More West Nile Virus Detected in Knightsen, Martinez and Walnut Creek

Photo provided by Contra Costa Mosquito Vector Control
CONCORD, CALIFORNIA – – The Contra Costa Mosquito & Vector Control District is reporting two more dead birds, two more chickens, and another group of mosquitoes have tested positive for the virus.
The mosquitoes and one chicken were from an area near Knightsen and another chicken was from Martinez. The dead birds were collected from Martinez and Walnut Creek.
For a list of all 2017 West Nile virus activity and locations, visit the District’s website.
“The cooler weather is arriving, which is good news,” said Deborah Bass, public affairs manager. “That slows down mosquito production as well as the virus.” 
District personnel are conducting extra surveillance and mosquito control in the areas where virus activity was found.
Residents can reduce their risk of contracting mosquito-borne diseases by following these guidelines:
  • Dump or drain standing water. Mosquitoes can’t begin their lives without water.
  • Defend yourself – use repellents containing DEET, Picaridin, or Oil of Lemon Eucalyptus.
  • Avoid being outdoors when mosquitoes are present, typically dawn and dusk.
  • Maintain neglected swimming pools. Just one can produce more than 1 million mosquitoes and affect people up to five miles away.
  • Report dead birds to the state hotline: by visiting the California Department of Public Health’s website. All reports are crucial.

Mosquito Samples: 8

n Date Reported City Cross Streets Species
1 7/26/17 DIscovery Bay Point of TImber Rd. x Poe Dr. Culex pipiens
2 8/2/17 Byron Byron Hwy x Rankin Rd. Culex tarsalis
3 8/16/17 Antioch E. 18th St. x Hillcrest Ave. Culex tarsalis
4 8/21/17 Discovery Bay Cherry Hills Dr. x Hwy 4 Culex pipiens
5 8/23/17 Brentwood Continente Ave x Date Nut St. Culex pipiens
6 9/11/17 Oakley Oakley Rd. x Main St. Culex tarsalis
7 9/27/17 Knightsen Holland Tract Rd. x Tranquility Bay Rd. Culex tarsalis
8 10/2/17 Knightsen Holland Tract Rd. x Tranquility Bay Rd. Culex tarsalis

Dead Birds: 18

n Date Reported City Cross Streets Species
1 7/26/2017 Walnut Creek Ygnacio Valley Rd. x Wiget Ln. American Crow
2 7/26/2017 Walnut Creek Ygnacio Valley Rd. x Wiget Ln. American Crow
3 8/1/2017 Walnut Creek Ygnacio Valley Rd. x Wiget Ln. American Crow
4 8/3/2017 Danville Brookside Dr. x Greenbrook Dr. American Crow
5 8/8/2017 Discovery Bay Highway 4 x Discovery Bay Blvd. Western Scrub Jay
6 8/24/2017 Danville Camino Tassajara x Fairwood Ct. Western Scrub Jay
7 9/7/2017 San Ramon Davona Dr. x Calais Drive American Crow
8 9/8/2017 Brentwood Byron Hwy. x Delta Rd. American Crow
9 9/10/2017 Antioch Hillcrest Ave. x Via Dora Dr. American Crow
10 9/12/2017 Pleasant Hill Gregory Ln. x Contra Costa Blvd. American Crow
11 9/18/2017 Alamo Golden Meadow Ln. x Red Wing Dr. Western Scrub Jay
12 9/21/2017 Walnut Creek Arbolado Dr. x Doncaster Dr. American Crow
13 9/24/2017 Walnut Creek Norris Rd. x San Miguel Dr. American Crow
14 9/27/2017 Pleasant hill Viking Dr. x Norse Dr. American Crow
15 9/27/2017 Martinez Lester Rd. x Milden Rd. Western Scrub Jay
16 9/27/2017 Walnut Creek N. California Blvd. x Pringle Ave. Western Scrub Jay
17 10/1/2017 Walnut Creek Palmer Rd. x Rudgear Rd. American Crow
18 10/2/2017 Martinez Alhambra Valley Rd. x Chelsea Dr. American Crow

Sentinel Chicken Flocks: 2

Note: Chickens do not die from West Nile virus. They develop antibodies to the virus which is detected in their blood.

#/10 Date Bleed Area
4/10 8/7/17 Knightsen
1/10 9/18/17 Martinez
1/10 10/2/17 Knightsen
1/10 10/2/17 Martinez

Horses: 1

n Date Reported City Dead/Euthanized
1 8/11/2017 Brentwood No
Since 2005, 58 people in Contra Costa County have been diagnosed with West Nile virus. In 2006, two people died from the disease. For a current list of West Nile virus activity this year, visit this page on the District’s website.  For human case information, please contact Contra Costa Health Services at 888-959-9911.
Contra Costa Mosquito & Vector Control District, an independent special district and public health agency, is located at 155 Mason Circle in Concord. Call the District to report mosquito problems at (925) 771-6195 or visit the office between 8:00 a.m. and 4:30 p.m. to get FREE mosquitofish for ornamental ponds, horse troughs or neglected swimming pools.