GREAT FALLS — The Montana Department of Public Health & Human Services (DPHHS) has confirmed that a man from Richland County has been diagnosed with hantavirus infection. The man acquired the illness while working out of state where there was an occupational exposure to mice. The man was hospitalized but is now in the process of recovering at home.
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.
DPHHS and public health agencies encourage people to be aware of the risk of hantavirus and to take precautions to avoid exposures to rodents, their droppings, and their nests.
Falls Pest Control owner Craig Mertes said the best thing homeowners can do is inspect their home frequently for gaps in doors, windows, and walls. Gaps bigger than a quarter of an inch could be a problem.
"It's closing doors, not leaving doors (and) windows open all the time. other than that, they can find their way in. (They'll) gnaw, scratch. For the most part, if they want to get in they'll get in,” Mertes said.
Hantavirus infections are relatively rare in the U.S. 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 percent 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.
“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, epidemiologist for the DPHHS Public Health & Safety Division.
DPHHS says the best protection against hantavirus is to control rodent populations in 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 5 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.
From May 2019: