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rhabdoviridae
- sense RNA, enveloped, broad host range, bullet shape.
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rabies
- Rhabdoviridae, - sense RNA, enveloped, broad host range, bullet shape.
- worldwide, urban (dogs, not in US) vs sylvatic (wildlife)
- transmission via bite, replicate in muscle tissues, peripheral motor nerves, retrograde spread to spinal cord, centrifugal spread to salivary glands, tissues, secretion in saliva.
- 14d-2y incubation
- prodromal phase = temperment change.
- 2 forms: furious (restlessness, nervousness, aggression, hypersalivation, hypersensitivity to light, sound, pain), and dumb/paralytic (depression, paralysis, seizures, coma, respiratory arrest, death)
- Mandatory vax, euth/quarantine/confinement for biting or bitten
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vesicular stomatitis virus (VSV)
- Rhabdoviridae, - sense RNA, enveloped, broad host range, bullet shape.
- vesicular dz of cattle, horses, pigs (rarely sheep and goats).
- Looks like foot and mouth so REPORTABLE
- transmitted by sand flies and black flies, breaks in mucosa (fomites), so seasonal. Unknown wildlife reservoir
- no viremia in domestic, dz NOT CONTAGIOUS.
- ZOONOTIC, flu-like in humans
- Economic impact
- 3-5d incubation, transient fever, lameness, vesicles and erosions usu in mouth, coronary band. Horses more affected.
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Reoviridae
- segmented dsRNA, non-enveloped, double or triple-layered capsid
- Includes Orbivirus (bluetongue and African Horse Sickness Virus, biting insects, endothelial cells, cell-associated viremia) and Rotavirus (enteritis, fecal-oral)
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Bluetongue Disease
- Reoviridae (Orbivirus, dsRNA, no envelope, triple capsid)
- spread by and replicate in biting midges (no-see-ems)
- Infects ruminants, mostly sheep. Not contagious, but ECONOMIC impact
- Attack endothelial cells, cell-associated viremia
- FFFs - fever, face and feet. Endothelial damage, so ulcers, hyperemia/cyanosis, edema, salivation, lameness. Abortion
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African Horse Sickness
- Reoviridae (Orbivirus, dsRNA, no envelope, triple capsid)
- transmitted by midge bites, high mortality.
- Zebras are natural reservoir, asymptomatic. Attacks donkeys, mules, horses
- peracute, subacute EDEMA, drown with petechiae.
- Endothelial damage, viremia. No effective tx. REPORTABLE
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Rotavirus
- Reoviridae (Orbivirus, dsRNA, no envelope, triple capsid)
- infect mature enterocytes in proximal ileum, kills apical enterocytes: shorten villi, loss of absorptive = fluid, dysfunction: reduced enzyme secretion, osmotic diarrhea. VIRAL TOXIN: induces chloride ion secretion. Villus ischemia, activation of enteric NS to increase motility.
- orofecal transmission, stable in environment and in water.
- All young domesticated animals. Diarrhea and depression, ocntinue to feed
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Birnaviridae
- non-enveloped dsRNA with 2 segments.
- Avibirnaviruses (Infectious bursal disease virus)
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Infectious Bursal Disease Virus (IBDV)
- birnavirus: dsRNA with 2 segments, non-enveloped. Avibirnavirus
- Gumboro Disease in Delaware
- Chickens 2-6w old
- orofecal
- infects Bursa of Fabricius, acquired B lymph deficiency = PERMANENT immunosuppression
- Stable in environment, highly contagious (fomites, insects)
- feather ruffling (ADR), watery diarrhea, trembling, dehydration
- changes, so vax is not great (moving target)
- Economic importants
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coronavirus and replication
- + RNA, enveloped, helical nucleocapsid
- so huge you can ID from EM
- direct fusion OR endocytosis (both use envelope to escape in)
- replication in cytoplasm of epithelial in gut or resp.
- multiple initiation sites for RNAPol = nested sets of subgenomic +RNAs (including large polyprotein)
- ER (glycoproteins) and cytoplasm (capsid proteins and genome).
- Bud into ER-Golgi intermediate (ERGIC)
- Exocytosis
- very diverse family, lots of bat viruses (probably become zoonotic)
- ALWAYS CHANGING: point mutation, recombination (co-infection, two viruses in nucleus), leads to new viruses and zoonoses
- Young (milk protects virus from acid) or immunocompromised/naive, causes diarrhea or resp dz.
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Infectious bronchitis Virus
- Chicken gamma-coronavirus, +RNA, enveloped, helical nucleocapsid
- respiratory (esp young), ENTIRE FLOCK WITHIN DAYS
- usu short duration but causes secondary bacterial infection
- catarrhal exudate in air sac, nasal, trachea, bronchi. Gasping, coughing, rales, nasal exudate, resp distress, lethargy, inappetance, death. Healing rapid, outbreaks explosive. Can affect kidney, oviduct (stop laying, abnormalities
- must give neuroaminidase before HA test
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Transmissible gastroenteritis of swine (TGEV)
- alphacoronavirus of swine, +RNA, helical nucleocapsid
- often fatal in <15d piglets from naive sow. Okay after 5w
- Fecal-oral
- kills villous tips, can cause fusion
- Diarrhea (supportive care, cause dehydration)
- Enzootic (regular recurrence, usu in farms that are not all in, all out)
- C/D can be infected, spread in feces
- "natural vaccine" - mutation lost enterotropism, protects against TGEV
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Porcine Epidemic Diarrhea Virus (PEDV)
- alphacoronavirus like TGEV (+RNA, enveloped, helical nucleocapsid), but occurs in TGEV-immune herds.
