virology wk 4

  1. Canine parvovirus
    • ssDNA, small, sturdy, non-enveloped capsid.  Replicates inside DIVIDING host cells.
    • Highly contagious, causing acute GI illness
    • signs: lethargy/anorexia/fever to vomiting and hemorrhagic small-bowel diarrhea (24-48h).  Can develop septic shock (long CRT, bad pulse, tachycardia, hypothermia).  
    • Shed in feces within 4-5d of exposure (pre-signs) and for 10 days after signs.
    • Infection: direct oral or nasal contact with viral feces or fomites.
  2. Feline herpesvirus
    • ds DNA, larger virus, glycoprotein-lipid envelope (fragile in environment).  Replicates in nucleus (intranuclear inclusions)
    • Feline Viral Rhinotracheitis: URI, often associated with secondary bacteria or calicivirus.  May be lifelong virus carriers.  Stress or steroids cause reactivation and shedding in oronasal and conjunctival.
    • Signs: acute rhinitis, conjunctivitis, fever, depression, anorexia. Ulcerative, dendritic keratitis.
    • Shedding in ocular, nasal and oral secretions for 3 weeks or more.  
    • Transmission by direct contact.
  3. Feline Calicivirus (FCV)
    • +RNA, non-enveloped, sphere capsid (cup = calici).  Resists heat-inactivation.  
    • subclinical oropharyngeal infection by 1/3 of cats.  May be repeatedly infected over lifetime. No clinical in older.  
    • Synergisms between FCV, panleukopenia, FHV, mycoplasma, chlamydiophila, bacteria.  
    • transient viremia then virus in epithelium of nasal passages, conjunctiva, tongue, palate, etc.  
    • Possibly diphasic fever (at 24h, then 4-7d just before recovery)
  4. paramyxoviruses
    • negative stranded RNA, enveloped
    • lytic replication with cell destruction
  5. Morbillivirus
    • type of paramyxovirus (-RNA, enveloped, lytic)
    • Hemoagglutination (NO neuraminidase)
    • distemper virus (dogs, carnivores)
    • Peste des petite Ruminants/Rinderpest (eradicated)
  6. Pneumovirus
    • Type of paramyxovirus (-RNA, enveloped, lytic)
    • Bovine respiratory syncytial virus (shipping fever)
    • no hemoagglutination
  7. Rubulavirus
    • type of paramyxovirus (-RNA, enveloped, lytic)
    • Hemoagglutinatinin-Neuraminidase, cleaves sialic acid to release virions and dissolve mucus
    • Canine Parainfluenza
    • Newcastle Disease Virus (avian paramyxovirus-1)
  8. Canine Distemper Virus
    • morbillivirus, paramyxovirus (-RNA, enveloped, lytic)
    • Hemoagglutination
    • Dogs, wild carnivores like foxes, raccoons, lions etc
    • Unvax = >50% morbidity, 10% mortality
    • Vax is EXCELLENT (modified live or subunit)
    • replicate in oral pharynx, cell-associated viremia in lymphocytes (ADR sympt), GI (VD, okay prognosis),Respiratory (cough, pneumonia, good prognosis), CNS (slow, demyelinating encephalitis, sz, bad prognosis).
    • Diphasic fever, leukopenia (early).  C/S dyspnea, sometimes V/D, ocular nasal d/c, catarrhal. Sometimes hyperkeratosis of footpads, nose (hardpad, diagnostic), hypersalivation, enamel hyperplasia of teeth.
    • Human measles as vax during maternal abs?
    • CNS by demyelination (due to replication) cause sz, incoordination, ataxia, tremors, head pressing.
  9. Bovine Respiratory Syncytial Virus
    • Pneumovirus, paramyxovirus (-RNA, enveloped, lytic)
    • Shipping fever if secondary bacterial (mannheimia)
    • sudden onset fever, inappetance, rhinits, nasal d/c, cough. Suborbital, submandibular edema.  Wheezes and crackles, subQ emphysema, dyspnea.
    • replicates in alveolar epithelia = interstital emphysema, destroys ciliated epithelium
    • Modified live or inactivated vax in bovine resp - reduce but don't prevent
  10. Rhinderpest virus
    • Morbillivirus, paramyxovirus (-RNA, enveloped, lytic)
    • eradicated, historically important. Agroterrorism?
    • Fever, anorexia, depression, mucosal lesions, mucopurulent d/c (ocular, oral).  May die before bloody diarrhea, dehydration, shock
    • morbidity 100%
    • maintained in environment (buffalo, giraffe, hippo, anything). African sheep asymptomatic.  
