Paramyxovirus

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Paramyxoviridae
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Family Paramyxoviridae
Enveloped, helical nucleocapsid, 220 nm
Single strand, non-segmented, negative sense RNA
Matrix (M) protein
Fusion (F) protein
Nucleocapsid
Nucleoprotein (NP) RNA
HN or G protein
Envelope
Haemagglutinin (H) Neuraminidase (N)
Lipid membrane
Not all Paramyxoviridae have haemagglutinin
or neuraminidase properties
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Paramyxoviridae
Nucleocapsid extruded from ruptured envelope
Nucleocapsid with helical symmetry (Herringbone
pattern)
Intact virion
All animal viruses with helical nucleocapsids are
enveloped
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Paramyxoviridae

• Pathogenesis
• Epitheliotropic and neurotropic
• Replicate in cytoplasm
• Eosinophilic inclusion bodies in cytoplasm
• Respiratory disease
• Neurological disease
• Alimentary tract disease
• Persistent infection (e.g. old dog encephalitis)

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Paramyxoviridae

• Immunity
• Effective immune response in most animals
• Antibodies are neutralising
• Vaccination is protective
• Some paramyxoviruses establish persistent
• infections in the central nervous system

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Family Paramyxoviridae

• Subfamily Paramyxovirinae
• Genus Morbillivirus
• Genus Rubulavirus
• Genus Avulavirus
• Genus Respirovirus
• Genus Henipavirus
• Subfamily Pneumovirinae
• Genus Pneumovirus
• Genus Metapneumovirus

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Family Paramyxoviridae
Subfamily Paramyxovirinae Respirovirus Parainflue
nza virus type 3
Respiratory disease in humans, calves and lambs
Parainfluenza virus type 3 pneumonia in a calf
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Family Paramyxoviridae
Subfamily Pneumovirinae Pneumovirus Respiratory
syncytial viruses
Acute viral respiratory disease in young
children and housed calves
Bovine respiratory syncytial virus pneumonia in a
calf
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Family Paramyxoviridae
Subfamily Paramyxovirinae Morbillivirus Canine
distemper virus Measles virus Rinderpest
virus Peste des petits ruminants Phocid
morbilliviruses Cetacean morbilliviruses
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Canine distemper virus
Terrestrial carnivores

• Canidae
• Dog
• Fox
• Coyote
• Wolf
• Jackal
• Dingo

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Canine distemper virus
Terrestrial carnivores

• Felidae
• Lion
• Leopard
• (Cat)
• (Tiger)

• Procyonidae
• Raccoon
• Kinkajou
• Coati
• Panda

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Canine distemper virus
Terrestrial carnivores

• Mustelidae
• Mink
• Ferret
• Weasel
• Skunk
• Badger
• Stoat
• Marten
• Otter

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Canine distemper in ferrets and mink
Ferret with distemper
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Canine distemper in dogs

• Acute disease
• Encephalitis
• Pneumonia, Rhinotracheitis, Conjunctivitis
• Gastroenteritis
• Chronic disease
• Old dog encephalitis
• Hardpad

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Canine distemper

• Histopathology
• Inclusion bodies
• Eosinophilic
• Intranuclear and cytoplasmic
• Formation of Syncytia
• Multinucleate cells
• Macrophages, Epithelial cells
• Lungs, lymph nodes

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Canine distemper

• Pathogenesis
• Replication in lymphoid tissue 7-10 days
• Tonsils, lymph nodes, spleen, bone marrow
• Replication in alveolar macrophages
• Immune suppression

Inclusion bodies especially in Lung, Urinary
bladder, Stomach, Intestine
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Canine distemper

• Nervous tissue
• Brain
• Neuronal degeneration
• Demyelination
• Nonsuppurative encephalomyelitis
• Viral persistence in central nervous system
• Reactivation ? cell-cell spread
• Immune response ? Old dog encephalitis

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Canine distemper

• Skin
• Footpads Hyperkeratosis Hardpad

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Canine distemper virus

• Diagnosis
• Virus isolation
• Serology Virus neutralisation test
• Acute and convalescent serum
• Histopathology
• Polymerase chain reaction

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Canine distemper epidemic in lions

• Serengeti Plain, Tanzania, 1994
• Fatal encephalitis and pneumonia
• Spread to Masai Mara, Kenya
• Antibodies against canine distemper
• virus in 55-85 of surviving lions

Kenya
Tanzania
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Measles

• Morbidity and mortality
• Fever, Rash
• Conjunctivitis
• Pneumonia
• Encephalitis
• Otitis media
• Subacute sclerosing panencephalitis

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Family Paramyxoviridae
Subfamily Paramyxovirinae Rubulavirus Mumps
virus Parainfluenza virus type 2 Menangle
virus Tioman virus Avulavirus Newcastle
disease virus
Henipavirus Hendra virus Nipah virus
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Family Paramyxoviridae
Subfamily Paramyxovirinae Morbillivirus Measles
virus Canine distemper virus Rinderpest
virus Peste des petits ruminants Phocid
morbilliviruses Cetacean morbilliviruses
Rinderpest virus
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Rinderpest

