TREATING THE

REHAB PATIENT

WITH WEST NILE

VIRUS

Amy J. Wilson MD

Medical Director, Baylor Institution of Rehabilitation

January 2014

FIGHT THE BITE!

1. Review local incidence of West

Nile virus and its impact on the

community

2. Discuss the neurologic

complications associated with

West Nile virus

3. Identify the rehabilitation

implications with the West Nile

virus patient population

OBJECTIVES

• West Nile Virus is a virus that can affect the central

nervous system, cause a range of minimal to severe

illness and can result in death. It is a member of the

flavivirus group of viruses, an Arthropod-borne virus

(insect-borne), requiring a vector.

– An emerging infectious disease

– Common in Africa, Middle East, Western Asia, Europe

– First isolated in US in 1999

WEST NILE VIRUS : AN OVERVIEW

North Dakota Department of Health (2005).

National Institute of Allergy and Infectious Diseases (2009).

• First isolated in Uganda, 1937

• Linked to meningitis/encephalitis outbreak in Israel in

1957

• Diseased horses noted in France and Egypt in 1960s

• In Western hemisphere, New York City, 1999

• Moved through Eastern to Western U.S. by 2003

• Recently noted in the Caribbean, South America,

Mexico

HISTORY OF WEST NILE

VIRUS

Centers for Disease Control and Prevention (2011).

Lim, S. M., Koraka, P., Osterhaus, A. E., & Martina, B. E. (2011).

HOW IS WNV SPREAD?

• Mosquito feeds on infected animal or bird and gets the virus (wild birds are most common reservoir hosts)

• Mosquito gives virus to another animal, or bird, or human while feeding on its blood

• Virus typically cycles between mosquitoes and birds, but it may be transmitted to incidental hosts such as humans and horses, the dead end for the virus

• Mother to child, blood transfusions, organ transplant Chakarova, S. R., Dimitrov, K. M., & Chenchev, I. I. (2011).

CDC Update 2012

• Temperate climates

• Highest bird mortality in early spring

• Highest equine mortality in early autumn

• Human cases tend to occur late summer, early autumn

• When mosquitoes die off, so does the transmission

SEASONAL

PATTERNS OF

WNV

TRANSMISSION

Chakarova, S. R., Dimitrov, K. M., & Chenchev, I. I. (2011).

• 48 states reporting WNV in people, birds or mosquitoes

• 2374 cases in people – 51% neuroinvasive

• Highest number of cases reported in 2012

• 114 deaths 2013 (134 in 2012)

• 7% of cases in Texas (CA, CO, NE 2013)

• 40% of cases in Texas 2012

CDC update January 7. 2014

NATIONAL

AND

STATE

FUN

FACTS

• 329 cases in 2012, but much fewer 2013 - 16

• 11 West Nile Fever

• 5 West Nile Neuroinvasive

• Fewer than Houston, SA or FW

DALLAS

COUNTY

FUN

FACTS

Texas Department of State Health Services – 12/2013

• Anyone who lives in an area where West Nile virus

has been identified

• Older or very young age

• Solid organ transplant recipients

• Immunocompromised (HIV, DM, chemo)

• People who spend time outdoors

WHO IS AT RISK FOR WNV?

Centers for Disease Control and Prevention (2011).

Mayo Clinic (2010).

YOUR

CHANCES…..

• < 1% chance if bitten by infected mosquito

INTERESTING INFORMATION FROM

THE CDC JANUARY 7, 2014…….

• Over 400 blood

donors tested positive in 2013

WNV

SYMPTOMS

Mild

• 80% cases: no

symptoms at all

• 20% cases:

• Fever

• Nausea

• Vomiting

• Skin rash

• Swollen glands

• Headache

• Body aches

Severe –“Neuroinvasive”

• <1% cases:

• High fever

• Stupor

• Disorientation

• Headache

• Convulsions

• Numbness

• Neck stiffness

• Paralysis

• Coma

Centers for Disease Control and Prevention (2012).

HOW IS HUMAN WNV

DIAGNOSED?

• Clinical symptoms

• Laboratory tests

– Blood tests (WNV

ab, WNV RNA

PCR)

– Lumbar puncture

• CT, MRI, EEG to

evaluate abnormalities

in the brain

Mayo Clinic (2010).

• No specific approved pharmaceutical therapy for human use

• Typically mild symptoms improve without treatment

• Supportive care for severe cases:

– Hospitalization and nursing care

– Intravenous fluids

– Respiratory support

– Prevention of secondary infections

• The trouble with treating WNV…….

WNV TREATMENT

NEUROINVASIVE

WNV

• Meningitis

• Encephalitis

• Acute flaccid paralysis

WEST NILE NEUROINVASIVE

DISEASE IS LIKE A……….

SHAMELESS PROMOTION #1

Rehab RN

WEST NILE NEUROINVASIVE

DISEASE……..

