Tularemia
is an infectious disease caused by a hardy bacterium, Francisella tularensis,
found in animals (especially rodents, rabbits, and hares).
People
can get tularemia many different ways, such as through the bite of an
infected insect or other arthropod (usually a tick or deerfly), handling
infected animal carcasses, eating or drinking contaminated food or water,
or breathing in F. tularensis.
Symptoms
of tularemia could include sudden fever, chills, headaches, muscle aches,
joint pain, dry cough, progressive weakness, and pneumonia. Persons with
pneumonia can develop chest pain and bloody spit and can have trouble
breathing or can sometimes stop breathing. Other symptoms of tularemia
depend on how a person was exposed to the tularemia bacteria. These symptoms
can include ulcers on the skin or mouth, swollen and painful lymph glands,
swollen and painful eyes, and a sore throat. Symptoms usually appear 3
to 5 days after exposure to the bacteria, but can take as long as 14 days.
Tularemia
is not known to be spread from person to person, so people who have tularemia
do not need to be isolated. People who have been exposed to F. tularensis
should be treated as soon as possible. The disease can be fatal if it
is not treated with the appropriate antibiotics.
A
vaccine for tularemia is under review by the Food and Drug Administration
and is not currently available in the United States.
How Soon Do
Infected People Get Sick?
Symptoms usually appear
3 to 5 days after exposure to the bacteria, but can take as long as 14
days.
What Should I Do if I Think I Have Tularemia?
Consult your doctor
at the first sign of illness. Be sure to let the doctor know if you are
pregnant or have a weakened immune system.
How Is Tularemia
Treated?
Your doctor will most
likely prescribe antibiotics, which must be taken according to the directions
supplied with your prescription to ensure the best possible result. Let
your doctor know if you have any allergy to antibiotics.
A vaccine for tularemia
is under review by the Food and Drug Administration and is not currently
available in the United States.
What Can I
Do To Prevent Becoming Infected with Tularemia?
Tularemia occurs naturally
in many parts of the United States. Use insect repellent containing DEET
on your skin, or treat clothing with repellent containing permethrin,
to prevent insect bites. Wash your hands often, using soap and warm water,
especially after handling animal carcasses. Be sure to cook your food
thoroughly and that your water is from a safe source.
Note any change in
the behavior of your pets (especially rodents, rabbits, and hares) or
livestock, and consult a veterinarian if they develop unusual symptoms.
Can Tularemia
Be Used As a Weapon?
Francisella tularensis
is very infectious. A small number (10-50 or so organisms) can cause disease.
If F. tularensis were used as a weapon, the bacteria would likely be made
airborne for exposure by inhalation. People who inhale an infectious aerosol
would generally experience severe respiratory illness, including life-threatening
pneumonia and systemic infection, if they are not treated. The bacteria
that cause tularemia occur widely in nature and could be isolated and
grown in quantity in a laboratory, although manufacturing an effective
aerosol weapn would require considerable sophistication.
More Questions
& Answers
Q.
What is tularemia?
A. Tularemia, also known as “rabbit fever,”
is a disease caused by the bacterium Francisella tularensis. Tularemia
is typically found in animals, especially rodents, rabbits, and hares.
Tularemia is usually a rural disease and has been reported in all U.S.
states except Hawaii.
Q.
How do people become infected with tularemia?
A. Typically, people become infected through the bite
of infected insects (most commonly, ticks and deerflies), by handling
infected sick or dead animals, by eating or drinking contaminated food
or water, or by inhaling airborne bacteria.
Q.
Does tularemia occur naturally in the United States?
A. Yes. Tularemia is a widespread disease in animals.
About 200 human cases of tularemia are reported each year in the United
States. Most cases occur in the south-central and western states. Nearly
all cases occur in rural areas, and are caused by the bites of ticks and
biting flies or from handling infected rodents, rabbits, or hares. Cases
also resulted from inhaling airborne bacteria and from laboratory accidents.
Q.
What are the signs and symptoms of tularemia?
A. The signs and symptoms people develop depend on how
they are exposed to tularemia. Possible symptoms include skin ulcers,
swollen and painful lymph glands, inflamed eyes, sore throat, mouth sores,
diarrhea or pneumonia. If the bacteria are inhaled, symptoms can include
abrupt onset of fever, chills, headache, muscle aches, joint pain, dry
cough, and progressive weakness. People with pneumonia can develop chest
pain, difficulty breathing, bloody sputum, and respiratory failure. Tularemia
can be fatal if the person is not treated with appropriate antibiotics.
Q.
Why are we concerned about tularemia being used as a bioweapon?
A. Francisella tularensis is highly infectious. A small
number of bacteria (10-50 organisms) can cause disease. If Francisella
tularensis were used as a bioweapon, the bacteria would likely be made
airborne so they could be inhaled. People who inhale the bacteria can
experience severe respiratory illness, including life-threatening pneumonia
and systemic infection, if they are not treated.
Q.
Can someone become infected with the tularemia bacteria from another person?
A. People have not been known to transmit the infection
to others, so infected persons do not need to be isolated.
Q.
How quickly would someone become sick if he or she were exposed to tularemia
bacteria?
A. The incubation period (the time from being exposed
to becoming ill) for tularemia is typically 3 to 5 days, but can range
from 1 to 14 days.
Q.
What should someone do if he or she suspects exposure to tularemia bacteria?
A. If you suspect you were exposed to tularemia bacteria,
see a doctor quickly. Treatment with antibiotics for a period of 10-14
days or more after exposure may be recommended. If you are given antibiotics,
it is important to take them according to the instructions you receive.
All of the medication you are given must be taken.
Local and state health
departments should be notified immediately so an investigation and infection
control activities can begin.
Q.
How is tularemia diagnosed?
A. When a person has symptoms that appear related to
tularemia, the healthcare worker collects specimens, such as blood or
sputum, for testing in a diagnostic or reference laboratory. Laboratory
test results for tularemia may be presumptive or confirmatory. Presumptive
(preliminary) identification may take less than 2 hours, but confirmatory
testing will take more time, often 24 to 48 hours or longer depending
on the methods that need to be used.
Depending on the circumstances,
a person may be given treatment based on symptoms before the laboratory
results are returned.
Q.
Can tularemia be effectively treated with antibiotics?
A. Yes. Early antibiotic treatment is recommended whenever
it is likely a person was exposed to tularemia or has been diagnosed as
being infected with tularemia. Several types of antibiotics have been
effective in treating tularemia infections. The tetracycline class (such
as doxycycline) or fluoroquinolone class (such as ciprofloxacin) of antibiotics
are taken orally. Streptomycin or gentamicin are also effective against
tularemia, and are given by injection into a muscle or vein. Health officials
will test the bacteria in the early stages of the response to determine
which antibiotics will be most effective.
Q.
How long can Francisella tularensis exist in the environment?
A. Francisella tularensis can remain alive for weeks
in water and soil.
Q.
Is there a vaccine available for tularemia?
A. A vaccine for tularemia was used in the past to protect
laboratory workers, but it is not currently available.
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