Respiratory Infections Part 2 (test 2) Flashcards
T or F
Gammaherpesvirinae subfamily viruses are ubiquitous in mammals, but most are pathogenic in the host
False, Ubiquitous in mammals, but most are non-pathogenic in the host
What was significant veterinary gammaherpesvirus that infected bison and cattle?
Malignant Catarrhal Fever
What are some natural hosts for Malignant Catarrhal Fever?
Does it cause disease in those hosts?
Sheep, Wildebeest
NOPE
Alcelaphine herpesvirus type 1 attack what species? where would you see it?
Attacks Wildebeests and mainly occurs in africa, zoos or game farms
Ovine herpesviruses are found in what species, but doesn’t cause disease?
Sheep, found in north america
List some symptoms of Malignant Catarrhal Fever
Pan systemic disease that affects lympohoid and epithelial tissues resulting in:
Clinical signs seen in: Upper respiratory, and intestinal tracts, eyes, lymph nodes
Lesions include: epithelial erosion, ulceration, mucopurulent repiratory exudate, melena, Corneal Opacity, epistaxis
Is MCF contagious?
No, usually sporadic, so you will typically see disease in a few animals in a group.
But you can see very high attack rates in highly susceptible species such as bison or deer
Sheep and wildebeest hosts of MCF show no clinical signs, but do they shed the virus at all times?
Nope, remember this is a herpes virus, which loves to transition to periods of latency…NO disease.
What cell type and tissues does MCF specifically infect in Cattle ?
Initial infection of lymphocytes, lymphoid tissues (may be difficult to detect viral replication early on but after several weeks to months you can see:
perivascular lymphofroliferative disease
OHV-2 genome in lymphoproliferative cells
Presuemd dysregulation of lymphocytes
Severe necrotizing vasculitis
ischemic necrosis leading to mucosal ulceration, disease
What about MCF that ends in fatalities?
It eventually targets the vascular walls and the fatal lesions are necrotizing vasculitis affecting primarily the respiratory and GI tracts
MCF is a herpesvirus, therefore…What is important for viral transmission?
Close contact for transmission (co-mingling, adjacent pens/feedlots)
Distance: the closer to sheep, more efficient the transmission
Environment: May live several days, travel farther in moist cool weather
Age of the sheep: shed most intensely at about 6-8 months of age; adult shed much lower levels and less often
What is an important differential for MCF?
Rule out Foot and mouth disease!
-Ulcerations in the stoma
How do you diagnosis MCF?
Clinical signs, exposure to carriers, vasculitis histopathology, PCR detection of virus in lymphoid tissues.
atibody testing is available, but limited
What is the best way to control transmission of MCF?
Physically separate sheep/wildebeest from cattle, bison, etc.
There is no vaccine available
