This month: tick-borne disease surveillance results, plans for the District centennial in 2016, water conservation at the District, and more.
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District News

  • The District has received a generous donation of photographs, publications, apparel, and other historical materials. These materials will be part of an upcoming historical display celebrating the District's centennial. Read more about the District's history.
  • On April 20th, the District detected West Nile virus in an American crow collected from The Willows neighborhood of Menlo Park. This was the first indication of West Nile virus in the county in 2015. Subsequent disease surveillance found no indication of the virus in adult mosquitoes in the area. Read more.
  • In April, two seasonal Vector Control Aides joined the District Staff. Juan and Walter will assist with catch basin treatments and invasive mosquito surveillance this summer.
  • On April 17th, District brochures were distributed to more than 16,000 households throughout the county as part of the Silver Dragon VII Emergency Drill. The District donated breakfast and lunch to participating CERT volunteers in Brisbane. Read more.
  • Laboratory staff detected invasive Aedes aegypti mosquito larvae at two more locations in Menlo Park in April. As of April 30th, this invasive mosquito has been detected at four locations in the immediate vicinity of Holy Cross Cemetery, where it was first discovered in 2014. Read more.
  • Three flocks of sentinel chickens were set up for the 2015 West Nile Virus season. The flocks are located in Woodside, San Mateo and East Palo Alto. Read more.
The District asks residents to report dead birds or tree squirrels at or by call 877-WNV-BIRD. Specimens that appear to have been dead for less than 24 hours and are in good condition will be tested for West Nile Virus.

Invasive Mosquitoes in San Mateo County

So far in 2015, Aedes aegypti has been detected six times in San Mateo County. Five of these detections were in the larval stages; one was an egg found in a District mosquito surveillance trap.  All detections remain in the neighborhood surrounding Holy Cross Cemetery in Menlo Park.

The District has intensified surveillance of Aedes aegypti for the warmer season during the month of April.  Laboratory staff have placed 30 ovicup traps in the area of Menlo Park surrounding the Aedes aegypti infestation, which are checked weekly for eggs.   A team of seasonal employees is conducting house to house inspections for mosquito breeding.  In the upcoming month, further expansion of the surveillance will include an increase in AGO traps in the area and additional ovicups at cemeteries and nurseries throughout the county to detect Aedes aegypti and other invasive mosquito species.

For more information about invasive Aedes aegypti mosquitoes in San Mateo County, visit our Invasive Mosquitoes information page.

Tick Surveillance Results for 2014/2015

Tick testing has been completed for the 2014-2015 tick season.  Ixodes pacificus (western black-legged ticks) were tested in house using RT-PCR for the presence of two bacteria, Borrelia burgdorferi, which can cause Lyme disease, and Borrelia miyamotoi, which can cause a type of tick-borne relapsing fever.  Ticks were collected from ten parks within San Mateo County.  The percent of infected ticks was variable among the parks, and ranged from 0 to 2 percent for each Borrelia species.  The results are summarized in the table below.

Celebrating the District's History

Did you know that San Mateo County Mosquito and Vector Control District has one of the oldest mosquito control programs in the US?

In 2016, the District will be celebrating its 100th year of providing mosquito and vector control services to the residents of San Mateo County. Plans are already underway to celebrate the District's centennial with an exhibit of historical materials, a community open house, and other events throughout the year.


In a photo from the 1980s, technicians and administrative staff pose outside the District office.

West Nile Virus Surveillance Update

In San Mateo County:

As of May 1,160 dead birds have been reported in San Mateo County in 2015. Of those, 43 have been suitable for testing and 1 has tested positive (2%) for West Nile Virus (WNV). Additionally, one dead squirrel has been sent to California Animal Health & Food Safety Laboratory for testing and results are pending. No mosquito pools in San Mateo County have tested positive for WNV

The district asks residents to call in to report dead birds or tree squirrels. Specimens that appear to have been dead for less than 24 hours and are in good condition will be tested for WNV. Residents should contact the state WNV hotline at 877-WNV-BIRD (968-2473). Reports can also be made online at

In California:

WNV has been detected in eight counties in 2015, compared to a five year average of 4 counties at this date. Statewide, 2,276 birds have been reported and 295 have been tested with 9 positive results (3%). Five mosquito pools from four counties throughout the state have been positive for WNV. No positive sentinel chickens or human cases of WNV have yet been reported. The most recent version of this map is available at

Conserving Water at the District

California is currently experiencing one of the worst droughts on record, and has been in a state of emergency since January, 2015. Here at the District, water conservation is always on our minds.

When taking steps to reduce water consumption, residents should remember to take mosquitoes into consideration. All rainbarrels and storm water collection systems should be screened or tightly covered to keep mosquitoes out. If pools are no longer maintained, they must be stocked with fish or treated for mosquito larvae. 

Residents who are concerned about water conservation should also check for leaks under their homes. Small leaks can waste gallons of water each day as well as creating standing water where mosquitoes can breed. A District technician can assist with inspecting for leaks, and can provide suggestions for conserving water without creating mosquito problems.

Read more about preventing mosquito problems around your home.

District Financial Information
for March 2015

Visit our Financial Information page for the latest District financial information, including the Consolidated Funds and Profit and Loss as of March 31st, 2015.

Mosquito Surveillance and Control Data for March 2015

Visit our Mosquito Surveillance and Control Updates page to get the latest data from our mosquito surveillance and control program.

Snapshots from the Field

The San Mateo sentinel flock settles into their new coop. These ten chickens, along with two other sentinel flocks, will provide blood samples for West Nile virus surveillance bi-weekly through the end of October. Read more.
District Manager Chindi Peavey receives the West Nile Virus and Mosquito and Vector Control Awareness Week 2015 proclamation from the City of San Bruno. West Nile Virus and Mosquito and Vector Control Awareness Week was April 19th through 25th. Read more.
San Mateo County Mosquito and Vector Control District
Protecting public health since 1916

1351 Rollins Rd. | Burlingame CA 94041
(650) 344—8592 |

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