' is transmitted by fleas (vector) and occurs naturally in a variety of animals, including rodents (reservoir) <ref> Schultz, C., & Koenig, K. Weapons of Mass Destruction. In Rosen's Emergency Medicine: Concepts and Clinical Practice (9th ed.). Philadephia, PA: Elsevier/Saunders. </ref>
*Two main forms are bubonic and pulmonic forms
*Considered a Class A bioterrorism agent

==Clinical Features==
[[File:Plague Buboes.jpg|thumb|Inguinal buboes]] [[File:Septicemic plague.jpg|thumb|Necrosis of the distal extremities in septicemic plague]]
[[File:PMC3223485 eplasty11e47 fig3.png|thumb|Patient with symptoms of plague including gangrene of the right hand causing necrosis of the fingers.]]
===Bubonic plague===
*Eschar often forms at site of vector bite (usually flea bite)
*Buboes (inflamed, necrotic or hemorrhagic lymph nodes) are pathognomonic
**Usually in axilla or groin
**Typically non-fluctuant, but can suppurate (rare)
*Liver and splenic involvement
*[[Sepsis|Septicemia]]
**The disease disseminates in about 50% of patients
**Leads to necrosis of tissues, especially digits and nose
**Can either be first manifestation of the disease or develop from untreated bubonic plague
*Death if untreated in 2-10 days

===Pulmonic plague===
*Very contagious
*Can be hematogenous or aerosolized (weapon form)
*[[Hemoptysis]]
*Mulilobar hemorrhagic pneumonia
*Sepsis
*Death if untreated in 48 hours
**Mortality rate nearly 100% without treatment <ref> Schultz, C., & Koenig, K. Weapons of Mass Destruction. In Rosen's Emergency Medicine: Concepts and Clinical Practice (9th ed.). Philadephia, PA: Elsevier/Saunders. </ref>

==Differential Diagnosis==
{{Lower respiratory zoonotic infections}}

{{Bioterrorism agents}}

'''Lymphadenopathy'''
*[[Cat-scratch disease]]
*[[Tularemia]]
*Staphylococcal and streptococcal infections

==Evaluation==
''Should be considered in any patient with clinical signs of plague and a recent history of travel to the western United States or any other plague endemic area.'' 

Possible diagnostic samples: 
*Lymph node aspirate
**Affected bubo should contain numerous organisms that can be evaluated microscopically and by culture.
*Blood cultures
**Organisms may be seen in blood smears if the patient is septicemic. 
**Blood smears taken from suspected bubonic plague patients early in the course of illness are usually negative for bacteria by microscopic examination but may be positive by culture.
*Sputum
**Culture is possible from sputum of very ill pneumonic patients
**However, blood is usually culture-positive at this time as well.
*Bronchial/tracheal washing
**May be taken from suspected pneumonic plague patients
**Not ideal for isolation of plague, since they often contain many other bacteria that can mask the presence of plague.

Gram, Wright, Giemsa, or Wayson's stained smears of peripheral blood, sputum, or lymph node specimen.
Visualization of bipolar-staining, ovoid, Gram-negative organisms with a "safety pin" appearance permits a rapid presumptive diagnosis of plague.

*If cultures yield negative results, and plague is still suspected, serologic testing is possible to confirm the diagnosis. 
**One serum specimen should be taken as early in the illness as possible, followed by a convalescent sample 4-6 weeks or more after disease onset.

==Management==
''[[Droplet precautions]] if pneumonic form suspected''
*Plague is a reportable disease to the CDC
*If bioterrorism suspected, health authorities must be contacted immediately
*Consult ID
*Do not perform an I&D as the buboes are responsive to antibiotics; performing an I&D risks disseminating the bacterium to health-care providers <ref> Schultz, C., & Koenig, K. Weapons of Mass Destruction. In Rosen's Emergency Medicine: Concepts and Clinical Practice (9th ed.). Philadephia, PA: Elsevier/Saunders. </ref>

===[[Antibiotics]]===
''Should be given within 24 hours for effective outcomes and continued for at least 10 days'' <ref> Schultz, C., & Koenig, K. Weapons of Mass Destruction. In Rosen's Emergency Medicine: Concepts and Clinical Practice (9th ed.). Philadephia, PA: Elsevier/Saunders. </ref>
{{Yersinia antibiotics}}

==Disposition==
*Admit
**Droplet precautions if pneumonic form suspected for at least 4 days after initiation of antibiotics <ref> Schultz, C., & Koenig, K. Weapons of Mass Destruction. In Rosen's Emergency Medicine: Concepts and Clinical Practice (9th ed.). Philadephia, PA: Elsevier/Saunders. </ref>

==See Also==
*[[Isolation Precautions]]
*[[Bioterrorism]]
*[[GEMC:Prehospital / Disaster / Mass Casualty Medicine]]

==External Links==
[https://www.cdc.gov/plague/index.html Plague | CDC]

==References==
<references/>

[[Category:ID]]