Eqine Encephalomyelitis

Question 1

What is the common name for equine encephalomyelitis?

Answer 1

Sleeping sickness

Question 2

This disease is characterized by ____ _______ and moderate to high _______.

Answer 2

CNS dysfunction; mortality.

Question 3

What family does equine encephalomyelitis belong to?

Answer 3

The Alphaviruses family

Question 4

What are the types of equine encephalomyelitis?

Answer 4

• Eastern Equine Encephalomyelitis
• Western Equine Encephalomyelitis
• Venezuelan Equine Encephalomyelitis

Question 5

Where do outbreaks of WEE typically occur?

Answer 5

In the west and midwest united states

Question 6

The current morbidity of WEE is low due to ________.

Answer 6

Vaccines

Question 7

EEE typically occur where?

Answer 7

Along the eastern seaboard and gulf coast (including LA)

Question 8

VEE was isolated in _____ in Venezuela.

Answer 8

1938

Question 9

In 1971, VEE spread into ____ _____ where _____ horses died.

Answer 9

Southwest Texas; 1500

Question 10

In the 1930’s an outbreak of WEE in California resulted in more than ______ horse deaths.

Answer 10

180,000

Question 11

What are the reservoir hosts for EE?

Answer 11

• Birds
• Rodents
• Reptiles

Question 12

What is the transmission vector for the spread of this disease?

Answer 12

Mosquitos

Question 13

This disease has been isolated from ____ different types of mosquitos in the U.S.

Answer 13

27

Question 14

How do infections spread from reservoir hosts to horses?

Answer 14

By mosquitos carrying virus

Question 15

Horses infected with WEE have a _____ viremia making them a “_____ ____ ____”

Answer 15

Low; Dead End Host

Question 16

What does it mean when a horse has a low viremia?

Answer 16

Infection does not spread from an infected horse to other healthy horses

Question 17

Horses infected with VEE have a ____ viremia.

Answer 17

High

Question 18

What does viremia result in that allows the infection to pass from horse to horse?

Answer 18

viral shedding in body fluids

Question 19

How can VEE spread to other horses?

Answer 19

Via aerosolized respiratory secretions or direct contact with body fluids

Question 20

Horses infected with EEE have a ______ but ______ viremia.

Answer 20

Transient but significant

Question 21

T or F: With EEE transmission from horse to horse is not possible.

Answer 21

False. This is possible

Question 22

________ are seasonal in temperate region, occurring during warm months but not during cold months

Answer 22

Epizootics

Question 23

In what state does transmission occur throughout the year with a peak in summer

Answer 23

Florida

Question 24

Initially horses are _____ and ______ with clinical neurologic signs generally occurring ____ post-infection

Answer 24

Quiet and depressed; 5 days.

Question 25

What are the clinical signs of this disease?

Answer 25

- Low grade fever - Altered mentation - Impaired vision - Aimless wandering - Head pressing - Circling - Inability to swallow - Irregular ataxic gait - Paresis and paralysis - Terminally, convulsions and death

Question 26

Most deaths occur within ______after onset of C.S.

Answer 26

2 - 3 days

Question 27

What is the medical term for the inability to swallow?

Answer 27

Dysphagia

Question 28

What are some examples of an altered mentation?

Answer 28

- Depression - Moribund - Comatose

Question 29

Surviving horses may be "dummies" what does this mean?

Answer 29

They may have permanent neurologic damage

Question 30

__________infections may occur with all of the sleeping sickness viruses

Answer 30

Asymptomatic

Question 31

The mortality rate for WEE is __ to __ %

Answer 31

20 to 50%

Question 32

The mortality rate for EEE is __ to __ %

Answer 32

50 to 90%

Question 33

The mortality rate for VEE is __ to __ %

Answer 33

50 to 75%

Question 34

Which type of EE has the highest mortality rate?

Answer 34

Eastern Equine Encephalomyelitis

Question 35

What different ways can sleeping sickness be diagnosed?

Answer 35

1. Presumptive diagnosis 2. Serologic titers 3. Virus isolation

Question 36

What is a presumptive diagnosis of sleeping sickness based on?

Answer 36

- Clinical signs in endemic areas and vaccination history

Question 37

How is a positive diagnosis with serologic titers made?

Answer 37

By a 4 fold increase between acute and convalescent samples

Question 38

How are samples taken for a serologic titer?

Answer 38

- 2 samples 4 weeks apart | - 1st taken when clinical signs apparent and then sample and test again 4 weeks later.

Question 39

How is virus isolation done for this disease?

Answer 39

The virus may be isolated from the CSF of horses with acute infection

Question 40

T or F: There is an antiviral drug available for the treatment of EE.

Answer 40

False, there is no specific antiviral drug available.

Question 41

What is the treatment protocol for sleeping sickness?

Answer 41

Supportive care including: - I.V. fluids, - Stomach tube feeding, - Anti-inflammatory agents (MIGHT reduce severity of C.S.) - anticonvulsants (For muscle spasm, tremors, seizures)

Question 42

T or F: this disease is not zoonotic.

Answer 42

False. This disease is zoonotic.

Question 43

How can humans contract this disease?

Answer 43

Not directly from the horse but from the vector.

Question 44

What are clinical signs in man?

Answer 44

Range from mild flu-like symptoms to death

Question 45

Who are the most susceptible humans to this disease?

Answer 45

Children, the elderly, and immunosuppressed individuals

Question 46

In humans the mortality rate of EEE is up to ___ %

Answer 46

75%

Question 47

In humans the mortality rate of WEE is ___ %

Answer 47

20%

Question 48

In humans the mortality rate of VEE is ___ %

Answer 48

40%

Question 49

For prevention you can use the ______ viral vaccine.

Answer 49

Inactivated

Question 50

This vaccine is available in ____, _____, or ____ form.

Answer 50

mono-, bi-, or trivalent form

Question 51

How is this vaccine given?

Answer 51

2 injections 30 days apart

Question 52

How often are boosters given?

Answer 52

Annually or Biannually

Question 53

How often must boosters be given in Louisiana?

Answer 53

Biannually

Question 54

_______ _______ will interfere with vaccination.

Answer 54

Maternal antibodies

Question 55

What is the vaccination protocol for foals?

Answer 55

At 3, 4, and 6 months of age

Question 56

What is the vaccination protocol for mares?

Answer 56

Vaccinated 3-4 weeks before foaling

Question 57

What is another important method of prevention?

Answer 57

Vector control --> controlling mosquito population (avoiding leaving stagnant water in yard, spraying pesticides, etc.)