DPHHS Confirms First Hantavirus Case For 2021

The Department of Public Health and Human Services (DPHHS) has confirmed that an adult male from Richland County has been diagnosed with hantavirus infection.

The individual acquired the illness while working out of state where there was an occupational exposure to mice. The individual was hospitalized but is now in the process of recovering at home.

DPHHS and local public health agencies remind Montanans and visitors to the state to be aware of the risk of hantavirus and to take precautions to avoid exposures to rodents, their droppings and nests. This is Montana’s first hantavirus case in 2021 and is the state’s 45th case since it was first identified in the state in 1993. Previously, the most recently reported case was in 2018.

“Although hantavirus infection can occur during any month, the risk of exposure is increased in the spring and summer as people are cleaning cabins and sheds, and are spending more time outside which may result in rodent exposures,” said Erika Baldry, DPHHS Public Health and Safety Division epidemiologist.

Hantavirus infections are relatively rare in the US and in Montana. Early symptoms of hantavirus include fatigue, fever and muscle aches with progression to coughing and extreme shortness of breath. Hantavirus infection can cause severe illness; about 25% of Montana’s cases have resulted in death. Supportive medical care is essential to survival and, if diagnosed early, can help victims through the period of severe respiratory distress.

Studies have shown that deer mice are the most common host of the virus and are well dispersed throughout Montana. People can become infected with hantavirus when saliva, urine, or droppings from an infected deer mouse are stirred up and inhaled. It is important to avoid activities that raise dust, such as sweeping or vacuuming, if there are signs of rodents in the area.

The best protection against hantavirus is to control rodent populations in the places where people live and work by taking these precautions:

• Seal Up: Prevent mouse entry into homes and sheds by sealing up holes and gaps in walls.

• Trap Up: Use snap traps to eliminate any mice indoors. Individuals can also reduce rodent populations near dwellings by keeping shrubbery near the home well-trimmed and moving woodpiles at least 100 feet from the dwelling and raising them at least one foot off the ground.

• Clean Up: Carefully clean up areas where mouse droppings are found.

• Avoid sweeping or vacuuming areas with rodent droppings and urine, as the action can stir up dust and aerosolize the droppings.

• If cleaning an area such as a cabin, camper or outbuilding, open windows and doors and air-out the space for 30 minutes prior to cleaning.

• Wear rubber or plastic gloves.

• Thoroughly spray or soak the area with a disinfectant or a mixture of bleach and water to reduce dust. Let soak for five minutes.

• Wipe up the droppings with a sponge or paper towel, then clean the entire area with disinfectant or bleach solution.

• When cleanup is complete, dispose of sponges and paper towels used to clean, remove and discard gloves and wash hands thoroughly with soap and warm water.

For those who think they have been exposed to hantavirus, monitoring for symptoms is vital. Anyone experiencing symptoms such as fever, muscle aches and shortness of breath after a potential rodent exposure, should see a medical provider immediately.

“Be sure to tell your doctor that you have been around rodents—this will alert your physician to look closely for any rodent-carried disease, such as hantavirus pulmonary syndrome,” Baldry advises.

For more information on hantavirus and prevention of disease, visit the DPHHS website at https://dphhs.mt.gov/.