CONCORD, CALIFORNIA – – The Contra Costa Mosquito & Vector Control District is targeting two types of mosquitoes in the eastern part of Contra Costa County. The first, a Culex mosquito, thrives in permanent or residential water sources and can transmit West Nile virus. The second, an Aedes mosquito, commonly known as a pasture mosquito, thrives in intermittent water sources such as coastal marshes and agricultural areas. The Aedes is not known to transmit the virus. The mosquitoes are just two types of 23 that inhabit Contra Costa County.
“Although the pasture mosquito is an extremely aggressive biter, it is not known to be a vector, a transmitter, of West Nile virus,” said Steve Schutz, Ph.D, scientific program manager for the District. “East county is home to duck clubs, agricultural areas, farms and ranches — it’s a very challenging area to maintain in terms of mosquito production where flooding occurs intermittently and often to us, unexpectedly. We are working to locate and treat the sources of mosquitoes as quickly as possible and fogging for adult mosquitoes when the number of mosquitoes trapped exceed thresholds.”
The District reports today (Friday) that a group of mosquitoes from Discovery Bay tested positive for West Nile virus as well as one bird from San Ramon. All 2014 West Nile virus activity can be found on the District’s website.
According to the California West Nile Virus website, so far this year there are 311 human cases compared to 150 last year, 2079 dead birds compared to 1067 last year, and 2853 mosquito samples compared to 2173 last year. Infected mosquitoes can infect people with the virus in just a single bite.
Residents are urged to help 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 against mosquitoes by using repellents containing DEET, Picaridin, or Oil of Lemon Eucalyptus.
- Avoid being outdoors when mosquitoes are present, typically dawn and dusk.
- Report neglected swimming pools by calling 925-771-6195 or visiting www.ContraCostaMosquito.com. Anonymous calls accepted. Just one neglected pool can produce more than 1 million mosquitoes and affect people up to five miles away.
- Report dead birds to the state hotline: 1-877-968-2473. All reports are crucial, even if the bird does not meet criteria for testing.
Since 2005, 48 people in Contra Costa County have been diagnosed with West Nile virus. In 2006, two people died from the disease. Recent studies have shown that the majority of cases are not diagnosed and are grossly underreported. For 2014, a total of 21 groups of mosquitoes, 13 chickens and 39 dead birds have tested positive for the virus.
Visit the District’s website or click on these links for current West Nile virus activity or to receive automatic emails for when the District fogs for adult mosquitoes.
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 their office between 8:00 a.m. and 4:30 p.m. to get FREE mosquitofish for ornamental ponds, horse troughs or neglected swimming pools.
Mosquito Samples: 21
n | Date Reported | City | Cross Streets | Species |
1 | 6/23/14 | Knightsen | Holland Tract Area | Culex tarsalis |
2 | 7/7/14 | Discovery Bay | Cherry Hills Drive | Culex pipiens |
3 | 7/7/14 | Martinez | I-680 x Waterfront Road | Culex tarsalis |
4 | 7/14/14 | Discovery Bay | Cherry Hills Drive x Marina Road | Culex pipiens |
5 | 7/16/14 | Discovery Bay | Bixler road x Balfour Road | Culex pipiens |
6 | 7/17/14 | Discovery Bay | Cherry Hills Drive x Wayfarer Drive | Culex tarsalis |
7 | 7/23/14 | Discovery Bay | Byron Tract Levee | Culex tarsalis |
8 | 8/6/14 | Discovery Bay | Point of Timber Road x Bixler Road | Culex pipiens |
9 | 8/12/14 | Discovery Bay | Highway 4 x Western Farms Ranch Road | Culex pipiens |
10 | 8/13/14 | Concord | David Avenue x Cayce Court | Culex tarsalis |
11 | 8/19/14 | Discovery Bay | Byron Tract SE | Culex pipiens |
12 | 8/19/14 | Discovery Bay | Byron Tract NW | Culex pipiens |
13 | 8/19/14 | Discovery Bay | Byron Tract NW | Culex tarsalis |
