West Nile Virus season is here.
While there have been no reported human cases of West Nile virus in San Mateo County, it's best to practice good prevention and fight the mosquito bite.
Although most people who become infected with the virus never develop any symptoms, some people may develop a more serious illness, such as meningitis or encephalitis. WNV is a seasonal epidemic in North America that flares up in the summer and continues into the fall.
West Nile virus in the U.S.
Since 1999, more than 30,000 people in the United States have been reported sick with West Nile virus, which is spread by infected mosquitoes.
In the U.S., there have been a total of nearly 700 human cases of West Nile virus disease this year, and 26 deaths related to the virus. This is the highest number of reported cases since West Nile virus was first detected in 1999. Most cases have been reported from six states, including California.
West Nile virus in California
In California, there have been 34 human cases of West Nile virus reported so far this year in 11 counties, including Butte (1 case), Fresno (5), Kern (6), Los Angeles (4), Merced (1), Orange (1), Sacramento (2), San Joaquin (2), Stanislaus (10), Sutter (1) and Ventura (1). One WNV-related death has been reported in Kern County. At this time last year, there were a total of 19 human cases reported in California.
There have been no reported human cases of West Nile virus in San Mateo County. So far this year, two dead birds have tested positive for being infected with the virus.
An additional seven animals (2 squirrels and 5 birds) tested positive for having what’s called a chronic WNV infection, which means it’s unlikely the animal was infected recently.
San Mateo County has a Mosquito Control Program
The San Mateo County Mosquito and Vector Control District is our County’s community-based mosquito control program: www.smcmad.org. A “vector” is an animal or insect that is capable of transmitting a disease to humans.
The Mosquito and Vector Control District uses different methods to help control the risk of disease in our County, including surveillance, prevention, and specific ways to control mosquitoes before they hatch.
To report a dead bird or squirrel visit the State’s reporting site
Vector Control does extra mosquito monitoring in neighborhoods where positive birds and squirrels are found. All mosquitoes that were trapped and tested in San Mateo County so far this year have tested negative for the virus.
Here’s what you can do to help control West Nile virus
Mosquitoes are most active at dusk and dawn so be sure to use insect repellent and try to wear long sleeves and pants during these times, or consider staying indoors.
Make sure you have good screens on your windows and doors to keep mosquitoes out.
Get rid of mosquito breeding areas by emptying standing water from anything that collects water, such as containers, flower pots, pet food and water dishes, swimming pool covers, buckets, etc. You can also report abandoned swimming pools by calling (650) 344-8592.
Report dead birds and squirrels by calling the West Nile virus hotline at 877-WNV-BIRD (877-968-2473) or online at www.westnile.ca.gov
For more details about West Nile virus, prevention, what insect repellents to use, and other important information, visit the Centers for Disease Control and Prevention (CDC) website at California West Nile Virus Website