Independently learned diseases

Question 1

Equine encephalomyelitis is

Answer 1

a zoonotic viral disease affecting Equidae, caused by an Alphavirus, characterized by characterized by fever, anorexia, and severe depression.

Question 2

Equine encephalomyelitis agent

Answer 2

Eastern, Western and Venezuelan equine encephalomyelitis viruses.
(EEE, WEE and VEE)

Genus Alphavirus, Family Togaviridae.

RNA virus

Question 3

Host range of Equine Encephalomyelitis

Answer 3

Affects primarily horses.
Principal reservoir hosts are birds.
NB zoonosis! Humans are dead-end host.

Question 4

Equine Encephalomyelitis Distribution:

Answer 4

present in the Americas

Question 5

Equine Encephalomyelitis Morbidity:

Answer 5

EEE: high morbidity, 90-95%
WEE: low morbidity
VEE: variable

Question 6

Equine Encephalomyelitis Mortality:

Answer 6

EEE: often fatal
WEE: approx. 30% mortality
VEE: mortality 20-80%

Question 7

Which Equine Encephalomyelitis variant is the “worst”?

Answer 7

EEE: high morbidity, 90-95% and
often fatal

Question 8

Equine Encephalomyelitis Transmission

Answer 8

vector-borne (mosquitos)

Question 9

IP of Equine Encephalomyelitis

Answer 9

EEE, 4-14 days;
WEE, 1-5 days;
VEE: 2-5 days.

Question 10

Equine Encephalomyelitis forms of disease

Answer 10

asymptomatic or subclinical, mild, acute, severe

Question 11

Clinical signs of Equine Encephalomyelitis

Answer 11

fever, anorexia, and severe depression.

In severe cases, it can progress to hyperexcitability, blindness, ataxia, severe mental depression, recumbency, convulsions, and death.

Most infections in birds are nonclinical.

Human symptoms: febrile illness and, in some cases, more severe neurological symptoms.

Question 12

Post-mortem lesions of equine Encephalomyelitis

Answer 12

Brain congestion, edema and/or hemorrhages

Meningeal inflammation

Neuronal damage

Perivascular cuffing around brain blood vessels

Question 13

Material for diagnosis of
equine Encephalomyelitis

Answer 13

blood, brain tissue, CSF

Question 14

Lab analyses for diagnosis of equine Encephalomyelitis

Answer 14

viral identification

serology

Question 15

Epizootic Hemorrhagic Disease is

Answer 15

an acute, infectious viral disease of wild ruminants, caused by Epizootic hemorrhagic disease virus (EHDV), characterized by widespread hemorrhage and oral ulceration.

Question 16

Agent for Epizootic hemorrhagic disease virus (EHDV)

Family & genus

Answer 16

Epizootic hemorrhagic disease virus

Family Reoviridae, Genus Orbivirus

RNA virus

Question 17

serovars of EHDV

Answer 17

Epizootic hemorrhagic disease virus (EHDV)

8+ serotypes plus Ibaraki virus

EHDV demonstrates immunological cross reactivity with the Bluetongue virus group.

Question 18

EHDV stability

Answer 18

inactivated by high temperatures, acidic and alkaline pH, and common disinfectants.

Resistant to UV light.

Question 19

Host range of Epizootic Hemorrhagic Disease

Answer 19

can infect most wild and domestic ruminants.

Particularly white-tailed deer in North America.

Can cause clinical disease in cattle (Ibaraki virus form).

Question 20

Distribution of EHD

Answer 20

most prominent in North America, Mediterranean countries.

Question 21

Morbidity of EHD

Answer 21

Morbidity and mortality may be as high as 90% in white tailed deer; however, severity varies depending on the year and geographical location.

Question 22

Mortality of EHD

Answer 22

Morbidity and mortality may be as high as 90% in white tailed deer; however, severity varies depending on the year and geographical location.

Question 23

Transmission of EHDV

Answer 23

vector-borne, Culicoides spp.

In temperate regions infection is most common in the late summer and autumn during peak vector population, while infection occurs throughout the year in tropical regions.

Question 24

IP of EHDV

Answer 24

estimated at 2–10 days.

Question 25

Forms of dz in EHD

Answer 25

Forms of disease: peracute, acute, chronic & Ibaraki disease in cattle.

Question 26

Clinical signs of EHD

Answer 26

Peracute – severe edema of head, neck, lungs

Acute – widespread hemorrhages and edema

Chronic – sloughing of hoof walls; rumen erosions, ulcers

Ibaraki – muscle degeneration, emaciation, erosions/ulceration

Question 27

Post mortem lesions of EHD

Answer 27

Widespread hemorrhages

Edema particularly evident in the lungs and the serous membranes lining the body cavities.

Ulcerations and erosions may be present in the oral mucosa, including the tongue, gums, and palate.

Swollen, congested LNs.

The spleen may be enlarged, congested, and show hemorrhagic areas.

The heart may show lesions, including congestion and hemorrhages.