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SGU Virology: Final - Avian Set 1
Terms in this set (100)
Newcastle disease belongs to which viral family?
What types of bird experience inapparent infections of Newcastle disease?
ducks and geese
How does newcastle disease present in humans?
What types of clinical signs may be seen with Newcastle disease?
respiratory, circulatory, gastrointestinal or nervous
The signs of Newcastle disease depend on what factors?
age and immune status of host
virulence and tropism of virus
Where does the virus for Newcastle disease replicate?
mucosal epithelium of the upper respiratory and intestinal tracts
Where does the virus for Newcastle disease go after the first viremia? Second viremia?
first: spleen and bone marrow
second: infection of lungs and CNS
What are the gross lesions associated with Newcastle disease?
eccymotic hemorrhages in the respiratory and GI tracts
What are the histologic lesions associated with Newcastle disease?
necrotic foci in the intestinal mucosa and lymphatic tissue
hyperemic changes in all organs
What determines the virulence of the Newcastle disease virus strain?
cleavability and activation of their hemagglutinin, neuraminidase and fusion glycoproteins
In Newcastle disease, what determines the tissue tropism?
presence of cellular proteases
strain's glycoproteins cleavability
What terms are used to describe Newcastle virus strains with high, moderate, and low virulence?
Maternal Ab protects chicks against newcastle disease for how long after hatching?
What are some diagnostic tools for Newcastle disease?
virus isolation from spleen, lung or brain in embryonated egg
IF of tracheal sections (not as sensitive)
Ab detection in unvaccinated flocks only
What factors are used to determine virulence of the virus causing Newcastle disease?
mean death time of chick embryos
plaque formation in chicken cells
How is Newcastle disease transmitted?
direct contact with infected birds or fecal material
indirect via contaminated people, vehicles, equipment, insects, rodents
Transovarian transmission is important for what virulence of Newcastle disease?
What is an important factor for introduction of velogenic strains of Newcastle disease?
caged birds imported from endemic areas
Laying hens are revaccinated against Newcastle disease how often?
every 4 months
Infectious bursal disease belongs to which viral family?
Infectious bursal disease is highly contagious in chickens of what age?
What type of chicken is highly susceptible for IBD?
Which type of IBD affects chickens? turkeys?
chickens: type I
turkeys: type 2
How is IBD transmitted?
also by fomites
How long does infection with IBD last?
What are clinical signs of the acute form of IBD?
prostrated, debilitated and dehydrated
Why are chickens with subclinical IBD more susceptible to opportunistic infections?
bursal atrophy with fibrotic or cystic follicles and lymphocytopenia
Enlarged kidneys and accumulation of urates is commonly seen with what disease?
Birds over what age are mostly resistant to IBD?
What will you see on necropsy of a chicken with IBD?
changes in bursa of Fabricius: swelling, edema, hemorrhage, jelly serosa transudate, atrophy
hemorrhages in skeletal muscle, intestine, kidney, spleen
How does the bursa appear in the acute stage of IBD?
enlarged and edematous
How long after infection with IBD will the bursa atrophy?
What are ways to diagnose IBD?
IF or IHC tests
viral isolation in embryonated eggs
serologic tests checking for Ab
What is the vaccine protocol for IBD?
oral-live vaccine in drinking water at 18wks followed by injection of inactivated adjuvanted vaccine
repeat 1 year later
Other than vaccines, what is a control method for IBD?
biosecurity with adequate restriction to farm visitation
Marek's disease belongs to which viral family?
What are the viral characteristics of Marek's?
double stranded DNA
intranuclear inclusion bodies
What is important to know for transmission of Mareks?
cell-free infectious virus from dander in the feather follicles
What are the 4 syndromes associated with Mareks?
What is a classic sign of the neurolymphomatosis syndrome of Mareks?
one leg forward and one back....chicken splits!
What is the presentation of the ocular lymphomatosis syndrome of Mareks?
graying of the iris
pupil is irregular, eccentric and partial/total blindness
How do chickens get infected with Mareks?
inhalation of dander
What type of viremia is associated with Mareks?
What type of cell are transformed by the virus that causes Mareks?
True/False: the Marek's disease virus has oncogenes
What is the most constant gross finding of Marek's disease?
enlargement of 1 or more peripheral nerve trunks
Lymphomatous lesions from Marek's disease cannot be distinguished from those of which other disease?
Where would you likely see lymphomatous lesions in Mareks disease?
ovary, heart, lung, splen
True/False: a common method of transmission of Mareks is vertical transmission/ in ovo
True/False: more than one avian tumor virus can be present in a single chicken
What are factors that help differentiate Mareks from lympoid leukosis and reticuloendotheliosis?
age: Mareks affects any age
clinical signs: frequent wing and leg paralysis
incidence: >5% in unvaccinated flocks
potential nerve enlargement
interfollicular tumors in bursa of Fabricius
lymhoid proliferation in skin and feather follicles
pleomorphic lymphoid cells in nerves and tumors
What are some diagnostic tests for Mareks?
