Hantavirus
June 2010
What is hantavirus?
Hantaviruses are a group of viruses that are carried by rodents. One of
them, Sin Nombre virus, is found in deer mice in North America.
Sin Nombre virus is the cause of Hantavirus Pulmonary Syndrome (HPS) in
people.
How are people exposed?
Deer mice excrete the virus in their urine, saliva, and droppings. A person
may be exposed to hantavirus by breathing contaminated dust after disturbing
or cleaning rodent droppings or nests, or by living or working in
rodent-infested settings.
Pets, snakes, and predators don’t become infected and can’t spread
hantavirus infection to people or other animals.
In
North America, there is no evidence that the disease spreads from one person
to another.
What are the symptoms of Hantavirus Pulmonary Syndrome?
Symptoms begin one to six weeks after inhaling the virus and typically start
with 3-5 days of "flu-like" illness including fever, sore muscles,
headaches, nausea, vomiting, and fatigue. As the disease gets worse, it
causes shortness of breath due to fluid filled lungs. Hospital care is
usually required. It is serious disease and about one out of three people
diagnosed with HPS have died.
Where is hantavirus found and how common is it?
The deer mouse (Peromyscus maniculatus) is the main carrier of
hantavirus in the western United States; however, all wild rodents should be
avoided. Deer mice live in all parts of Washington, but mainly in rural
areas. Deer mice pass the virus to each other and some of the population is
usually infected, but deer mice do not get sick or have any symptoms. In
Washington, about 14% of over 1,100 tested deer mice have been infected with
Sin Nombre virus.
Since infected deer mice live throughout the state, human cases of
hantavirus pulmonary syndrome can occur in any part of Washington. Typically
one to five cases are reported each year.
What does the deer mouse look like?
The deer mouse is about six inches long from the nose to the tip of its
tail. It is grayish to light brown on top, with large ears, a white belly,
and a furry tail that is white on the underside. There are many other types
of mice in Washington that don’t have those features.
How long does hantavirus remain infectious in the environment?
The length of time hantaviruses can remain infectious in the environment is
variable and depends on environmental conditions, such as temperature and
humidity, whether the virus is indoors or outdoors or exposed to the sun,
and even on the mouse’s diet (which would affect the chemistry of its
urine). The bottom line is that you can’t tell how old a dropping is, so all
rodent droppings should be handled as if they are infectious. Areas with
ongoing rodent infestation are particularly risky and the recommendations
for prevention should be followed.
How do I prevent Hantavirus pulmonary syndrome?
Keep rodents out of your home and workplace. Always take precautions when
cleaning, sealing and trapping rodent-infested areas.
Seal up cracks and gaps in
buildings that are
larger than 1/4 inch including window and door sills, under sinks around the
pipes, in foundations, attics and any rodent entry hole.
Trap indoor rats and mice with snap traps.
Remove rodent food sources. Keep food (including pet food) in rodent proof
containers.
Clean up rodent infested areas:
-
Wear rubber,
latex, vinyl or nitrile gloves.
-
Do not stir
up dust by vacuuming, sweeping, or any other means.
-
Thoroughly
wet contaminated areas including trapped mice, droppings, and nests with a
10% hypochlorite (bleach) solution: Mix 1½ cups of household bleach in 1
gallon of water (or 1 part bleach to 9 parts water). Once everything is
soaked for 10 minutes, remove all of the nest material, mice or droppings
with damp towel and then mop or sponge the area with bleach solution.
-
Steam clean
or shampoo upholstered furniture and carpets with evidence of rodent
exposure.
-
Spray dead
rodents with disinfectant and then double-bag along with all cleaning
materials. Bury, burn, or throw out rodent in appropriate waste disposal
system.
-
Disinfect
gloves with disinfectant or soap and water before taking them off.
-
After taking
off the clean gloves, thoroughly wash hands with soap and water (or use a
waterless alcohol-based hand rub when soap is not available).
For more details see the Centers for Disease Control and Prevention
recommendations at:
http://www.cdc.gov/rodents/cleaning/index.html.
What precautions should I use working, hiking, or camping outdoors?
- Avoid coming
into contact with rodents and rodent burrows or disturbing dens (such as pack
rat nests).
- Air out cabins
and shelters, then check for signs of rodent infestation. Do not sweep out
infested cabins. Instead, use the guidelines above for disinfecting cabins or
shelters before sleeping in them.
- Do not pitch
tents or place sleeping bags near rodent droppings or burrows.
- If possible, do
not sleep on the bare ground. Use tents with floors or a ground cloth.
- Keep food in
rodent-proof containers!
- Handle trash
according to site restrictions and keep it in rodent proof containers until
disposed of.
- Do not handle or
feed wild rodents.
What should I do if I think I have been exposed to mouse droppings?
If you
have been exposed to rodents or rodent infested buildings and have symptoms
of fever, muscle aches, and severe shortness of breath, see your health care
provider immediately. Inform your health care provider of possible rodent
exposure so that he/she is alerted to the possibility of rodent-borne
diseases, such as hantavirus pulmonary syndrome.
Where can I get more information about hantavirus or hantavirus pulmonary
syndrome?
Call
your local health department or the Washington State Department of Health
-
Zoonotic Disease program (360) 236-3385
- Communicable Disease Epidemiology Section (206) 418-5500, or toll
free (877) 539-4344
Visit
our website (http://www.doh.wa.gov/notify/nc/hantavirus.htm)or
the Centers for Disease Control and Prevention website (http://www.cdc.gov/ncidod/diseases/hanta/hps/index.htm).
Documents posted in .pdf version on the Department of Health Web site
will be made available in an alternative format on request to users who
are unable to download or view .pdf files on the Web.
To request an alternative
format, contact: Webmaster.
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