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Paramyxoviridae

RNA viruses. Paramyxoviridae. 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)

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Paramyxoviridae

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  1. RNA viruses Paramyxoviridae

  2. 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

  3. Paramyxoviridae Nucleocapsid extruded from ruptured envelope Nucleocapsid with helical symmetry (“Herringbone” pattern) Intact virion All animal viruses with helical nucleocapsids are enveloped

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

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

  6. Family Paramyxoviridae • Subfamily Paramyxovirinae • Genus Morbillivirus • Genus Rubulavirus • Genus Avulavirus • Genus Respirovirus • Genus Henipavirus • Subfamily Pneumovirinae • Genus Pneumovirus • Genus Metapneumovirus

  7. Family Paramyxoviridae Subfamily Pneumovirinae Pneumovirus Respiratory syncytial viruses Acute viral respiratory disease in young children and housed calves Bovine respiratory syncytial virus pneumoniain a calf

  8. Family Paramyxoviridae Subfamily Paramyxovirinae Respirovirus Parainfluenza virus type 3 Respiratory disease in humans, calves and lambs Parainfluenza virus type 3 pneumonia in a calf

  9. Family Paramyxoviridae Subfamily Paramyxovirinae Rubulavirus Mumps virus Parainfluenza virus type 2 Menangle virus Tioman virus Avulavirus Newcastle disease virus Henipavirus Hendra virus Nipah virus

  10. 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

  11. Family Paramyxoviridae Subfamily Paramyxovirinae Morbillivirus Canine distemper virus Measles virus Rinderpest virus Peste des petits ruminants Phocid morbilliviruses Cetacean morbilliviruses

  12. Canine distemper virus Terrestrial carnivores • Canidae • Dog • Fox • Coyote • Wolf • Jackal • Dingo

  13. Canine distemper virus Terrestrial carnivores • Procyonidae • Raccoon • Kinkajou • Coati • Panda • Felidae • Lion • Leopard • (Cat) • (Tiger)

  14. Canine distemper virus Terrestrial carnivores • Mustelidae • Mink • Ferret • Weasel • Skunk • Badger • Stoat • Marten • Otter

  15. Canine distemper in ferrets and mink Ferret with distemper

  16. Canine distemper in dogs • Acute disease • Encephalitis • Pneumonia, Rhinotracheitis, Conjunctivitis • Gastroenteritis • Chronic disease • “Old dog” encephalitis • “Hardpad”

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

  18. 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

  19. 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”

  20. Canine distemper • Skin • Footpads: Hyperkeratosis: “Hardpad”

  21. Canine distemper virus • Diagnosis • Virus isolation • Serology: • Virus neutralisation test • Acute and convalescent serum • Histopathology • Polymerase chain reaction

  22. Tanzania 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

  23. Family Paramyxoviridae Subfamily Paramyxovirinae Morbillivirus Measles virus Canine distemper virus Rinderpest virus Peste des petits ruminants Phocid morbilliviruses Cetacean morbilliviruses Measles virus

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

  25. Family Paramyxoviridae Subfamily Paramyxovirinae Morbillivirus Measles virus Canine distemper virus Rinderpest virus Peste des petits ruminants Phocid morbilliviruses Cetacean morbilliviruses Rinderpest virus

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

  27. 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: >1 million cattle died

  28. 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

  29. 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

  30. Rinderpest in cattle Oral ulceration and necrosis Oral erosions with necrotic plaques

  31. Rinderpest in cattle Gross pathology Necrosis and haemorrhage of ruminal mucosa Haemorrhagic enteritis with erosion of Peyer’s patches

  32. 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

  33. 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

  34. Ocular, nasal and oral Mucopurulent discharge Peste des petits ruminants Ulcers and necrotic plaques on oral mucosa

  35. Haemorrhagic pneumonia Peste des petits ruminants Ulcers in oral cavity and linear erosions in intestine

  36. Family Paramyxoviridae Subfamily Paramyxovirinae Avulavirus Newcastle disease virus (formerly Rubulavirus)

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

  38. 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/gizzard junctions

  39. 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”

  40. 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

  41. 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.

  42. Newcastle disease virus • Diagnosis • Virus isolation • Inoculation of 10-day-old embryonated eggs • Serology • Haemagglutination inhibition

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