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Hanta Virus

For the most current information, see the CDC webpage on Hantaviruses.


Hantaviruses are carried by rodents. One recently identified strain is present in a California species of deer mouse. This particular strain causes a severe respiratory illness that can be fatal.

To date, there have been only two cases of fatal hantavirus infection in California, one in Santa Barbara and another in Mono County. However, the rodent species that carries this potentially deadly virus is present at the SLAC site and throughout the State of California. This deer mouse species (Peromyscus maniculatis) has brownish-gray fur, a white stomach, and disproportionately large ears. Urine, droppings, and saliva from an infected mouse can all carry the virus.

To avoid any risk of contracting the hantavirus, use a hose spray or spray bottle of dilute water/bleach solution (5:1) to wet down any work areas where there is a generous infestation of mouse droppings. The droppings look like black, cooked rice grains. Then, wearing a dust mask and gloves, wipe the sprayed surface clean. You should dispose of dead mice by dampening the body with the spray solution, picking it up with gloves, and placing it into a plastic bag. Do not clear droppings or dead mice with a blower, vacuum, or hand broom!

Avoiding the aerosol or dust from these droppings is all you need to do to prevent infection. You cannot get this illness from another person.

If you are concerned or unclear about exposure to hantaviruses in your work area, call the ESH Division to help you check any areas before you begin work there.

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