West Nile Already as Far West as Wyoming

May 28, 2003
By BRODIE FARQUHAR Star-Tribune staff writer

Evidence of West Nile virus appeared for the first time in Wyoming this mosquito season in the form of a dead blue jay found east of Cheyenne.

Terry Creekmore, West Nile virus surveillance coordinator for the Wyoming Department of Health, said a Cheyenne area resident saw a blue jay acting ill. The bird then fell dead. The dead bird was sent to the state for testing and was positive for the virus, Creekmore said.

"We know that the culex mosquito overwintered from last year," Creekmore said.

An overwintering adult mosquito is the likely source of infection, he said, since large mosquito hatches have yet to occur in a cool spring.

Blue jays and other members of the corvidae family, such as crows, ravens and magpies, are particularly vulnerable to the disease. Creekmore expects the culex mosquitos to feed on fledgling birds in May. Culex populations peak from late August through mid-September, he said, which is when culex mosquitos will feed on large mammals, such as horses and people.

The first, big hatchings of mosquitos in Wyoming are typically the aedes species, which has not yet been proven to carrier West Nile virus, Creekmore said. Of 52 mosquito species in Wyoming, only four have been found to transmit the virus, said Dr. Stan Hartman, Laramie County deputy health officer.

Creekmore and Hartman participated in a Tuesday press conference in Cheyenne, at which health officials spoke about the disease, efforts to control mosquito populations and what individuals can do to prevent mosquito bites.

According to Scott Seys, deputy state epidemiologist, public health programs around the state were being notified that the virus is again active in Wyoming.

Creekmore said he wasn't surprised that Laramie County was the first to detect West Nile virus this season.

"The area has lower elevation and is further south," he said -- a warmer environment for mosquitos to either emerge from winter shelter or hatch in standing water.

Last year, the first for West Nile Virus in Wyoming, was a short season, Creekmore said, lasting from August 16 to late October. This year will have a longer season, from late May to late October, he said.

People who find a dead bird on their property should not send it to state or local health agencies but call the West Nile virus toll-free number at 1-877-WYO-BITE for instructions.

Public health officials in Laramie County and elsewhere around the state are using larvicides to kill mosquito larvae before they hatch. Officials are also urging the public to drain standing water around their homes and property. Officials recommend that people avoid being outside when mosquitos are most active, or wear long-sleeved shirts and long pants, as well as insect repellent.

John Lehman, director of the Natrona County mosquito control program, said the discovery of West Nile virus was expected.

"We'll be pulling out all the stops," on Natrona County larvicide programs, as control efforts continue through the year.

West Nile virus is historically found in portions of Africa, the Middle East, and Central Europe. In 1999, the virus was found in New York City and has since spread to all but four states in the continental United States.

Nationwide, last year 4,161 people became ill and 284 people died from the infection. Fewer than 1 percent of the people infected with the virus become seriously ill, about one-third of the people infected develop flu-like symptoms, while the majority of people never get sick.

Two nonfatal human cases were reported in Wyoming last year, but the number of human infections will likely increase as the virus continues to expand throughout the state, said Creekmore.

Last year, the state public health lab tested 90 human cases with two positives; the state veterinary lab tested 342 horses with 96 positives and 273 birds with 20 positives.

http://www.casperstartribune.net/articles/2003/05/28/news/wyoming/4246075d1210c
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