    • REPORTABLE (as eradicated)
  11. Neuraminidase
    • in Rubulavirus, Respirovirus (paramyxovirus (-RNA, enveloped, lytic))
    • allows release of particles from surface -- cleaves sialic acid bound to new virions
    • (parainfluenza and Newcastle)
  12. Peste de Petit Ruminants (ovine rinderpest)
    • HIGHLY effective vaccine, no eradication plan
    • Morbillivirus, paramyxovirus (-RNA, enveloped, lytic)
    • Agroterrorism?
    • Fever, anorexia, depression, mucosal lesions, mucopurulent d/c (ocular, oral).  May die before bloody diarrhea, dehydration, shock
    • morbidity 90-100%
  13. Bovine parainfluenzavirus
    • Respirovirus, paramyxovirus (-RNA, enveloped, lytic)
    • infects tracheal and bronchial, destroys ciliated epithelium to decrease clearance (2 bacterial, Mannheimia)
    • STRESS, housed together.  Shipping fever.  
    • Mild respiratory signs if uncomplicated with bacteria (then pneumonia)
    • abx if bacteria
    • modified live and inactivated vax suck, immunity short-lived.  Ventilation helps
  14. Avian pneumovirus 1/Newcastle disease virus
    • chickens worldwide
    • 3 pathotypes: lentogenic (less virulent), mesogenic, velogenic (highly virulent - REPORTABLE, systematic spread through smuggling exotics)
    • survive in feces, wet litter
    • shed by aerosol or ingestion
    • IgG blocks viremia but doesn't stop infection or cell-cell spread
    • see crop dilation, yellow diarrhea, hemorrhages around esophagus, dyspnea, cyanosis, head swelling, NEURO, conjunctivitis
    • quickly fatal
    • Modified live vax, not usually used.
  15. canine parainfluenza virus 5
    • rubulavirus, paramyxovirus (-DNA, lytic, enveloped)
    • part of a group of viruses and bacteria that cause "kennel cough"
  16. Orthomyxoviruses
    • influenza viruses.  -RNA, pleiomorphic enveloped particles with spikes of Hemagglutinin and Neuraminidase, helical nucleocapsid. 
    • Replicate in nucleus, bud at plasma membrane (endocytosis)
    • sensitive to heat, acid, lipid solvents and detergents.  
    • Practice genetic reassortment
    • A: common, birds and mammals (humans) - aquatic bird reservoir (replicate in intestinal epithelium, fecal-oral)
    • B: humans, rarely seals
    • C: humans and swine, mild disease
  17. Influenza A (mammals)
    • orthomyxovirus (-RNA, enveloped, pleiomorphic with helical capsid)
    • target epithelial cells in upper and lower resp tract (serous d/c, inflamm vs laryngitis, tracheitis, bronchitis, interstitial pneumonia), 2ndary bacterial. 
    • Clumping of cilia, exudate into airways, necrosis and desquamation of respiratory epithelial cells.
  18. equine influenza
    • orthomyxovirus (-RNA, enveloped, pleiomorphic with helical capsid)
    • high morbidity
    • attacks resp epithelium causing necrosis, exudate in airways, damage cilia.  Harsh cough, reddening of nasal mucosa, conjunctivitis, d/c, secondary bacterial infections
    • self-limiting disease
    • highly contagious during incubation
    • quarantine and vax (inactivated, modified live, recombinant)
  19. canine influenza
    • orthomyxovirus (-RNA, enveloped, pleiomorphic with helical capsid)
    • Two strains (H3N8, H3N2)
    • most infections mild respiratory, esp in shelters
    • inactivated vax available, esp for boarding
  20. swine influenza
    • orthomyxovirus (-RNA, enveloped, pleiomorphic with helical capsid)
    • two variants
    • mild or inapparent, from humans, birds
    • Fever, nasal and ocular discharge, coughing, lethargy, anorexia.  Rapid spread, 1 wk. Quick recovery. 
    • Can cause LRT infections, fever, apathy, inappetence, coughing, rhinitis, nasal d/c
    • inactivated vax
    • zoonotic and reverse zoonotic - resp disease.
  21. avian influenza
    • orthomyxovirus (-RNA, enveloped, pleiomorphic with helical capsid)
    • "Fowl Plague"
    • LOTS of "bird flu"s. 
    • Virulent: sudden death, stop laying, resp distress, lacrimation, sinusitis, diarrhea, edema of head and neck.  
