County's First 2025 Case Of Hantavirus Found In Mouse

SAN DIEGO, CA — County health officials Monday announced the first San Diego area detection of hantavirus in 2025.

A deer mouse collected Jan. 3 in Cuyamaca Rancho State Park near Julian tested positive for the potentially deadly virus, according to the county's Environmental Health and Quality Department.

Finding hantavirus in wild rodents is not uncommon in the county, health officials said. There were a total of 25 cases in 2024, and increase from 17 in 2023. However, people rarely come into direct contact with infected animals because wild rodents naturally avoid humans.

While exposure to hantavirus is rare, officials warned people should be careful around wild rodents because there is no cure or vaccine for hantavirus.

Symptoms of hantavirus usually develop between one to eight weeks after exposure. Symptoms include severe muscle aches; chills, fever or fatigue; headache or dizziness; nausea, vomiting or stomach pain; and difficulty breathing.

Anyone who thinks they may have been exposed to hantavirus should seek medical attention immediately, officials said.