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About Rabies
Rabies
is one of the oldest known deadly viral diseases, yet today it continues
to remain a significant public health issue.
Rabies affects the central nervous system of unvaccinated
animals, including humans, that are exposed to the virus and unless
treated is ultimately fatal.
Rabies is a preventable viral disease of mammals most often
transmitted through the bite of a rabid animal.
Over
the past 30 years, management of rabies in the United States has shifted
in focus from domestic pets being primary carriers to wild animals as
being the vector reservoirs (including: skunks, foxes, raccoons,
coyotes, bats). According
to the Centers for Disease Control and Prevention (www.cdc.gov),
wildlife currently account for at least 90 percent of all reported cases
of rabies in the country.
Rabies virus infects the central nervous
system, causing encephalopathy and ultimately death. Early symptoms of
rabies in humans are nonspecific, consisting of fever, headache, and
general malaise. As the disease progresses, neurological symptoms appear
and may include insomnia, anxiety, confusion, slight or partial
paralysis, excitation, hallucinations, agitation, hypersalivation,
difficulty swallowing, and hydrophobia (fear of water). Death usually
occurs within days of the onset of symptoms.
Because rabies is a fatal disease, the
goal of public health is, first, to prevent human exposure to rabies by
education and, second, to prevent the disease by anti-rabies treatment
if exposure occurs. Tens of thousands of people are successfully treated
each year after being bitten by an animal that may have rabies. A few
people die of rabies each year in the United States, usually because
they do not recognize the risk of rabies from the bite of a wild animal
and do not seek medical advice.
In Wyoming, the predominant types of
rabies for the terrestrial species (skunks and other mammals) is the
North Central Skunk Strain. Each species of bat carries their own
type of the virus, but the most identified strain is the Silver Haired
Bat virus.
Frequently Asked Questions
Pets
How can I protect my pet from rabies?
There are several things you
can do to protect your pet from rabies. First, visit your veterinarian
with your pet on a regular basis and keep rabies vaccinations up-to-date
for all cats, ferrets, and dogs. Second, maintain control of your pets
by keeping cats and ferrets indoors and keeping dogs under direct
supervision. Third, spay or neuter your pets to help reduce the number
of unwanted pets that may not be properly cared for or vaccinated
regularly. Lastly, call animal control to remove all stray animals from
your neighborhood since these animals may be unvaccinated or ill.
Why does my pet need the rabies
vaccine?
Although the majority of rabies cases occur in wildlife, most humans are
given rabies vaccine as a result of exposure to domestic animals. This
explains the tremendous cost of rabies prevention in domestic animals in
the United States. While wildlife are more likely to be rabid than are
domestic animals in the United States, the amount of human contact with
domestic animals greatly exceeds the amount of contact with wildlife.
Your pets and other domestic animals can be infected when they are
bitten by rabid wild animals. When "spillover" rabies occurs
in domestic animals, the risk to humans is increased. Pets are therefore
vaccinated by your veterinarian to prevent them from acquiring the
disease from wildlife, and thereby transmitting it to humans
What happens if a neighborhood
cat bites me?
You should seek medical evaluation for any animal bite. However, rabies
is uncommon in dogs, cats, and ferrets in the United States. Very few
bites by these animals carry a risk of rabies. If the cat (or dog or
ferret) appeared healthy at the time you were bitten, it can be confined
by its owner for 10 days and observed. No anti-rabies prophylaxis is
needed. No person in the United States has ever contracted rabies from a
dog, cat or ferret held in quarantine for 10 days.
If a dog, cat, or ferret appeared ill at
the time it bit you or becomes ill during the 10 day quarantine, it
should be evaluated by a veterinarian for signs of rabies and you should
seek medical advice about the need for anti-rabies prophylaxis.