    • Less virulent: lower egg, resp dz
    • REPORTABLE/notifiable, restrict mvmt, restrict access of wild birds
    • resp and intestinal tracts (high path is systemic viremia). visceral and lymphoid necrosis = pancreatitis, myocarditis, myositis, encephalitis.  Petechial hemorrhages.
  22. myxoviruses
    • ss RNA, segmented genome, enveloped with surface glycoproteins
    • reservoir in aquatic birds
    • zoonotic and reverse zoonotic
    • vax can be effective, may need to change frequently (equine)
  23. Bunyaviridae
    • ss - RNA, enveloped, 3 nucleocapsid segments.  Glycoproteins spikes
    • >350 members (differentiate via neutralization and HA), arthropod-vertebrate-arthropod transmission (hanta different).  Vectors like mosquitos, ticks, midges, flies.  Lifelong for insect, all but hanta are transient for mammal. Sensitive to heat, acid, detergent, solvent, disinfectant. 
    • hantavirus, rift valley fever, cache valley fever/akabane disease, nairobi sheep disease, crimean-congo hemorrhagic fever
  24. Rift Valley Fever
    • bunyaviridae (-RNA, enveloped, glycoprotein spikes, sensitive to heat, acid, detergents, etc)
    • disease of sheep, lesser of cattle
    • inappetance, mucopurulent nasal d/c, bloody diarrhea, abortion
    • Mosquito transmission, trans-ovarian., high titers in liver and reticulothelial organs, widespread pathology.  Recovery rapid, immunity long
    • mild zoonosis
    • modified live vax in sheep (not pregnant), inactivated.
  25. Akbane disease/cache valley fever
    • bunyaviridae (-RNA, enveloped, glycoprotein spikes, sensitive to heat, acid, detergents, etc)
    • disease of sheep, cattle, goats
    • arthrogryposis (rigid fixation of limbs due to loss of spinal motor neurons. Survivors have sensory, motor, optic nerve damage.  hydranencephaly of fetal/newborns, abortion (early in pregnancy).  No maternal disease.
    • mosquito- and culicoides-borne.  
    • RARE zoonosis
    • inacctivated vax, effective. 
    • Australia, Israel, Japan, US
  26. Nairobi sheep disease
    • bunyaviridae (-RNA, enveloped, glycoprotein spikes, sensitive to heat, acid, detergents, etc)
    • sheep and goats in Africa (similar in western Africa and India
    • high fever, hemorrhagic enteritis, prostration, abortion
    • Brown ear tick - transovarial transmission
    • Control tick = control disease (dipping and ear treatments
  27. Crimean-Congo Hemorrhagic Fever (CCHF)
    • bunyaviridae (-RNA, enveloped, glycoprotein spikes, sensitive to heat, acid, detergents, etc)
    • ticks, birds, sheep, goats, cattle in central Asia, eastern Europe, middle east, Africa
    • humans: severe hemorrhagic disease
    • transovarially transmitted in ticks
    • zoonotic
    • IgG and IgM in serum (ELISA)
  28. hantavirus
    • bunyaviridae (-RNA, enveloped, glycoprotein spikes, sensitive to heat, acid, detergents, etc)
    • disease of rodents and humans
    • hemorrhagic fever and renal syndrome, hantavirus pulmonary syndrome
    • contact with rodents, exposure to rodent urine or feces
    • contact with rodents, exposure to rodent urine or feces
  29. California (La Cross Virus) encephalitis
    • bunyaviridae (-RNA, enveloped, glycoprotein spikes, sensitive to heat, acid, detergents, etc)
    • squirrels and chipmunks (silent), mosquitos, humans
    • mild encephalitis, seizures, little mortality, most cases subclinical
    • squirrels, chipmunks give to mosquitos, transmit to children/humans
    • zoonotic
  30. Arenavirus
    • - ss RNA, enveloped, 2 genome segments, host cell ribosomes packaged
    • exocytosis.
  31. Lymphocytic choreomeningitis virus
    • Arenavirus, -ssRNA, enveloped, 2 genome segments, exocytosis
    • mice and hamsters, human.  Others can be infected
    • largely asymptomatic (runt, lower repro), immune complex disease, vasculitis, glomerulonephritis, choriomeningoencephalitis, lymphocyte infiltration in visceral organs
    • LOTS of cell types infected: cytotoxic cells, so can't clear,  Loss of cell functions like pituitary (growth hormone, thyroid hormones) - stunted growth, mild flu-like, fever, myalgia, aseptic meningitis, encephalomyelitis.  Fetal or neonatal death.
