San Diego County environmental health officials are keeping a close eye on Los Peñasquitos after a western harvest mouse trapped near the historic ranch house tested positive for hantavirus, marking the county’s first rodent detection of 2026. The virus is known to circulate in wild rodents, but county staff stress that human exposure is rare and that routine monitoring is in place.
Where the Positive Mouse Was Found
The county’s hantavirus activity log lists the western harvest mouse as testing positive last Thursday, the first confirmed rodent detection of the year, according to San Diego County Vector Control. The program routinely traps and tests wild mice, then posts any positive results on its current activity page so the public can track where the virus is turning up.
Symptoms and Risk to People
Hantavirus infection in people can start off looking a lot like the flu, typically one to eight weeks after exposure. Early symptoms may include severe muscle aches, fever, headache, dizziness and gastrointestinal upset. The illness can then progress quickly to serious breathing problems, and there is currently no specific cure or vaccine, according to the Centers for Disease Control and Prevention.
Local Reminders and Recent Findings
County staff are using this latest detection as a reminder to be cautious in dusty, enclosed spaces such as attics, sheds and garages, and to avoid stirring up rodent droppings, as reported by 10News. The outlet also noted the county’s count of 16 positive rodent tests in 2025, emphasizing that these findings reflect ongoing surveillance rather than a sign of widespread human danger.
How to Reduce Your Risk
If you find rodent nests or droppings, the county advises a wet-cleaning method, using a bleach or disinfectant solution and letting it soak the affected area for 15 to 20 minutes before wiping, instead of sweeping or vacuuming, according to San Diego County Vector Control. Officials also recommend wearing gloves and sealing all contaminated waste in plastic bags. Residents who have questions or want guidance can contact the county Department of Environmental Health at 858-694-2888 or email [email protected].
