Human West Nile Virus
Cases In CA, MT And WA

From Patricia Doyle, PhD

A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases
Montana: first probable human cases of West Nile virus infection
By Bob Anez Great Falls Tribune Fri 15 Aug 2003 [edited]
HELENA -- Four Montanans have tested positive for West Nile virus, marking the first probable human cases contracted in the state, a state official said on Thursday. Dr Michael Spence, the state's chief medical officer, said the state health laboratory detected the positive cases on Thu 14 Aug 2003. They are 2 men and 2 women from Blaine, Custer, Fallon and Stillwater counties, he said. The ages of the patients range from 12 to 61, he added.
Spence said at least 3 of them were in hospital and state health officials would monitor their condition. The state technically will not count the instances as official cases of West Nile virus infection until confirmed by the Centers for Disease Control and Prevention in 7 to 10 days, but Spence said health officials presume them to be cases of West Nile virus infection.
Spence said the first human case of the virus in Montana was expected, as the number of cases nationwide continue to explode and move westward. Last week alone, 400 new cases were diagnosed, a threefold increase over the week before, he said. Spence said more Montanans may have been infected, but never displayed any symptoms. Over 90 per cent of those who get the disease never know they have it, he said.
Last year, 2 human cases of West Nile were confirmed in the state, but they were believed to have contracted the virus elsewhere. Montana's first case of West Nile virus infection was confirmed in August 2002 in a Yellowstone County horse. Last year, 134 horses in 26 counties were diagnosed with the disease. Of those, 38 died or were euthanized.>
-- ProMED-mail <>
[Although not the first occurrence of West Nile virus in Montana, this report is posted separately as it records the westward spread of human infection. - Mod.CP]
Date: Fri 15 Aug 2003 From: ProMED-mail <> Source: San Francisco Chronicle, Fri 15 Aug 2003 [edited] <>
California: first human case of West Nile virus infection probably imported ---------------------------------------------------------------------------
An Alameda County woman is the first Californian to test positive this year for the West Nile virus, but health officials said on Thu 14 Aug 2003 that they believe she picked up the virus on a recent trip to Colorado, where the disease has hit hard.
There is no evidence yet that infected mosquitoes or birds have turned up in California, but health officials say it is just a matter of time since infected mosquitoes have moved steadily west ever since they first showed up in New York City in 1999. With the peak season for West Nile disease now under way, federal health officials announced Thursday that the number of cases nationwide doubled over the past week, to nearly 400. Last year, the virus infected 4156 Americans and killed 284. Recently, Arizona officials said they detected the virus in a mosquito pool there, leaving only Oregon, Nevada, and Utah as states that have yet to detect it in either humans or animals.
"I think people have no cause for concern at this time, but we should keep in mind that West Nile has been making a steady push across the country, and it will eventually end up in California, if not this summer, then certainly next year," said Dr Anthony Iton, a health officer for Alameda County. The 47 year old Alameda County woman is in hospital with severe muscle weakness in her legs, according to state and county health officials. An outdoor sports enthusiast, the woman reported being bitten by mosquitoes in late July while traveling in north eastern Colorado, which health officials describe as a West Nile "hot spot." On Thursday, Colorado officials reported a sixth death due to West Nile, and a total of nearly 200 cases statewide so far this year. The woman returned from Colorado 26 July. Her symptoms first struck on 30 July and she was admitted to hospital on 7 August, but it wasn't until Thursday that California health officials said they had enough laboratory proof to announce the case.
It remains classified as "probable" until more sophisticated tests can be run to confirm it, which will take another week or two, according to Lea Brooks, a spokeswoman for the California Department of Health Services. The woman is in a stable condition and is expected to recover.
A Los Angeles County woman who recovered last year was the state's first case. But because no animals in the state have yet tested positive, health officials believe she may have been infected by a mosquito that caught a ride on a plane or in a car, rather than arriving through natural migration.
(byline: Ulysses Torassa)
-- ProMED-mail <>
[The origin of the previous human case of West Nile virus infection in California (in 2002) was not determined, whereas in the present case there is a clear history of travel to area of high risk. There is no confirmation yet that West Nile virus has penetrated as far west as California. - Mod.CP]
Date: Fri 15 Aug 2003 From: ProMED-mail <> Source: The Seattle Times, Fri 15 Aug 2003 [edited] <>
Washington: first probable human case of West Nile virus infection ------------------------------------------------------------------
The mosquito bite on his knee was so red and swollen Darryl Baker pointed it out to his mom and brother while they were bowling. He figured he had gotten it in his back yard the night before, during a game of lawn darts. But the 36 year old Yakima delivery-truck driver didn't figure the itchy nuisance would lead to what state health officials yesterday said is very likely the first human case of West Nile virus contracted in Washington.
Two rounds of tests at the Washington State Department of Health laboratory in Shoreline came up positive for the potentially deadly virus, said health secretary Mary Selecky. The US Centers for Disease Control and Prevention is conducting a more sophisticated test to verify the state's finding, with results expected in 2 to 3 weeks.
Experts said West Nile virus is entering its peak season across the country. Nationally this year, nearly 450 people have been sickened by the virus, with 10 deaths reported. Colorado has been hit hardest, with almost 250 cases and 6 deaths. Last year, more than 4000 people were infected with the virus and 284 died in the most severe outbreak since the disease was detected on the east coast in 1999. Health officials warn this year's numbers could go higher.
Washington is one of only 9 states with no confirmed human cases. In May, a Tri-Cities-area man was suspected of West Nile virus infection, but further tests ruled out the diagnosis. Health experts think the man had St Louis encephalitis, a similar, mosquitoborne disease. Since then, the state health department has improved its screening, with a test that can distinguish between West Nile virus and St Louis encephalitis.
Like other states, Washington has been monitoring dead birds, particularly crows, as a way to detect the presence of the virus. Last year, the virus turned up in 2 dead crows. Two horses also came down with the disease. So far this year, no animal cases have been detected.
[byline: Sandi Doughton]
-- ProMED-mail <>
[Although not the first occurrence of West Nile virus in Washington state, this report is posted separately as it records the extent of westward spread of human infection. - Mod.CP]
Patricia A. Doyle, PhD Please visit my "Emerging Diseases" message board at: Zhan le Devlesa tai sastimasa Go with God and in Good Health




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