A deer mouse found in Cuyamaca Rancho State Park has tested positive for hantavirus.
The mouse, which was discovered on Jan. 3, 2025, is the first local case of the year.
Hantavirus is common in wild rodents, and deer mice are the main carriers of the virus in San Diego County. While people rarely come into contact with wild rodents, it is important to take basic precautions. There is no cure or vaccine for hantavirus, and it is potentially deadly in humans.
Symptoms of hantavirus include:
- Severe muscle aches
- Chills, fever or fatigue
- Headache or dizziness
- Nausea, vomiting or stomach pain
- Difficulty breathing
Symptoms develop between one and eight weeks after exposure. Seek medical attention immediately if you think that you have been exposed.
People may be exposed to hantavirus if wild rodents invade their living area. Infected rodents spread the virus through their urine, feces, and saliva. This can be stirred into the air where people can potentially inhale the virus.
If people find wild rodents or signs of them in their living spaces, they should use “wet cleaning” methods such as bleach or other disinfectants, rubber gloves and bags. They should not sweep or vacuum, which could stir hantavirus into the air where it could be inhaled.
Other ways to avoid exposure:
- Seal up all external holes in homes, garages, and shed larger than a dime to prevent rodents from getting in.
- Eliminate rodent infestations immediately.
- Avoid rodent-infested areas and do not stir up dust or materials that may be contaminated with rodent poop and urine.
- Clean up rodent poop and urine using the “wet cleaning” methods.
There were 25 cases in total last year in San Diego.
