West Nile Virus on the Move

by Cat Urbigkit

Sublette County Public Health Officer Dr. J. Thomas Johnston joined state health officials last week in urging public surveillance of dead birds as an indicator of the movement of the West Nile Virus.

Terry Creekmore, West Nile Virus (WNV) project coordinator for the Wyoming Department of Health, said that WNV has made a significant westward move in the past two weeks. The virus has now been found as far west as Manitoba, Nebraska, North Dakota, South Dakota, Oklahoma and Texas.

"We are urging state residents to be vigilant in reporting dead or dying birds now that WNV has been found in Nebraska," said Creekmore. "It is critical that we test birds from all across Wyoming, especially the Eastern half of the state," he said.

People who find dead birds (especially jays, crows, and magpies) should contact Terry Creekmore at (307) 742-6638. He will determine if the sample is usable and in some cases contact someone locally to make the pickup.

WNV has reportedly re-emerged in Arkansas, Missouri and Wisconsin. Nebraska and Oklahoma reported their first positives ever since the outbreak began in 1999. In addition, the provinces of Quebec and Manitoba also reported the presence of WNV for the first time. All of the positives were reported from dead birds.

Louisiana has confirmed seven human cases of WNV so far in 2002. The ages of the cases have ranged from 34-78 years and none have been fatal.

To date, 60 birds from 12 Wyoming counties and 42 horses from 19 counties have been tested this year. All have been negative for WNV.

Consultation on WNV for horse owners and veterinarians is available through the Wyoming State Veterinary Laboratory, University of Wyoming. Dr. Todd Cornish, veterinary pathologist, can be reached at (307) 742-6638.

WNV Facts:

• West Nile virus is a mosquito-transmitted disease that affects birds, humans and horses. It was first identified in the U.S. in New York City in 1999 and has since spread to 25 states, three provinces and Washington, D.C. WNV is ultimately expected to spread to the entire country and in 2001 was found as far west as Iowa, Missouri, Arkansas and Louisiana. It is unknown when - or if - WNV will be identified in Wyoming this year.

• Infected birds such as crows, bluejays and magpies usually begin to die several weeks before humans or horses become ill from WNV.

• Less than 1 percent of people infected with WNV develop serious illness, and it is fatal in about 10 to 15 percent of those seriously ill people. The majority of humans infected with the virus develop unapparent infections or have a flu-like illness.

• Over 700 horses in the U.S. were infected with WNV in 2001 and about 30 percent of those animals died from the disease. A WNV vaccine is currently available for horses but a human vaccine has not yet been produced.

People should:

• Limit outdoor activities between dusk and dawn when mosquitoes bite,

• Wear long pants and long-sleeved shirts when outside,

• Eliminate stagnant water in containers around homes where mosquitoes can lay their eggs (e.g., buckets, flowerpots, old tires, wading pools and birdbaths),

• Keep mosquitoes from entering their home by repairing screens in windows and doors,

• Use insect repellent that contains DEET and is approved by the Environmental Protection Agency (read instructions carefully).