Western Equine Encephalitis / Encephalomyelitis
Put Your Name Here
Veterinarian Assistant Program, Module 7
Put Your College Here
Put Your Teacher Here

Table of Contents

Title Page…………………….…………………………..……………………………….…1
Table of Contents…………………………….……..…………………………..…………...2
Abstract………………………….………...…………………………………..………….…3
What is a good description of Western Equine Encephalitis?................................................4
What kind of disease is it and how does the disease work?...................................................4
When was Western Equine Encephalitis Discovered / History?............................................4
Which animals/species/age group are at risk for Western Equine Encephalitis?..................5
What diseases can WEE be confused or misdiagnosed for?.................................................5
What are the symptoms of Western Equine Encephalitis?....................................................5
Is Western Equine Encephalitis treatable and what is the treatment?...................................6
Is Western Equine Encephalitis zoonotic?............................................................................6
Why is Western Equine Encephalitis relevant to our local environment?............................6
Is Western Equine Encephalitis preventable and what are the preventions?........................7
Conclusion………………………………………………………………………………....8
References / Bibliography…………………………………………………………………9
Appendix A……………………………………………………………………………….10
Appendix B………………………………………………………………………………..11
Appendix C………………………………………………………………………………..12

Abstract
In this research paper I will discuss, in detail, the specifics of Western Equine Encephalitis / Encephalomyelitis. I have used credible resources to back my findings on this infectious virus. A few of the main topics will include: symptoms, treatments, and who is affected.

What is a good description of Western Equine Encephalitis? There are three known types of equine encephalitis; Eastern Equine, Western Equine, and Venezuelan Equine. The Venezuelan is not much of a concern, here in the United States, because there has been no reported outbreaks since 1970. The Eastern Equine Encephalitis has been reported in the Eastern states of the United States, mostly east of the Mississippi River and is terrifying to families with and without animals. The Western Equine Encephalitis is described as cases effected on the west side of the Mississippi River.
Western Equine Encephalitis is an infectious disease carried by reservoirs such as birds and rodents. The disease is caused by an arborvirus (Alphavirus-Togaviridae) and transmitted by infected mosquitoes of the genera culex and coliseta. People and horses are dead-end hosts for the virus, in that the concentration of virus particles circulating in the blood stream of humans and horses is too low to infect a blood feeding mosquito. See Appendix A
Components in the Transmission and Maintenance of WEE “Arboviral Encephalitis”
What kind of disease is it and how does the disease work? Western Equine Encephalitis is an arbovirus (arthropod-borne virus). This virus primarily attacks the central nervous system and severity can range from asymptomatic to severe complications and even death in rare cases (rightdiagnosis.com, 2015). It aggressively attacks the brain and brain stem. It is the causative agent of a relatively uncommon viral disease.
When was Western Equine Encephalitis Discovered / History? During the summer of 1930, the San Joaquin Valley of California had clinical cases of encephalitis in horses. The initial epizootic of WEE in the San Joaquin Valley in 1930 affected approximately 6,000 horses with a case fatality rate of 50%. Several outbreaks occurred in several western states from 1931 to 1934. In 1938, more than 300,000 horses and mules were stricken in the United States. In 1941, there were 1,094 human cases reported in Canada and 2,242 human cases in the U.S. An outbreak in California’s Central Valley in 1952 resulted in 813 cases of encephalitis in humans with an attack rate in Kern County of 50/100,000 humans and 1120/100,000 horses. Outbreaks of WEE in the 1930’s and 1940’s caused serious losses in horses and mules that were used as drought animals, adversely affecting agricultural production (LAwestVector, 2015).
Which animals/species/age group are at risk for Western Equine Encephalitis? Western Equine Encephalitis occurs in all age groups of animals and humans. The most popular species that are associated with WEE are rodents, birds, mosquitos, horses, and humans. While anyone can get WEE, some people are at an increased risk; people that live, work or visit areas where the disease is common and people that participate in outdoor recreational activities in areas where the disease is common.
What diseases can WEE be confused or misdiagnosed for? WEE can easily be misdiagnosed as other problems. After about two days of being infected the horses will start showing clinical signs and appear to have depression, clumsiness, ataxia, and maybe even a spinal injury. These symptoms are common with other equine ailments and may prolong a correct prognosis and proper treatment (Steve Reed, 2014).
What are the symptoms of Western Equine Encephalitis? Some of the more severe symptoms of this infection may appear 7 to 21 days after a bite from an infected mosquito. The disease is most severe in infants and small children and can result in permanent brain damage or death. Symptoms range from mild to severe and may include only fever and headache to encephalitis with delirium, disorientation or come. There are many other symptoms of WEE including: nausea, vomiting, diarrhea, tachycardia, tremors, cyanosis seizures, increased reflexes, lymphadenopathy, malaise, rash, myalgia, stiff neck, photophobia, lethargy, coma aphasia, anosmia, asymptomatic febrile illness, drowsiness, irritability, confusion, weakness.
Is Western Equine Encephalitis treatable and what is the treatment? At this time, there is no vaccine or medical treatment available to treat the WEE. The only successful treatment is supportive medical care. This type of care will include; providing fluids, shelter, vitamins intravenously, and slinging them. This critical time of care, after infection, will help keep the horses comfortable and in a position from hurting themselves.
See Appendix B Supportive Medical Care
Is Western Equine Encephalitis zoonotic?
Western Equine Encephalitis is a mosquito-borne zoonotic infection. Zoonotic can be defined as a disease that can be transmitted from animals to people or, more specifically, a disease that normally exists in animals but that can infect humans. There are multitudes of zoonotic diseases. Some examples of common zoonotic infections that you may recognize are: rabies, anthrax, and the West Nile Virus.
Why is Western Equine Encephalitis relevant to our local environment? Despite low numbers of human cases in recent years, mosquito-borne encephalitis remains an alarming disease to both the public and medical community. Diseases which appear quickly as epidemics, cause severe illness in children, and are transmitted by mosquitoes, producing a high level of public concern.
In 1969, the threat of an impending encephalitis outbreak in California resulted in the appropriation of $1.12 million of emergency funding in addition to the $10 million already budgeted for vector control. See Appendix C
Seroconversions to St. Louis Encephalitis (SLE) and Western Equine Encephalomyelitis (WEE) viruses from pooled mosquitoes (Culex tarsalis) in California, 1990-1999
Is Western Equine Encephalitis preventable and what are the preventions?
There are practices in place to help prevent WEE outbreaks. Organized mosquito abatement has reduced the incidence of WEE in California over the past two decades (LACountyVector, 2015). Because both the vector, culex tarsalis, and WEE virus are still present over a widespread geographic range, public health agencies maintain preventative programs including reporting systems, surveillance programs, and vector control.
Vector control is presently the only practical approach to the control of WEE. Organized mosquito abatement practices have led to the gradual reduction of human cases in Southern California.

