Health Officials Warn: Hantavirus Found Near Half Moon Bay

Hantavirus was recently discovered again in deer mice in San Mateo County, prompting public health officials to issue a warning this week.

According to the San Mateo County Mosquito and Vector Control District, this isn't the first case of the virus being found in local rodents– in fact, it's been found routinely in the county since the late 90s– but it does serve as a reminder to take certain precautions to expose your risk to the disease.

The most recent discovery was in samples collected in May and June in the area of San Bruno Mountain and Montara.

Wild rodents carry the virus and people most frequently contract the virus when they breathe in dust contaminated with the saliva, urine and droppings of infected rodents. Breathing the dust could occur when people are opening or cleaning previously vacant buildings.

In California, deer mice of the genus Peromyscus carry the virus. Rodents such as house mice, roof rats or Norway rats, which live near humans, do not.

“There has never been a human case of hantavirus acquired in San Mateo County,” District Manager Dr. Chindi Peavey said in a news release, “but we do know that hantavirus circulates at low levels in deer mouse populations in our county.”

Symptoms of the virus usually develop from one to eight weeks after exposure and early symptoms include fatigue, fever and muscle aches followed by a severe respiratory infection that often causes death. No cure, treatment or vaccine exists for the people who contract the virus.

Peavey said in her statement that the virus has been found routinely in San Mateo County since 1998.

Health officials want to remind residents and visitors to rural areas of the county to keep mice out of homes and structures by taking precautions like:

• Rodent-proof homes and other structures to keep mice out; clear vegetation and debris around homes that may provide habitat for rodents
• Take precautions when cleaning up after rodent infestations or entering structures that have not been entered recently; never sweep, vacuum, or breathe in dust in areas that may have been contaminated by rodents
• Avoid contact with rodents and their nests when hiking and camping, including when using cabins and trail shelters

– Bay City News Service contributed to this report. Image via San Mateo County Mosquito and Vector Control District.