Paramyxoviridae Flashcards
Paramyxoviridae transmission
Respiratory droplets
- initiate infection in respiratory tract
Morbillivirus
- canine distemper (single serotype)
- rinderpest
- peste de petis ruminants virus
- human measles
What was eradicated in 2001, after smallpox?
Rinderpest
- affected cattle, buffalo
Paramyxovirus
- parainfluenza
- avian paramyxovirus
- sendal virus
- mumps
- hendra virus
- nipah virus
Parainfluenza
Serotypes 1-4
- canine paramyxovirus, parainfluenza virus serotype 2: one cause of kennel cough
- parainfluenza serotype 3: infect cattle, sheep, horse
New castle disease virus belongs to what serotype?
Avian paramyxovirus serotype 1
Sendal virus
Murine parainfluenza virus type 1 (hemagglutinating virus of Japan)
- mice, hamsters, guinea pigs, rats, occasionally pigs
- homologous to human parainfluenza virus type 1 but not infect humans
Mumps
Measles, mumps, rubella, and varicella
Pneumorvirus
- human respiratory syncytial virus
- bovine RSV
- avian pneumorvirus
- pneumorvirus in mice
Bovine RSV
Affects young beef/dairy cattle
- component of bovine respiratory disease complex due to frequency of occurrence, predilection for lower respiratory tract, ability to predispose respiratory tract to secondary bacterial infection
- high morbidity, up to 20% fatality rate
Turkey Rhinotracheitis Virus is an ________
Avian pneumorvirus
- swollen head syndrome
Characteristics of paramyxoviridae
Spherical, enveloped pleomorphic particles
- ssRNA, negative sense, non segmented
- 6+ proteins
Envelop proteins
- HN, H, G: viral attach proteins
- M: assembly of virions
- F: factor active in fusion of cells, hemolysis, viral entry
Nucleocapsid protiens
- NP: protect viral RNA
- P: possible part of transcription complex
- L: polymerase
Which viral family has HA and H activities?
Morbillivirus
Which viral family has HN, both H + N activities?
Paramyxovirus
Which viral family has G activity?
Pneumovirus
- no H or N!
Canine distemper hosts
- canidae family
- procyonidae family (red panda, racoon)
- mustelidae family (ferret, mink, skunk)
- large cats
- phocine and dolpins
Factors affecting pathogenesis
- virus strain
- age of host
- host immune status/competence
Canine distemper diagnosis
- hematology: acute cases
- cytology: acute cases
- viral isolation
- PCR
- CSF analysis
- serology (ELISA)
- samples from serum, blood smear, conjunctival smear
Which diagnostic techniques are complicated by canine distemper vaccine?
ELISA
- IgM persist in dogs with distemper for 5 weeks to 3 months
- IgM lasts for 3 weeks after vaccination
Presence of both IgM and IgG, but negative blood smear and conjunctival smear
CNS distemper or successful vaccination in 3 weeks
Presence of IgG, but negative for IgM, blood and conjunctival smear
Not infected with CDV, protected by vaccination or previous infection
Presence of IgM, but negative to IgG, blood and conjunctival smear
Early vaccine titer, not disease
- rare
Positive blood smear, possible positive conjunctival smear, no signs of IgM or IgG
Very early acute CDV (rare)
No signs of IgM, IgG, negative blood smear and conjunctival smear
No infection, no protection
New Castle Disease
APMV-1 (family paramyxoviridae)
- lentogenic, mesogenic, velogenic
- neurotrophic, viscerotropic
Exotic Newcastle Disease
US definition for velogenic viscerotropic strains of Newcastle
Hendra virus
Respiratory and neurological disease in horses
What are 3 new viruses carried by fruit bats?
- hendra
- nipah
- menangle
Nipah virus
Primarily affects adult males with swine contact
- swine: severe respiratory disease, transmitted by movement of infected pigs
- human: febrile encephalitis, high mortality
- no vaccine available
Reservoir
- flying foxes (fruit bats) –> are not affected
- virus found in urine and partially eaten fruit
- no known secondary host
