1. West Nile Virus A guide for people who enjoy the outdoors of Utah
Louise Saw, MPH Student
Walden University
PUBH Environmental Health
Instructor: Dr. Rebecca Heick
Winter 2009
My name is Louise Saw. I am a Masters of Public Health student at Walden University. For a service-based learning project in my Environmental Health course I have prepared this presentation on West Nile Virus for people who enjoy being outside. I aim to provide information on West Nile Virus, how it is spread and how you can protect yourself while still enjoying your time in the BEAUTIFUL Utah outdoors.

2. What is West Nile Virus? Name comes from where it was isolated :
In the West Nile Province of Uganda-1937
A virus
The virus causes
inflammation of the
spinal cord and brain
West Nile Virus was first isolated in the West Nile Province of Uganda in As indicated by its name it is a virus. More specifically it is an RNA Flavivirus with fellow members of its genus including Yellow Fever, Dengue, St. Louis Encephalitis and Japanese Encephalitis (Microbiologybytes, 2007). The virus causes a severe human meningitis or encephalitis which means the inflammation of the spinal cord and brain. Other symptoms occur as a result of and along with this. We will go over those later in the presentation.
Reference: Microbiologybytes (2007). Flaviviruses. Retrieved January 2010 from:

3. The geographic spread First detected in the Western Hemisphere in 1999
Then spread across the United States from the east coast to the west
Seen in Utah in 2003
West Nile Virus was first detected in the Western Hemisphere in It is an arbovirus which means it is transmitted to humans primarily through the bite of an infected mosquito.
By October 1999 there were 62 cases in New York with 7 deaths (CDC, 2004). It then spread across the United States. To get a better picture nationally I want to first show the spread of West Nile Virus by CDC’s Incidence maps from
In a similar fashion to the old cartoons, I will show the spread of West Nile Virus throughout the United states over recent years. Click quickly through these next eleven slides to create an illusion of the movement.
Reference: CDC (2004) West Nile Virus. Background: Virus History and Distribution. Retrieved January 2010 from:

4. 1999
Reference: CDC (2009) West Nile Virus. Division of Vector Born Infectious Disease. Retrieved January 2010 from:

5. 2000
Reference: CDC (2009) West Nile Virus. Division of Vector Born Infectious Disease. Retrieved January 2010 from:

6. 2001
Reference: CDC (2009) West Nile Virus. Division of Vector Born Infectious Disease. Retrieved January 2010 from:

7. 2002
Reference: CDC (2009) West Nile Virus. Division of Vector Born Infectious Disease. Retrieved January 2010 from:

8. 2003
Reference: CDC (2009) West Nile Virus. Division of Vector Born Infectious Disease. Retrieved January 2010 from:

9. 2004
Reference: CDC (2009) West Nile Virus. Division of Vector Born Infectious Disease. Retrieved January 2010 from:

10. 2005
Reference: CDC (2009) West Nile Virus. Division of Vector Born Infectious Disease. Retrieved January 2010 from:

11. 2006
Reference: CDC (2009) West Nile Virus. Division of Vector Born Infectious Disease. Retrieved January 2010 from:

12. 2007
Reference: CDC (2009) West Nile Virus. Division of Vector Born Infectious Disease. Retrieved January 2010 from:

13. 2008
Reference: CDC (2009) West Nile Virus. Division of Vector Born Infectious Disease. Retrieved January 2010 from:

14. 2009
Reference: CDC (2009) West Nile Virus. Division of Vector Born Infectious Disease. Retrieved January 2010 from:

15. Incidence Summary Activity was largely within the continental US
2007 and Puerto Rico
No activity in Alaska and Hawaii
Utah first detected West Nile Virus in 2003.
The spread of West Nile Virus remains largely contained in the continental United States. Puerto Rico had activity in 2007 and 2008 (CDC,2009). Alaska and Hawaii do not have any West Nile Virus activity to date (CDC,2009). Utah first detected West Nile Virus in 2003 (Utah Department of Health, 2009).
References:
CDC (2009) West Nile Virus. Division of Vector Born Infectious Disease. Retrieved January 2010 from:
Utah Department of Health(2009).West Nile Virus. Retrieved from

16. Utah West Nile Virus Season Comparison 2003-2009
2004
2005
2006
2007
2008
2009
Human 1 11 52
158 70 27 2
Horse 35 5 68 59 18 8 6
Bird 22 76 19 3 -
Chicken 9 32 79
107 74 16
Mosquito Pools
181 80
466
225
140
284
Counties with Detection 17 14 12
Now that we have a national picture, let’s bring it down to our state level. This table shows the West Nile Virus activity in Utah from (Utah Department of Health, 2009). It compares the counts of virus detection by season and vector. The columns list the year it was detected and the rows list where it was detected. I want to highlight the human cases that started in 2003 with 1, went to 11 then 52 and peaked with 158 in They then fell from 70 to 27 and then down to 2 in The other indicators such as horse, bird, chicken and mosquito pool showed similar trends, with the exception of a late spike in mosquito pool detection in 2009.
Reference: Utah Department of Health(2009).West Nile Virus. Retrieved January 2010 from