The quarantine period is a precaution
against the remote possibility that an animal may appear healthy, but
actually be sick with rabies. To understand this statement, you have to
understand a few things about the pathogenesis of rabies (the way the
rabies virus affects the animal it infects). From numerous studies
conducted on rabid dogs, cats, and ferrets, we know that rabies virus
inoculated into a muscle travels from the site of the inoculation to the
brain by moving within nerves. The animal does not appear ill during
this time, which is called the incubation period and which may last for
weeks to months. A bite by the animal during the incubation period does
not carry a risk of rabies because the virus is not in saliva. Only late
in the disease, after the virus has reached the brain and multiplied
there to cause an encephalitis (or inflammation of the brain), does the
virus move from the brain to the salivary glands and saliva. Also at
this time, after the virus has multiplied in the brain, almost all
animals begin to show the first signs of rabies. Most of these signs are
obvious to even an untrained observer, but within a short period of
time, usually within 3 to 5 days, the virus has caused enough damage to
the brain that the animal begins to show unmistakable signs of rabies.
As an added precaution, the quarantine period is lengthened to 10 days.
For more information on recommendations
about biting incidences, quarantine, and postexposure prophylaxis (PEP),
see: Compendium
of Animal Rabies Control, 2000 and Rabies
Prevention - United States, 1999 Recommendations of the Immunization
Practices Advisory Committee (ACIP).
What happens if my
pet (cat, dog, ferret) is bitten by a wild animal?
Any animal bitten or
scratched by either a wild, carnivorous mammal or a bat that is not
available for testing should be regarded as having been exposed to
rabies. Unvaccinated dogs, cats, and ferrets exposed to a rabid animal
should be euthanized immediately. If the owner is unwilling to have this
done, the animal should be placed in strict isolation for 6 months and
vaccinated 1 month before being released. Animals with expired
vaccinations need to be evaluated on a case-by-case basis. Dogs and cats
that are currently vaccinated are kept under observation for 45 days.
For information on rabies in
domestic ferrets, see: Niezgoda, M., Briggs, D. J., Shaddock, J.,
Dreesen, D. W., & Rupprecht, C. E. (1997). Pathogenesis
of experimentally induced rabies in domestic ferrets. American
Journal of Veterinary Research, 58(11), 1327-1331.
I am moving to a rabies-free country
and want to take my pets with me. Where can I get more information?
The details of regulation about importing pets into rabies-free
countries vary by country. Check with the embassy of your destination
country.
Human
Rabies
How do people get rabies?
People usually get get rabies from the bite of a rabid animal. It is
also possible, but quite rare, that people may get rabies if infectious
material from a rabid animal, such as saliva, gets directly into their
eyes, nose, mouth, or a wound.
Can I get rabies in
any way other than an animal bite?
Non-bite exposures to rabies are very rare. Scratches, abrasions, open
wounds, or mucous membranes contaminated with saliva or other
potentially infectious material (such as brain tissue) from a rabid
animal constitute non-bite exposures. Occasionally reports of non-bite
exposure are such that postexposure prophylaxis is given.
Inhalation of aerosolized
rabies virus is also a potential non-bite route of exposure, but other
than laboratory workers, most people are unlikely to encounter an
aerosol of rabies virus.
Other contact, such as
petting a rabid animal or contact with the blood, urine or feces (e.g.,
guano) of a rabid animal, does not constitute an exposure and is not an
indication for prophylaxis.
How soon after an
exposure should I seek medical attention?
Medical assistance should be obtained as soon as possible after an
exposure. There have been no vaccine failures in the United States
(i.e., someone developed rabies) when postexposure prophylaxis (PEP) was
given promptly and appropriately after an exposure.
What medical
attention do I need if I am exposed to rabies?
One of the most effective methods to decrease the chances for infection
involves thorough washing of the wound with soap and water. Specific
medical attention for someone exposed to rabies is called postexposure
prophylaxis or PEP. In the United States, postexposure prophylaxis
consists of a regimen of one dose of immune globulin and five doses of
rabies vaccine over a 28-day period. Rabies immune globulin and the
first dose of rabies vaccine should be given by your health care
provider as soon as possible after exposure. Additional doses or rabies
vaccine should be given on days 3, 7, 14, and 28 after the first
vaccination. Current vaccines are relatively painless and are given in
your arm, like a flu or tetanus vaccine.
Will the rabies
vaccine make me sick?
Adverse reactions to rabies vaccine and immune globulin are not common.
Newer vaccines in use today cause fewer adverse reactions than
previously available vaccines. Mild, local reactions to the rabies
vaccine, such as pain, redness, swelling, or itching at the injection
site, have been reported. Rarely, symptoms such as headache, nausea,
abdominal pain, muscle aches, and dizziness have been reported.
