Mosquitoes carrying West Nile virus were found in Atherton on July 28, prompting the San Mateo County Mosquito and Vector Control District to schedule fogging to kill mosquitoes in parts of Atherton and Redwood City early Saturday morning, July 30.
Seven dead birds infected with West Nile virus had been found in the nearby area between July 6 and July 20.
“Given the number of infected birds and mosquitoes found in this area, it’s very important that we act quickly,” said Megan Caldwell, the district’s public health education and outreach officer. “We know the virus is circulating and there is an immediate risk of human infection.”
Brian Weber, the district’s assistant manager, said the district is “very concerned about the risk of human West Nile virus infection in this area.” Residents are strongly encouraged to avoid mosquito bites by wearing insect repellent or staying indoors around dusk and dawn.
While infected adult mosquitoes are capable of transmitting West Nile virus to humans, many of those infected show no symptoms, Ms. Caldwell said. Adults over age 50 are at higher risk of severe illness if infected.
The primary hosts of West Nile virus are birds, but humans, horses and other animals can get the disease if bitten by an infected mosquito. It cannot be spread from person to person.
District technicians will be in the area this week, finding and treating or eliminating any standing water to prevent more mosquitoes from hatching.
Mosquitoes will be collected in the area after the treatment is complete. If post-treatment mosquito samples are carrying West Nile virus, additional adult mosquito control treatments may be necessary, the district says.
Residents can report dead birds or squirrels, an early indication that West Nile virus is circulating in the environment, to the West Nile virus hotline, online at westnile.ca.gov or by phone at 877-WNV-BIRD (877-968-2473).
For more information or assistance with a mosquito problem, call the district at (650) 344-8592, Monday through Friday from 8 a.m. to 4:30 p.m. or check smcmvcd.org.
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