Surveillance for Hantavirus and Plague
San Bruno Mountain

On March 21, the laboratory staff did an annual rodent survey for hantavirus at San Bruno Mountain County Open Space Preserve and State Park. Out of the 43 rodents collected, 5 were positive for hantavirus for an infection prevalence of 11.6%. Results for plague are still pending. The laboratory will schedule a follow-up survey for hantavirus at San Bruno Mountain in the summer and are on-schedule to complete our annual survey for rodent-borne diseases at Montara Mountain in May.

Hantavirus (also called Hantavirus Pulmonary Syndrome) is caused by the Sin Nombre virus which is carried in the urine and feces of small rodents. Early symptoms include high fever with aches, chills, dizziness, vomiting, and diarrhea. The lungs then fill with fluid causing shortness of breath and an intense tightening sensation across the chest. The disease can be fatal. Cases of hantavirus are sporadic and are usually associated with buildings or cabins with rodent infestations. When urine, feces or saliva containing the virus is stirred up into the air, either through sweeping or wind gusts, it may be inhaled causing disease.

To minimize contact with rodents and avoid hantavirus exposure, make sure to rodent-proof your home and seal away food sources that may tempt them to invade. If you are camping or staying in a region where hantavirus has been detected, look for evidence of rodents (including chew marks, holes, feces or urine markings) and avoid those areas.