    • from rodent urine, feces or saliva, eating contaminated food, mucus membranes infected, wounds. No person-to-person transmission except mother-fetus
  32. Lassa Fever virus
    • -ssRNA, enveloped, 2 genome segments, exocytosis
    • subclinically infects African rodents (chronic shedding), hosts.  
    • primates can get mild or severe disease (anorexia, vascular collapse, shock)
    • other locations  - hemorrhagic fever
    • zoonotic
    • acts as vaccine for Junin virus
  33. Flaviviridae
    • enveloped, layer of protein on the outside
    • ss + RNA, small, spherical, surface glycoproteins, icosahedral structure
    • 1 long open reading frame
    • not stable in environment, but possibly survives in meat from infected animals
    • 5' cap but no polyA tail
    • broad host and cell tropisms
  34. St. Louis Encephalitis
    • Flavivirus,  + ss RNA, enveloped with layer of protein on outside, 1 long genome
    • passerine (perching) birds, mosquito
    • zoonotic
  35. Wesselsbron disease
    • Flavivirus,  + ss RNA, enveloped with layer of protein on outside, 1 long genome
    • Sheep in sub-saharan africa (hoses, cattle, swine subclinical infections), humans
    • fever, jaundice, SQ edema, abortions.  Humans: febrile disease with myalgia and arthralgia
    • attenuated live vaccine
  36. West Nile Virus
    • Flavivirus,  + ss RNA, enveloped with layer of protein on outside, 1 long genome
    • birds, horses (most susceptible), humans (mosquitos), subclinical in other animals
    • horses: most subclinical, inappetence, poor coordination, confusion, fever, stiffness, muscle tremors, weakness.
    • replicates widely, enters CNS (basal nuclei through brain stem to sacral spinal cord
    • birds: robins, crows, blue jays. Control mosquito population and birds.
    • inactivated or canarypox subunit vaccine
  37. Tick bourne Encephalitis
    • Flavivirus,  + ss RNA, enveloped with layer of protein on outside, 1 long genome
    • small mammals and ticks (live for several years in stages, across eggs)
  38. Louping ill
    • Flavivirus,  + ss RNA, enveloped with layer of protein on outside, 1 long genome
    • infectious encephalomyelitis of sheep (occasionally horses, cattle, deer)
    • viremia (infect ticks), biphasic fevers, then enters CNS (cerebellar ataxia, tremors, hyperexcitability, paralysis)
    • inactivated vaccine, control ticks
    • zoonotic (biphasic disease in humans - influenza like then meningitis, resolves)
  39. Bovine Viral diarrhea
    • Flavivirus,  + ss RNA, enveloped with layer of protein on outside, 1 long genome
    • two strains, cross-protect.  Postnatal (after 3-8m of maternal): fever, leukopenia, diarrhea, oculo and nasal d/c, erosive stomatitis.  Persistant infection can see virus as "self".  If not, fever, anorexia, profuse watery diarrhea, nasal d/c, erosive or ulcerative stomatitis, dehydration, emaciation, death.  Pregnant transmit transplacentally.  fetal death or low birth weight, retinal dysplasia, cerebellar disease.
    • modified live vax, only seropositive cattle into herd.
  40. Border Disease aka "hairy shaker"
    • Flavivirus,  + ss RNA, enveloped with layer of protein on outside, 1 long genome
    • like BVD.  COngenital disease in lambs, born with hairy coat, low birth weight and viability, tremors.  
    • Adults subclinical, fetal infection = dead.
  41. Classical Swine Fever/Hog Cholera
    • Flavivirus,  + ss RNA, enveloped with layer of protein on outside, 1 long genome
    • Eradicated in N America (most of Europe but wild pigs). 
    • acute infection = fever, anorexia, conjunctivitis, VD, pneumonia, nervous signs.  Diffuse hyperemia, purpura on abdomen and ears. 
    • Mortality up to 100%.  Can infect in utero
    • oronasal infection to lymphoid organs and endothelial cells.  hemorrhage, leukopenia, thrombocytopenia, infarctions, DIC, encephalitis with perivascular cuffing, necrotic lesions in chronic. 
    • survives in frozen pork. Attenuated vaccine.
  42. Togavirus
    • +RNA, small spherical, capsid with envelope with glycoprotein spikes.  Single linear RNA with cap and tail.  
    • Alphaviruses and a few rubiviruses.  Includes EEE, WEE, VEE
  43. Eastern Equine Encephalitis virus
    • togavirus: +RNA, small spherical, capsid with envelope with glycoprotein spikes.  Single linear RNA with cap and tail.
