We have officially started our adult mosquito surveillance program. The district would like to remind the public during the season mosquito traps will be placed throughout the county. Traps are set during the week in the evening time and picked up the following morning. We ask that the traps are left alone. Adult mosquito surveillance allows the district to monitor the Culex mosquito. The female Culex is known to vector the West Nile virus. When the traps are picked up the following morning, they are brought back to the districts lab. In the lab each trap is speciated and counted. If the Culex mosquito is present, a West Nile test will be preformed in the lab.

During the months of May- September the Vector district places mosquito traps at different locations around the county.  Below you will find the the current Culex mosquito count (the mosquitoes that can transmit the West Nile Virus) and the location of positive mosquito traps. 

Current as of: 9/11/2025

Total Traps Set: 698

Culex mosquito count: 7,939

Total mosquitoes caught in the district: 24,244

Jordan Valley & Surrounding Areas Data: 

Culex mosquito count: 1,230

Total mosquito count: 7,517

*Please note: Jordan Valley mosquito count is included in total mosquitoes caught in the district. 

Positive Mosquito Trap Location: 

Current season positive West Nile press releases can be found below:

August 25, 2025 

For Immediate Release

West Nile Virus Found in Two More Mosquito Pools in Malheur County, Bringing the Total to Eight for 2025 

West Nile virus (WNv) has been detected in mosquitoes at two testing sites in Malheur County, according to Malheur County Vector Control. The samples were collected from Annex and five miles north of Vale. Full Press Release

August 5, 2025

For Immediate Release

Three addtional West Nile virus pools reported. The samples were collected from Vale, and between Vale and Ontario.  

Health officials are advising people in Malheur County to take precautions against mosquitoes to avoid the risk of infection, including preventing mosquito bites. West Nile virus is spread to humans through the bite of an infected mosquito. Communities and individuals living in or spending significant time outdoors, particularly near irrigated land, waterways, standing water, and used tires, including those working in agriculture, such as migrant and seasonal farm workers—may be at increased risk of mosquito bites and related diseases.

Additional information about West Nile virus:

Oregon Health Authority website: http://public.health.oregon.gov/DiseasesConditions/DiseasesAZ/WestNileVirus/Pages/survey.aspx

July 8, 2025

For Immediate Release

West Nile detected in Little Valley (14 miles West of Vale) 

West Nile virus (WNv) has been detected in mosquitoes at a testing site in Malheur County according to Malheur County Vector Control. The sample was collected in Little Valley (14 miles West of Vale). Click here for full press release

Previous years positive West Nile press releases can be found below:

2024 mosquito season final data collected with adult mosquito surveillance

Culex Mosquito Count: 2,789

Total Mosquitoes Caught: 11,202

Positive Mosquito Trap Location: 3

July 31, 2024 

For Immediate Release

West Nile detected in Jordan Valley

West Nile virus (WNv) has been detected in mosquitoes at a testing site in Malheur County according to Malheur County Vector Control. The sample was collected in Jordan Valley. Full Press Release

July 15, 2024

For Immediate Release

First West Nile Virus Reported in Mosquitoes in Malheur County for 2024

West Nile virus (WNv) has been detected in mosquitoes at testing sites in Malheur County according to Malheur County Vector Control. The samples were collected in Little Valley (14 miles West of Vale) and South of Vale.  Full Press Release

Previous years positive West Nile press releases can be found below:

August 21, 2023

West Nile detected in Harper 

For Immediate Release 

Additional mosquitoes test positive for West Nile in Malheur County, OR for 2023

West Nile virus (WNv) has been detected in mosquitoes at a testing site in Malheur County according to Malheur County Vector Control. The samples were collected in Harper (22 miles West of Vale)

August 3, 2023 

West Nile detected in between Vale and Ontario

For Immediate Release 

Additional mosquitoes test positive for West Nile in Malheur County, OR for 2023

Oregon State University, Veterinary Laboratory confirmed West Nile virus in two additional mosquito traps located between Vale and Ontario. This will bring the total of positive mosquito traps to 7 for Malheur County in 2023 

July 24, 2023

West Nile detected in Willowcreek (11 miles North of Vale) and on Little Valley Rd (6miles East of Harper)

For Immediate Release

Additional mosquito test positive for West Nile virus in Malheur County, OR for 2023

Oregon State University, Veterinary Laboratory confirmed West Nile virus in Willowcreek (11miles North of Vale) and on Little Valley Rd (6miles East of Harper) and in Annex and Vale for a total of 5 mosquito pools so far in 2023.

Communities and individuals living in or spending significant time outdoors, particularly near irrigated land, waterways, standing water, and used tires—including those working in agriculture, such as migrant and seasonal farm workers—may be at increased risk of mosquito bites and related diseases.

West Nile detected in Vale and Annex Area.

 July 19, 2023

For Immediate Release

Second and Third West Nile Virus Reported in Mosquitos in Malheur County for 2023

West Nile virus (WNv) has been detected in mosquitoes at a testing site in Malheur County according to Malheur County Vector Control. The presumptive sample is being processed for confirmatory results through Oregon State University, Veterinary Laboratory. The mosquitoes, were found in traps located in the Vale and Annex area. In addition, last week’s presumptive mosquito pool identified between Nyssa and Adrian, OR was confirmed  Oregon State University, Veterinary Laboratory.  7/19/2023 Full Press Release

West Nile detected between Nyssa OR,  and Adrian, OR Press Release 7/14/2023

West Nile detected in between Nyssa and Adrian OR.

July 14, 2023, 2023
For Immediate Release

First West Nile Virus Reported in Mosquitos in Malheur County for 2023

West Nile virus has been detected in mosquitoes at a testing site in Malheur County according to Malheur County Vector Control. The test sample is being processed for confirmatory results through Oregon State University laboratory. The mosquitoes, found in an area between Nyssa and Adrian, are the first to test positive for the disease in the county in 2023.