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  • Highly infectious after aerosolization
  • Person-to-person and animal-to-human transmission can occur with pneumonic plague via respiratory droplet


  • Incubation period is 1-3 days (ranges up to 7 days)
  • Aerosolization would most likely result in pneumonic plague
  • Pneumonic plague presents with acute onset of high fevers, chills, headache, malaise and a productive cough, that is initially watery before becoming bloody

Laboratory Diagnosis

  • Bacterial cultures (blood, sputum, or lymph node aspirate specimens) should be handled in a Biosafety Level 2 facility
  • Wright, Giemsa, or Wayson stain shows gram negative coccobacilli with bipolar "safety-pin" appearance
  • Organism grows slowly (48 hrs for observable growth) on standard blood and MacConkey agar
  • Immunoflourescent staining for capsule (F1 antigen) is diagnostic

Patient Isolation

Strict respiratory isolation with droplet precautions (gown, gloves, and eye protection) until the patient has received at least 48 hours of antibiotic therapy and shows clinical improvement.


  • Streptomycin (1 g IM bid) or gentamicin (5 mg/kg IM or IV qd) are the preferred antibiotics
  • Tetracyclines or flouroquinolones are alternative choices
  • Co-trimoxazole is recommended for pregnant women and children between the ages of 2 months and 8 years
  • Chloramphenicol should be used for plague meningitis


  • Antibiotic prophylaxis is recommended for all persons exposed to the aerosol or persons in close physical contact with a confirmed case
  • Tetracyclines or flouroquinolones are recommended for 7 days from last exposure to a case

Thanks to Santa Clara County for information provided on this page.

´╗┐Physicians who need to report a suspected public health emergency should contact the Public Health division immediately at 925-313-6740; or after hours, call the sheriff's dispatch at 925-646-2441 and ask for the Health Officer On Call.

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