Viruses and vesicle formation

Question 1

Define vesicle

Answer 1

circumscribed epidermal elevation in the skin containing clear fluid
usually less than 5mm indiameter

Question 2

What is a bulla?

Answer 2

circumscribed epidermal elevation in the skin containing clear fluid
greater than 5mm

Question 3

What is acantholysis?

Answer 3

death and loss of stratum spinosum cells -> clear fluid forms between overlying layers and stratum basale

Question 4

What is an erosion?

Answer 4

partial loss of epidermis that does not penetrate beneath the basal laminar zone due to a bullar or vesicle bursting

Question 5

What is an ulcer?

Answer 5

a loss of epidermis and dermis (and somtimes deeper tissue) due to a bulla or vesicle bursting

Question 6

Name some vesicular diseases that cause oral lesions in farm animals and what species do they affect?

Answer 6

Foot and mouth disease (FMD) - cattle, sheep, pigs
Swine vesicular disease (SVD) - pig
Vesicular stomatitis (VS) - cattle, pigs, horses

Question 7

Describe the features of Picornaviridae

Answer 7

virions are spherical, non enveloped
genome = single molecule os +ve sense RNA
replicates in the cytoplasm of host cells

Question 8

What are the important genera of Picornaviridae and what diseases are included?

Answer 8

Apthovirus - FMD
Enterovirus - SVD

Question 9

How is FMD (foot and mouth disease) transmitted?

Answer 9

respiratory infection
ingestion of contaminated food
direct inoculation

Question 10

Clinical signs of FMD (foot and mouth disease)

Answer 10

Fever
Inappetance
Decreased milk production
Hypersalivation
vesicles on tongue, teats and feet (lameness)
abortion (due to fever)

Question 11

What are the secondary consequences of oral vesicles in FMD (foot and mouth disease)?

Answer 11

oral vesicles rupture due to smacking of lips
-> large denuded ulcerative lesions
-> secondary bacterial infection

Question 12

What samples are required for FMD (foot and mouth disease) diagnosis?

Answer 12

vesicular fluid
epithelial tissue from edge of vesicle
blood in anticoagulant
serum
pharyngeal fluid

Question 13

What test is used to diagnose FMD (foot and mouth diseas)?

Answer 13

ELISA
PCR

Question 14

How is FMD (foot and mouth disease) controlled

Answer 14

culling
quarantine and restricted movement

Question 15

Clinical signs of SVD (swine vesicular disease)

Answer 15

fever
lameness due to lesions on coronary bands

Question 16

How is SVD (swine vesicular disease) diagnosed?

Answer 16

ELISA or virus isolation

Question 17

Control of SVD (swine vesicular disease)

Answer 17

culling

Question 18

Describe the features of Rhabdoviridae and which disease belong to the family

Answer 18

single stranded
-ve sense
non-segmented RNA genome
red shaped
enveloped
Vesivular stomatitis virus

Question 19

How does vesicular stomatitis enter the body?

Answer 19

through breaks in the mucosa and skin
minor abrasion
arthropod bites e.g., mosquito

Question 20

Clinical signs of vesicular stomatitis

Answer 20

Fever
hypersalivation
lameness
vesicles
blisters on oral mucous membranes
vesicular lesions on teats, coronary bands, snout

Question 21

How is vesicular stomatitis diagnosed?

Answer 21

immunofluorescent antibody staining of vesicle tissue
ELISA on vesicular fluid
PCR
Cell culture

Question 22

Describe the genome of caliciviridae

Answer 22

single molecule of linear, +ve sense, ssRNA
Replicate in cytoplasm

Question 23

What are the 2 main causes of cats with upper resp tract disease?

Answer 23

feline calicivirus
feline herpes virus

Question 24

Clinical signs of FCV?

Answer 24

conjunctivitis
rhinitis
tracheitis
pneumonia
vesiculation and ulceration of oral epithelium
fever
lethargy
anorexia
stiff gait

Question 25

Clinical signs of feline herpes virus

Answer 25

sneezing
coughing
nasal and ocular discharge
corneal ulcers
frothy salivation

Question 26

Diagnosis of FHV

Answer 26

Virus isolation or PCR

Question 27

Diagnosis of FCV (feline calicavirus)

Answer 27

Virus isolation

Question 28

Treatment of FCV and FHV

Answer 28

fluid therapy to correct dehydration
antibiotics to prevent secondary infections

Question 29

Prevention of FCV and FHV

Answer 29

vaccines
quarantine

Question 30

Explain how toxicity can cause ulcers

Answer 30

primary photosensitisation due to plant infestion (e.g., St Johns wort, alfalfa)
secondary to liver disease
phenylbutazone toxicity in horses -> oral ulcers