NEURO ISSUES AS A RESULT OF

WNV

• Confusion/Cognitive Issues

• Weakness

• Paralysis /Poliomyelitis

• Seizures

• Tremors

• Impaired coordination

• Dysphagia

• Fatigue

• Body aches/arthralgia/myalgia

• Neuropathic pain

• Hyponatremia

• Headache

• Malaise

• Anorexia

• Photophobia

OTHER MEDICAL ISSUES AS

A RESULT OF WNV

• Chronic Kidney Disease 4-9 years after infection

• Parkinsonian features due to basal ganglia involvement

• Postpolio syndrome (LMN and anterior horn cell involvement)

• Lesson – recovery is variable in looking at all studies, often incomplete recovery

LONG -

TERM

ISSUES

AS A

RESULT

OF WNV

• Licensed vaccine for horses

• No approved vaccine yet for human use

• Comprehensive mosquito surveillance

• Disease surveillance

• Source reduction

WNV

PREVENTION

AND

CONTROL

Centers for Disease Control and Prevention (2012)

National Institute of Allergy and Infectious Diseases (2010)

• Source reduction: activities to decrease or eliminate mosquito breeding

• Local source reduction is extremely important

• Greatest increase in risk is associated with factors that encourage mosquito

populations

WNV PREVENTION:

REDUCING THE SOURCE OF

THE PROBLEM

– Use DEET-based, picaridin, IR3535, or oil of

lemon eucalyptus repellants on skin and clothing – Wear long sleeves/pants – Take precautions when mosquitoes are most

likely to bite – Avoid the outdoors at dawn and dusk – Report dead birds; symptomatic horses – Protect your home – Repair screens/windows – Be aware of who is at higher risk for severe

disease

INDIVIDUAL-LEVEL WNV

PREVENTION

Centers for Disease Control and Prevention (2012).

Texas Department of State Health Services (2013)

• Number one prevention is to vaccinate – Not completely protective

– Frequency based on risk, age, gestation • Dusk to dawn: horses in the barn

• Remove muck/manure frequently

• Circulate air with fans

• Mosquito dunks

• Horse-safe topical repellants

PREVENTING WNV IN

HORSES

American Association of Equine Practitioners (2005).

Gee, thanks!

• If my community doesn’t spray for mosquitoes, I’m at risk.

– Not necessarily. The most important controls begin with eliminating risks around your personal outdoor environment

• I should invest in a bunch of bug zappers.

– No. These actually attract insects, including mosquitoes.

• I’ve heard that putting up a bat house will help, since they eat mosquitoes.

– No proof exists that bats, purple martins, or any other animals eat enough adult mosquitoes to make a difference – and bats carry rabies and should not become your yard guests.

Texas Department of State Health Services (2014).

Squirrel Feeders

OTHER FUN FACTS

SHAMELESS

PROMOTION

#2

COMING UP…..

• There is much the individual can do to effectively protect against West Nile.

• Most people bitten by mosquitoes will not become ill with WNV.

• Most people infected with WNV will have no symptoms or very mild symptoms that do not require treatment.

• If you have WNV neuroinvasive, the best place to receive rehabilitative care is Baylor Institute for Rehabilitation

CONCLUSION

Texas Department of State Health Services (2012).

• American Association of Equine Practitioners (2005). West nile virus vaccination guidelines. Retrieved from http://www.aaep.org/pdfs/AAEP_WNV_Guidelines_2005.pdf

• Centers for Disease Control and Prevention (2011). Division of vector-borne diseases: west nile virus. Retrieved from http://www.cdc.gov/ncidod/dvbid/westnile/index.htm

• Chakarova, S. R., Dimitrov, K. M., & Chenchev, I. I. (2011). Etiology, epidemiology, clinical features and laboratory diagnostics of west nile fever – a review. Bulgarian Journal of Veterinary Medicine, 14(2), 71-79. Retrieved from EBSCOhost.

• Lim, S. M., Koraka, P., Osterhaus, A. E., & Martina, B. E. (2011). West Nile Virus: Immunity and Pathogenesis. Viruses (1999-4915), 3(6), 811-828. doi:10.3390/v3060811

• Mayo Clinic (2010). West nile virus. Retrieved from http://www.mayoclinic.com/health/west-nile-virus/DS00438/DSECTION=tests-and-diagnosis

• National Institute of Allergy and Infectious Diseases (2010). West nile virus. Retrieved from http://www.niaid.nih.gov/topics/westnile/Pages/default.aspx

• North Dakota Department of Health (2005). Flaviviruses fact sheet. Retrieved from http://www.ndhealth.gov/EPR/public/viral/FlavivirusFact.htm

• Texas Department of State Health Services (2013). West nile virus in Texas. Retrieved from http://www.dshs.state.tx.us/idcu/disease/arboviral/westnile/

• WildPro (2008). Habitat management for control of West nile virus. Retrieved from http://wildlife1.wildlifeinformation.org/S/00Man/WNVOverviews/08WNVHabitatMan.htm

• Centers for Disease Control and Prevention (2013). Fact sheet CD online. Retrieved from http://www.cdc.gov/ncidod/dvbid/westnile/WNV_onlineCD.html

• National Wildlife Health Center (2011). Retrieved from http://www.nwhc.usgs.gov/disease_information/west_nile_virus/index.jspWest nile virus.

(West Nile maps, prevention information and resources)