On November 14th, District staff, in conjunction with the
California Department of Public Health, trapped and tested
rodents for Sin Nombre hantavirus at San Pedro Valley County
Park. Staff set 100 traps and caught twenty six rodents in
them. Each rodent was anesthetized, then measured and
checked for parasites. Laboratory staff then drew blood for
the hantavirus antibody test. After recovering from
anesthesia, each rodent was carefully released at the exact
location where it was trapped. Staff tested a total of
twenty four mice. Test results showed that none of the
animals tested had antibodies to Sin Nombre Virus.
Sin Nombre Virus is the strain of hantavirus that causes Hantavirus Pulmonary Syndrome (HPS) in California. It is typically contracted through exposure to the dried urine of Peromyscus maniculatus (deer mice) in enclosed spaces. One to five weeks after exposure, an individual may experience flu-like symptoms, followed by nausea and vomiting, then difficulty breathing. Surveillance from 1975 to present day has shown a 7.5% infection rate of Peromyscus mice at trapping sites along the coast and at San Bruno Mountain in San Mateo County, but no human cases of HPS have been determined to be contracted within the county. Counties in California where exposure to Sin Nombre Virus is highest are Mono, Inyo, Mariposa, Tuolumne, Nevada and Kern Counties.