Final: Birnaviridae And Caliciviridae Flashcards
What family of viruses are non-enveloped viruses, hexagonal in outline, single shell with icosahedral symmetry and have two segments of linear ds RNA?
Birnaviridae
Infectious burial disease (IBD) belongs to what family of viruses? Is also known as what disease? Where does it live in the body?
Birnavirus
AKA Gumboro Disease
Predilection for the bursa of Fabricius (cloacal bursa)
Infectious Bursal Disease Virus (IBDV) has how many serotypes?
2
What is serotype 1 of IBDV?
Pathogenic to chickens
Has 3 antigenic subgroups:
Variant viruses (no mortality), classic or standard viruses (10-50% mortality), and very virulent viruses (50-100% mortality)
What is serotype 2 of IBDV?
Asymptomatic infections in chickens and turkey
Transmission of IBDV?
Virus excreted by infected birds infects a healthy bird by direct contact or the fecal-oral transmission.
Virus is very stable in nature. Can survive in poultry houses even after cleaning and disinfection procedures are followed. Detected in water and feed even after 52 days.
What is the pathogenesis of IBDV?
Oral infection -> replication in gut associated macrophages and lymphocytes in the ceca and small intestine -> liver -> blood stream ->virus replicated in the Burse of Fabricius and depletes the lymphoid B cells (highest susceptibility is between 3-6 weeks) -> secondary viremia -> localization in other tissues, including other lymphoid tissues -> IBDV trigger both direct (macrophage activation) and indirect (T cell activation) to induce a cytokine storm in acute phase of the disease -> mortality
Immunosuppression: in recovered birds or subclinical cases, diminished antibody response and increased susceptibility to a wide range of opportunistic infectious agents
What are the clinical signs of IBDV?
Distress, depression, ruffled feathers Diarrhea, anorexia Dehydration Swollen bursa Fabricius with hemorrhages Subcutaneous and intramuscular hemorrhages
What are the stages of the bursa infections and what can be seen?
Acute stage -> enlarged edematous bursa
5 days post infection bursa returns to normal size. May be hemorrhagic as in this specific bursa
8 days post infection bursa atrophied and up to 1/8 of normal size
T/F: Live IBD vaccines are produced from fully or partially attenuated strains of virus, known as mild, intermediate, or intermediate plus?
True
T/F: Mild vaccines strains that cause no burial lesions cannot be used effectively in chicks with maternal-derived antibodies (MDA) until about 4 weeks of age as they are neutralized
True
In ovo vaccinations of immune complex (live IBD vaccine virus + anti-IBDV antibody) can be injected at how many days of incubation?
18
What type of vaccine that uses a viral vector to express the VP2 antigen of IBDV in chickens has been licensed recently?
Live recombinant vaccine
T/F: Serotype-2 Birnavirus causes IBD in chickens
False
T/F: Calicivirus derive their name from the Latin word for calix, or ____, as some members of this family have 32 cup-shaped surface depressions that give it a unique appearance.
Cup
What are the two Genus that we are interested in for family Caliciviridae?
Norovirus -> cause gastroenteritis
Vesivirus -> vesicular exanthema of swine virus and feline calicivirus
Feline Calicivirus (FCV) is a highly infectious pathogen of what species?
Felines
That was an easy one
FCV belongs to genus _____, family __________.
Vesivirus; Caliciviridae
T/F: Being genetically diverse, FCV is associated with a range of clinical syndromes.
True
Clinical syndromes may range from inapparent infections to typically mild or acute ____ and upper ______ tract disease in cats
Oral; respiratory
Some strains of FCV will induce what?
Lameness, known as limping syndrome
What has emerged most recently in the USA and is associated with a systemic infection that is frequently fatal?
Highly virulent forms of the FCV virus
What is the pathogenesis of FCV?
Carrier, recovered, mildly infected cat, or acutely infected cats -> virus is shed in oral, nasal and conjunctival secretions largely by direct contact -> conjunctiva, inhaled or ingested by healthy cat
What are the routes of infection for FCV in healthy cats?
In healthy cat, FCV replicated mainly in the oral and respiratory tissues. Strains may differ in their tissue tropisms and pathogenicity. Viruses even found in feces and urine.
What are the clinical signs of FCV-associated oral and upper respiratory tract diseases?
Tongue ulcers (most prominent lesion)
Sloughing oral ulcer & rhinitis
Chronic ulcerative proliferative gingivostomatitis. Possibly an immune mediated reaction to FCV, not clear.
Tongue ulcerative glossitis
Pneumonia (acute exudative followed by proliferative interstitial pneumonia)
T/F: FCV-associated lameness (limping syndrome) always occurs
False, only occasional
During the last decade, a severe form of ___ disease with high mortality rates has been reported in cats
FCV
T/F: In all of the reported outbreaks, vaccinated cats have been affected, suggesting that current vaccines may not protect against FCV-VSD disease.
Unfortunately true
The clinical-pathological features of FCV-VSD differ substantially from those of ‘classical’ FCV disease.
Fun fact
What are the vaccines for FCV?
Most FCV vaccines are in combo with FHV or with more additional antigens.
Modified-live and inactivated parenteral vaccines exist, the modified-live intranasal vaccine has been discontinued in Europe, but still available in USA
Early vaccination of FCV should be considered for who?
Kittens from queens that have had infected litters previously, or for cats at risk of infection
T/F: There is no need to vaccinate healthy cats against FCV
False, stab those babies
T/F: Cats that have recovered from Calicivirus disease are probably protected for life, particularly against disease caused by different strains. Vaccination of these cats is still recommended.
False, they are protected for life which is why the vaccines are still recommended.
ID
An acute, highly infectious viral disease characterized by fever and formation of vesicles on the snout, oral mucosa, soles of the feet, the coronary band and between the toes
Vesicular exanthema of swine (VES)
T/F: In pigs, the clinical disease of vesicular exanthema of swine (VES)is indistinguishable from foot-and-moth disease, vesicular stomatitis and swine vesicular disease. Chances of secondary bacterial infection.
True
What is the transmission of VES?
Direct contact with infected animals and ingestion of raw garbage containing infected pork scraps.
Which country was declared VES free?
USA
T/F: Calicivirus can cause fatal systemic disease in cats
True
