West Nile Virus on the Move - Texas Preparing

[Guest guest]

http://www.dallasnews.com/lifestyles/stories/STORY.eaaa8221a0.b0.af.0.a4.88474.h\

tml

Virus on the move: Texas officials brace for arrival of West Nile, a threat to

birds, horses, and sometimes humans

12/10/2001

By SHERRY JACOBSON / The Dallas Morning News

When the recent blast of frigid weather brought an end to mosquito season for

most of the state, public health officials were even more relieved than usual.

It meant that mosquitoes wouldn't have a chance to spread the deadly West Nile

virus in Texas, at least not until next spring. However, it would not have

surprised health officials if the virus, which is harbored in birds and spread

by mosquitoes, had turned up here this year. In the two years since it was first

detected in the United States, West Nile has spread to 27 states, including

Louisiana.

Along the way, the virus killed thousands of birds and left hundreds of horses

sick or dying. More than 140 people became severely ill, and 14 died.

Texas " escaped it this year, but who knows about next year? " says Dr. Raouf

Arafat, chief of epidemiology for Houston's Health and Human Services

Department. " It's next door in Louisiana, so I think we need to be prepared. "

This year, state health officials told local governments to test for the West

Nile virus in the blood of " sentinel " chickens that had been placed at hundreds

of sites across the state. In addition, the state began to collect dead birds,

primarily American crows, blue jays, and hawks, to see whether West Nile caused

their demise. And several cities, including Dallas, began to test mosquitoes for

the virus.

Everything came up negative. But it wasn't much comfort to those who are

watching how fast the virus is sweeping across the country.

" If you look at how West Nile has moved from New York in just two years, going

south to Florida, north to Canada and as far west as the Mississippi River,

there seems to be no question that it will reach East Texas by next summer, "

agrees Dr. B. Tesh, a professor of pathology at the University of Texas

Medical Branch at Galveston.

Although the virus is mostly an infection of birds, it can infect horses and

cause a range of illness in people from mild flulike symptoms to encephalitis,

an inflammation of the brain that can be fatal. However, most people exposed to

the virus do not get sick.

" Our message to people when West Nile gets here is not to panic, " says Jan Buck,

who takes dead-bird reports for the Texas Department of Health's regional office

in Arlington. " The majority of people who are bitten aren't going to have any

illness. We feel it takes multiple bites by an infected mosquito to get ill. "

But no one seems to know how to stop the virus' spread other than to detect its

arrival in a new area, alert the public, and then work to eliminate mosquitoes.

" In my opinion, all the predictions about controlling the spread of West Nile

have been wrong, " says Dr. Tesh, who assists mosquito control efforts in

County. " I don't think it's going to go away. It will probably continue to

spread south. "

Since the virus was discovered in the West Nile district of Uganda in 1937, it

has spread throughout Africa, Asia, and the Middle East. But it did not reach

the Western Hemisphere until the summer of 1999.

Public health investigators in New York City diagnosed the virus after a series

of puzzling illnesses among birds, and later among people. The outbreak started

with crows that were found dead near the Bronx Zoo, followed by the deaths of

some of the zoo's exotic birds. Eventually, 62 people in the New York area

became ill, seven of them fatally.

The government had tried to stem the virus' spread beyond the New York area by

spraying large areas with insecticides and encouraging people to eliminate

standing water that could serve as a breeding ground for mosquitoes.

Nonetheless, the virus kept moving.

" West Nile is sort of on a roll because we have what we call a 'naive'

population, " observes Dame, past president of the American Mosquito

Control Association, a group of 1,800 researchers and pest control experts.

" Once humans and animals have been exposed to the virus for a period of time,

they will have more antibodies to resist it. "

Meanwhile, public health experts are building a body of knowledge about West

Nile virus after three summers of failing to stop it.

They know that the virus has infected more than 80 species of birds, although

most survive the infection. They know the virus seems to be spreading along

migratory paths used by the infected birds. And they know that a dozen mosquito

species that feed on those birds can spread the virus to people and other

animals.

" Many different species of mosquitoes appear to have the capacity for picking up

the virus, although we don't know if they all can transmit it, " Mr. Dame says.

The areas of the country that seem to be most susceptible to West Nile are those

that have ignored their mosquito habitats in recent years, say the experts. Such

was the case in Florida, where West Nile was first detected in July and where 11

people later were infected, none fatally.

Most of the infections occurred in rural areas of north Florida, where little

was being done in the way of mosquito control, says H. Burgess, supervisor

of the Lee County Mosquito Control District in Fort Myers. " We get a lot of

migratory birds that come through the state and stop before they head down to

South America. That's when we got hit. "

In Dallas, efforts to monitor and control mosquitoes have been ongoing since a

1966 outbreak of St. Louis encephalitis, another mosquito-borne virus, says Dr.

