Plague
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?
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.
Who is at risk for
plague?
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:
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:
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
bemuse for self-diagnosis or as a substitute for consultation with
health-care provider. If you have any questions about the disease
described above, consult a health-care provider.
Source: http://www.dhpe.org/infect/plague.html
