paramyxo Flashcards

Question

describe the five pathotypes of newcastle dz virus

Answer 1

1)asymptomatic enteric2)lentogenic - less virulentvND(virulent Newcastle dz)3)mesogenic - moderately virulent4/5)velogenic pathotype strains - highly virulent (viscerotropic and neurotropic)Exotic Newcastle Dz(END): US name for velogenic viscerotropicvelogenics aren't present in usa, but are brought in via illegally imported game chickens and exotic birds

Answer 2

most avians-pigeons highly susceptible-canaries, finches pretty resistant-humans: conjunctivitis

Answer 3

 Respiratory secretions and feces contain high concentrations of virus. Virus is shed for up to 4 weeks in all secretions and excretions of birds that survive the infection. Major route of transmission: Inhalation of aerosols and dust particles Ingestion of contaminated feed and water Contaminated fomites. Mechanical spread between flocks is facilitated by the relative stability of the virus and its wide host range. Vertical transmission rare: reported for lentogenic virus strains

Answer 4

Initially it replicates in the mucosal epithelium of the URT and GIT, then one of two things can happen:1) no further dz spread for lentogenic and enteric strains2)vND: primary viremia --> spread to bone marrow and spleen --> secondary viremia --> infection of other target organs; lung, intestine, CNS

Answer 5

respiratory, w/ depression, watery green diarrhea, and swelling of the head and neckhemorrhages and ulcer-like lesions are seen in the digestive tractmortaliy approaches 100% in all age groups

Answer 6

respiratory signs, followed by nervous signs of tremors, paralyzed wings and legs, twisted necks, circling, clonic spasms, and complete paralysiscns lesions are encephalomyelitis, with neuronal necrosishemorrhages absent from GI tractmortality approches 100% in all age groups

Answer 7

mesogenic: acute respiratory dz, reduced egg production, and uncommonly neuro signs; mortality aproaches 25% in young chickens, rare in adultslentogenic: respiratory signs of gasping, coughing sneezing and rales predominatethe dz in turkeys is similar but usually less severe than that in chickens; there are signs of respiratory and nervous involvement

Answer 8

false, ruffled feathers are associated

Answer 9

false; severe acute conjunctivitis and edema are associated with newcastle dz

Answer 10

virus isolation, RT-PCR, and serology

Answer 11

intracerebral pathogenicity index in day old chickens (0.7 or more)presence of a specified amino acid motif at the cleavage site of the fusion protein(F) precursor(FO).

Answer 12

quarantine and depopulation.Newcastle DZ is REPORTABLE

Answer 13

-live lentogenic vaccines, chiefly B1 and LaSota strains, are widely used and typically administered to poultry by mass application in drinking water of by spray-oil adjuvanted inactivated vaccines are also used after live vaccine in breeders and layers-fowlpox or turkey herpesvirus-vectored NDV vaccines are commercially available for chickens

Answer 14

ndv can produce a transitory conjunctivitis in humans, and occurs primarily in laboratory workers and in members of vaccination teams

Answer 15

canine parainfluenza virus-5

Answer 16

one of several pathogens that cause kennel cough

Answer 17

aerosolized microdroplet

Answer 18

the virus causes destruction of the ciliated epithelial cells of the respiratory tract, predisposing to secondary infections

Answer 19

the 3 D's: discharge, diarrhea, and death

Answer 20

canine morbillivirus

Answer 21

there are at least ten strains, based on differences in the hemagglutinin gene.

Answer 22

snyder hillA75/17R252

Answer 23

in warm climates, the virus will not persist in kennels after infected dogs have been removedin near freezing temperatures (0-4 C) the virus survives in the environment for weeks

Answer 24

ordinary disinfectants can inactivate the virus

Answer 25

domestic and wild dogsraccoon, panda, ferret, mink, bears, etcCNS infections in exotic felidae

Answer 26

inhalation of infected dropletstransplacental infections can occur from viremic dams

Answer 27

macrophagest and b lymphocytesepithelial cellsnervous tissue

Answer 28

1) the virus replicates in the macrophages in URT tissues, then spreads to tonsils and regional lnn.2)after multiplication in the lymph nodes, the virus enters the bloodstream, circulating in b and t lymphocytes.3)virus spreads to lymphoid tissues in body; GALT, mesenteric lymph nodes, kupffer's cells of the liver4) virions formed in these sites are then carried by blood mononuclear cells during secondary viremia5) further spread of CDV to epithlial and CNS tissues on day 8-9 PI occurs hematogenously, and depends on the dog's cell-mediated and humoral immune response

Answer 29

in dogs with >1:100 antibody titers, on day 8 or 9, there is no more spread of virus, and it is cleared from lymphoid tissues. the infection remains subclinical.In dogs with low antibody titers and poor cell-mediated immune response by day 14 post-infection: virus spreads to many tissues including the epithelium of the GI tract, respiratory tract and genitourinary tract.

Answer 30

true - details to know:Infection of the central nervous system occurs relatively late in the course of infection.Dogs producing anti-envelope antibodies appear to prevent persistent infection of CNS.

Answer 31

occurs in young and immunosuppressed animals, and is characterized by direct viral replication and injury to CNS.  Acute noninflammatory demyelination in microglial and astroglial cells

Answer 32

characterized by reduced expression of CDV antigen and a strong upregulation of inflammatory response.  The immune reaction rather than virus replication causes demyelination at this stage.  Chronic perivascular cuffing with demyelination

Answer 33

Observed in old dogs. These may also be seen in dogs with no history of earlier acute or subacute disease. Hardpad disease: Hyperkeratosis of foot pads and the nose due to virus multiplication in the skin. Old Dog Encephalitis:  Extremely rare, chronic , progressive inflammatory disease of gray matter of cerebral hemispheres and brainstem of CNS. Occurs in immunocompetent animals with persistent virus in their neurons in a replication defective form.  Often marked by ataxia, compulsive movements such as head pressing.

