Plague
- Plague
is a bacterial disease of rodents that can
be spread to humans and other animals by infected
fleas.
- Plague
has three forms: bubonic plague (infection
of the lymph glands), septicemia plague (infection
of the blood), and pneumonic plague (infection
of the lungs). Pneumonic plague can spread
from person to person.
- People
can get plague: by the bites of infected fleas;
by direct contact with the tissues or body
fluids of a plague-infected animal; by inhaling
infectious airborne droplets from persons
or animals with plague pneumonia; or by laboratory
exposure to plague bacteria.
- Plague
is treatable with antibiotics if detected
early.
- Prevention
consists of controlling rodent fleas, educating
the public and the medical community in places
where plague occurs, and using preventive
medicines and vaccines as appropriate.
What is plague?
Plague is a disease of rodents that can be
spread to humans another animals by infected
fleas. In people, plague has three forms: Bubonic
plague, infection of the lymph glands; septicemia
plague, infection of the blood; and pneumonic
plague, infection of the lungs. Pneumonic plague
is the most contagious form because it can spread
from person to person in airborne droplets.
What is the infectious agent that causes
plague?
Perinea pests cause plague, a bacterium
that is spread from rodent to rodent by infected
fleas. Periodic outbreaks of plague kill large
numbers of rodents (called a "die-off"). The
risk of infection to humans and other animals
in the area increases when the rodent hosts
die and infected fleas look for other sources
oxblood.
Where is plague found?
Plague is found in some semi-arid areas in
Asia, Eastern Europe, Africa, South America,
and North America. In the United States, most
cases in humans occur in two regions: 1) northern
New Mexico, northern Arizona, and southern Colorado,
and 2) California, southern Oregon, and far
western Nevada.
In the southwestern United States, rock squirrel
fleas are the most common source of infection
in people. In the Pacific states, California
ground squirrel fleas are the most common source.
Many other types of rodents -- including other
ground squirrels, prairie dogs, chipmunks, wood
rats, wild mice, and voles -- suffer plague
outbreaks and are occasional sources of human
infection. Domesticates can be infected by fleas
or by eating infected wild rodents and can be
a direct source of infection to people. Dogs
rarely suffer severe illness and have yet to
be shown to be sources of infection for humans.
How do people get plague?
- By
the bites of infected fleas
- By
direct contact with the tissues or body fluids
of a plague-infected animal
- By
inhaling infectious airborne droplets from
persons or animals, especially cats, with
plague pneumonia
- By
laboratory exposure to plague bacteria
What are the signs and symptoms of plague?
When a person is bitten by an infected flea
or is infected by handling an infected animal,
the plague bacteria move through the bloodstream
to the lymph nodes. The lymph nodes swell, causing
the painful lumps ("buboes") that are characteristic
of bubonic plague. Other symptoms are fever,
headache, chills, and extreme tiredness. Some
people have gastrointestinal symptoms.
If bubonic plague goes untreated, the bacteria
can multiply in the bloodstream and produce
plague septicemia (septicemia plague), severe
blood infection. Signs and symptoms are fever,
chills, tiredness, abdominal pain, shock, and
bleeding into the skin another organs. Untreated
septicemia plague is usually fatal.
Pneumonic plague, or plague pneumonia, develops
when the bacteria infect the lungs. People with
plague pneumonia have high fever, chills, difficulty
breathing, a cough, and bloody sputum. Plague
pneumonia is considered a public health emergency
because a cough can quickly spread the disease
to others. Untreated pneumonic plague is usually
fatal.
How soon after exposure do symptoms appear?
Symptoms usually begin within 2 to 6 days after
exposure to the plague bacteria.
How is plague diagnosed?
U.S. health-care providers should suspect plague
in anyone with large, painful, very tender lymph
gland accompanied by fever, extreme tiredness,
and a history of exposure to possibly infected
rodents and their fleas in the western United
States. Plague should also be suspected in a
person with plague symptoms plus a history of
handling sick or dead cats, or wild animals
such as rabbits.
Patients with suspected plague should be hospitalized,
placed in isolation, have specimens obtained
for plague diagnosis, and immediately treated.
All suspected plague cases must also be reported
to local and state health departments.
What is the treatment for plague?
If diagnosed in time, plague is treatable with
antibiotics. Treatment of suspected plague cases
should start as soon as possible after the laboratory
specimens are taken. The drug of choice is streptomycin,
but several other antibiotics are also effective.
How common is plague?
In the United States, human plague cases average
about 10 to 15per year. Worldwide, there are
1,000 to 2,000 cases each year.
< for risk at is>
- People
who live in rural areas where plague occurs
in wild rodents
- People,
such as biologists, trappers, and hunters,
who handle potentially infected animals
- Campers,
hikers, travelers, and others in areas where
plague is known to exist
- People
in close contact with pneumonic plague patients
Is plague a new or emerging infectious disease?
Plague is an ancient disease that occurs
in irregular cycles and remains a public health
hazard in parts of Asia, the Middle East, Eastern
Europe, Africa, and South America, as well as
the United States. Epidemics of plague in humans
usually involve house rats and their fleas.
Rat-borne epidemics continue to occur in some
developing countries, particularly in rural
areas. Highly publicized outbreaks of bubonic
and pneumonic plague occurred in 1994 in India,
leading toad heightened international reaction.
The last rat-borne epidemic in the United States
occurred in Los Angeles in 1924-1925. Since
then, all human plague cases in the United States
have been associated with plague outbreaks in
wild rodents and their fleas.
How can plague be prevented?
1. People who live, work, or play in areas
with active plague infection in wild rodents
should take these precautions:
- Eliminate
food and shelter for rodents around homes,
work places, and certain recreation areas,
such as picnic sites or campgrounds where
people congregate. Remove brush, rock piles,
junk, and food sources, including pet food.
- Allow
health authorities to use appropriate and
licensed insecticides to kill fleas during
plague outbreaks in wild animals.
- Treat
pets (cats and dogs) for flea control regularly.
- Avoid
sick or dead animals, and report such animals
to the health department. Hunters and trappers
should wear rubber gloves when skinning animals.
- Use
insect repellents when outdoors in areas where
there is a risk of flea exposure.
2. Preventive treatment with antibiotics
is recommended for: 1) people who are bitten
by fleas during a local outbreak or who are
exposed to tissues or fluids from a plague-infected
animal; 2) people living in a household with
a bubonic plague patient, since they may also
be exposed to infected fleas; and 3) people
in close contact with a person or pet with suspected
plague pneumonia. Close contacts defined as
face-to-face contact or being in the same closed
space, such as a room or vehicle.
3. People who travel to countries where
plague occurs should take these additional precautions:
- Avoid
exposure to fleas from diseased rats. The
risk of being bitten by infected fleas is
especially high after large numbers of plague-infected
rats have died. Therefore, avoid places that
are infested with rats or where large numbers
of rats have reportedly died.
- If
travel to such areas is essential, apply insect
repellent containing DEET to legs and ankles.
Also apply repellents and insecticides to
clothes and outer bedding according to manufacturers'
instructions.
- Take
preventive antibiotics if the risk of exposure
is high.
Where can I find more information about
plague?
CDC
http://www.cdc.gov/ncidod/dvbid/dvbid.html
This fact sheet is for information only
and is not meant to be used for self-diagnosis
or as a substitute for consultation with a health-care
provider. If you have questions about the disease
described above, consult a health-care provider.