Facts about Pneumonic Plague
Contact: CDC, Division of Media Relations
(404) 6393286
Biological Weapon
Facts about Pneumonic Plague
Contact: CDC, Division of Media Relations
(404) 6393286
Biological Weapon
A weapon designed to aerosolize the plague bacterium could cause a
rapidly severe and fatal disease in exposed persons.
The Yersinia pestis, the causative agent of plague, is found in
rodents and their fleas in many areas around the world, and can be grown in
large quantities and disseminated by aerosol, the result could be an epidemic
of the pneumonic form with the potential for secondary spread of cases.
A bioterrorism attack would be characterized by pneumonic cases
occurring simultaneously in persons 1 to 6 days following a common exposure,
and in a secondary wave in unprotected case contacts.
There are no effective environmental warning systems to detect an
aerosol of plague bacilli.
The Disease
Although pneumonic plague is an uncommon form of the disease, large
outbreaks of pneumonic plague have occurred.
The patient typcially experiences fever, prostration and rapidly
developing pneumonic plague (shortness
of breath, chest pain, and cough), often accompanied by gastrointestinal
symptoms (nausea, vomiting, abdominal pain and diarrhea).
The first signs of illness would be expected to be fever, headache,
weakness and cough with bloody, sometimes watery sputum. In 2 to 4 days the
illness would lead to septic shock and without early treatment high mortality.
Before antibiotic treatment, nearly 100 percent of cases were reported
to be fatal.
A pneumonic plague outbreak would initially resemble an outbreak of
other severe respiratory illnesses, but would quickly be distinguished by the
rapid development of life threatening respiratory failure, sepsis, and shock.
Antibiotics need to be given within 24 hours of first symptoms to
prevent high mortality.
The Risk
Primary pneumonic plague results from the inhalation of plague bacilli.
Person-to-person transmission of pneumonic plague occurs through
respiratory droplets, which can only infect those who have direct and close
(within 6 feet) exposures to the ill patient.
Yersinia pestis is very sensitive to the action of sunlight and does not
survive long outside the host. Research
suggests it may survive in the exposed environment for up to one hour.
Immediate notification of suspected plague to local or state health
departments is essential for rapid investigation and control activities, and
for definitive tests through a state reference laboratory or the CDC.
Confirmatory testing for Yersinia pestis usually takes from 24 to
48 hours; presumptive identification by fluorescent antibody testing takes less
than 2 hours.
Few physicians in the United States have ever seen a case of pneumonic
plague.
Vaccine against plague does not prevent the development of primary
pneumonic plague, and is not presently available in the U.S.
The fatality rate of patients when treatment is delayed more than 24
hours after symptom onset is extremely high.
Treatment
Early treatment and prophylaxis with streptomycin or gentamicin
antibiotics, or the tetracycline or fluoroquinolone classes of antimicrobials
are advised.
In a community experiencing a pneumonic plague epidemic, all persons who
develop a fever or new cough should promptly begin antibiotic treatment.
Persons having household, hospital, or other close contact with persons
with untreated pneumonic plague should receive postexposure antibiotic
treatment for 7 days. (Close contact is defined as contact with a patient at
less than 2 meters.)
The use of disposable surgical masks is recommended to prevent the
transmission of pneumonic plague to persons in close contact with cases.
For more information about pneumonic plague see Plague as a Biological
Weapon, Medical and Public Health Management: JAMA, May 3, 2000Vol 283. No.
17, pp. 22812290
Additional information about biological agents is available online at http://www.bt.cdc.gov/bioagents.asp