Answer 34

 Clinical signs:1) Transient fever usually occurs 3–6 days after infection with leukopenia (especially lymphopenia). 2) A second febrile response indicates serious phase of the infection, accompanied by profound leukopenia. 3) Serous or mucopurulent nasal discharge, conjunctivitis, and depression.4) Some dogs show primarily respiratory signs, whereas others develop gastrointestinal signs: Respiratory signs reflect inflammation and injury to the upper respiratory tract and large airways. Productive cough; bronchitis and interstitial pneumonia may follow. Gastrointestinal involvement: vomiting and watery diarrhea. Both respiratory and GI signs may be complicated by secondary bacterial infection.5) Dogs surviving the acute phase may have hyperkeratosis of the footpads and epithelium of the nasal planum. Hyperkeratosis of the nose and footpads is often found in dogs with neurologic manifestations

Answer 35

Immunofluorescent assay or reverse transcriptase (RT) PCR

Answer 36

 Control: Control of canine distemper virus infection is based on adequate diagnosis, quarantine, sanitation, and vaccination.  The virus is very fragile, and susceptible to standard disinfectants. Vaccination: Successful immunization of pups with canine distemper modified live virus (MLV) vaccines depends on the lack of interference by maternal antibodyAlternatively, measles virus vaccine induces immunity to canine distemper virus in the presence of relatively greater levels of maternal distemper antibody.  Remember:  MLV vaccines should not be used in late-pregnant or early-lactation bitches.  MLV vaccines can produce postvaccinal illness in some immunosuppressed dogs.

Answer 37

Peste des petits ruminants (PPR)aka Goat Plague

Answer 38

Peste des petits ruminants virus has been grouped into four distinct lineages based on the sequence of the F protein. Lineages 1 and 2 occur in West Africa Lineage 3 in East Africa, the Middle East, and southern India Lineage 4 extends from the Middle East to Tibet

Answer 39

Host: Goats and Sheep.  More severe in goats than in sheep.

Answer 40

 Infection is primarily by inhalation There is no carrier state in goats and sheep

Answer 41

Inhalation--> Retropharyngeal mucosa--> Viremia--> damage to alimentary, respiratory and lymphoid systems. Infected cells undergo necrosis, resulting in mucosal erosions and lymphopenia. Death may occur from severe diarrhea and dehydration, before respiratory lesions become severe

Answer 42

 The acute form of the disease is seen in goats and similar to rinderpest, except that severe respiratory distress is a common feature of PPR. Early, the nasal discharge is serous; later, it becomes mucopurulent and gives a putrid odor to the breath. Extensive erosions and necrosis in the mucosal lining of the oral cavity, and also in esophagus, abomasum, and small intestine (necropsy) Profuse catarrhal conjunctivitis, high fever, necrotic stomatitis Diarrhea may be profuse Bronchopneumonia Pregnant animals may abort

Answer 43

 Clinical signs: Necrotic lesions in mouth, profuse diarrhea Necropsy: Streaks of congestion with “zebra-striped” appearance in large intestine. Field conditions: Agar-gel immuno-diffusion test and the PPR penside test ELISA RT-PCR

Answer 44

 Local and federal authorities should be notified when PPR is suspected. Eradication is recommended when the disease appears in previously PPR-free countries. Attenuated vaccine has been prepared in Vero cell culture

Answer 45

genus pneumovirustwo antigenic subtypes based on differences of the G protein.

Answer 46

cattle of all ages, but mostly <6 months of age Bovine respiratory syncytial virus (BSRV) infection occurs most often during the winter months, when are housed in confined conditions. Virus spreads rapidly, probably through aerosols or droplets of respiratory tract excretions.

Answer 47

 Pathogenesis: BSRV causes rhinitis, tracheitis, bronchitis, bronchiolitis & mild interstitial pneumonia. The pathogenesis of fatal pneumonia due to BSRV may be associated with an immune mediated mechanism (hypersensitivity reaction mediated by IgE).  The severe highly fatal form of the disease, known as “malignant form” or “the Paroxystic Respiratory Distress Syndrome (PRDS) , has been associated with extensive pulmonary mast cell degranulation.  Gross lesions include a diffuse interstitial pneumonia with subpleural and interstitial emphysema along with interstitial edema

Answer 48

 Syncytial cells in bronchiolar epithelium and lung parenchyma. Intracytoplasmic inclusion bodies. Edema, and hyaline membrane formation

Answer 49

 Fever (104–108°F [40–42°C]), depression, decreased feed intake, increased respiratory rate, cough, and nasal and lacrimal discharge are common. Dyspnea, possibly with open-mouthed breathing, later stages of disease. Secondary bacterial pneumonia is a frequent occurrence

Answer 50

 Diagnosis: Clinical signs Necropsy: Dramatic distension of lungs by edema, alveolar hyperinflation, emphysema. Histopathology Virus isolation: Transtracheal aspirate. Difficult as virus is fragile. Specimens should not be frozen.  FAT test or immunohistochemical staining RT-PCR VN test on paired sera (convalescent and acute samples)  Control: Immunity is incomplete and transient following natural BRSV infection of calves