CONCORD, CALIFORNIA – The Contra Costa Mosquito & Vector Control District received reports of three more people testing positive for West Nile virus and is reporting another dead bird and mosquito sample as well.
“These people were most likely infected in August or September, with symptoms presenting themselves usually three to 14 days later. That, combined with doctor’s visits, a thorough investigation including travel history, testing and notification to the various agencies takes time and is why cases are announced at a later date,” said Steve Schutz, Ph.D., scientific program manager for the District. “Our District is notified by the local health department of locations where human infections may have occurred and we respond immediately, even before travel history is known, to conduct thorough surveillance and control, if needed, in those areas.”
The District works collaboratively with the health department due to the nature of vectors — animals or insects that transmit disease or cause discomfort to people. All questions concerning human cases should be directed to the state or local health department.
Other West Nile virus activity continues in Contra Costa County. The District reports today that another group of mosquitoes from an agricultural area east of Discovery Bay tested positive for West Nile virus as well as one dead bird from Alamo. All 2014 West Nile virus vector activity can be found on the District’s website.
According to the California West Nile Virus website, so far this year compared to the same time last year there are 488 human cases compared to 236 last year, 2275 dead birds compared to 1168 last year, 3139 mosquito samples compared to 2440 last year, and 382 chickens compared to 425 last year .
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, 52 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 five people, 23 groups of mosquitoes, 14 chickens and 43 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: 23
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 |
22 | 9/22/14 | Discovery Bay | Byron Tract NW | Culex tarsalis |
23 | 10/6/14 | Discovery Bay | Byron Tract NW | Culex pipiens |
Dead Birds: 43
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 |
40 | 9/21/14 | Danville | Camino Ramon x El Capitan Dr. | American Crow |
41 | 9/24/14 | Discovery Bay | Clubhouse Dr. x Edgeview Dr. | American Crow |
42 | 9/29/14 | Martinez | Glacier Dr. x Olympic Dr. | Western Scrub Jay |
43 | 10/8/14 | Alamo | Royal Oaks Dr. x Peake Pl. | American Crow |
Sentinel Chicken Flocks: 3 (14 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 |
1/10 | 9/22/14 | Holland Tract |
Horses: 0
n | Date Reported | City | Dead/Euthanized |