Assefa Tulu, county epidemiologist. That year, 200 people in Dallas County were

stricken and 30 died.

" We monitor very closely for these diseases during mosquito season, which

usually starts in the spring and ends in October or November, " he notes. The few

mosquitoes that stay active in North Texas throughout the winter are not known

to transmit viruses.

Florida's experience with West Nile also is noteworthy because that's where most

of the 400 horses were stricken in the country this year. More than 250 Florida

horses suffered a variety of West Nile symptoms, including muscle tremors and an

inability to stand. About one in five died or was euthanized.

Those deaths were a wake-up call to the owners of the estimated 7 million horses

in the United States, says J. Timoney, a veterinary virologist at the

Gluck Equine Research Center of the University of Kentucky in Lexington.

" We were very taken aback when West Nile arrived here this year, even though

there was evidence that the virus was on the move and would reach us

eventually, " says Dr. Timoney of the eight confirmed equine cases in Kentucky.

" At least now the industry has come to accept that West Nile virus is here, and

it's here to stay. "

However, horses may soon be spared the threat of West Nile. A new vaccine was

approved Aug. 1 that should protect them. So far the manufacturer has shipped

out 1 million doses. The vaccine is likely to be in demand in Texas, the state

with the most horses in the nation, about 600,000, Dr. Timoney says.

While humans may not be so fortunate as to have a vaccine, at least there is

time to take a breather before the West Nile watch resumes when the mosquitoes

come back.

" Not having West Nile virus [appear in Texas] this year is good, " says

Rawlings, an epidemiologist for the state Department of Health. " But it may be

here already, and we just have not picked it up. "

T.O.I.L. for Lyme!

T=Teach tolerance; O=Overcome ignorance; I=Initiate insurance reform; L=Labor

for Lyme literacy

*Websites*

http://www.angelfire.com/tx3/RoseWriter or

http://www.angelfire.com/biz/romarkaraoke/james.html

---------------------------------

[Guest guest]

Dear Rose & All,

A couple of cases have been confirmed now in No IL (Ill & Annoyed) -

one was a horse; I think the other a bird. Great job they've done in

spreading this one, hu?

Rose - how's the baby?

Blessings,

Chris

>

http://www.dallasnews.com/lifestyles/stories/STORY.eaaa8221a0.b0.af.0.

a4.88474.html

> Virus on the move: Texas officials brace for arrival of West Nile,

a threat to birds, horses, and sometimes humans

>

> 12/10/2001

>

> By SHERRY JACOBSON / The Dallas Morning News

>

> When the recent blast of frigid weather brought an end to mosquito

season for most of the state, public health officials were even more

relieved than usual.

>

> It meant that mosquitoes wouldn't have a chance to spread the

deadly West Nile virus in Texas, at least not until next spring.

However, it would not have surprised health officials if the virus,

which is harbored in birds and spread by mosquitoes, had turned up

here this year. In the two years since it was first detected in the

United States, West Nile has spread to 27 states, including

Louisiana.

>

> Along the way, the virus killed thousands of birds and left

hundreds of horses sick or dying. More than 140 people became

severely ill, and 14 died.

>

> Texas " escaped it this year, but who knows about next year? " says

Dr. Raouf Arafat, chief of epidemiology for Houston's Health and

Human Services Department. " It's next door in Louisiana, so I think

we need to be prepared. "

>

> This year, state health officials told local governments to test

for the West Nile virus in the blood of " sentinel " chickens that had

been placed at hundreds of sites across the state. In addition, the

state began to collect dead birds, primarily American crows, blue

jays, and hawks, to see whether West Nile caused their demise. And

several cities, including Dallas, began to test mosquitoes for the

virus.

>

> Everything came up negative. But it wasn't much comfort to those

who are watching how fast the virus is sweeping across the country.

>

> " If you look at how West Nile has moved from New York in just two

years, going south to Florida, north to Canada and as far west as the

Mississippi River, there seems to be no question that it will reach

East Texas by next summer, " agrees Dr. B. Tesh, a professor of

pathology at the University of Texas Medical Branch at Galveston.

>

> Although the virus is mostly an infection of birds, it can infect

horses and cause a range of illness in people from mild flulike

symptoms to encephalitis, an inflammation of the brain that can be

fatal. However, most people exposed to the virus do not get sick.

>

> " Our message to people when West Nile gets here is not to panic, "

says Jan Buck, who takes dead-bird reports for the Texas Department

of Health's regional office in Arlington. " The majority of people who

are bitten aren't going to have any illness. We feel it takes

multiple bites by an infected mosquito to get ill. "

>

> But no one seems to know how to stop the virus' spread other than

to detect its arrival in a new area, alert the public, and then work

to eliminate mosquitoes.

