old shedHantavirus pulmonary syndrome (HPS) is a life-threatening disease caused by the Sin Nombre virus. It is spread by:

  • Inhaling airborne particles of urine, droppings, and saliva from infected rodents spreads
  • Handling infected rodents, their nests, or droppings and then touching the mouth, nose, or eyes.

Symptoms develop within one to five weeks and are flu-like, including:

  • Fever
  • Headache
  • Shortness of breath
  • Coughing
  • Vomiting
  • Stomach pain

As hantavirus progresses, respiratory failure may occur. If you may have been exposed to deer mice and become sick, seek medical attention immediately. Be sure to let your health care provider know where you have been and what you were doing.

What activities increase risk of exposure?

Exposure to the Sin Nombre virus may occur when entering or cleaning buildings that have been closed for a long period of time, including hunting shacks, garages, storage sheds, or anywhere with deer mouse droppings.

How do you recognize an infected rodent?

In Oregon, Sin Nombre virus is primarily carried by deer mice (Peromyscus maniculatis). Deer mice are recognized by their large eyes and ears and a bi-colored tail. However, because it is extremely difficult to tell the kind of mouse it is as it runs across the floor, and it is nearly impossible to distinguish an infected mouse from one that is not, it is best to consider all mice infected.

Preventing Hantavirus

The best way to protect yourself from hantavirus pulmonary syndrome is to control rodents in and around your home. You can reduce your risk by following these tips:

  • Keep your home clean – Clean up spilled food and keep stored food in sealed containers. Remove trash regularly.
  • Keep rodents out – A mouse can fit through a hole the size of a dime. Seal off any opening into your home.
  • Keep rodents away – Reduce shelter and food sources within 100 feet of your home. For example, keep grass and shrubs cut and thinned, and keep woodpiles elevated 18 inches off the ground and away from your house.

How to clean up after a rodent infestation

  • Never dry sweep or vacuum a rodent-infested area. Always use wet cleaning methods.
  • While cleaning, wear long sleeves, rubber gloves, and a dust mask. This will protect you from contamination and stop you from rubbing your face while you clean.
  • Use a 10% bleach and water solution or household disinfectant such as Lysol to disinfect infested and contaminated areas. Liberally soak the contaminated area and allow the disinfectant to remain for at least 20 minutes.
  • Use the “Wash Twice” rule. After cleaning, wash the gloves in hot soapy water before removing. Then wash your hands after removing the gloves. Launder clothes normally.
  • Dispose of dead rodents by disinfecting, as stated above. Then use a tool to pick up the carcass and triple bag it.

Helpful Documents

Hantavirus Brochure (573.9 KB)


Contact Us

Multnomah County Vector Control
5235 N Columbia Blvd
Portland, Oregon
503.988.3464