Protecting You and Your Community from

Protecting You and Your Community fromWest Nile Virus

Utah Public Health Departments and Partners

2005

What is West Nile virus?

• West Nile virus causes illness in people, horses, and birds.

• Most people are not seriously affected however, West Nile illness can be very serious and cause death or disability.

How do you get West Nile virus?

• It is spread from the bite of infected mosquitoes. • You cannot get West Nile virus directly from

other people, horses, or birds.• Less common ways it is spread:

– It is very rare, but possible, to get West Nile virus by receiving blood or an organ transplant.

– It is NOT possible to get West Nile virus by donating blood or an organ.

– Pregnant or nursing mothers may pass the infection to their baby.

Is West Nile Virus New?

• Previously found in Africa, Middle East, West and Central Asia, and Eastern Europe.

• The name, “West Nile Virus”, comes from the place in Uganda where it was discovered.

• In 1999, it was found in New York City.

• Since 1999, it has moved westward across the United States.

1999

WNV activity in animals only

Human illnesses reported

• 7 deaths• 1 state (NY)• Illness onset: 8/2 – 9/24/1999

2000• 2 deaths2 deaths• 3 states (NY, CT,NJ)3 states (NY, CT,NJ)• Illness onset: 7/20 – 9/27/2000Illness onset: 7/20 – 9/27/2000



2001• 7 deaths7 deaths• 10 states 10 states • Illness onset: 7/13 - 12/7/2001Illness onset: 7/13 - 12/7/2001



2002• 284 deaths284 deaths• Est. 300K – 500K infectionsEst. 300K – 500K infections• 39 states & D.C.39 states & D.C.• Illness onset: 5/19 – 12/19/2002Illness onset: 5/19 – 12/19/2002



2003• 264 deaths264 deaths• 44 states & D.C.44 states & D.C.• WNND; 2866, WNF; 6830WNND; 2866, WNF; 6830• Illness onset: 3/28 – 10/21/2002Illness onset: 3/28 – 10/21/2002



2004• 100 deaths100 deaths• WNND; 1142, WNF; 1269WNND; 1142, WNF; 1269• 40 states + DC40 states + DC

Cumulative data for 2004 reported as of January 11 th, 2005

• 3 deaths 3 deaths • 38 states38 states• 109 cases109 cases• WNND; 31, WNF; 69WNND; 31, WNF; 69

2005 West Nile virus activity data, reported as of July 5th, 2005

2005

West Nile virusHuman Disease

• People get West Nile virus through the bite of an infected mosquito.

• People may become ill 2 to 14 days later.• Most people will not have severe

symptoms.

West Nile Fever• Some people will get a flu-like illness known as West

Nile Fever:– Fever– Headache and body aches– Nausea and vomiting– Some people have a rash

• This illness usually lasts several days, but may last up to several weeks.

• There is no treatment for West Nile Fever (antibiotics don’t work!)

• People recover completely.

West Nile Neurologic Disease• About 1 in 150 infected people develop a severe form of the

disease:– Meningitis (inflammation of the spinal cord)

• Fever, stiff neck, and severe headache

– Encephalitis (inflammation of the brain)• Fever, severe headache, possible mental confusion, convulsions, coma.

– Muscle weakness or paralysis

• About 10% of people with neurologic disease will die.• Others may have long-lasting or permanent nerve damage

similar to a stroke.• There is no treatment for West Nile virus infection, but

supportive treatment may be needed.

Severe Disease and Death

• People over age 50 are more likely to develop severe disease than are people under age 50.

• For people over the age of 50, the risk of severe disease rises with increasing age.

• Most deaths due to West Nile virus occur in people over 50.

WNV Human infection pyramid

~80%Asymptomatic

~20%“West Nile Fever”

<1%CNS

disease

~10% fatal(<0.1% of total infections)

WNV Human Infection “Iceberg”

1 CNS disease case=

~150 total infections

Very crude estimates

How do you know it’s West Nile virus?• The symptoms of West Nile virus are similar to other

viruses or even stroke.• Anyone with fever, severe headache, and stiff neck

should see a doctor immediately. A rash sometimes accompanies West Nile Fever.

• Anyone with convulsions, paralysis, or serious mental confusion or muscle weakness should see a doctor immediately.

• Although there is no treatment for West Nile virus, you will need a doctor’s care if you develop the serious form of West Nile virus.

West Nile Virus Human Disease Summary

• Usually no symptoms or mild illness but can be very serious

• No treatment (antibiotics won’t work)

• No human vaccine

• Prevention is key!

Prevention

• Personal protection

• Mosquito control

Personal ProtectionAvoid Mosquito Bites!

• Public health encourages active, healthy behaviors.– Prevent mosquito bites from dusk to dawn

• Use repellents with DEETAdults use repellents with up to 35% DEET

Children 2mo-12yr use up to 10% DEET

Children under 2 mo do not use DEET

• For additional protection wear pants and long sleeved-shirts.

DEEDEETT

DEEDEETT

DEEDEETT

DEEDEETT

DEEDEETT

DEEDEETT

Is DEET Safe?

• DEET has been used for years.• DEET is well tested.• DEET is the most effective insect repellent

available.• DEET keeps mosquitoes off of you, it does not

kill mosquitoes.• Repellents without DEET are much less effective

and put you and your family at risk of West Nile virus.

DEET and Mosquito Repellent• Higher concentrations of DEET protect longer!

– Determines length of protection• 30% lasts about 5 hours, 10% lasts 2 hours

• When should I reapply DEET?– DEET works at short distances, so you may still see

mosquitoes flying around. Only reapply if they begin biting you.

• Who should use DEET, and how much?– Everyone:

• Adults: up to 35%• Children older than 2 months: about 10%• Pregnant women CAN use DEET

Mosquito Control

• Repair/replace screens on doors and windows.

• Recycle old tires.

• Fix sprinklers so that you don’t have “swampy” areas in your yard.

• Consider using mosquito fish or mosquito dunks in ponds or stock tanks.

Mosquito Control

• Mosquito control begins at home!– Empty water from buckets, cans, pool covers,

flowerpots, old tires, etc.

– Discard or cover up items that you aren’t using.

– Clean pet water bowls and bird baths weekly.

– Clean out rain gutters.

• Mosquitoes can lay eggs in a very small amount of water!

Report Dead Birds• Notify your local Division of Wildlife Resources if

you see a dead:– Corvid (such as a crow, raven, or jay)– Raptor (such as a hawk or eagle)– Owl

• The bird must be fresh (not decomposed) and there should not be an obvious means of death (not killed by car or flying into window).

• Small birds, such as sparrows, wrens, robins, etc. are not good indicators of West Nile virus. Carefully discard all small dead birds.

Community Education• Community groups can assist in “Fight the

Bite”!– Help neighbors with gutter cleaning, screen

repair, trash removal etc.– Spread the word, especially to those over 50, to

wear DEET from dusk to dawn.

Dusk To Dawn Dusk To Dawn Put Your DEET Put Your DEET

On!On!

What is Utah doing to prepare?

• Testing dead birds, mosquitoes, sentinel chickens, horses, and humans for presence of virus.

• Tracking the presence of the virus.• Get the word out to “Fight the Bite”, through TV,

radio, educational material, and motivating the community.

How Can You Help?

Protecting You and Your Community from

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