Hantavirus: Are We at Risk?

The image shows a close-up view of various virus particles captured using electron microscopy.
Electron microscope  image of Sin Nombre virus (SNV) particles, or virions. SNV  is one  of  several types of hantavirus. Photo credit:  Brian W.J. Mahy, PhD; Luanne H. Elliott, M.S.

Although recent news about a hantavirus outbreak on a cruise ship has raised concerns about this disease, the risk from widespread infection in the U.S. is extremely low.

The infected passengers tested positive for the Andes strain of hantavirus.  The chances of getting infected by this strain in the U.S. are extremely low because:

  • this strain is present only in South America;
  • it is only carried  by rodents native to South America -  these rodent species are not found in the United States;
  • you must have close or long-term exposure to individuls  infected with this particular virus.

Hantavirus in California

There are different strains of hantavirus; the Sin Nombre virus (SNV),  is found in California. Fortunately, this virus is not highly contagious, does not spread from person to person and exposure to the virus is not likely to occur in urban and suburban environments.

The image features an illustration of a white-footed mouse, scientifically known as Peromyscus.
Deer mice are also known as white-footed mice. Drawing  courtesy of the CDC , by Dr.  Harold George Scott

The SNV strain is carried in small, wild rodents like deer mice and voles, which are common in rural and wilderness areas.  Structures like cabins, sheds and other outbuildings  located in these  areas can be infested by deer mice.  Other small rodents like squirrels, chipmunks, gophers, house mice and rats are not known to be a source of  SNV.

People get infected with SNV  by breathing in contaminated dust particles in areas soiled by rodent urine and droppings. You can avoid and greatly reduce the chance of  hantavirus infection when cleaning up rodent waste by taking some extra precautions. Click here to learn how to safely and properly clean up rodent droppings and waste.

A rustic, weathered wooden shed stands alone in a grassy field, surrounded by trees in the background.
When out in wilderness and rural areas, be very careful when  going inside old , unoccupied  structures, which can be infested by deer mice .  Photo credit: Pixabay

For more details  about hantavirus and deer mice in California, visit these websites:

  • University of California hantavirus webpage. (Note: for those of you who do not like  seeing mice, the home page features a very large photo of a deer mouse, so be prepared to see this image if you decide to go to this page.)
  • California Department of Public Health Vector-Borne Disease hantavirus page.

Detailed information on diseases in rodents, including SNV, can be found in Chapter 4  of this CDPH annual report (click on image to open it): 

The image features the cover of the 2024 annual report from the California Department of Public Health on vector-borne diseases.

 

 

A deer mouse, Peromyscus maniculatus. Photo credit: CDC
A deer mouse, Peromyscus  maniculatus.  About 13% of deer mice tested by CA Dept. of Public Health (CDPH) biologists between 2015 and 2024, had evidence of Sin Nombre virus. Photo credit: Centers for Disease Control