Hantavirus Surveillance
May 2018

The laboratory began yearly surveillance for hantavirus with a rodent survey at San Bruno Mountain on May 2-3. Peromyscus maniculatus (deer mice) were trapped and blood samples were taken for testing. The mouse carcasses will be tested by the California Department of Public Health (CDPH) and positive samples will be used for a study of the geographical distribution of different hantavirus strains in California.

Nineteen Peromyscus maniculatus were captured during the rodent survey. Of the nineteen, blood from four of the mice tested positive for hantavirus. The blood samples were tested at the CDPH laboratory. District laboratory staff and CDPH staff will conduct another rodent survey for hantavirus in early June in La Honda.

Hantavirus is usually contracted when a person inhales dried mouse urine or feces within a confined space that has been sealed and infested with deer mice. When first entering a building that might have deer mice within it, such as sheds or seasonal cabins in rural areas, open all doors and windows for at least 30 minutes. Before cleaning, wet down all surfaces with a bleach solution before mopping. Avoid using brooms or vacuums, which could blow particles into the air.