August 30, 2005 by DYLAN
DARLING
The presence of West Nile
virus in Klamath County was confirmed by health
officials Monday after tests detected the disease
in a dead bird found last week southwest of
Klamath Falls.
It was Klamath County's first case of the disease
that has spread across the country over the past
several years, and reached scattered parts of
Oregon last year.
A local resident contacted
health officials last Wednesday after finding a
dead scrub jay.
The bird was tested twice, first by the Klamath
Vector Control District and then by Oregon State
University's School of Veterinary Medicine in
Corvallis.
"It was definitely positive for West Nile," said
Michael Morstad, manager of the Klamath Vector
Control District.
Morstad said the bird was found within a few hours
after it had died. The man who found it had heard
that officials were interested in testing dead
corvids - jays, crows and magpies - because they
are usually the first animal to show that West
Nile has arrived in a particular area.
Health officials wouldn't disclose which
neighborhood the bird was found in because they
don't want to alarm its residents.
West Nile is transmitted by the bite of a
mosquito. Birds, horses and humans are most
commonly affected, according to the Klamath County
Department of Public Health.
The Klamath Vector Control
District - the agency responsible for controlling
mosquito populations - has been on the lookout for
the disease for several years, using two methods.
Three flocks of chickens - dubbed "sentinel
chickens" - have been maintained at scattered
locations for the collection of blood samples. The
district also traps mosquitoes, separates them by
species, and grinds them up for testing.
Neither method had revealed any sign of the virus.
Officials have also been asking people to call in
if they find a freshly dead corvid. Last year they
tested 14 of the birds, but none showed signs of
West Nile.
This year vector control
is using more accurate testing tools, Morstad
said.
"We could have had it last year here and not known
it because our equipment was not sensitive
enough," he said.
The infected jay was the second bird tested
this year.
Alise Barlow, a lab technician at the vector
control district, said the bird had a high level
of West Nile in it, but the test had to be double
checked by the lab in Corvallis.
Barlow said people should
be careful about mosquitoes, although the chance
of catching the disease is low.
Most people who get West Nile won't realize it.
Symptons show in only 20 percent of people
infected, and it tends to simulate the flu. But
the virus can be deadly for the young and elderly
or those with weak immune systems.
The West Nile virus can
cause encephalitis, an inflammation of the brain.
The virus, which had been found in Asia and the
Mediterranean, and came to New York City in 1999.
From there is has spread south and westward and
now is found in most states.
The virus had spread to Europe from Africa, where
was first reported in 1937 in Uganda, according to
the Centers for Disease Control and Prevention.
There is a vaccine against the virus for horses,
but none for humans.
To keep mosquito numbers down, the vector control
district sprays malathion in neighborhoods from
pickups, and other pesticides on farm fields from
crop dusters.
The tax-supported vector control district's budget
this year is $400,000, including $100,000 for
chemicals, Morstad said.
The vector district will continue to monitor for
West Nile and manage mosquitoes for the rest of
the summer.
"We'll keep surveying, keep spraying," Barlow
said. "It's all we can do."
To collect mosquitoes, vector controls puts out
traps with dry ice as the bait. The dry ice emits
carbon dioxide, the same gas that attracts the
insects to people.
West Nile has also shown up this year in dead
birds in the neighboring counties of Jackson and
Josephine, as well as in Malheur county this year.
The virus has also been found in horses in Baker
and Harney counties this year.
The virus was detected last year in Siskiyou and
Modoc counties in California.
So far, it has not be detected in Lake County.
By far, the biggest West Nile numbers in the
United States are to the south in California,
where 370 human cases have been reported this
year, including 83 in Sacramento County.
"And Sacramento isn't that far from us," Morstad
said.
He said it's not clear whether the jay found here
last week was infected with the virus in Oregon,
or came up with it from California, which is about
10 miles south from where it was found.
For more information call the Oregon Department of
Human Services hotline toll-free at (866)
703-4636, or the Klamath County Health Department
at 882-8846.
On the Net: www.cdc.gov/westnile
http://www.oregon.gov/DHS/ph/acd/diseases/wnile/wnile.shtml
