West Nile Virus Statistics

WNV Activity From Mosquito Samples and Dead Birds

2015 Activity Summary

Case Breakdown 2015
Mosquito Samples 1
Dead Birds 0
Chickens 0
Humans* 0 (0**)

Page updated March 2015

*Number of people within GLACVCD jurisdiction. Get county-wide data at County of LA Public Health


Please click on the following links to jump down to the appropriate data:

2015 Monthly Mosquito Samples

2015 Monthly Dead Birds

2015 Monthly Chickens

Data from Previous Years

2015 Monthly Mosquito Samples

Mosquito Testing Disease surveillance is conducted to detect St. Louis encephalitis (SLE), Western equine encephalomyelitis (WEE) and West Nile virus (WNV) transmission within District boundaries. Initial surveillance begins by setting mosquito traps to collect adult mosquitoes for identification. Because they require a blood meal to produce eggs and are involved in the disease transmission cycle, only female mosquitoes are submitted for virus testing. Ten to 50 live anesthetized female mosquitoes are deposited into vials to comprise a mosquito pool. These pools are stored at minus 70 degrees Celsius and shipped to the University of Davis Arbovirus Research Unit (DARU) for testing. Nearly every community in the District's jurisdiction has at least one mosquito trap.

Samples recorded below are when they were reported and may not include all current data.

Monthly Data for 2015

City or Community Zip Code(s) Number of WNV+ mosquito samples collected
Sylmar 91342 1
Total: 1

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2015 Monthly Summary - Dead Birds

Dead Bird Surveillance Program Wild birds are the animals from which mosquitoes primarily acquire West Nile virus. Although many birds that are infected with WNV will not appear ill, WNV can cause serious illness and death in some birds. The most severe illnesses are seen among the corvids (including crows, jays, ravens, and magpies). Dead American Crows are the most commonly reported bird infected with WNV. If you find a bird that has recently died, particularly a crow or other corvid, please contact Westnile.ca.gov.

Numbers recorded below are when they were reported and may not include all current data.

Monthly 2015 Dead Birds

City or Community Zip Code(s) WNV+ dead bird
None reported

Total: 0

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2015 Monthly Summary - Chickens

Sentinel Chicken Testing The sentinel chicken flocks also serve as an early warning indicator system for detection of SLE, WEE, and WNV transmitted by mosquitoes that can potentially infect people and animals. Blood samples are taken bi-weekly from the sentinel chickens and analyzed by the state health department's Viral and Rickettsial Disease Lab to determine the presence of virus antibodies, indicating whether mosquitoes in the area have transmitted a virus. This early detection allows the opportunity to prevent the occurrence of human infections. The Vector Ecologists maintain seven chicken flocks throughout the District year-round.

Numbers recorded below are when they were reported and may not include all current data.

Monthly 2015 Chickens

City or Community Zip Code(s) WNV+ Chicken(s)
None reported

Total: 0

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Yearly Activity Summary

Case Breakdown 2008 2009 2010 2011 2012 2013 2014
Mosquito Samples 472 91 56 448 318 393 324
Dead Birds 259 38 31 159 70 75 30
Chickens 37 0 0 40 26 50 40
Humans* 83(15**) 8(1) 1 44 (2) 95 (2) 104 (5) 112 (8)

*Numbers indicate how many people tested positive for West Nile virus within GLACVCD. For Los Angeles County-wide numbers, please visit the County of Los Angeles Public Health website


Up-to-date West Nile virus statistics for all counties in California and additional information can be viewed at the CA Department of Public Health website. Just visit www.westnile.ca.gov.

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District Programs

There are a number of Mosquito Species and Mosquito-Borne Diseases known to occur within the Greater Los Angeles County Vector Control District.

Click here to learn more.