Local pain and low-grade fever may follow injection of rabies immune
globulin.
What if I cannot get
rabies vaccine on the day I am supposed to get my next dose?
Consult with your doctor or state or local public health officials for
recommended times if there is going to be a change in the recommended
schedule of shots. Rabies prevention is a serious matter and changes
should not be made in the schedule of doses.
Can rabies be
transmitted from one person to another?
The only documented cases of rabies caused by human-to-human
transmission occurred among 8 recipients of transplanted corneas.
Investigations revealed each of the donors had died of an illness
compatible with or proven to be rabies. The 8 cases occurred in 5
countries: Thailand (2 cases), India (2 cases), Iran (2 cases) the
United States (1 case), and France (1 case). Stringent guidelines for
acceptance of donor corneas have reduced this risk
In addition to transmission from corneal transplants, bite and non-bite
exposures inflicted by infected humans could theoretically transmit
rabies, but no such cases have been documented. Casual contact, such as
touching a person with rabies or contact with non-infectious fluid or
tissue (urine, blood, feces) does not constitute an exposure and does
not require postexposure prophylaxis. In addition, contact with
someone who is receiving rabies vaccination does not constitute rabies
exposure and does not require postexposure prophylaxis.
For more information on
person-to-person transmission of rabies, see: Fekadu, M., Endeshaw, T.,
Alemu, W., Bogale, Y., Teshager, T., & Olson, J. G. (1996).
Possible human-to-human transmission of rabies in Ethiopia. Ethiopia
Medical Journal, 34, 123-127.
Wild
Animals
What animals get rabies?
Any mammal can get rabies. The most common wild
reservoirs of rabies are raccoons, skunks, bats, foxes, and coyotes.
Domestic mammals can also get rabies. Cats, cattle, and dogs are the
most frequently reported rabid domestic animals in the United States.
How can I find out
what animals have rabies in my area?
Each state collects specific information about rabies, and is the best
source for information on rabies in your area. In addition, the CDC
publishes rabies surveillance data every year for the United States. The
report, entitled Rabies
Surveillance in the United States, contains information about the
number of cases of rabies reported to CDC during the year, the animals
reported rabid, maps showing where cases were reported for wild and
domestic animals, and distribution maps showing outbreaks of rabies
associated with specific animals. A summary of the report can be found
in the Epidemiology
section of this web site.
What is the risk of
rabies from squirrels, mice, rats, and other rodents?
Small rodents (such as squirrels, rats, mice, hamsters, guinea pigs,
gerbils, and chipmunks, ) and lagomorphs (such as rabbits and hares) are
almost never found to be infected with rabies and have not been known to
cause rabies among humans in the United States. Bites by these
animals are usually not considered a risk of rabies unless the animal
was sick or behaving in any unusual manner and rabies is widespread in
your area. However, from 1985 through 1994, woodchucks accounted for 86%
of the 368 cases of rabies among rodents reported to CDC.
Woodchucks or groundhogs (Marmota monax) are the only rodents
that may be frequently submitted to state health department because of a
suspicion of rabies. In all cases involving rodents, the state or local
health department should be consulted before a decision is made to
initiate postexposure prophylaxis (PEP).
For more information about
rabies in rodents and lagomorphs, see: Childs, J. E., Colby, L., Krebs,
J. W., Strine, T., Feller, M., Noah, D., Drenzek, C., Smith, J.S., &
Rupprecht, C. E. (1997). Surveillance and spatiotemporal
associations of rabies in rodents and lagomorphs in the United States,
1985-1994. Journal of Wildlife Diseases, 33(1), 20-27.
Bats and Rabies
Do bats get rabies?
Yes. Bats are mammals and are susceptible to rabies, but most do not
have the disease. You cannot tell if a bat has rabies just by looking at
it; rabies can be confirmed only by having the animal tested in a
laboratory. To minimize the risk for rabies, it is best never to handle
any bat.
What should I do if
I come in contact with a bat?
If you are bitten by a bat -- or if infectious material (such as saliva)
from a bat gets into your eyes, nose, mouth, or a wound -- wash the
affected area thoroughly and get medical attention immediately. Whenever
possible, the bat should be captured and sent to a laboratory for rabies
testing.