• Cattle plague
• Highly infectious disease of cattle
• Respiratory and alimentary tract disease

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Rinderpest

• History
• 900-1800 AD Europe Epidemics every 50 years
• 1890s Sub-Saharan Africa 80-90 of cattle died
• 1962-1976 Africa Vaccination campaign
• 1979-1984 Africa Epidemic gt1 million cattle
  died

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Rinderpest

• Epidemiology Transmission
• Direct contact
• Faecal contamination of drinking water
• Respiratory aerosols
• Infection of wild ungulates and pigs
• Movement of livestock
• Trade
• Pastoral migrations
• War

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Rinderpest

• Clinical signs
• High fever
• Nasal discharge
• Ocular discharge
• Excess frothy salivation
• Oral and nasal erosions and ulcerations
• Constipation followed by diarrhoea
• Death after a few days

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Rinderpest in cattle
Oral ulceration and necrosis
Oral erosions with necrotic plaques
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Rinderpest in cattle
Gross pathology
Necrosis and haemorrhage of ruminal mucosa
Haemorrhagic enteritis with erosion of Peyers
patches
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Peste des petits ruminants (PPR)
Pest of small ruminants Stomatitis-pneumoenteritis
Pseudo-rinderpest Kata (Catarrh)

• Acute to subacute contagious viral disease
• of goats and sheep
• Distribution
• Central Africa
• Middle East
• Arabian Peninsula
• India

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Peste des petits ruminants (PPR)

• Phylogenetically related to rinderpest virus
• Similar epidemiology and pathogenesis
• Respiratory and alimentary tract disease
• Clinical Signs
• Erosive stomatitis
• Conjunctivitis
• Diarrhoea
• Pneumonia

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Ocular, nasal and oral Mucopurulent discharge
Peste des petits ruminants
Ulcers and necrotic plaques on oral mucosa
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Haemorrhagic pneumonia
Peste des petits ruminants
Ulcers in oral cavity and linear erosions in
intestine
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Family Paramyxoviridae
Subfamily Paramyxovirinae Morbillivirus Measles
virus Canine distemper virus Rinderpest
virus Peste des petits ruminants Phocid
morbilliviruses Cetacean morbilliviruses
Measles virus
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Family Paramyxoviridae
Subfamily Paramyxovirinae Rubulavirus Mumps
virus Parainfluenza virus type 2
Canine infectious tracheobronchitis Canine
parainfluenza virus type 2 (CPiV) Bordetella
bronchiseptica (kennel cough) Canine adenovirus
type 2
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Family Paramyxoviridae
Subfamily Paramyxovirinae Avulavirus Newcastle
disease virus (formerly Rubulavirus)
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Newcastle disease virus

• Avian paramyxovirus type 1
• First recognised in Newcastle, UK, in 1926
• Epidemic disease of poultry
• Domestic fowl
• Turkeys
• Pheasant
• Ducks
• Geese

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Newcastle disease virus

• Tissue trophism
• Neurotropic form Encephalitis Faeco-oral
• Respiratory form Pneumonia Inhalation
• Viscerotropic form Systemic disease
• Virulent velogenic strains cause predominantly
  hemorrhagic lesions, in particular at the
  esophagus/proventriculus and proventriculus/gizzar
  d junctions

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Newcastle disease virus

• Affects wide range of other species of birds
• Psittacines Cockatoos, Parakeets
• Passerines Finches
• Ratites Ostriches
• Migratory waterfowl Long distance spread
• Avian paramyxovirus types 2-9
• Pigeon paramyxoviruses

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Newcastle disease virus

• Strain virulence
• High Velogenic
• Produce acute disease with high mortality (up to
  90)
• Some strains cause respiratory disease while
  others cause enteric or neurological disease
• Medium Mesogenic
• Produce respiratory disease and a drop in egg
  production
• Low Lentogenic V4 strains Vaccination
• Hitchner B1 is widely used as a live virus
  vaccine

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Newcastle disease virus

• Clinical findings
• A combination of inspiratory dyspnea (gasping),
  cyanosis of comb and wattles
• Intestinal symptoms may include crop dilatation,
  presence of foamy mucus and fibrinous exudate in
  the pharynx, a similar discharge from the beak,
  and yellow-green diarrhoea.
• Nervous system involvement is indicated by
  paralysis of wings and/or legs, torticollis,
  ataxia or circular movements, bobbing-and-weaving
  movements of the head.
• The disease in turkeys is similar there are
  signs of respiratory and nervous system
  involvement. Airsacculitis rather than tracheitis
  is the most common lesion.
• In ducks and geese most infections are
  inapparent.

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Newcastle disease virus

• Diagnosis
• Virus isolation
• Inoculation of 10-day-old
• embryonated eggs
• Serology
• Haemagglutination
• inhibition