IF and IHC looking for Ag
virus isolation in chicken kidney or embryonated egg inoculated with buffy coat or spleen cells
What is the only known method to preventing tumor development in chickens infected with Mareks virus?
When is the earliest a vaccines can be given to protect against Mareks?
**or sub-q inoculation in 1-day old chicks
Birds carrying ______ have some genetic resistance to Mareks
Avian leukosis belongs to which viral family?
True/False: roosters have no part in congenital infection of avian leukosis
Do replication-competent avian retroviruses have oncogenes?
What is the rate of tumor development for replication defective avian retroviruses?
Which syndromes of avian retroviruses are replication competent?
True/False; serology can be used to diagnose avian leukosis
How is avian leukosis excreted?
saliva and feces
How is avian leukosis transmitted?
horizontally and vertically
Why is hygiene especially important after egg hatching to prevent avian leukosis?
b/c if egg is infected, large amounts of virus is shed in meconium at hatching which results in environmental contamination
What are some methods for control of avian leukosis?
hygiene at hatching
genetics --> resistance to virus
vaccines (limited success)
Avian influenza belongs to which viral family?
What are the viral characteristics of avian influenza?
single stranded RNA
segmented -- reassortment
Which type of avian influenza undergoes antigenic shift and drift?
Avian influenza affects which birds?
chickens and turkeys
What is the major reservoir for avian influenza?
True/False: avian influenza is zoonotic
What are the clinical signs of avian influenza in humans?
febrile respiratory disease
death may occur as a result of viral/bacterial pneumonia
Highly pathogenic strains of which viral disease is known as fowl plague?
Which are some clinical signs of older birds infected with highly pathogenic strain of avian influenza?
cessation of egg laying
respiratory distress, sinusitis
edema of face and neck
cyanosis of comb and wattle
What factors could exacerbate clinical signs of avian influenza?
concurrent infections, live-vaccines or environmental stressors
What is important for determining virulence of avian influenza?
Where is viral HA cleaved in patients with avian influenza?
respiratory and GI tract
in other tissues leads to systemic disease and death
What type of bird is refractory to most virulent strains of avian influenza?
What is the pathogenesis of virulent strains of avian influenza?
multifocal lymphoid and visceral necrosis
What are the gross lesions associated with avian influenza?
petechial hemorrhages and serous exudates in respiratory, digestive and cardiac tissues
What diagnostic tool is necessary to determine virulence of avian influenza?
virus isolation from cloacal swabs
Virulence of avian influenza is determined by ______ and ____ pathogenicity
intracerebral and intravenous
Which diagnostic test has the best sensitivity and specificity for avian influenza?
Which diagnostic test for avian influenza is used to give a type-specific diagnosis?
serology (looking for Ab)
How is avian influenza shed?
shed in high concentrations in feces and survives long time in water at low temp
True/False: vaccines are used for control of avian influenza
What are the control methods for avian influenza at the international, national and local levels?
international: notifiable disease
national: quarantine and removal programs
local: prevent introduction from wild birds
Avian infectious bronchitis belongs to which viral family?
Clinical signs of avian infectious bronchitis depend on what factors?
age, route of infection, immune status and viral strain
What are clinical signs of virulent strain of avian infectious bronchitis in chickens 1-4 weeks old?
gasping, coughing, rales, nasal exudates and respiratory distress
**signs last 5-7 days
Why would mortality be high in broilers with avian infectious bronchitis?
due to secondary infection with E. Coli
What are clinical signs in egg-producing birds with avian infectious bronchitis?
cessation of egg laying
**pasting may occur
Where does the virus for avian infectious bronchitis replicate?
ciliated epithelium of the respiratory tract
bursa of fabricius
Viremia from avian infectious bronchitis damages which organs?
What are the gross lesions associated with avian infectious bronchitis?
serous or catarrhal exudate in nares, trachea, bronchi and air sacs
yellow casts block bronchi
Infection with avian infectious bronchitis induces production of which antibodies?
IgM, IgY and IgA
What are the diagnostic tests for avian infectious bronchitis?
direct IF of tracheal smears (used in early dz)
serology (determines types)
How is avian infectious bronchitis transmitted?
aerosols, ingestion of feces-contaminated feed, fomites
What is the major control method for avian infectious bronchitis?
vaccines: in water, spray or in conjunctiva
**outbreaks decline but dz may still occur with vax
vax breaks common b/c new antigentic varients
Why is control of avian infectious bronchitis difficult?
new antigenic variants
persistently infected chickens
Recommended textbook explanations
Fundamentals of Biochemistry
Charlotte W. Pratt, Donald Voet, Judith G. Voet
Miller and Levine Biology
Joseph S. Levine, Kenneth R. Miller
Campbell Biology (AP Edition)
Cain, Jackson, Minorsky, Reece, Urry, Wasserman
Lehninger Principles of Biochemistry
David L Nelson, Michael M. Cox
Sets found in the same folder
SGU Virology Final: Swine
SGU Virology: Final - Avian Set 2 And Ruminant
SGU Virology Final: Equine
SGU Virology: Midterm Set 1
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