EEE, WEE, VEE

Question 1

epidemiology

Answer 1

transmission between birds or rodents and mosquitoes, clinical disease occurs during mosquito season: late summer and early fall in temperate zones and year-round in tropical zones

Question 2

EEE

Answer 2

more prevalent in southeastern states (north florida and carolinas), affects hundreds of horses every year with poor vaccination history, about 10 fatal human cases every year, horses and humans are affected but do not produce high enough viremia to serve as a reservoir (considered dead end hosts)

Question 3

WEE

Answer 3

since 1964, WEE has been reported in 640 people, in the 30’s thousands of people succumbed to WEE, reports of WEE today are sporadic, mortality rate is 50%

Question 4

VEE

Answer 4

one of the most important human and veterinary pathogens in the western hemisphere, large outbreaks affect horses and humans in large geographic areas, case fatality rate is 90%,

Question 5

VEE transmission

Answer 5

VEE has efficient amplification and the horse serves as a reservoir to spread the disease, rabbits, dogs and small ruminants also envelop the disease, human disease has never been demonstrated in the absence of equine disease

Question 6

Clinical findings

Answer 6

EEE and VEE are more neuroinvasive than WEE, children and young animals are more likely to develop CNS disease than adults

Question 7

clinical signs

Answer 7

obtunded mentation, ataxia, paralysis, ultimately stupor, irregular gait, grinding of teeth, incoordination, circling, head pressing, hyper excitability, profound depression:sleeping sickness. Clinical signs are progressive in nature. Mortality: EEE>WEE and VEE

Question 8

diagnosis

Answer 8

definitive diagnosis ante-mortem may not be possible-serology may be indicative, rising antibody titers in horses that survive, rabies, hepatic encephalopathy, EPM, WNV and EHV-1 neurologic all have similar symptoms. it is paramount to obtain a definitive diagnosis of the encephalitis in the horse because we need to know what the horse had so it isn’t passed to humans and which form of the disease the horse had so we know if a foreign disease has entered the country

Question 9

Treatment

Answer 9

support, corticosteroid (if the brain is so inflamed it is more beneficial to give the steroid), tranquilizers and diuretics to make the brains shrink

Question 10

prevention

Answer 10

vaccination, mosquito control, aerial spraying of insecticide, treat bodies of water, spray horses with permethrin-based products (lasts longer than pyrethran)

Question 11

West Nile

Answer 11

originated in the US in 1999, horses that generally get west nile have poor vaccination history, case fatality rate is about 30-40%, same symptoms as EEE