Plague is caused by a bacterium, Yersinia pestis,
which is carried by fleas that feed on infected
Human plague is very rare, but when a
person does get plague, it usually occurs during
summer months, when people are active outdoors
and flea activity is greatest.
Who gets plague?
Anyone can get plague. However, people in
occupations such as laboratory work, geology, or
biology may have more contact with infected
rodents and fleas.
Young people under the age of 20
also seem to have a greater risk. Possible reasons for
plague in young people may be:
Young people are more active and inquisitive
and may be more likely to find and play with a
sick or dead rodent.
Children are more likely to play where rodents
Young people may have more contact with pets
that may carry infected fleas.
Teenage boys have more contact with rodents
and their fleas because of hunting and other
How is plague spread?
The most common source of plague in humans has
been the bite of infected fleas.
Other sources include
the handling of tissues of infected animals, especially
rodents and rabbits.
Domestic pets, particularly
house cats, may carry plague-infected fleas into
homes and occasionally transmit infection by their
bites or scratches.
Occasionally, cats or humans
infected with plague pharyngitis or pneumonia may
spread plague in airborne droplets.
Careless handling of laboratory cultures can also result in
What are the symptoms of plague?
Plague appears in humans in one of three forms:
Any form of plague can be fatal if not treated. Septicemic and pneumonic plague are more often fatal than bubonic because they are harder to recognize. Fortunately, these types of plague are less common.
Bubonic plague is the most common form of plague. Symptoms include:
Severe malaise (feeling unwell)
Death may occur if not properly diagnosed.
The most distinctive
symptom is swelling of the lymph nodes in the
groin, armpits, or neck.
The swollen lymph nodes
are called buboes.
These become painful, pus-filled,
and may rupture and ooze fluid.
plague occurs when the
bacterium enters the blood stream. Symptoms of septicemic plague are similar to
bubonic, only without an increase in the size of the
lymph nodes. This form can be serious because it can
be difficult to diagnose.
Pneumonic plague occurs when infection
moves to the lungs. Symptoms of pneumonic
How soon after infection do symptoms
Symptoms usually start two to six days after
exposure for bubonic plague and two to four days
after exposure for pneumonic plague.
What is the treatment for plague?
Streptomycin is the drug of choice. Tetracycline or
chloramphenicol are also effective. Tetracycline
should not be given to children under age nine.
How can plague be prevented?
Wear long sleeved shirts and long pants,
and tuck pant legs into socks when camping
Avoid flea infested areas during summer
Use insect repellents containing DEET on
your skin or pyrethrin on your clothing. Be sure
to follow the directions on the container and
wash off repellents when going indoors.
Avoid handling rodents, especially dead or
diseased rodents. Don't attempt to care for sick
Report large numbers of dead or sick
rodents to your local or state health department.
Give your pets weekly flea treatments with
flea powder (especially in areas where plague is
Where can I get more information?
Contact your physician or the Southern Nevada Health District, Office of Epidemiology at (702) 759-1300.