West Nile virus confirmed in mosquitoes trapped in Keating Valley

Written by Baker City Herald August 06, 2014 11:50 am

West Nile virus was detected in two pools of mosquitoes collected on July 21 in Keating Valley.

This is the first detection of West Nile virus in Baker County in 2014.

Oregon State University Veterinary Diagnostic Laboratory in Corvallis confirmed the positive mosquito pools, Matt Hutchinson, manager of the Baker Valley Vector Control District, announced in a press release.

The virus has not been found in any birds, horses or people in Baker County this year.

Hutchinson said the Vector Control District, which receives its operating money from a pair of property tax levies, "will increase surveillance and control measures within the district in response to the positive mosquito pool."

West Nile virus has infected mosquitoes in Baker County in several summers over the past decade.

Last summer, mosquitoes trapped on July 25 near Haines and in Keating Valley were infected with the virus.

So far this summer, the virus has been found in mosquito pools in three counties: Morrow (8 pools); Baker (2 pools) and Klamath (1 pool). 

The Vector Control District routinely sets 24 adult mosquito traps, baited with carbon dioxide, weekly throughout Baker, Bowen and Keating valleys. The mosquitoes caught are then identified to species, counted and pooled into groups of 10 to 50 insects and sent onto the OSU Veterinary Diagnostic Laboratory in Corvallis for testing.

District officials have also been examining dead birds in the district. People who notice sick or dead birds such as crows, magpies, jays  and robins should contact the vector control district at 541-523-1151 so the birds can be picked up for testing.

Most people who become infected with West Nile virus do not become sick. Some people might develop mild flu-like symptoms such as fever, headache, body aches, and occasionally swollen lymph glands or rash. In some cases, West Nile may cause encephalitis, or inflammation of the brain. It can be fatal, but only rarely.

People over 50, those with high blood pressure or are immunosuppressed are at higher risk to get severe illness. People over the age of 50, those with high blood pressure or are immunosuppressed are more likely to develop serious symptoms of WNV if they do get sick and should take special care to avoid mosquito bites.  

Although the risk of people being infected with the virus is low, the Vector Control District recommends people take precautions to avoid mosquito bites.

These include:

• Eliminate all sources of standing water that can be breeding ground for biting mosquitoes such as flooded fields, watering troughs, birdbaths, wading pools, clogged gutters and old tires. If it holds water for 7 days it can produce mosquitoes.

• Avoid outdoor activities at dusk and dawn when mosquitoes are most active.

• Wear long-sleeved shirts and long pants when in mosquito infested areas.  

• Use mosquito repellents containing DEET, Oil of Lemon Eucalyptus or Picardin making sure to follow the directions on the container.  

• Make sure all screen doors and windows are in good repair and fit tightly.  

More information is available from the West Nile virus hotline, 1-800-702-INFO, the Baker County Health Department at 541-523-8211, or online at www.cdc.gov/ncidod/dvbid/westnile/