- high mortality and effusive diarrhea in piglets
- Infects respiratory tract and alveolar macrophages
- vax for endemic
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Porcine hemagglutinating encephalomyelitis virus (PHEV)
- betacoronavirus (+RNA, unenveloped, helical nucleocapsid)
- vomiting and wasting disease, with CNS (paddling, hyperesthesia, tremors).
- very common but disease infrequent (neonates protected by maternal)
- Spread by respiratory, invades respiratory and/or gut epithelium, can migrate up axons to sensory ganglia of trigeminal and vagus, to brain stem, cerebrum, cerebellum.
- No vaccine
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Bovine coronavirus (BCoV)
- beta coronavirus (+RNA, unenveloped, helical nucleocapsid)
- calf scours
- calves less than 2 months old
- very common.
- Replicates at tips of villi.
- Diarrhea, usually mild. Sometimes dehydration/shock
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feline coronavirus (FCoV)
- +RNA, unenveloped, helical nucleocapsid
- Feline Enteric Coronavirus and Feline Infectious Peritoneal virus are biotypes of feline alphacoronavirus with serotypes I and II (any combo, so FECV-1 and FECV-2, FIPV-1 and FIPV-2) Type 2 mutated from canine. Type 1 most common, but often have both.
- Virus isolation only with type 2
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Feline Enteric Coronavirus (FECV)
- biotype of feline coronavirus (+RNA, unenveloped, helical nucleocapsid), can be serotype 1 or 2 (with FIP)
- ubiquitous - >6 cats WILL have it (shelters)
- mild diarrhea, occasionally more severe. Infects tips of villi. persistent shedding for weeks, can re-infect/auto-infect.
- Fecal-oral and very efficient
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Feline Infectious Peritonitis Virus (FIP)
- biotype of feline coronavirus (+RNA, unenveloped, helical nucleocapsid), can be serotype 1 or 2 (with FECV)
- rare, fatal mutation. 5% of infected FCoV cats.
- more common with high cat density, young or immune suppressed (high viral load)
- Requires antibody production and rarely transmits
- viremia, infects monocytes, deposits ag/ab complexes to attract more. Vascular inflammation, vascular compromise, death.
- prolonged fever, inappetance, weight loss, sometimes icteric. Wet (sticky fluid with high protein in abdomen, dyspnea) or dry (none, may have retinal/uveitis/neuro). Polygammopathy = decreased Ig/albumin ratio <0.4
- pyogranulomas on viscera (octopus legs).
- hard to dx, negatives useful but + just Co. Vaccines dangerous.
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Canine Coronavirus
- alphacoronavirus, +RNA, unenveloped, helical nucleocapsid
- fecal-oral, kills villous tips
- sometimes acquire with parvo (tips and crypts, bad news), VERY severe diarrhea.
- Diarrhea, two serotypes like feline but though some systemic leukopenia, NO FIP LIKE SYMPTOMS
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Canine Respiratory Coronavirus (CRCoV)
- betacoronavirus, +RNA, unenveloped, helical nucleocapsid
- circulates in high-density housing, part of "kennel cough" complex
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Porcine deltacoronavirus
- deltacoronavirus, +RNA, unenveloped, helical nucleocapsid
- reservoir in birds, from leopard cat CoV
- New and novel, economic loss.
- diarrhea, stomach lesions.
- Virus isolation in swine testicle cells.
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Asfivirus (and ASFAR)
- large double stranded DNA, Icosahedral, envelope. Like pox. Replication in cytoplasm, exocytosis.
- causes African Swine Fever (and Related Viruses)
- ONLY arbovirus (ARTHROPOD BORNE VIRUS) among DNA, carried by ticks as BIOLOGIC vector (virus MATURES IN TICK, transovarial, transstadial, sexual transmission in ticks).
- all breeds of domestic pigs and wild
- Sylvatic cycle: infects wild young warthogs asymptomatically, viremia infects argasid tick. Adults are immune. Virus replicates and shared among ticks (biological vector), transmit with each blood meal.
- domestic cycle: tick feeds, viremia, shed in all body secretions, rapid spread between pigs (can get it from eating uncooked garbage, fomites, air, etc.
- Replicates in reticuloendothelial (leukocytes = leukopenia, RBC = viremia, endothelial cells = vascular damage = edema/hemorrhage. NOT intestines (no diarrhea)
- peracute: fever, hyperemia, death
- acute: fever, cough, severe leukopenia, hemorrhage, abortion
- chronic: arthritis, pneumonia, red/necrotic skin lesions.
- 5 genotypes with variation in virulence. Not in N. America. REPORTABLE in US
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