Difference between revisions of "Paramyxoviridae"

From WikiVet English
Jump to navigation Jump to search
(Redirected page to Category:Paramyxoviridae)
(62 intermediate revisions by 5 users not shown)
Line 1: Line 1:
−
#REDIRECT[[:Category:Paramyxoviridae]]
+
<big><center>[[Viruses|'''BACK TO VIRUSES''']]</center></big>
 +
 
 +
 
 +
===Overview===
 +
 
 +
*Systemic infections - controlled by '''live monotypic vaccination'''
 +
*Respiratory infections - ''not'' controled by '''live monotypic vaccinations'''
 +
 
 +
 
 +
===Classification===
 +
 
 +
*'''Paramyxovirinae'''
 +
**[[Paramyxoviridae#Bovine Parainfluenza - 3 (PI-3)| Bovine Parainfluenza 3]]
 +
**[[Paramyxoviridae#Canine Parainfluenza - 2|Canine Parainfluenza 2]]
 +
**[[Paramyxoviridae#Murine Parainfluenza - 1 (Sendai virus)|Murine Parainfluenza 1 (Sendai virus)]]
 +
**[[Paramyxoviridae#Newcastle Disease Virus (NDV)|Newcastle Disease (NDV)]] - avian paramyxovirus serotype 1
 +
**Avian Paramyxoviruses serotypes 2-9
 +
**[[Paramyxoviridae#Reptilian Paramyxoviruses|Reptilian Paramyxoviruses]]
 +
**Mumps
 +
*'''Morbilliviruses'''
 +
**[[Paramyxoviridae#Canine Distemper Virus (CDV)|Canine Distemper (CDV)]]
 +
**Rinderpest
 +
**Pest de petit ruminant (PPR)
 +
**Measels
 +
**Seal virus - phocine distemper
 +
**Dolphin Morbillivirus
 +
**Hendra virus
 +
**Nipah virus
 +
*'''Pneumovirinae'''
 +
**Bovine Respiratory Syncytial Virus (BRSV)
 +
**Turkey Rhinotracheitis Virus
 +
 
 +
 
 +
===Virus properties===
 +
 
 +
====Structure====
 +
 
 +
*Negative sense '''RNA''', unsegmented, single stranded
 +
**-> '''Reasortment''' and '''antigenic shift''' cannot occur
 +
*'''HN spike''' contains:
 +
**'''Haemagglutinin (H)'''- attachment protein
 +
**'''Neuraminidase (N)'''
 +
*'''Fusion''' glycoprotein (F) spike
 +
**-> Viral lipid bilayer can fuse directly with host plasma membrane
 +
***-> RNA released into cytoplasm
 +
**->Syncytium (multinucleated giant cells) in lesions and cell culture
 +
**Host antibody response to this protein is most important
 +
***Best induced by '''live attenuated vaccines'''
 +
 
 +
====Growth ''in vitro''====
 +
 
 +
*Allantoic cavity of 10-day-old eggs
 +
*Followed by '''haemagglutination'''
 +
 
 +
====''In vivo''====
 +
 
 +
*Cell tropism for upper respiratory tract epithelium
 +
**All replicate in these cells
 +
*Some replicate in the gut
 +
*Most virulent replicate in lymphoid cells and neurons ([[Paramyxoviridae#Canine Distemper Virus (CDV)|Distemper]], [[Paramyxoviridae#Newcastle Disease Virus (NDV)|NDV]])
 +
*Links to the readiness to cleave Fo and Ho precursors in different cells
 +
 
 +
====Antigenic differentiation====
 +
 
 +
*Major conserved immunodominant virus-specific antigens on [[Paramyxoviridae#Structure|F and HN]]
 +
**-> Vaccines protect against all isolates of the same virus
 +
*Minor morbillivirus-specific epitopes on [[Paramyxoviridae#Structure|F]]
 +
**Some crossprotectin between [[Paramyxoviridae#Canine Distemper Virus (CDV)|canine distemper]], measels and rinderpest
 +
*Minor variable epitopes of [[Paramyxoviridae#Structure|F, HN and '''NP''']]
 +
**Allows antigenic '''fingerprinting'''
 +
 
