Hantavirus Facts and Prevention Tips

Quick Tips #325

Hantavirus Pulmonary Syndrome (HPS), also known as the Hantavirus, is considered by the Centers for Disease Control and Prevention (CDC) to be a health risk to the general public. Hantavirus has been recognized as a disease since 1993 when the four corner states (Arizona, Colorado, New Mexico and Utah) experienced a sudden outbreak of the virus.

The first reports of the, then unknown, virus involved deaths from acute respiratory failure involving seemingly healthy individuals. Within weeks of these reports, area medical investigators and virologists were able to link the pulmonary syndrome to a virus that was carried by rodents. Researchers then began to examine stored lung tissue from people in the area who died from unexplained lung diseases. They found evidence of infection from the Hantavirus as early as 1959 indicating the virus existed, unrecognized, for several decades.

How the Virus is Transmitted

The initial outbreak in the four corner states was caused by a 1993 increase of rainfall in the area. The resulting spike in crop production meant more food for rodents. The CDC estimates the rodent population increased 10 times over the prior year. This spike in population led to increased rodent contact with people.

In the U.S., the deer mouse is the leading carrier of the Hantavirus. Other rodents such as the white-footed mouse in New York, cotton rats in Florida and rice rats in Louisiana have also been identified as carriers. The Hantavirus is transmitted by breathing in dust or eating food that is contaminated by rodent droppings, urine or saliva. Although it's rare, the virus can also be transmitted by a bite. The Hantavirus cannot be transmitted from person-to-person, from farm animal or pet-to-person (including dog, cat, gerbil, hamster or guinea pig) contact. A person cannot receive the virus through blood transfusion from someone who has been diagnosed with the virus and survived.

Occupations such as construction, utility, agricultural, pest-control workers, grain farmers and livestock specialists are more susceptible to contracting the Hantavirus. However, anyone who comes in contact with a rodent is at risk. Through December 2011, there were 587 confirmed cases of the Hantavirus in the U.S. This map from the CDC shows the breakdown for each state (June 29, 2012):

Symptoms and Treatment

The average time someone may show symptoms of the virus is two to three weeks after contact with a carrier. The Hantavirus can incubate for up to 6 weeks or present itself as early as four days from time of exposure. Symptoms include fever, muscle aches, headache, coughing, nausea, vomiting, diarrhea and severe shortness of breath. Because most of these symptoms resemble those of the common flu, it can be difficult to determine whether a person has Hantavirus. It's vital that an individual with symptoms (especially severe shortness of breath) following exposure to a potential carrier let his/her physician know to test for rodent-carried diseases.

Although the risk of being infected by the Hantavirus is very low it can be deadly. According to the CDC, more than half of those infected have died from the virus, mainly due to pulmonary edema (also known as fluid in the lungs). Currently there is no vaccine or cure for the Hantavirus. Treatment usually consists of oxygen therapy and medication to reduce fever and pain. The sooner the virus is detected the better the chances a patient has for survival.

Prevention, Personal Protection and Cleaning

The first step in preventing the Hantavirus is eliminating the rodent population. Just like any wildlife, rodents live where they have access to water, food and shelter. To help control the rodent population

  1. Seal up all possible points of entry, inside and outside your home or facility using patching materials.
  2. Store all food, including animal feed, in containers with lids.
  3. Don’t leave animal food out for more than one day if uneaten.
  4. Keep a lid on all garbage containers.
  5. Clear brush, wood piles, hay and any other garbage at least 100 feet from your home or building. These act as great nesting materials for rodents.
  6. Place traps along baseboards where most rodent traffic takes place.
  7. Poisons can be used but with caution especially around children and pets.
  8. Clean counters and floors regularly to reduce food droppings that attract rodents.
Photo of spray down of nesting and droppings prior to collection courtesy of the CDC.

Before entering a potentially rodent-inhabited location for cleaning or performing work, you should wear the appropriate protective equipment. For protection against the Hantavirus, you should wear a respirator with at least a P100 rating, disposable coveralls, gloves and shoe covers that are rated for resistance to the cleaning solution being used. For locations that have been closed off for a month or more (such as a cabin or work shed) you should ventilate the area for at least 30 minutes before entry to reduce the amount of potentially contaminated dust prior to cleaning. Personal protective equipment should be worn prior to ventilating an area. Once ventilation is complete, you can focus on cleaning the rodent-inhabited area. When cleaning, do not sweep or vacuum rodent nesting materials or droppings. This will cause contaminated dust to become airborne. You will want to saturate the materials using either a detergent or bleach water mixture (1-1/2 cups of bleach for every gallon of water) to deactivate the virus. Then use a damp towel to collect the materials. Once all of the solid materials are gathered, you should disinfect the surface using the same solution. Dispose of all materials collected and used for cleaning by double-bagging then burying or burning them. If there is a large amount of materials to dispose of, contact your local health department for guidance.

For more information on the Hantavirus, visit the CDC online at


(Rev. 1/2012)



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