Rabbit Hemorrhagic Disease Flashcards
Structure
lagovirus, non-enveloped, positive sense ssRNA several strains
Mortality
up to 100%
Is it zoonotic
no
Species at rick
New england cottontail, Snowshoe hare, european rabbits, Black-tailed jackrabbits, Eastern cottontails, Volcano rabbits
History
identified in 1984
used against invasive rabbits in Australia
Classified as Foreign Animal Disease
sporadic domestic rabbit outbreaks of RHDv2 between 2018-2020
Special Properties
Very resistant to inactivation when in tissues-> last up to 7.5 months in 39F temp
>3 months in 68F and dried organ tissue
unprotected viruses don’t last more than few weeks
Can survive exposure to pH 3.0, heat of 122F for an hour and freeze-thaw cycles
Transmission methods
direct contact or exposure to contaminated excretions or blood
can survive and spread from carcasses, food, water, and any contaminated materials
people can spread the virus indirectly by carrying it on their clothing and shoes
Insects have been shown to also be mechanical transmission method
oral
Pathogenesis
target cells-> hepatocytes
Causes cell lysis-> mass cell death in liver-> hemorrhage that leads to secondary complications
Incubation
1-3 days
Per-acute clinical signs
sudden death within 12-36 hrs post infection
fever
Subclinical seen in rabbits
<4-8 weeks of age
Acute clinical signs
depression, anorexia, reddening of conjunctiva, respiratory signs, jaundice, ocular hemorrhage/epistaxis, incoordination
Pathologic Lesions
diffuse centrilobular hepatocellular degeneration, liver necrosis, splenomegaly, hyperemic tracheal mucosa, edematous and congested lungs, disseminated intravascular coagulation
Diagnosis
necropsy-> PCR and postmortem changes
Hemagglutination inhibition, Indirect ELISA, Competiticve ELISA
Effects on wildlife
epidemics-> 30-100% declines
creates unstable ecosystems