    • subclinical or fever, drowsiness, incoordination, then depression, wide stance, hanging head, flaccid lips, irregular gait and encephalitis (impaired vision, photophobia, inability to swallow, circling), head pressing, paralysis, convulsions.  50-90% fatal
    • specific to EEE: endemic in N America, central and N S. America.  Seasonal with vectors, maintained in wild birds and commercial chicken/duck
    • transmitted via mosquito, virus to lymphoid tissues then systemic.  High titers in blood infect more mosquitos.  Replicate in muscle, CT, reticulendothelial cells, neurons, choroid plexus, ependyma and meninges.  Causes neuronal necrosis, mononuclear cell infiltration, interstitial edema.  Immunity long lived.
  44. Western Equine Encephalitis virus
    • togavirus: +RNA, small spherical, capsid with envelope with glycoprotein spikes.  Single linear RNA with cap and tail.subclinical or fever, drowsiness, incoordination, then depression, wide stance, hanging head, flaccid lips, irregular gait and encephalitis (impaired vision, photophobia, inability to swallow, circling), head pressing, paralysis, convulsions.  20-40% fatal
    • specific to WEE: widely distributed, birds and mosquitos.  
    • transmitted via mosquito, virus to lymphoid tissues then systemic.  High titers in blood infect more mosquitos.  Replicate in muscle, CT, reticulendothelial cells, neurons, choroid plexus, ependyma and meninges.  Causes neuronal necrosis, mononuclear cell infiltration, interstitial edema.  Immunity long lived.
  45. Venezuelan Equine Encephalitis
    • togavirus: +RNA, small spherical, capsid with envelope with glycoprotein spikes.  Single linear RNA with cap and tail.subclinical or fever, drowsiness, incoordination, then depression, wide stance, hanging head, flaccid lips, irregular gait and encephalitis (impaired vision, photophobia, inability to swallow, circling), head pressing, paralysis, convulsions.  50-80% fatal
    • specific to VEE: several types, mosquitos and small mammals.  Endemic cycles in S. America 10y apart.  
    • more systemic disease with fewer neuro signs.  transmitted via mosquito, virus to lymphoid tissues then systemic.  High titers in blood infect more mosquitos.  Replicate in muscle, CT, reticulendothelial cells, neurons, choroid plexus, ependyma and meninges.  Causes neuronal necrosis, mononuclear cell infiltration, interstitial edema.  Immunity long lived.
  46. immunodiffusion
    precipitation - when ab binds to and crosslinks ag, forms precipitate that makes a visible line or circle, depending on medium.
  47. hemoagglutination inhibition
    • detects antibody
    • dilutions of test sera are added to wells with known amount of agglutinating antigen (usu virus), allowed to incubate, then add RBC. Agglutination particles are blocked antibodies, preventing them from binding to RBCs.  Button is POSITIVE, lattice is negative.  Titer determined when RBC stop making buttons and start making lattices.  
    • Parvo and influenza
  48. Hemoagglutination
    • Viruses bind and cross-link sugar molecules on surface of RBC.  Serial dilution, titer is last lattice before buttons start.
    • Detects Antigen
  49. ELISA
    • Enzyme Linked ImmunoSorbant Assay, detects viral antibody or antigen.
    • Direct: primary antibody conjugated to enzyme/molecule
    • Indirect: secondary antibody conjugated against primary antibody.  
    • Most primary for antigen is capture (sandwich) ELISA: plate bound to ab, ag added, nonspecific doesn't bind and washes away.  2nd ab added, recognizes different epitope. enzyme-conjugated 2nd ab added, binds to specific ab (2nd).  Substrate added, cleaved to produce color.
  50. viral neutralization
    • tests for antibodies
    • cytopathic virus put into susceptible plate of cells.  Serum added.  Fewer plaques means serum has antibody.  Titer is dilution that reduces number of plaques by 50%
  51. PCR or RT-PCR
    • detects viral nucleic acids by amplifying DNA
    • Polymerase chain reaction for DNA viruses
    • Reverse-transcription polymerase chain reaction for RNA
  52. direct or indirect immunofluorescence
    • direct: ab with indicator binds to viral antigen
    • indirect: ab with indicator binds to virus-specific ab (bound to antigen)
  53. viral isolation
    measures cytopathic effects - can tell if animal is SHEDDING INFECTIOUS VIRUS
Author
XQWCat
ID
324712
Card Set
virology wk 4
Description
IV virology 4
Updated