Anthrax

Background

  • Gram positive rod, Bacillus anthracis, which is capable of surviving inhospitable condition through the formation of endospores. tough spores
  • Incubation period is 10 days with no ability for human to human transmission and therefore, no need for respiratory isolation
    • Though human to human transmission does not occur, potential harbors of spores (patient clothes) need to be isolated and decontaminated with 10% bleach[1]
  • In general there is cutaneous, inhalational, and gastrointesinal anthrax.

Inhalational (5%)

  • Biphasic course

Prodrome Period

  • Early prodromal period often appears as an influenza like illness
  • Fever, dry cough, mylagia, malaise
  • Transient clinical improvement followed by rapid decline

Acute phase

  • Severe respiratory distress with symptoms consisting of[2]:
    • Hypoxia, tachypnea, cyanosis
    • Severe dyspnea, chest pain
    • Shock
    • Mediasitinits

Cutaneous (95%)

Cutaneous anthrax
  • The disease will start as an area of errythema and edema and progress to a vesicle which ruptures forming a central black eschar
  • Total course of lesion evolution occurs over 1 week

Gastrointestinal

  • Over the course of 7 days, nonspecific abdominal pain, nausea and vomitting with progress to severe abdominal pain, bloody emesis and diarrhea (usually bloody)[3]

Differential Diagnosis

Cutaneous (painless)

Inhalational

Lower Respiratory Zoonotic Infections

Bioterrorism Agents[4]

Category A

Category B

  • Ricin
  • Brucellosis
  • Epsilon toxin
  • Psittacosis
  • Q Fever
  • Staph enterotoxin B
  • Typhus
  • Glanders
  • Melioidosis
  • Food safety threats
  • Water safety threats
  • Viral encephalitis

Category C

Evaluation

CXR/CT

  • Widened mediastinum representing hemorrhagic mediastinitis
  • Infiltrate, pleural effusion
  • Hyperdense mediastinal lymphadenopathy

Management

Contact CDC Emergency Hotline 1-707-488-7100 for all suspected bioterrorism cases

Postexposure Prophylaxis

Patient should be vaccinated at day #0, #14, #28

Cutaneous Anthrax (not systemically ill)

  • Ciprofloxacin 500mg PO q12hrs x 60 days
  • Doxycycline 100mg PO q12hrs x 60 days

Inhalation or Cutaneous with systemic illness

Pediatric Postexpsoure Prophylaxis

Pediatric Cutaneous Anthrax (not ill)

  • Same as post exposure dosing and duration

Pediatric Inhalational or Cutaneous (systemically ill

Disposition

  • Admit

See Also

References

  1. Heninger SJ et al. Decontamination of Bacillus anthracis Spores: Evaluation of Various Disinfectants. Appl Biosaf. 2009 Jan 1; 14(1): 7–10.
  2. Medscape: Anthrax
  3. CDC. Gastrointestinal anthrax after an animal-hide drumming event - New Hampshire and Massachusetts, 2009. MMWR Morb Mortal Wkly Rep. 2010 Jul 23;59(28):872-7. http://www.ncbi.nlm.nih.gov/pubmed/20651643
  4. https://www.niaid.nih.gov/topics/biodefenserelated/biodefense/pages/cata.aspx Accessed 02/26/16