Final: Reoviridae

Question 1

Mature reovirus particles are composed of what 3 concentric layers?

Answer 1

Outer
Middle/intermediate
Inner

Question 2

The outer layer of reoviruses has what type of symmetry?

Answer 2

Icosahedral

Question 3

What is the viral genome of reovirus composed of?

Answer 3

Segmented double-stranded RNA (dsRNA)

Question 4

What does “Reo” stand for?

Answer 4

Respiratory enteric orphan

Question 5

Does genetic reassortment between viruses with a genus or serogroup happen with reoviruses?

Answer 5

Yes

Question 6

What diseases occur from genus orbivirus?

Answer 6

African horse sickness virus

Blue tongue virus

Question 7

What disease occurs with rotaviruses?

Answer 7

RVA (group A rotavirus)

Question 8

What disease occurs with orthoreovirus?

Answer 8

Avian reovirus

Question 9

Which virus is an infectious, non-contagious, insect-borne disperse of domestic and wild ruminants caused by a member of Orbivirus?

Answer 9

Bluetongue, caused by Bluetongue virus

Question 10

Who are the hosts of BTV?

Answer 10

Sheep (most common/susceptible)

Deer (white-tail)

Question 11

T/F: Bluetongue is a List A disease of the office of international epizootics (OiE)

Answer 11

True

Question 12

What are the routes of transmission of BTV?

Answer 12

Biologically by certain Culicoides

Less significant:
Trans-placental transmission
Venereal transmission

Question 13

What is the pathology of BTV in sheep?

Answer 13

Damage to vascular endothelium
Intravascular coagulation
Necrosis of tissues and organs supplied by damaged capillaries
Edema
Hemorrhage
Congestion
Abortion
CNS malformations

Question 14

What are clinical signs of BTV?

Answer 14

Cyanosis, necrotic ulceration of tongue
Erosion of dental pad, necrosis, hyperemia and ulceration in oral cavity 
Coronitis and laminitis causing lameness
Extensive facial swelling
Aborted, macerated fetuses

Question 15

What are prevention methods of BTV?

Answer 15

Vaccines: attenuated vaccines, which are available in countries including the US, are generally serotype specific; polyvalent vaccines are available in South Africa, Israel and other countries

Vector control: use of repellents and insecticides, lodging animals indoors during night since Culicoides have nocturnal feeding habits, using nets in windows and doors of animals shelters, not allowing animals to graze near possible insect breeding area

Question 16

What is African horse sickness (AHS)?

Answer 16

Infectious, non-contagious, arthropod-borne disease of horses, donkeys and mules

Question 17

T/F: Dogs can contract a highly fatal form of AHS

Answer 17

True

Resulting from the ingestion of infected carcass material from horses that have died from AHS

Question 18

T/F: AHS is also a list A infectious disease of the OiE?

Answer 18

True

Enzootic in sub-Saharan Africa, although occasional outbreaks have occurred in Northern Africa, Middle East and in Europe.

Question 19

What causes AHS?

Answer 19

A virus in the genus Orbivirus

Question 20

How do Culicoides transmit AHS?

Answer 20

Get blood meal from infected horses or zebra reservoirs -> healthy horses

Pathogenesis is the same as Bluetongue in sheep

Question 21

What are the forms of AHS?

Answer 21

Acute (pulmonary) Horse sickness (Dunkop)

Subacute (cardiac) horse sickness (Dikkop)

Question 22

How do we prevent and control AHS?

Answer 22

Vaccination in enzootic areas
Control vector population
Reduced exposure to biting insects
Slaughter of sick or viremic animals

Question 23

What virus is a major cause of severe viral diarrhea in young mammals and birds

Answer 23

Rotavirus

Question 24

T/F: based on differences in VP6 protein and VP6 gene, rotaviruses are classified into at least 6 groups/species, designated as RVA-RHV

Answer 24

False, 8 groups, not 6

Question 25

RVAs are the most common cause of what in the young of humans and a wide variety of animal species and birds?

Answer 25

Viral diarrhea

Question 26

What is the transmission of rotavirus in animals and humans?

Answer 26

Infected stool contains large number of viruses Fecal-oral transmission is the most likely route of rotavirus spread Virus can survive in environment, is resistant to common disinfectants, and can be transmitted through contaminated objects, water or food The main site of viral multiplication is the mature enterocytes on the villi of upper small intestine

Question 27

What are the symptoms common with rotavirus?

Answer 27

Severe diarrhea in young animals Profuse diarrhea, anorexia, dehydration and occasionally mild fever Uncomplicated cases usually recover within 3-4 days

Question 28

What are the vaccines available for rotavirus?

Answer 28

Equine RV Vaccine Bovine RV Vaccines: Adjuvanted. Bovine rota-coronavirus inactivated virus, Cl perfringens type C toxoid, Escherichia coli Bacterin. For vaccination of healthy, pregnant cows. [Bovine rotavirus-coronavirus vaccine, killed virus, Clostridium perfringens types C and D Escherichia coli bacterin-toxoid]. For vaccination of healthy pregnant cows.

Question 29

Are rotaviruses zoonotic?

Answer 29

YES

Question 30

What is avian reovirus?

Answer 30

Avian reoviruses are involved in a variety of disease conditions in domestic poultry of which the most important is viral arthritis/tenosynovitis in chickens

Question 31

Who are the hosts of avian reovirus?

Answer 31

Broilers tend to get viral arthritis/tenosynovitis and leg weakness.

Question 32

What is the transmission of avian reovirus?

Answer 32

Fecal-oral route Transovarial Inhalation

Question 33

What is the pathogenesis of avian reovirus?

Answer 33

After intestinal replication, the virus spreads via the bloodstream to all parts of the body. Pathogenic viruses localize in the hock joint, where they cause arthritis

Question 34

What are the clinical findings with avian reovirus?

Answer 34

``` Lameness Viral arthritis/tenosynovitis Swollen and inflamed hock joints Clear synovial fluid and inflammation of synovial membranes Ruptured gastrocnemius tendons ```

Question 35

How can we prevent avian reovirus arthritis?

Answer 35

Lived and killed vaccines are available. Since chicks are the most susceptible to avian reovirus infection immediately after hatching, vaccine protocols aim at offering passive immunity to chicks from maternal antibody following vaccination of the hen, or by active immunity after early vaccination with a live vaccine.

Question 36

Can you name the common biological vector of BTV?

Answer 36

Culicoides

Question 37

Rotavirus is primarily transmitted by ____?

Answer 37

Fecal-oral route

Question 38

Dunkop and Dikkop forms are clinical forms of _____?

Answer 38

African Horse Sickness