West Nile virus confirmed in chickens at Holland Tract Marina
CONCORD, CALIFORNIA – – The Contra Costa Mosquito & Vector Control District confirmed today that the first two chickens have tested positive for West Nile virus this year in Contra Costa County. The chickens are located in Holland Tract near the marina.
“At this time last year, we had much more West Nile virus activity,” said Deborah Bass, public affairs manager for the District. “Nonetheless, the chickens are in a stationary location which indicates that virus transmission is taking place at that location, unlike the scenario with wild birds. Everyone needs to take the necessary precautions to avoid mosquito bites.”
Chickens serve as sentinels for West Nile virus. The chickens, unlike other birds, do not get sick or die from the disease but develop antibodies that are detected in their blood. District vector ecologists sample the chickens’ blood bi-weekly to determine if there is West Nile virus in a given area. Five flocks of chickens are maintained in Contra Costa County for this purpose.
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, 54 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 2015, a total of two groups of mosquitoes, one bird, and two chickens 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: 2
| n | Date Reported | City | Cross Streets | Species |
| 1 | 6/15/15 | Oakley | E. Summer Lakes Dr. x E. Cypress Rd. | Culex tarsalis |
| 2 | 6/15/15 | Oakley | Oakley Rd. x Main St. | Culex tarsalis |
Dead Birds: 1
| n | Date Reported | City | Cross Streets | Species |
| 1 | 7/14/15 | Oakley | Neroly Rd. x Oakley Rd. | American Crow |
Sentinel Chicken Flocks: 1
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 |
| 2/10 | 7/13/15 | Holland Tract |