>

> " In my opinion, all the predictions about controlling the spread of

West Nile have been wrong, " says Dr. Tesh, who assists mosquito

control efforts in County. " I don't think it's going to go

away. It will probably continue to spread south. "

>

> Since the virus was discovered in the West Nile district of Uganda

in 1937, it has spread throughout Africa, Asia, and the Middle East.

But it did not reach the Western Hemisphere until the summer of 1999.

>

> Public health investigators in New York City diagnosed the virus

after a series of puzzling illnesses among birds, and later among

people. The outbreak started with crows that were found dead near the

Bronx Zoo, followed by the deaths of some of the zoo's exotic birds.

Eventually, 62 people in the New York area became ill, seven of them

fatally.

>

> The government had tried to stem the virus' spread beyond the New

York area by spraying large areas with insecticides and encouraging

people to eliminate standing water that could serve as a breeding

ground for mosquitoes. Nonetheless, the virus kept moving.

>

> " West Nile is sort of on a roll because we have what we call

a 'naive' population, " observes Dame, past president of the

American Mosquito Control Association, a group of 1,800 researchers

and pest control experts. " Once humans and animals have been exposed

to the virus for a period of time, they will have more antibodies to

resist it. "

>

> Meanwhile, public health experts are building a body of knowledge

about West Nile virus after three summers of failing to stop it.

>

> They know that the virus has infected more than 80 species of

birds, although most survive the infection. They know the virus seems

to be spreading along migratory paths used by the infected birds. And

they know that a dozen mosquito species that feed on those birds can

spread the virus to people and other animals.

>

> " Many different species of mosquitoes appear to have the capacity

for picking up the virus, although we don't know if they all can

transmit it, " Mr. Dame says.

>

> The areas of the country that seem to be most susceptible to West

Nile are those that have ignored their mosquito habitats in recent

years, say the experts. Such was the case in Florida, where West Nile

was first detected in July and where 11 people later were infected,

none fatally.

>

> Most of the infections occurred in rural areas of north Florida,

where little was being done in the way of mosquito control, says

H. Burgess, supervisor of the Lee County Mosquito Control

District in Fort Myers. " We get a lot of migratory birds that come

through the state and stop before they head down to South America.

That's when we got hit. "

>

> In Dallas, efforts to monitor and control mosquitoes have been

ongoing since a 1966 outbreak of St. Louis encephalitis, another

mosquito-borne virus, says Dr. Assefa Tulu, county epidemiologist.

That year, 200 people in Dallas County were stricken and 30 died.

>

> " We monitor very closely for these diseases during mosquito season,

which usually starts in the spring and ends in October or November, "

he notes. The few mosquitoes that stay active in North Texas

throughout the winter are not known to transmit viruses.

>

> Florida's experience with West Nile also is noteworthy because

that's where most of the 400 horses were stricken in the country this

year. More than 250 Florida horses suffered a variety of West Nile

symptoms, including muscle tremors and an inability to stand. About

one in five died or was euthanized.

>

> Those deaths were a wake-up call to the owners of the estimated 7

million horses in the United States, says J. Timoney, a

veterinary virologist at the Gluck Equine Research Center of the

University of Kentucky in Lexington.

>

> " We were very taken aback when West Nile arrived here this year,

even though there was evidence that the virus was on the move and

would reach us eventually, " says Dr. Timoney of the eight confirmed

equine cases in Kentucky. " At least now the industry has come to

accept that West Nile virus is here, and it's here to stay. "

>

> However, horses may soon be spared the threat of West Nile. A new

vaccine was approved Aug. 1 that should protect them. So far the

manufacturer has shipped out 1 million doses. The vaccine is likely

to be in demand in Texas, the state with the most horses in the

nation, about 600,000, Dr. Timoney says.

>

> While humans may not be so fortunate as to have a vaccine, at least

there is time to take a breather before the West Nile watch resumes

when the mosquitoes come back.

>

> " Not having West Nile virus [appear in Texas] this year is good, "

says Rawlings, an epidemiologist for the state Department of

Health. " But it may be here already, and we just have not picked it

up. "

>

>

>

>

>

> T.O.I.L. for Lyme!

> T=Teach tolerance; O=Overcome ignorance; I=Initiate insurance

reform; L=Labor for Lyme literacy

> *Websites*

> http://www.angelfire.com/tx3/RoseWriter or

http://www.angelfire.com/biz/romarkaraoke/james.html

>

>

>

> ---------------------------------

>