People usually know when
they have been bitten by a bat. However, because bats have small teeth
which may leave marks that are not easily seen, there are situations in
which you should seek medical advice even in the absence of an obvious
bite wound. For example, if you awaken and find a bat in your room, see
a bat in the room of an unattended child, or see a bat near a mentally
impaired or intoxicated person, seek medical advice and have the bat
tested.
People cannot get rabies
just from seeing a bat in an attic, in a cave, or at a distance. In
addition, people cannot get rabies from having contact with bat guano
(feces), blood, or urine, or from touching a bat on its fur (even though
bats should never be handled!).
What should I do if
I find a bat in my home?
If you see a bat in your home and you are sure no human or pet exposure
has occurred, confine the bat to a room by closing all doors and windows
leading out of the room except those to the outside. The bat will
probably leave soon. If not, it can be caught, as described below, and
released outdoors away from people and pets.
However, if there is any
question of exposure, leave the bat alone and call animal control or a
wildlife conservation agency for assistance. If professional assistance
is unavailable, use precautions to capture the bat safely, as described
below.
What you will need:
leather work gloves (put them on)
small box or coffee can
piece of cardboard
tape
When the bat lands, approach it slowly and place a box or coffee can
over it. Slide the cardboard under the container to trap the bat inside.
Tape the cardboard to the container securely. Contact your health
department or animal control authority to make arrangements for rabies
testing.
How can I tell if a
bat has rabies?
Rabies can be confirmed only in a laboratory. However, any bat that is
active by day, is found in a place where bats are not usually seen (for
example in rooms in your home or on the lawn), or is unable to fly, is
far more likely than others to be rabid. Such bats are often the most
easily approached. Therefore, it is best never to handle any bat.
Travel
Should I be concerned about rabies when I travel outside the United
States?
Yes. Rabies and the rabies-like viruses can occur in animals anywhere in
the world. In most countries, the risk of rabies in an encounter with an
animal and the precautions necessary to prevent rabies are the same as
they are in the United States. When traveling, it is always prudent to
avoid approaching any wild or domestic animal.
The developing countries in
Africa, Asia, and Latin America have additional problems in that dog
rabies is common there and preventive treatment for human rabies may be
difficult to obtain. The importance of rabid dogs in these countries,
where tens of thousands of people die of the disease each year, cannot
be overstated. Unlike programs in developed countries, dog rabies
vaccination programs in developing countries have not always been
successful. Rates of postexposure prophylaxis in some developing
countries are about 10 times higher than in the United States, and rates
of human rabies are sometimes100 times higher. Before traveling
abroad, consult a health care provider, travel clinic, or health
department about your risk of exposure to rabies and how to handle an
exposure should it arise.
Should I receive
rabies preexposure vaccination before traveling to other countries?
In most countries, the risk of rabies and the precautions for
preventing rabies are the same as they are in the United States.
However, in some developing countries in Africa, Asia, and Latin
America, dog rabies may be common and preventive treatment for rabies
may be difficult to obtain. If you are traveling to a rabies-endemic
country, you should consult your health care provider about the
possibility of receiving preexposure vaccination against rabies.
Preexposure vaccination is suggested if:
-
Your planned activity
will bring you into contact with wild or domestic animals (for
example, biologists, veterinarians, or agriculture specialists
working with animals).
-
You will be visiting
remote areas where medical care is difficult to obtain or may be
delayed (for example, hiking through remote villages where dogs are
common).
-
Your stay is longer than
1 month in an area where dog rabies is common (the longer you stay,
the greater the chance of an encounter with an animal).
If I get preexposure
vaccination before I travel, am I protected if I am bitten?
No. Preexposure prophylaxis is given for several reasons. First,
although preexposure vaccination does not eliminate the need for
additional therapy after a rabies exposure, it simplifies therapy by
eliminating the need for human rabies immune globulin (HRIG) and
decreasing the number of doses needed – a point of particular
importance for persons at high risk of being exposed to rabies in areas
where immunizing products may not be readily available. Second, it may
protect persons whose postexposure therapy might be delayed. Finally, it
may provide partial protection to persons with inapparent exposures to
rabies.
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