Lecture 9 - Bluetongue, Salmonellosis, Paratuberculosis Flashcards
BLUETONGUE (BT) is a
non-contagious viral disease of ruminants
transmitted by midges (Culicoides spp),
caused by Orbivirus,
characterized by fever, oral lesions, cyanotic tongue and coronitis.
BLUETONGUE (BT) is a non-contagious viral disease of ruminants transmitted by
midges (Culicoides spp),
caused by Orbivirus,
characterized by fever, oral lesions, cyanotic tongue and coronitis.
BLUETONGUE (BT) is a non-contagious viral disease of ruminants transmitted by midges (Culicoides spp), caused by
Orbivirus,
characterized by fever, oral lesions, cyanotic tongue and coronitis.
BLUETONGUE (BT) is a non-contagious viral disease of ruminants transmitted by midges (Culicoides spp), caused by Orbivirus, characterized by
fever, oral lesions, cyanotic tongue and coronitis.
BTV
Bluetongue virus
What genus and family does BTV belong to?
Genus Orbivirus,
family Reoviridae
What type of virus is BTV?
RNA virus
How many serotypes does BTV have?
26
In what circumstances is BTV inactivated?
Inactivated in pH <6 and >8
Disinfectants: sodium hypochlorite (bleach), 3% sodium hydroxide (lye).
Virus does not persist once cold weather kills the Culicoides vectors.
Why does BTV not persist once cold weather hits?
Virus does not persist once cold weather kills the Culicoides vectors (biting midges).
Host range of BTV.
Host range: all ruminants
Primary host – sheep
Other infected – cattle, goats, deer etc.
Primary host of BTV
Sheep, though affects all ruminants.
Morbidity of BTV in sheep.
Sheep are the primary host.
Severity of dz varies by breed, virus strain and environmental stress.
Morbidity <100%
Mortality of BTV in cattle & goats.
CATTLE & GOATS
Death is rare
Morbidity of BTV in cattle & goats.
CATTLE & GOATS
Morbidity <5%
Mortality of BTV in sheep.
Sheep are the primary host.
Severity of dz varies by breed, virus strain and environmental stress.
Mortality 0-30%
Recent distribution of BTV.
Transmission of BTV. (3)
Biting midges – Culicoides spp
In utero
Mechanical (iatrogenic by blood e.g. needles and instruments)
Excretion of BTV.
Venereal possible?
Is excreted in semen but venereal transmission is uncommon.
The incubation period for bluetongue is
5 to 10 days.
The vast majority of infections with bluetongue are
clinically inapparent aka asymptomatic.
Clinical signs of BTV in sheep. (4)
Oral lesions and ulceration.
Tongue – swollen, protruding, cyanotic (= ‘blue-tongue’).
Reproductive failure.
Coronitis – inflammation of coronary band leading to lameness.
What might the image depict?
coronitis and consequent lameness due to bluetongue disease
Clinical signs of BTV in cattle & goats. (5)
Usually subclinical.
Vesicles or ulcers in the mouth.
Erosions, crusts around nose and teats.
Coronitis.
Reproduction failure.
Post mortem lesions of BTV in sheep. (5)
Face and ears edematous
Dry, crusty exudate on nostrils
Coronary bands hyperemic
Internal hemorrhaging
Hydranencephaly, cerebellar dysplasia
Post mortem lesions of BTV in cattle. (2)
Skin: edematous, ulcerated, dry, thick folds
Mouth: vesicles, ulcers, necrosis
Post mortem lesions of BTV in newborns and fetuses. (3)
Hydranencephaly
Cerebellar dysplasia
Cerebral cysts
DDx for BTV. (6)
FMD (both have lameness and oral lesions)
Vesicular stomatitis (both have oral lesions)
Peste des petits ruminants
Malignant catarrhal fever
Bovine virus diarrhea
Infectious Bovine Rhinotracheitis
Material for diagnosis of BTV. (3)
Blood
Spleen, liver, red bone marrow, heart blood, LNs.
Aborted and congenitally infected newborns: pre-colostrum serum.
Lab analyses for diagnosis of BTV. (4)
Virus isolation
Immunological tests
PCR
Serology (ELISA, AGID)
What is the only vesicular disease of horses?
vesicular stomatitis, a viral disease
(can also affect cattle and pigs but not really as much anymore, mostly a horse thing in America)
Treatment of BTV.
no treatment, is viral disease
Prevention & control of BTV in Disease free areas: (3)
Quarantine and restriction of movements,
serological survey.
Vector control.
Prevention & control of BTV in Infected areas: (1)
vector control
Vaccination toward BTV.
Live attenuated vaccines are serotype specific.
Can be transmitted to unvaccinated animals and could reassort with field strains with a potential risk of new viral strains?
Killed vaccines also available.
Another name for Salmonellosis.
paratyphoid
SALMONELLOSIS is a disease of
multiple animal species,
caused by Salmonella spp.,
associated with septicemia, diarrhea and abortions.
SALMONELLOSIS is a disease of multiple animal species, caused by
Salmonella spp. bacteria,
associated with septicemia, diarrhea and abortions.
SALMONELLOSIS is a disease of multiple animal species, caused by Salmonella spp. bacteria, associated with (3)
septicemia, diarrhea and abortions.
Describe salmonella species.
Gram–, facultatively anaerobic rods.
What family and genus do Salmonella spp. belong to?
Family Enterobacteriaceae, genus Salmonella
over 2500 serovars!
Salmonella serotypes are typically divided into
typhoidic and non-typhoidic.
(s.typhimurium & s.enteridis)
over 2500 serovars!
Most zoonotic salmonella spp. belong to what species?
Salmonella enterica subsp. enterica (subspecies I)
Serovars referred by name, e.g. S. enterica subsp. enterica serotype Enteritidis or Salmonella ser. Enteritidis or Salmonella Enteritidis
Shortname S. enterica subsp. I, refers to?
Full name is: S. enterica subsp. enterica (subspecies I)
S. enterica subsp. II is short for…?
Short for: S. enterica subsp. salamae (subsp. II)