17. How does WNV affect humans? Central Nervous System
80% no symptoms
20% mild symptoms
ex: fever, headache, nausea, rash
1 in 150 severe symptoms
ex: encephalitis, tremor, coma, vision loss,
death
Now that we have a little background of the virus, how it was spread and its prevalence, let’s move on to how West Nile Virus affects humans.
As I previously mentioned West Nile Virus causes swelling of the spinal cord and brain. It is important to note that no symptoms are noted in most (80% or 4 out of 5) infected people, which skews the surveillance data (CDC, 2006). The virus affects the central nervous system.
Mild symptoms occur in approximately 20% of infected people and include fever, headache, body ache, nausea, vomiting, with more rarely occurring rash and swollen lymph glands (CDC, 2006). These symptoms often resolve within a short time; however, serious symptoms occur in 1 in 150 infected people and can include high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness and paralysis (CDC, 2006). The devastating aspect of these is that since they affect the central nervous system, the neurological effects may be permanent.
Reference:CDC (2006). Fact sheet -West Nile Virus: What you need to know. Retrieved January 2010 from

18. What does this mean to me?
RISK
PREVENTION
Now that you are an expert on West Nile Virus, how it was discovered and spread, how common it is and how the disease impacts human health, you are left to ask yourself “What does this mean to me?” Well, if you love spending time outdoors in Utah, then it seems pertinent to know the risks of West Nile Virus and how some actions you could take could affect the risk.

19. Prevention Actions “Fight the Bite” Exposure time dusk to dawn
CDCs Campaign logo
Exposure time dusk to dawn
Bug spray
DEET
Picaridin
Oil of lemon eucalyptus
Light colored long sleeves and long pants
Nets
“Hooked on fishing? Don’t be the bait – put a little repellent in your tackle box and save the biting for the fish.” –CDC, 2009
Truly you must “Fight the Bite” to avoid West Nile Virus as CDC’s campaign logo states.
Dusk and dawn are the time that mosquitoes are most active, which is also, awhhh, the perfect fishing times. Which doesn’t mean you have to give up fishing or hiking or camping for that matter, just know this is a time that mosquitoes will be out and take further precautions like using a bug spray that has DEET (n, N-diethyl-m-touluamide) or picaridin or oil of lemon eucalyptus. The American Academy of Pediatrics recommends not using DEET on children under 2 months, but everyone over that can use repellents containing up to 10% DEET (as cited by CDC, 2009) Depending on the length of time you’ll be outdoors, you could use repellents with concentrations of ~20%-50% DEET. You can also treat clothing with permethrin to protect against mosquitoes and ticks for multiple washings (CDC, 2009). The resources at the end of this presentation have more information on this including a site you can visit to print a guide for bug repellant use. It includes concentrations and exposure time.
I love this quote from the CDC’s fight the bite campaign “Hooked on fishing? Don’t be the bait – put a little repellent in your tackle box and save the biting for the fish.” (CDC, 2009)
The clothes you wear can make a difference too. Choose light colored long sleeve and long pants consider using mosquito nets. You can get ones to wear over your head/hat. You can get ones for sleeping too, but appropriately using enclosed tents with built in screens can help keep the bugs out of where you sleep while camping. It’s just a matter of keeping it zipped up!
Reference: CDC (2009) West Nile Virus. Division of Vector Born Infectious Disease. Retrieved January 2010 from:

20. More prevention Eliminate standing water
There are things you can do to modify your environment in order to reduce mosquito activity overall. Since mosquitoes breed in water, you can remove standing water to help reduce the number of mosquitoes around your house. This is truly a community effort though, and if you are traveling outdoors you might not have a whole lot of control over this. But for areas you do have influence over, you can make a difference by removing standing water in old tires or buckets. If you have things outside that are designed to have standing water like birdbaths, pet food dishes, change the water at least once or twice a week (CDC, 2009).
Reference: CDC (2009) West Nile Virus. Division of Vector Born Infectious Disease. Retrieved January 2010 from:

21. Watch for symptoms Seek medical care Especially pregnant women
nursing mothers
Despite your efforts to prevent West Nile Virus, you should watch for symptoms. The CDC notes that milder cases improve on their own, and people do not necessarily need to seek medical attention for this infection though they may choose to do so (2009). However, you should seek medical attention immediately if you develop symptoms of severe West Nile Virus, such as unusually severe headaches or confusion. Two special populations to be noted as an exception to this are pregnant women and nursing mothers. If they develop any symptoms that could be West Nile Virus, they should talk to their doctor.
Reference: CDC (2009) West Nile Virus. Division of Vector Born Infectious Disease. Retrieved January 2010 from:

22. Summary Virus that causes encephalitis
Be aware of West Nile Virus activity
nationally and locally
Use awareness to “Fight the Bite”
Use bug spray
Appropriate clothing
Nets
Eliminate standing water
In summary of what we have gone over in this presentation:
1- West Nile Virus is a virus that can cause inflammation of the brain and spinal cord (encephalitis)
2-Be aware of the national and local West Nile Virus activity each season
3-Use this awareness to guide your prevention efforts such as using bug sprays, wearing light colored long sleeve shirts and long pants, diligently using nets and screens, and eliminate standing water in order to “Fight the Bite”

23. References
Centers for Disease Prevention and Control, CDC (2009) West Nile Virus. Division of Vector Born Infectious Disease. Retrieved January 2010 from:
CDC (2006). Fact sheet -West Nile Virus: What you need to know. Retrieved January 2010 from
CDC (2004) West Nile Virus. Background: Virus History and Distribution. Retrieved January 2010 from:
Microbiologybytes (2007). Flaviviruses. Retrieved January 2010 from:
Utah Department of Health(2009).West Nile Virus. Retrieved January 2010 from

24. Additional Resources
Utah Department of Health West Nile Virus website provides up to date information to the pubic on detection activity, prevention, health, and other links:
The Utah Mosquito Abetment Association Website has information on mosquito control and related work:
Driven by the Weather Channel, the Mosquito Activity Forecast can be narrowed to your city:
The CDC’s West Nile Virus website has many great resources such as bug repellant guides, education and training, ecology and virology information, frequently asked questions and news links: