About the Epidemiology and Pathogenesis of Plague
1. Usually spread by rodent fleas; cases are occasionally seen in the southwestern United States.
2. The former Soviet Union and the United States developed methods to aerosolize the bacillus.
3. Ingested by PMNs and monocytes, able to replicate in monocytes.
a. Produces acute inflammation and tissue necrosis.
b. Spreads to regional lymph nodes, forming fluctuant buboes.
About the Clinical Manifestations of Plague
1. In the flea-transmitted form of the disease, incubation of 2–8 days is followed by
a. fever, chills, weakness, and headache; and
b. bubo formation (very painful).
c. Within 2–4 days, septic shock leads to peripheral gangrene and death.
2. Pneumonic form more likely in a bioterrorist attack.
a. Incubation period is 2–4 days, leading to chills, fever, and myalgias.
b. Within 24 hours, bloody sputum production and chest pain begin, followed by dyspnea and
cyanosis.
c. Death follows within 18 hours if antibiotic treatment is not started
About the Diagnosis, Treatment, and Prevention of Plague
1. The disease is readily diagnosed by Gram stain of sputum or lymph node aspirate; cultures
usually
require 48 hours. A sensitive PCR method and a rapid antigen detection assay are available.
2. Treat with streptomycin, gentamicin, or doxycycline for 14 days; delaying beyond 24 hours can
lead to
death.
a. Ciprofloxacin and levofloxacin may be ew ective.
b. Use chloramphenicol for meningitis.
3. Prophylaxis:
a. Take respiratory (droplet) precautions for pneumonic plague for 48 hours ax er the start of
antibiotic
treatment.
b. Give doxycycline for 7 days ax er respiratory exposure.
c. Vaccine is under development.