1. Ethicon Endo-Surgery, Inc.
West Nile Virus
Presented by
Lori L.Goss, BS, RVT
Clinical Education
Ethicon Endo-Surgery, Inc.

2. Topics of Interest What is West Nile Virus (WNV)? Clinical Signs
Diagnosis/Treatment
What is status of WNV in Ohio?
Prevention
Frequently Asked Questions

3. What is West Nile Virus (WNV)?
Member Japanese encephalitis virus complex of the genus Flavivirus, family Flaviviridae
Mainly carried by the Culex pipiens mosquito (N. House Mosquito) with birds as the reservoir
West Nile causes mortality mainly in humans, wildlife and domestic animals
Viral disease = encephalitis ( infection of brain and spinal cord)
Mosquitoes (only females) feed on infected birds, become infected themselves and then bite humans or animals
Crows and blue jays (most likely to die)
Horses
People cannot get virus from another human or horse

4. What is West Nile Virus (WNV)?
WNV not seen in Western Hemisphere before 1999
Geographic range greater than any prior arbovirus
Africa, north to central Europe and eastern Asia
Earliest epidemic in Israel
Largest epidemic in South Africa-1974
Recent epidemics-1996, 1997, 1998, 1999, 2000
Unsure how virus entered the U.S.
Importation of birds
Mosquito getting free ride to U.S. by ship/plane
Arbovirus-A large group of viruses carried by mosquitoes, ticks or other arthropods, that include those that cause encephalitis, yellow fever, and dengue. MOSQUITOES ARE ARTHROPODS.
Israel-500 hospitalized
South Africa-thousands infected
Romania, Czech, Italy, Russia and Israel
Re-emerging mosquito-borne disease

5. What is West Nile Virus (WNV)?
Viral disease; can cause encephalitis
Infection of brain and spinal cord
1999 (U.S.)=62 human cases with 7 fatalities
Virus has rapidly spread to 44 states and the District of Columbia
2002 (U.S.)=3737 human cases with 201 fatalities
As you can see the increase in cases
With all the attention on severe acute respiratory syndrome (SARS) this year, the West Nile virus hasn't been in the news as much as it was last year.
But according to Dr. Paul Epstein of the Harvard Medical School Center for Health and the Global Environment, so far SARS is less of a threat in the United States than West Nile virus. He points out that SARS hasn't caused any deaths in the U.S. to date, compared to 284 deaths from West Nile virus in Although there's no need to panic -- the CDC says that the number of people infected with the virus is actually quite low –
it's a good idea to protect yourself

7. Clinical Signs-Humans
Mild infection
Low-grade fever
Head-ache
Body aches
Skin rash
Swollen lymph glands
Severe Infections
High fever
Neck stiffness
Stupor
Disorientation
Coma
Tremors and occasional convulsions
Paralysis
Rarely death (in persons over 50)

8. Diagnosis-Humans Medical history Travel history
Been in area(s) where WNV activity identified
Persons older than 50 years of age
Draw 2 blood samples (two-three weeks apart)
Send to commercial or public health lab for confirmation
Medical history to assess symptoms
Travel history
Last 2 months
50 yrs. Of age (high risk)-get older harder to fight off disease
High risk and have symptoms of enceph
Also people with compromised immune systems

10. Treatment-Humans No specific treatment Severe cases Supportive therapy
Hospitalization
IV fluids
Airway management
Respiratory support (Ventilator)
Prevention of secondary infections
Good nursing care
** pneumonia, urinary tract etc..

11. Clinical Signs-Horses
Loss of appetite
Depression
Fever (not always)
Weakness or paralysis in hind limbs
Muscle fasciculations or muscle twitching
Impaired vision
Ataxia (incoordination)
Head pressing
Aimless wandering and circling
Convulsions
Inability to swallow
Hyperexcitability
Coma
Death within 5 days
Causes encephalitis
Not all clinical signs of encephalitis have WNV
Other options:
EPM
Rabies
Botulism
E/W Venezuelan enceph.
Incubation period: days
Horses cannot infect other horses or humans. Dead end host.
Wise to isolate infected animal.

