Jayson Jacoby
The Baker City Herald

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 caughtare identified by species, counted and pooled into groups of 10 to50 and sent to the Oregon State UniversityVeterinary Diagnostic Laboratory in Corvallis for testing.

West Nile Virus has been previously detected in Baker County during the 2005, 2006,2007, 2008 and 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 maydevelop mild flu-like symptoms such as fever, headache, body aches, and occasionallyswollen lymph glands or rash. In some cases, West Nile may cause encephalitis, orinflammation of the brain. Individuals with severe or unusual headaches should seekmedical care as soon as possible.

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

andbull; Eliminate all sources of standing water that can be breeding ground for bitingmosquitoes such as flooded fields, watering troughs, birdbaths, wadingpools, clogged gutters and old tires. If it holds water for seven days it can producemosquitoes.

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

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

andbull; Use mosquito repellents containing DEET, Oil of Lemon Eucalyptus orPicardin making sure to follow the directions on the container.

andbull; 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. Additionalinformation on West Nile Virus is on the Web at:

andbull; http://www.cdc.gov/ncidod/dvbid/westnile/

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