Conclusion
When the first Western and Eastern Equine outbreaks happened almost 100 years ago, tragedy and death shook the farm lands. It is so disappointing to me to know that a century later, we still have no cure for such a deadly virus. Part of the problem was in the misdiagnosis of this virus. It was easily thought to be a spinal injury or similar ailments. By the time WEE was pinpointed, it was too late to save the victims.
This virus is terrifying to local communities with and without horses. The thought of losing the lives of not only friends and family members, but beloved equine companions, should make people take action against deadly viruses. This should make each and every one of us get involved in the research of medicine and treatment for viruses such as this deadly virus.

References / Bibliography https://www.avma.org/public/Health/Pages/Outdoor-Enthusiasts-Precautions.aspx, Retrieved, November 9, 2015 http://gcmad.org/Documents/Western_Equine_Encephalitis.pdf, Retrieved, November 9, 2015 http://www.lawestvector.org/wee.htm, Retrieved, November 9, 2015 http://www.medicinenet.com/script/main/art.asp?articlekey=12958, Retrieved, November 8, 2015 http://www.rightdiagnosis.com/w/western_equine_encephalitis/basics.htm, Retrieved, November 7, 2015 http://wn.com/western_equine_encephalitis, Steve Reed (2014), Retrieved, November 7, 2015

Appendix
Appendix A
Components in the Transmission and Maintenance of WEE “Arboviral Encephalitis”

Appendix B Supportive Medical Care

Appendix C
Seroconversions to St. Louis Encephalitis (SLE) and Western Equine Encephalomyelitis (WEE) viruses from pooled mosquitoes (Culex tarsalis) in California, 1990-1999