 +
 
 +
===Canine Distemper Virus (CDV)===
 +
 
 +
*Canine Distemper virus in [[Nasal cavity - inflammatory#Infectious causes of rhinitis|rhinitis]] and [[Viral infections#In Dogs|Infectious canine tracheitis]] ?Paramyxovirinae, morbillivirus, also in [[Pancreas - inflammatory#Chronic interstitial pancreatitis|chronic interstitial pancreatitis]]
 +
**May cause [[Bones - developmental#Retention of elongated primary trabeculae|growth retardation lattice]]
 +
{Canine distemper - a pantropic virus which has a suppressing effect on lymphoid tissue,
 +
and which may trigger latent Toxoplasmosis. After aerosol infection, the virus multiplies in the bronchial and other lymph nodes. It then spreads to a variety of epithelium depending upon the strain of virus including that of the respiratory and alimentary tracts, skin and later (1-5 wk. post infection) to the brain, causing a mucopurulent oculonasal discharge with keratitis and an interstitial pneumonia, a smelly sometimes bloody diarrhoea, eruptions on the skin including hyperkeratosis of the nose and pads, and encephalitis respectively. The essential feature of the last mentioned is demyelination particularly in the cerebellum resulting in ataxia. Convulsions, coma and paralysis may occur, and chorea (rhythmic motor movements) may be seen in recovered animals. Intracytoplasmic inclusions may be found in most affected tissues
 +
and inclusions persist longest in the brain (may be intranuclear) and the alveolar macrophages.
 +
Giant cells may be seen in the alveoli. The severity of the disease may vary; if enough neutralising antibody develops in the early stages, the virus maybe kept restricted largely to the lymph nodes. Severe clinical pneumonia follows secondary infection with ''Bordetella bronchiseptica''.} <small>From RVC respiratory notes 2006 by B.Smyth</small>
 +
 
 +
 
 +
===Newcastle Disease Virus (NDV)===
 +
 
 +
*'''Hosts'''
 +
**Gallinaceous birds, pigeons, parrots, finches
 +
**Subclinical carriers: ducks, ostriches
 +
**Causes conjunctivitis in humans
 +
 
 +
*'''Virulence'''
 +
**Disease ranges from subclinical [[Viral infections|respiratory tract infections]] -> torticollis -> haemorrhages and death
 +
 
 +
*'''Epidemiology'''
 +
**Air-born
 +
**Direct contact of poultry
 +
 
 +
*'''Diagnosis'''
 +
**Samples of trachea and gut of 20 birds are tested in eggs
 +
**'''HI''' using anti-NDV serum (to differentiate '''HA''' caused by [[Orthomyxoviridae|avian influenza]]
 +
**Animal test: virulence of isolate tested by the speed it kills chicks
 +
**Sequencing the cleavage site of [[Paramyxoviridae#Structure|H]] gene
 +
***The more basic amino acids the more virulent the virus
 +
***Now replacing the animal test
 +
 
 +
*'''Control'''
 +
**Isolation of stock
 +
**Vaccination of chickens and racing pigeons
 +
**Surveillance of imported exotic birds
 +
**Notifiable disease
 +
**Infected premises to be culle and firebreak cull if spread
 +
 
 +
 
 +
===Reptilian Paramyxoviruses===
 +
 
 +
*Infect central nervous system and lungs
 +
*Kill particularly snakes
 +
*Healthy reptiles may be carriers
 +
*Testing by serology - '''HI test'''
 +
*Aim to keep virus free collection and prevent spread back into the wild
 +
 
 +
 
 +
===Murine Parainfluenza - 1 (Sendai virus)===
 +
 
 +
*Endemic in many mouse colonies
 +
*Most mice show no symptoms due to maternal antibodies
 +
*But minor respiratory lesions may invalidate carcinogenic or toxicological studies
 +
*Immunological studies also confused due to virus activating [[General Pathology - Antigen Recognition, Processing and Presentation#NK Receptors|NK cells]] via high circulating [[General Pathology - Innate Immunity#Interferons|IF]] 3-4 days post-infection
 +
*Control achieved by:
 +
**Purchasing specific pathogen free (SPF) mice
 +
**Kill whole colony in an outbreak -> disinfection -> formalin fumigation
 +
 
