Hantavirus pulmonary syndrome (HPS) is a deadly disease transmitted by infected rodents through urine, droppings, or saliva. Humans can contract the disease when they breathe in aerosolized virus. Rodent control in and around the home remains the primary strategy for preventing hantavirus infection.

What is hantavirus?

Hantaviruses are a family of several viruses found in rodents. These viruses havecaused serious human health problems in other parts of the world (mainly the FarEast, Scandinavia, and eastern Europe). In 1993, a new strain of hantavirus wasidentified as the cause of severe illnesses in the southwestern U.S. This new strainattacks the lungs and causes a condition called Hantavirus Pulmonary Syndrome.

How is hantavirus transmitted?

The virus is thought to be mainly carried by two common rodents: the white-footed mouse and the deer mouse. These mice are native to most of the U.S.,including Vermont. Infected rodents shed the virus in saliva, feces, and urine.Humans can become infected when they breathe in dust that contains the driedurine or feces from an infected rodent—or when fresh or dried materials contain-ing infected rodent feces come into direct contact with broken skin, or the eyes,nose or mouth.

The virus may also be spread by a bite from an infected rodent,but this type of spread is very rare. Insect bites and household pets are notthought to play a role in hantavirus transmission. In addition, squirrels, birds,hamsters, and rabbits are not known carriers of the hantavirus. There is noevidence of person-to-person transmission of the hantavirus in the U.S.

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What type of illness does hantavirus infection cause?

Typical cases of Hantavirus Pulmonary Syndrome begin with flu-like signs ofsickness (especially fever and muscle aches) one to six weeks after exposure,followed by difficulty breathing, which is caused by fluid build-up in the lungsand quickly progresses to an inability to breathe. Once this phase begins, thedisease progresses rapidly. About a third of people who have been diagnosed withthis disease in the U.S. since 1994 have died. However, there may have beenmany milder cases that were never diagnosed.

Can a person get hantavirus here in Vermont?

Although hantavirus infections are very rare in the U.S., it is possible to gethantavirus in Vermont. Very few cases of human infection from this virus havebeen reported east of the Mississippi River. However, it is a good idea to avoidcontact with rodents and their droppings, since the white-footed mouse and thedeer mouse, which are associated with hantavirus in other states, are native toVermont. (Guidelines for this are on the reverse.)

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Common-sense Guidelines for Decreasing Exposure to Rodents

There are a number of health reasons to avoid mice and their droppings. Hantavirus is carried by rodentssuch as white-footed mice and deer mice. These mice are native to most of the U.S., including Vermont.Simple measures that can be taken to decrease exposure to mice and mouse droppings are given below.

To clean houses or buildings with rodent droppings

To rodent-proof buildings

When camping or hiking in areas such as southwestern United States where mosthantavirus cases have been identified

There is no evidence to suggest that travel into affected areas should be restricted. However, anyone camping, hiking, or engaging in other outdoor activities should take precautions to avoid exposure.

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