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West Nile Virus Activity


The Oregon Health Authority, Public Health Division works with local health departments, mosquito control districts and other agencies to detect and test for the presence of West Nile virus. Health care providers, veterinarians and diagnostic laboratories take part in surveillance efforts.

2021 Data

Oregon Cases

2020 map
2021

Number Positive

Humans0
Sentinel Chickens0
Birds2
Mosquitoes (pools)
49
Horses1
Squirrel0
Dogs0
As of Sept 2, 2021
U.S. West Nile cases by state - CDC website

Data from Previous Years

2020 map
Cases by county (pdf)

20​20

Number Positive

Humans0
Sentinel Chickens0
Birds1
Mosquitoes (pools)3
Horses0​
Squirrel0
Dogs0
As of October 2020​

U.S. West Nile cases by state - CDC website

2019 map
Cases by county (pdf)

20​19

Number Positive

Humans9*
Sentinel Chickens0
Birds0
Mosquitoes (pools)85
Horses7
Squirrel0
Dogs0
As of October 2019
*1 case acquired out-of-state
U.S. West Nile cases by state - CDC website

2018 map
Cases by county (pdf)

2018

Number Positive

Humans2
Sentinel Chickens0
Birds1
Mosquitoes (pools)57
Horses2
Squirrel0
Dogs0
As of Oct. 2018
U.S. West Nile cases by state - CDC website

2017 map
Cases by county (pdf)

2017

Number Positive

Humans6
Sentinel Chickens0
Birds1
Mosquitoes (pools)92
Horses5
Squirrel0
Dogs0
As of Dec. 2017
U.S. West Nile cases by state - CDC website

2016 map
Cases by county (pdf)

2016

Number Positive

Humans4
Sentinel Chickens0
Birds12
Mosquitoes (pools)51
Horses6
Squirrel0
Dogs0
As of Nov. 22, 2016
U.S. West Nile cases by state - CDC website

2015 map
Cases by county (pdf)

2015

Number Positive

Humans1
Sentinel Chickens0
Birds11
Mosquitoes (pools)59
Horses6
Squirrel0
Dogs0
As of Dec 31, 2015
U.S. West Nile cases by state 2015 - CDC website

2014 map
Cases by county (pdf)

2014

Number Positive

Humans8
Sentinel Chickens0
Birds7
Mosquitoes (pools)58
Horses3
Squirrel0
Dogs0
As of Oct. 29, 2014

U.S. West Nile cases by state
2014
- CDC website


2013 map
Cases by county (pdf)

2013

Number Positive
* 1 acquired out of state

Humans17*
Sentinel Chickens0
Birds2
Mosquitoes (pools)

89

Horses6
Squirrel0
Dogs0
As of Dec 30, 2013
U.S. West Nile cases by state
2013
- CDC website

2012 map
Cases by county (pdf)

2012

Number Positive

Humans12
Sentinel Chickens0
Birds2
Mosquitoes (pools)71
Horses2
Squirrel0
Dogs0
As of Nov. 1, 2012
U.S. West Nile cases by state
2012
- CDC website

2011 map
Cases by county (pdf)

2011

Number Positive

Humans0
Sentinel Chickens0
Birds0
Mosquitoes (pools)3
Horses2
Squirrel0
Dogs0
As of December 30, 2011
U.S. West Nile cases by state
2011
- CDC website

2010 map
Cases by county (pdf)
 

2010

Number Positive

Humans0
Sentinel Chickens0
Birds0
Mosquitoes (pools)4
Horses0
Squirrel0
Dogs0
As of December 31, 2010
U.S. West Nile cases by state
2010
- CDC website

2009 map
Cases by county (pdf)

2009

Number Positive

Humans12
Sentinel Chickens0
Birds16
Mosquitoes (pools)266
Horses5
Squirrel0
Dogs1
As of December 29, 2009
U.S. West Nile cases by state
2009
- CDC website

2008 map
Cases by county (pdf)

2008

Number Positive

Humans16
Sentinel Chickens0
Birds2
Mosquitoes (pools)16
Horses0
Squirrel0
Dogs0
As of October 17, 2008
U.S. West Nile cases by state
2008
- CDC website

2007 map
Cases by county (pdf)

2007

Number Positive

Humans27
Sentinel Chickens11
Corvids52
Sage Grouse0
Mosquitoes (pools)32
Horses16
Squirrel1
Dogs2
As of November 9, 2007
U.S. West Nile cases by state
2007
- CDC website

2006 map
Cases by county (pdf)

2006

Number Positive

Humans73
Sentinel Chickens0
Birds25
Mosquitoes 1100
Horses35
As of November 21, 2006
U.S. West Nile cases by state
2006
- CDC website

2005 map
Cases by county (pdf)

2005

Number Positive

Humans8
Sentinel Chickens17
Birds (Corvids)15
Mosquitoes (pools)11
Horses46
As of October 14, 2005
U.S. West Nile cases by state
2005
- CDC website
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Suspect Cases

If you find a sick or dead bird

Birds are a natural host for West Nile virus; in Oregon particularly crows, ravens, jays, magpies, and sage grouse. A large or continuous die-off of birds may be a local indicator of WNV activity.

Contact one of the following Oregon agencies for collection and testing for West Nile virus surveillance:


If you suspect a horse has WNV infection

Veterinarians are required to report horses with the appropriate clinical signs. Refer to West Nile Virus testing for further information and contact the Oregon Dept. of Agriculture at 503-986-4760 before submitting horse samples.


Other animals

Any other animal suspected of having West Nile virus or other viruses carried by mosquitoes will be tested at a laboratory. If you have any questions, please call the state public health epidemiologist on call at Oregon Health Authority, Public Health Division, 971-673-1111.

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