 +
 
 +
===Canine Parainfluenza - 2===
 +
 
 +
*or Parainfluenza - 5
 +
*Infects dogs
 +
*May cause mild upper respiratory infection, [[Nasal cavity - inflammatory#Infectious causes of rhinitis|rhinitis]]
 +
**Virus shed for a short time only
 +
*Also part of kennel cough ([[Viral infections#Infectious canine tracheitis|Infectious canine tracheitis]]), together with [[Bordetella bronchiseptica and Bordetella avium|''Bordetella bronchiseptica'']]
 +
*Control:
 +
**'''Live attenuated vaccine''' may be incorporated in multivalent vaccines
 +
***Immunity is short-lived
 +
***Only reduces severity of clinical signs
 +
 
 +
 
 +
===Bovine Parainfluenza - 3 (PI-3)===
 +
 
 +
*Virulence varies with isolates
 +
*Cessation of [[Respiratory system - general introduction#Mucociliary escalator|ciliary clearance]] and epithelial necrosis predisposes to secondary bacterial infections -> cough
 +
*May cause [[Viral infections#Parainfluenza- 3|rhinitis]] of cattle
 +
*With other agents causes [[Bacterial infections#Enzootic pneumonia of calves|calf pneumonia ]]
 +
**Together with managemental factors (overcrowding, poor ventilation, high humidity, deprivation of colostrum and stress caused by transport or mixing of stock)
 +
*'''Diagnosis'''
 +
**Diseased lung tissue from dead animals or centrifuged cells from lung lavage
 +
**Virus is too fragile for cell culture isolation (often inactivated intransport)
 +
**Antigen detection by ''' immunocytochemistry''' for intracytoplasmic viral inclusions containing labelled viral protein
 +
**Serology: 4-fold rise in ELISA antibody in paired serum samples from several animals
 +
 
 +
 
 +
 
 +
 
 +
 
 +
 
 +
 
 +
 
 +
 
 +
 
 +
 
 +
===Bovine Respiratory Syncytial Virus===
 +
 
 +
*Bovine respiratory syncytial virus in [[Viral infections#Respiratory syncytial virus|respiratory infection]]
 +
*Diagnosis is same as for [[Paramyxoviridae#Parainfluenza -3 (PI-3)|PI-3]]
 +
 
 +
 
 +
 
 +
*Hendra virus in [[Viral infections#Hendra virus|respiratory infections]]
 +
 
 +
 
 +
 
 +
[http://www.pitt.edu/~super1/lecture/lec3401/index.htm On line lecture by P. Russell]
 +
 
 +
<big><center>[[Viruses|'''BACK TO VIRUSES''']]</center></big>

Revision as of 15:39, 9 December 2007

BACK TO VIRUSES


Overview

  • Systemic infections - controlled by live monotypic vaccination
  • Respiratory infections - not controled by live monotypic vaccinations


Classification


Virus properties

Structure

  • Negative sense RNA, unsegmented, single stranded
    • -> Reasortment and antigenic shift cannot occur
  • HN spike contains:
    • Haemagglutinin (H)- attachment protein
    • Neuraminidase (N)
  • Fusion glycoprotein (F) spike
    • -> Viral lipid bilayer can fuse directly with host plasma membrane
      • -> RNA released into cytoplasm
    • ->Syncytium (multinucleated giant cells) in lesions and cell culture
    • Host antibody response to this protein is most important
      • Best induced by live attenuated vaccines

Growth in vitro

  • Allantoic cavity of 10-day-old eggs
  • Followed by haemagglutination

In vivo

  • Cell tropism for upper respiratory tract epithelium
    • All replicate in these cells
  • Some replicate in the gut
  • Most virulent replicate in lymphoid cells and neurons (Distemper, NDV)
  • Links to the readiness to cleave Fo and Ho precursors in different cells

Antigenic differentiation

  • Major conserved immunodominant virus-specific antigens on F and HN
    • -> Vaccines protect against all isolates of the same virus
  • Minor morbillivirus-specific epitopes on F
  • Minor variable epitopes of F, HN and NP
    • Allows antigenic fingerprinting


Canine Distemper Virus (CDV)

