Hantavirus is a disease spread by rodents that is similar to the flu.

Hantavirus has probably caused people to get sick for years in the United States, but it was not recognized until recently.

In 1993 there was an outbreak of fatal respiratory illness on an Indian reservation at the border of Utah, Colorado, New Mexico, and Arizona. Researchers discovered that hantavirus caused the epidemic. Since that discovery, hantavirus disease has been reported in every western state, and in many eastern states.

Hantavirus is carried by rodents, especially deer mice. The virus is in their urine and feces, but it does not make the carrier animal sick. Humans are thought to become infected when they are exposed to contaminated dust from mice nests or droppings.

The disease is not passed between humans. People may encounter contaminated dust when cleaning long-empty homes, sheds, or other enclosed areas.

The U.S. Centers for Disease Control and Prevention (CDC) reported that rodents carrying hantavirus have been found in at least twenty national parks. The CDC says it is possible that the virus is in all of the parks.

The CDC suspects that campers and hikers may be more likely to catch the disease than most people. This is because they pitch tents on the forest floor and lay their sleeping bags down in musty cabins.

So far, however, only a couple of cases have been directly linked to camping or hiking. Most people who are exposed to the virus have come in contact with rodent droppings in their own homes.

The early symptoms of hantavirus disease are flu-like (fever, chills, muscle aches). For a very short period of time, the infected person starts to feel better. Then, within 1 - 2 days, the person may develop shortness of breath. The disease gets worse quickly and leads to respiratory failure.

Other symptoms may include:

• Dry cough
• General ill feeling (malaise)
• Headache
• Nausea and vomiting
• Rapid shallow breathing

A doctor may notice signs of:

• Acute respiratory distress syndrome (ARDS)
• Decreased blood pressure (hypotension)
• Decreased levels of oxygen in the blood (hypoxia), causing the skin to have a bluish color (cyanosis)
• Kidney failure

Tests include:

• Complete blood count (CBC)
• Hematocrit
• Liver enzymes
• Platelet count
• Serological testing for hantavirus
• Serum albumin
• Serum chemistry
• X-ray of the chest

An effective treatment for hantavirus infection involving the lungs is not yet available.

Hantavirus hemorrhagic fever that involves the kidneys (with renal syndrome) does respond to treatment with ribavirin given through a vein (intravenously). This medication shortens the illness and reduces the risk of death.

Treatment must be given in the hospital. Often patients are admitted to an intensive care unit.

Oxygen therapy is used. Blood gases are closely monitored. Severe cases will need respiratory support with a breathing tube (endotracheal tube) and ventilator.

Hantavirus is a serious infection. Even with aggressive treatment, more than half of the cases are fatal.

• Cardiorespiratory failure
• Death
• Kidney failure

Call your health care provider if you develop flu-like symptoms after being exposed to mouse urine or feces (excreta), or dust that may have been contaminated with mouse excreta.

Avoid exposure to rodent urine and feces.

• When hiking and camping, pitch tents in areas where there are no rodent droppings.
• Avoid rodent dens.
• Drink disinfected water.
• Sleep on a ground cover and pad.
• Keep your home clean. Clear out potential nesting sites and clean your kitchen.

If you must work in an area where contact with rodent urine and feces is possible, follow these recommendations from the Centers for Disease Control and Prevention (CDC):

1. When opening an unused cabin, shed, or other building, open all the doors and windows, leave the building, and allow the space to air out for 30 minutes.
2. Return to the building and spray the surfaces, carpet, and other areas with a disinfectant. Leave the building for another 30 minutes.
3. Spray mouse nests and droppings with a 10% solution of chlorine bleach or similar disinfectant. Allow it to sit for 30 minutes. Using rubber gloves, place the materials in plastic bags. Seal the bags and throw them in the trash or an incinerator. Dispose of gloves and cleaning materials in the same way.
4. Wash all potentially contaminated hard surfaces with a bleach or disinfectant solution. Avoid vacuuming until the area has been thoroughly decontaminated. Then, vacuum the first few times with enough ventilation. Surgical masks may provide some protection.

Bell M. Viral hemorrhagic fevers. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier;2007:chap 404.