Epizootic Hemorrhagic Fever/Disease

Question 1

Family

Answer 1

Reoviridae

Question 2

Structure

Answer 2

Double-layered protein capsule, dsRNA that replicates in cytoplasm

Question 3

Reservoir Species

Answer 3

White-tailed deer
Mule deer, pronghorn antelope, mountain goats, bison, elk, bighorn sheep

Question 4

Zoonotic?

Answer 4

NO

Question 5

Transmitted through

Answer 5

biting midges (Culicoides spp)

Question 6

Morbidity and Mortality

Answer 6

90% morbidity and 60% mortality

Question 7

Transmission Cycle

Answer 7

NEEDS VECTOR
midge bites midge-> bites animal
not transmitted animal to animal

Question 8

Pathogenesis

Answer 8

saliva->replicates in endothelial cells of lymphatics near bite

Question 9

Primary viremia

Answer 9

systemic spread-> secondary replication in lymph nodes and spleen
continued viremia for about 3 weeks

Question 10

Incubation Time

Answer 10

2-10 days in intended hosts
die within 36 hrs of clinical signs

Question 11

Clinical Signs

Answer 11

swelling of face, anorexia, lethargy, nasal discharge, bloody diarrhea (hematochezia), redness/heat from skin (hyperemia), swelling of tongue, petechiation or ecchymosis around mouth and nose

Question 12

Pathologic Lesions

Answer 12

-Multisystemic severe edema, congestion, acute vascular necrosis, and hemorrhage on skin and heart
-ulcers or erosions of the tongue, dental pad, palate, rumen and abomasum
-vasculitis with thrombosis, endothelial swelling, grey plaques on the surface of the gallbladder mucosa

Question 13

Diagnostics

Answer 13

IFA, RT-PCR, serum neutralizing antibody tests

Question 14

Management

Answer 14

midges can’t handle the cold- die during 1st frost
no current management methods or concerns for control