{Canine distemper - a pantropic virus which has a suppressing effect on lymphoid tissue, and which may trigger latent Toxoplasmosis. After aerosol infection, the virus multiplies in the bronchial and other lymph nodes. It then spreads to a variety of epithelium depending upon the strain of virus including that of the respiratory and alimentary tracts, skin and later (1-5 wk. post infection) to the brain, causing a mucopurulent oculonasal discharge with keratitis and an interstitial pneumonia, a smelly sometimes bloody diarrhoea, eruptions on the skin including hyperkeratosis of the nose and pads, and encephalitis respectively. The essential feature of the last mentioned is demyelination particularly in the cerebellum resulting in ataxia. Convulsions, coma and paralysis may occur, and chorea (rhythmic motor movements) may be seen in recovered animals. Intracytoplasmic inclusions may be found in most affected tissues and inclusions persist longest in the brain (may be intranuclear) and the alveolar macrophages. Giant cells may be seen in the alveoli. The severity of the disease may vary; if enough neutralising antibody develops in the early stages, the virus maybe kept restricted largely to the lymph nodes. Severe clinical pneumonia follows secondary infection with Bordetella bronchiseptica.} From RVC respiratory notes 2006 by B.Smyth


Newcastle Disease Virus (NDV)

  • Hosts
    • Gallinaceous birds, pigeons, parrots, finches
    • Subclinical carriers: ducks, ostriches
    • Causes conjunctivitis in humans
  • Epidemiology
    • Air-born
    • Direct contact of poultry
  • Diagnosis
    • Samples of trachea and gut of 20 birds are tested in eggs
    • HI using anti-NDV serum (to differentiate HA caused by avian influenza
    • Animal test: virulence of isolate tested by the speed it kills chicks
    • Sequencing the cleavage site of H gene
      • The more basic amino acids the more virulent the virus
      • Now replacing the animal test
  • Control
    • Isolation of stock
    • Vaccination of chickens and racing pigeons
    • Surveillance of imported exotic birds
    • Notifiable disease
    • Infected premises to be culle and firebreak cull if spread


Reptilian Paramyxoviruses

  • Infect central nervous system and lungs
  • Kill particularly snakes
  • Healthy reptiles may be carriers
  • Testing by serology - HI test
  • Aim to keep virus free collection and prevent spread back into the wild


Murine Parainfluenza - 1 (Sendai virus)

  • Endemic in many mouse colonies
  • Most mice show no symptoms due to maternal antibodies
  • But minor respiratory lesions may invalidate carcinogenic or toxicological studies
  • Immunological studies also confused due to virus activating NK cells via high circulating IF 3-4 days post-infection
  • Control achieved by:
    • Purchasing specific pathogen free (SPF) mice
    • Kill whole colony in an outbreak -> disinfection -> formalin fumigation


Canine Parainfluenza - 2

  • or Parainfluenza - 5
  • Infects dogs
  • May cause mild upper respiratory infection, rhinitis
    • Virus shed for a short time only
  • Also part of kennel cough (Infectious canine tracheitis), together with Bordetella bronchiseptica
  • Control:
    • Live attenuated vaccine may be incorporated in multivalent vaccines
      • Immunity is short-lived
      • Only reduces severity of clinical signs


Bovine Parainfluenza - 3 (PI-3)

  • Virulence varies with isolates
  • Cessation of ciliary clearance and epithelial necrosis predisposes to secondary bacterial infections -> cough
  • May cause rhinitis of cattle
  • With other agents causes calf pneumonia
    • Together with managemental factors (overcrowding, poor ventilation, high humidity, deprivation of colostrum and stress caused by transport or mixing of stock)
  • Diagnosis
    • Diseased lung tissue from dead animals or centrifuged cells from lung lavage
    • Virus is too fragile for cell culture isolation (often inactivated intransport)
    • Antigen detection by immunocytochemistry for intracytoplasmic viral inclusions containing labelled viral protein
    • Serology: 4-fold rise in ELISA antibody in paired serum samples from several animals






Bovine Respiratory Syncytial Virus



On line lecture by P. Russell

BACK TO VIRUSES
Retrieved from "https://en.wikivet.net/index.php?title=Paramyxoviridae&oldid=12632"