Caliciviridae, Birnaviridae, Rhabdoviridae (Final) Flashcards
Caliciviridae General Features
- structure
- genome
- replication location
- non-enveloped, icosahedral
- 32 cup-shaped surface depressions
- linear, single stranded, pos sense RNA
- genomic RNA is infectious
- replication in cytoplasm
Feline Calicivirus
- genus
- types of disease
- Vesivirus
- highly infectious pathogen of cats
- inapparent infections to oral and upper respiratory tract disease
- some induce lameness (limping syndrome)
Feline Calicivirus
- transmission and pathogenesis
- virus shed in oral, nasal, and conjunctival secretions (direct contact)
- infected via inhalation, ingestion, and conjunctiva
- virus replicated in oral and respiratory tissues
- recovered or mild infected cats can act as carriers
Feline Calicivirus clinical signs
- tongue uclers
- sloughing oral ulcers and rhinitis
- gingivostomatitis, glossitis
- pneumonia
- limping syndrome: acute synovitis, thickening of synovial membrane and increase synovial fluid
FCV-associated Virulent Systemic Disease
- patholgy
- ulceration of oral and nasal tissues
- hyperemia, sloughing of foot pad
- pneumonia
- necrosis of liver, spleen, and pancreas
- infections of endothelial cells
FCV-associated Virulent Systemic Disease
- clinical signs
- pyrexia, subcutaneous facial and limb edema
- crust lesions, ulcers, alopecia
- anorexia, jaundice, respiratory distress
Vesicular Exanthema of Swine
- family, genus
- clinical signs
- transmission
- Caliciviridae, Alphavirus
- fever, formation of vesicles on snout, oral mucosa, feet, coronary band, and between toes
- transmission by direct contact with infected animals and ingestion of raw garbage with infected pork scraps
San Miguel Sea Lion Virus
- family, genus
- clinical signs
- Caliciviridae, Alphaviris
- vesicles in oral cavity and on flippers
Birnaviridae General Features
- structure
- genome
- replication location
- non-enveloped
- hexagonal, icosahedral
- two segments of linear dsRNA
- virus replication in cytoplasm
Infectious Bursal Disease
- family, genus
- host
- target organ/tissue
- serotypes
- transmission
- Birnaviridae, Avibirnavirus
- young chickens
- targets lymphoid tissue, mainly Bursa
- Serotype 1: pathogenic to chickens
- Serotype 2: asymptomatic infections in chickens and turkeys
- fecal-oral, very stable
Pathogenesis of Infectious Bursal Disease
- virus replication in macrophages and lymphocytes in ceca and small intestine
- travels to liver then enters bloodstream
- goes to Bursa and deplete B-cells
- secondary viremia
- localizes in other tissues and lympoid tissues
- induces cytokine storm
- immunosuppression
Clinical Signs of Infectious Bursal disease
- distress, depression, ruffled feathers
- diarrhea, anorexia, dehydration
- swollen Bursa with hemorrhage
- Bursa atrophies after 8 days
- subcutaneous and intramuscular hemorrhages
What are the 4 genera of Rhabdoviridae?
Lyssavirus
Vesiculovirus
Ephemerovirus
Novirhabdovirus
Rhabdoviridae General Features
- structure
- genome
- replication location
- enveloped, rod or cone-shaped
- single stranded, linear, neg sense RNA
- replicated in the cytoplasm
What are proteins associated with Rhabdoviridae?
- G protein: glycoprotein spikes covering the virion
- N protein: makes up the nucleocapsid
- P protein: a co-factor of viral polymerase
- M protein: an inner protein that facilitates virion budding
- L protein: an RNA-dependent RNA polymerase
Rabies virus
- family, genus
- hosts/reservoirs
- transmission
- rhabdoviridae, lyssavirus
- all mammals including humans
- reservoirs: skunks, raccoons, wolves, foxes, and bats
- transmitted via bite of rapid animal
- urban and sylvatic cycles
Describe the phases of Rabies infection
Prodromal Phase: behavioral changes - aggressiveness, no fear of humans - nocturnal animals awake in the day Excitative (fury) Phase: - severe agitation and aggressiveness - animal bites any material - high barking sound in dogs Paralytic (dumb) Phase: - inability to swallow, hydrophobia - foaming, excess salivation - paralysis, death
Pathogenesis of Rabies Virus
- virus replicates in muscle tissue
- accesses peripheral nerves and binds to acetylcholine receptor at NMJ
- moves to infect CNS
- reaches limbic system and replicates rapidly, leading to fury
- later, virus reaches salivary glands
Diagnosis of Rabies Virus
- tissue from two locations in the brain: stem and cerebellum
- negri bodies in neurons are diagnostic of rabies
- diagnosis only performed in reference labs
- gold standard: FAT
Vesicular Stomatitis Virus
- family, genus
- hosts
- Rhabdoviridae, Vesiculovirus
- cattle, swine, horses
- zoonotic
- reportable
Clinical features of Vesicular Stomatitis Virus
- excessive salivation and fever: first signs in cattle and horses
- lameness: first sign in swine
- vesicles on tongue, oral mucosa, teats, and coronary bands
- in horses: tongue lesions most pronounced
Vesicular Stomatitis
- transmission
- pathogenesis
- transmitted by biting insects
- enters body through mucosal or skin abrasions
- replicates in intraepithelium of mucosa and skin, leading to edema (vesicles with fluid)
Viral Hemorrhagic Septicemia Virus
- family, genus
- hosts
- Rhabdoviridae, Novirhabdovirus
- systemic infection in salmonids
Clinical signs of Viral Hemorrhagic septicemia virus
- lethargy
- spiral swimming pattern
- darkened body color
- pale gills
- exophthalmia
- hemorrhage at base of fins
- mottled and congested liver
Infectious Hematopoietic Necrosis Virus
- family, genus
- host
- Rhabdoviridae, Novirhabdovirus
- salmonid fish
Clinical signs of infectious hematopoietic necrosis virus
- darkened body color
- lethargy
- pale gills indicating anemia
- bilateral exophthalmia
- distention of abdomen due to ascites
- hemorrhage at base of fin
Bovine Ephemeral Fever VIrus
- family, genus
- other name
- host
- transmission
- Rhabdoviridae, Ephemerovirus
- 3-day stiff sickness
- cattle and water buffalo
- tranmission by Cullicoides
Clinical features of Bovine Ephemeral Fever virus
- fever
- immediate drop in milk production
- nasal and ocular discharge
- cessation of rumination
- constipation and abortion
- diarrhea, paresis
What is the gold standard diagnostic test for bovine ephemeral fever virus?
virus isolation in mosquito cell culture or suckling mouse brain
