TREATING THE REHAB PATIENT WITH WEST NILE VIRUS Amy J. Wilson MD Medical Director, Baylor Institution of Rehabilitation January 2014
FIGHT THE BITE!
OBJECTIVES 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
WEST NILE VIRUS : AN OVERVIEW 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 North Dakota Department of Health (2005). National Institute of Allergy and Infectious Diseases (2009).
HISTORY OF WEST NILE VIRUS 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 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
SEASONAL PATTERNS OF WNV TRANSMISSION 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 Chakarova, S. R., Dimitrov, K. M., & Chenchev, I. I. (2011).
NATIONAL AND STATE FUN FACTS 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
DALLAS COUNTY 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 Texas Department of State Health Services 12/2013
WHO IS AT RISK FOR WNV? 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 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 Centers for Disease Control and Prevention (2012). <1% cases: High fever Stupor Disorientation Headache Convulsions Numbness Neck stiffness Paralysis Coma
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).
WNV TREATMENT 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.
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
OTHER MEDICAL ISSUES AS A RESULT OF WNV Fatigue Body aches/arthralgia/myalgia Neuropathic pain Hyponatremia Headache Malaise Anorexia Photophobia
LONG - TERM 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
WNV PREVENTION AND CONTROL Licensed vaccine for horses No approved vaccine yet for human use Comprehensive mosquito surveillance Disease surveillance Source reduction Centers for Disease Control and Prevention (2012) National Institute of Allergy and Infectious Diseases (2010)
WNV PREVENTION: REDUCING THE SOURCE OF THE PROBLEM 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
INDIVIDUAL-LEVEL WNV PREVENTION 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 Centers for Disease Control and Prevention (2012). Texas Department of State Health Services (2013)
PREVENTING WNV IN HORSES 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 Gee, thanks! American Association of Equine Practitioners (2005).
Squirrel Feeders 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).
OTHER FUN FACTS
SHAMELESS PROMOTION #2 COMING UP..
CONCLUSION 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 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-nilevirus/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/vir al/flavivirusfact.htm Texas Department of State Health Services (2013). West nile virus in Texas. Retrieved from http://www.dshs.state.tx.us/idcu/diseas e/arboviral/westnile/ WildPro (2008). Habitat management for control of West nile virus. Retrieved from http://wildlife1.wildlifeinformation.org/s /00Man/WNVOverviews/08WNVHabitat Man.htm
Centers for Disease Control and Prevention (2013). Fact sheet CD online. Retrieved from http://www.cdc.gov/ncidod/dvbid/west nile/wnv_onlinecd.html National Wildlife Health Center (2011). Retrieved from http://www.nwhc.usgs.gov/disease_info rmation/west_nile_virus/index.jspwest nile virus. (West Nile maps, prevention information and resources)