12. Diagnosis-Horses
All horses who develop neurologic signs between June and October *
Whole blood, serum and CSF samples
Submitted to ODA/ADDL
Complete history also submitted with all samples
Rapidly progressive neurologic signs with recumbency
Animal submitted to ODA/ADDL
Rabies and WNV testing
Other diagnostics
PCR of CNS tissues
Immunohistochemistry
Postmortem in field-follow USDA guidelines
Especially if virus has been detected in Ohio close to animal being examined
Ohio Dept. Agriculture
Animal Disease Diagnostic Lab (Reynoldsburg)
**PCR=polymerase chain reaction

14. Currently-no specific treatment Supportive veterinary care
Treatment-Horses
Currently-no specific treatment
Supportive veterinary care
New vaccine (killed)
Initially-Twice-3 to 6 weeks apart (prior to mosquito season)
Yearly booster
Show/race horses
2 boosters annually in April and late July*
Efficacy data not available, but Very safe vaccine
e-w, Venezuelan equine encephalitis does not protect against WNV
Foreign countries have banned the importation of horses from New York

15. What is status of WNV in Ohio?
Infected mosquitoes in 88 counties
Surveillance is done
Epizootic*
Mosquitoes
Trapped from April to October (gravid traps)
# sites, frequency of trap placement, # traps per site
determines where virus is most likely to be present
Mosquitoes sent for identification
Total number
Type
Sex (only females spread virus)
*Epidemic in wide animals need to know to prevent spill-over into the human population
HEADS UP-A disease that has no vaccination or effective treatment (mosquito borne virus) such as WNV.

16. What is status of WNV in Ohio?
Birds-natural reservoir
Wild bird surveillance
Blood samples taken
ODH Vector-borne Disease Program tested 5,152 birds
1,002 + birds found
American Crow-death rate of 1.5 per square mile prelude to human cases
Clusters of dead crows and blue jays= ^risk*
2 confirmations of infections= WNV present and active
Further testing needed
* Local health department collect and test for WNV

17. What is status of WNV in Ohio?
Horses-dead end host
Surveillance
Areas with history of infection
Investigate suspect cases
No quarantines placed on non-clinically ill horses
Foreign countries banned importation of NY horses
Do not maintain sufficient virus in the blood to infect other mammals including man
Suspect areas and east coast of US

18. Prevention Reduce mosquito breeding areas
Eliminate standing water (old tires, buckets, clogged gutters)
Clean water troughs frequently
Ponds should be aerated and stocked with fish (goldfish)
Larvacide usage (talk with local pest control co.)
Bacillus sphaericus
Temephos (Organophosphorus insecticide)
Growth regulators
Oils and mono-molecular films
Repair window/door screens
Wear mosquito repellent when outdoors
Add some tips for schools, day camps, day cares

19. Prevention Horses House horses indoors during peak mosquito period
Dusk to dawn
Avoid turning on lights inside stable during evening*
Place incandescent bulbs around perimeter of stable
Remove all birds, nests ….**
Check property for dead birds
Eliminate standing water
Topical repellants should be used
Use fans on horses while stabled
Fog stables with pesticide during evening hours
Mosquitoes attracted by lights
**If dead birds found contact local health department
Where gloves when handling dead birds

20. Frequently asked ?’s What should I do if I find a dead crow?
Do I risk exposure to WNV if I handle a dead bird?
When will I receive test results from dead bird?
Should I worry about a lot of roosting crows?
Are crows the only bird affected?
What about my pet bird?
Call your local health department.
2. No evidence. Bare handed contact with dead birds should be avoided. USE gloves or a shovel
3. ASAP
4. No. Alive and well is good.
5. No, but crows and blue jays are most likely to die.WNV has been found in 70 species of birds found dead in US
Some healthy birds have the disease and survive.
6. Poultry do not seem infected.
Pet birds-little evidence, but can have the disease with no symptoms. Should protect birds from biting mosquitoes.

21. Frequently asked ?’s Can a dead bird pose a risk to my dog or cat?
Can I get West Nile if I eat wild meat?
Is feeding wild birds a health risk?
Are any other wild animals at risk?
SOME DOGS/CATS HAVE BEEN REPORTED WITH WNV-PROTECT PETS FROM BITING MOSQUITOS.
*NO EVIDENCE (INCLUDING EATING A BIRD INFECTED WITH WNV)
**PROPER COOKING KILLS THE VIRUS. HUNTERS SHOULD WEAR GLOVES WHEN CLEANING ALL GAME
***KEEP BIRD BATHS CLEAN
****STILL LEARNING. DOES APPEAR OTHER MAMMALS ARE AFFECTED
CROWS AND MEMBERS OF CROW FAMILY MOST AFFECTED

22. Questions?