The first hantavirus case of 2025 in San Diego County was detected in a deer mouse captured on January 3 at Cuyamaca Rancho State Park, near Julian.

In 2024, 25 positive hantavirus cases were reported in rodents, marking an increase from the 17 cases reported in 2023.

Although it is rare for humans to come into direct contact with infected animals—since wild rodents typically avoid humans—health officials advise caution. There is no cure or vaccine for hantavirus. 

You might also be interested in its Spanish version: Detectan “Hantavirus” en el condado de San Diego

To minimize the risk of inhaling viral particles, authorities recommend avoiding rodent-infested areas and using wet cleaning methods when removing droppings or nests.

Hantavirus symptoms can appear between one and eight weeks after exposure and include severe muscle aches, chills, fever, fatigue, headache, dizziness, nausea, vomiting, abdominal pain, and difficulty breathing. Anyone suspecting exposure is urged to seek medical attention immediately.