14 | 8/19/14 | Discovery Bay | Byron Tract NW | Culex tarsalis |
15 | 8/20/14 | Discovery Bay | Bixler Road x Point of Timber Road | Culex pipiens |
16 | 8/18/14 | Discovery Bay | Cherry Hills Drive | Culex pipiens |
17 | 8/25/14 | Discovery Bay | Byron Tract NW | Culex pipiens |
18 | 8/26/14 | Discovery Bay | Bixler Rd. x Point of Timber Rd. | Culex pipiens |
19 | 8/27/14 | Discovery Bay | Willow Lake Rd. x Beaver Ln. | Culex pipiens |
20 | 9/11/14 | Brentwood | Orwood Tract | Culex pipiens |
21 | 9/16/14 | Discovery Bay | Agricultural Area | Culex pipiens |
Dead Birds: 39
n | Date Reported | City | Cross Streets | Species |
1 | 4/23/14 | Alamo | Danville Blvd. x Camille Ave. | American Crow |
2 | 5/18/14 | Pleasant Hill | Monument Blvd. x Mohr Ln. | American Crow |
3 | 6/9/14 | San Ramon | Norris Canyon Rd. x Bollinger Canyon Rd. | American Crow |
4 | 614/14 | Oakley | Empire Ave. x Main St. | American Crow |
5 | 6/17/14 | Oakley | Empire Ave. x Hemlock Dr. | American Crow |
6 | 6/17/14 | Oakley | Empire Ave. x Hemlock Dr. | American Crow |
7 | 6/20/14 | Brentwood | Lone Tree Wy x O’Hara Ave. | American Crow |
8 | 6/25/14 | Antioch | Hillcrest Ave. x Sunset. Dr. | American Crow |
9 | 6/26/14 | San Ramon | Bollinger Canyon Rd. x Norris Canyon Rd. | American Crow |
10 | 7/2/14 | Bethel Island | Bethel Island Rd. x Gateway Rd. | American Crow |
11 | 7/9/14 | Walnut Creek | Arroyo Wy. x N. Broadway | American Crow |
12 | 7/10/14 | Oakley | Kay Ave. x O’Hara Ave. | Western Scrub Jay |
13 | 7/13/14 | Antioch | Camby Rd. x G St. | Western Scrub Jay |
14 | 7/14/14 | Brentwood | Foothill Dr. x Balfour Rd. | American Crow |
15 | 7/16/14 | Danville | Hartford Rd. x Danville Blvd. | American Crow |
16 | 7/17/14 | Antioch | Hargrove St. x E. 18th St. | American Crow |
17 | 7/17/14 | Brentwood | Minnesota Ave. x Windmeadows Dr. | Western Scrub Jay |
18 | 7/21/14 | Antioch | Judsonville Dr. x Hansen Dr. | Western Scrub Jay |
19 | 7/23/14 | Concord | Bancroft Rd. x Hookston Rd. | Western Scrub Jay |
20 | 7/29/14 | Pinole | Mann Drive X Appian Way | Western Scrub Jay |
21 | 8/6/14 | Concord | Ryan Road x Wilmore Avenue | American Crow |
22 | 8/6/14 | Alamo | Stone Valley Road x Roundhill Road | American Crow |
23 | 8/7/14 | Danville | Montcrest Place x Love Lane | Western Scrub Jay |
24 | 8/7/14 | Discovery Bay | Cherry Hills Dr. x Wayfarer Dr. | American Crow |
25 | 8/10/14 | Concord | David Ave. x Getoun Dr. | American Crow |
26 | 8/11/14 | Brentwood | Burghley Ln. x Centennial Dr. | American Crow |
27 | 8/20/14 | Concord | Treat Blvd. x San Simeon Dr. | American Crow |
28 | 8/21/14 | Walnut Creek | Oak Rd. x Jones Rd. | American Crow |
29 | 8/21/14 | Concord | Whitman Rd. x W Gilardy Dr. | American Crow |
30 | 8/27/14 | Walnut Creek | Bancroft Rd. x Treat Blvd. | American Crow |
31 | 8/28/14 | Danville | Harlan Dr. x St. Helena Dr. | American Crow |
32 | 9/2/14 | Walnut Creek | Walnut Ave. x Warwick Dr. | Western Scrub Jay |
33 | 9/2/14 | Oakley | Empire Ave. x Truman Ln. | American Crow |
34 | 9/2/14 | Brentwood | Forest View Common x Central Blvd. | American Crow |
35 | 9/4/14 | Brentwood | Payne Ave. x Walnut Blvd. | Western Scrub Jay |
36 | 9/8/14 | San Ramon | Broadmoor Dr. x Pine Valley Rd. | American Crow |
37 | 9/8/14 | Orinda | Altamount Dr. x Moraga Wy. | Stellar’s Jay |
38 | 9/12/14 | Danville | Verona Ave. x Love Ln. | American Crow |
39 | 9/15/14 | San Ramon | Ascot Dr. x Broadmoor Dr. | American Crow |
Sentinel Chicken Flocks: 3 (13 chickens)
Note: Chickens do not die from West Nile virus. They develop antibodies to the virus which is detected in their blood.
# of Chickens out of 10 (10 per Flock) | Date Bled | Area |
1/10 | 6/16/14 | Holland Tract |
3/10 | 6/30/14 | Holland Tract |
1/10 | 7/14/14 | Holland Tract |
1/10 | 7/14/14 | Oakley |
1/10 | 7/28/14 | Holland Tract |
1/10 | 8/11/14 | Holland Tract |
1/10 | 8/11/14 | Oakley |
3/10 | 8/11/14 | Walnut Creek |
1/10 | 8/25/14 | Walnut Creek |
Horses: 0
n | Date Reported | City | Dead/Euthanized |