More Baker County mosquitoes test positive for West Nile virus

Written by Baker City Herald August 27, 2013 06:40 am

Eight pools of mosquitoes trapped in the past two weeks in Baker County tested positive for West Nile virus.

That brings the total of infected mosquito pools this summer to 10.

No cases of West Nile virus have been confirmed in birds, horses or people, however.

A "pool" of mosquitoes consists of 10 to 50 insects.

Of the eight recent mosquito pools that were infected with the virus, six were trapped in Keating Valley, and two in Haines, according to a press release from the Baker Valley Vector Control District.

The district, which is managed by Matt Hutchinson and paid for by a pair of property tax levies, one permanent and one subject to voter approval, covers 200,000 acres in the Baker, Keating and Bowen valleys.

The Baker Valley Vector Control District routinely sets 24 adult mosquito traps each week, baited with carbon dioxide. The mosquitoes caught are identified by species, counted and pooled into groups of 10 to50 and sent to the Oregon State University  Veterinary Diagnostic Laboratory in Corvallis for testing.  

West Nile Virus has been previously detected in Baker County during the 2005, 2006, 2007, 2008 & 2009 mosquito seasons. 

In addition to trapping and testing mosquitoes, district workers are looking for sick or dead birds that might have been bitten by an infected mosquito. 

Most people who become infected with West Nile Virus do not become sick. Some may 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. Individuals with severe or unusual headaches should seek medical care as soon as possible.  

The Vector Control District suggests ways for people to reduce their possible exposure to West Nile virus:

• 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 seven 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.

The state has set up a West Nile Virus Hotline at 1 800 702-INFO. Additional information on West Nile Virus is on the Web at:

• http://www.cdc.gov/ncidod/dvbid/westnile/

• http://oregon.gov/DHS/ph/acd/diseases/wnile/survey.shtml