• Genome: ss(-)RNA 11-15kb
• Five proteins: N, P, M, G, L
• Enveloped? Yes
• Capsid shape? Helix
• Transcriptional polarity
  
• Diseases: Lyssavirus- Rabies, Vesciculovirus- vesicular stomatitis

• Location: cytoplasm

• Location: cytoplasm

• Requires a complete complementary copy of (-) RNA
  –Called vcRNA, (+) sense
  –Distinct from mRNA
  –Requires ongoing Protein synthesis
  –vRNA and vcRNA are always encapsidated
  –Replication takes place in the nucleocapsid (RNP)
  •P, N, L, (+)RNA
  –Complimentary 3’ and 5’ ends: “inverted repeats”

• Rhabdoviridae Lyssavirus spp
• Old disease (written history, Eshnunna Code Mesopotamian law 4000 yrs old)
• Dumb rabies/ Mean rabies
• Resevoir species switched from dogs to wildlife in US during 1960's(carnivores and bats)
• Prevention: vaccination with human diploid vaccine
• Treatment: Human immunoglobin and vaccine
• 10-14 day quaruntine for animal if human is bitten

• Hosts: horses,cattle,pigs>humans (minor zoonosis)
• Wildlife:whitetail deer, small mammals in the tropics
• Transmission: saliva, exudate, contact, Vector(Sand Fly, soil or plants.. maybe)
• Occurs in the Americas
• Similar to that of foot and mouth!!!!
  –Excessive salivation
  –Blisters on the nose and in the mouth
• Clears up in about 2 weeks
• Trade restrictions and quarintines
  

• ss(-) RNA viruses
• 7 families

1. Rhabdoviridae
2. Filoviridae
3. Paramyxoviridae
4. Bornaviridae
5. Orthomyxoviridae (segmented)
6. Bunyaviridae (segmented)
7. Arenaviridae (segemented)

• Genome: ss(-)RNA virus ~ 15 kb
• Capsid shape? Helix
• Enveloped? Yes
• Transcriptional polarity
• Proteins: N P(C V) M G L
• Diseases: Measels/Cannine distemper/Renderpest-Morbillivirus, Hendra/Nipah-Henipavirus,Respiratory Syncytial Virus-Pnuemovirus

• Location: cytoplasm

-Requires RdRP

• Utilizes frameshift
• Alternate insert of G to get C V which blocks interferon

• Genome length can be divided by 6
• Utilizes "switch" when a certain amount of NP (Nucleoprotein) has been made

• Mononegavirales Paramyxoviridae (subfamily) Paramyxovirinae Morbillivirus spp
• Historical name Rubeola
• "Morbilli" means little plague
• Only infects Humans and primates
• Most contagious virus of man
• Kills ~ 160,000 kids/yr
• High mortality in naive population
• "Disease of civilization" needs 200-500k hosts in close proximity to survive
• Originated in the last 4-5k years
• Closely related to Rinderpest(eradicated)
• Spread by Aerosals
• Attacks lymphoid cells => immunosuppresion =>  2^o infections
• Clinical signs are a rash and cough
• Can cause nuerological symptoms very rarely
• Prevention: vaccination, Vit A, Nutrition
• Killed vaccine can amplify the virus
• Candidate for erradication

• Only one serotype of the virus
• No animal reservoir
• Effective vaccine
• Early diagnosis by Koplik's spots
• Setbacks:
• vaccine immunity isn't lifelong
• >95% coverage is needed to be effective
• only 82% worldwide (92% in the US)
• vaccine fails when HIV is present in the body
• Fear of vaccine-induced autism
  

• Mononegavirales Paramyxoviridae (subfamily) Pnuemovirinae Pnuemovirus spp
• Most important cause of viral lower respiratory tract infection in the world
• Ubiquitous and pandemic
• No vaccine (Attempted, but failed)
• Kills about 1% of humans, mostly very young and very old.
  
• Antigen Masking, Antigen sheding (prevents immune response) Reinfection common.
  
• Spread by fomites and aerosols, shed for 1-3 weeks
  

• Mononegavirales Paramyxoviridae (subfamily) Paramyxovirinae Morbillivirus spp
• Biphasic disease
• Respiratory, Gastrointestinal signs, Immunosuppression (primary replication in lymph nodes)
• Spread via aerosal, 10-14 day incubation period
• Death rate: 50% in adults, 80% in puppies
• Clinical signs: vomiting, hyperkerotosis of pads, nasal discharge
• vaccine available

• Mononegavirales Paramyxoviridae (subfamily) Paramyxovirinae Morbillivirus spp
• This Bitch is eradicated! (2011)
• Looks like FMD

• Mononegavirales Paramyxoviridae (subfamily) Paramyxovirinae Henipavirus spp
• New viruses
• Hendra: In brisborne Australia, Respiratory infection of horses, ZOONOTIC!
• Bats are the endemic reservoir
• Nipah:Respiratory disease of pigs, 105 human deaths, direct contact with pigs, 1.1 mil pigs culled
• Found in southeast Asia

• Segmented negavirales
• Genome: ss (-) RNA segmented, (8 for influenza A&B, 7 for influenza C)
• Capsid Shape? helix
• Enveloped? yes
• 1 segment = 1mRNA except for splicing... 10 RNAs
• Transcibes, translates and replicates in the nucleous in the Nucleous
• Diseases: Influenza A,B & C
• Orthomyxo means "true mucus"

• Entry site:

1. HA binds to saliac acid
2. Endocytosis
3. Fusion

• ØRNP enters nucleus
  ØTranscription (splicing is a possibility)
  ØProtein Translation
  ØReplication –encapsidation of vRNA and vcRNA
  ØAssembly
  ØRelease from cell
  Ø  NA is important here
  ØMaturation is extracellular
  ØHA must be cleaved to be infectious
• Biphasic activation
  –1. Cleavage of HA (or HE) into HA1 and HA2
  –2. pH shift causes conformational change with fusion peptide insertion into membrane

• Occurs in the nucleus
• No caping mechanims for mRNA
• 5' cap is added by "cap snatching mechanism", steals 5' cap from cellular mRNA
• Poly A tail is added
• Not encapsilated, so its free for translation

• Segmented-Negavirales Orthomyxoviridae
• One species, influenza C virus
• Humans, dogs, and pigs
• Occasionally a cause of severe illness and local epidemics
• Less common
• Mild respiratory disease in children
• Only 7 segments
• Uses HE instead of HA and NA

• Segemented-Negavirales Orthomyxoviridae
  
• Host = humans (seals and ferret)
• Respiratory disease; mild to severe
• World-wide distribution
• Closely related to Influenza A, but humans are the natural host
• No subtypes but different strains do exist
• Mutates 2–3 times slower than type A
• Less genetically diverse

• Segmented-Negavirales
• Birds are the natural reservoir and typically have mild disease
• Infects a wide range of species: humans, horses, swine, poultry, waterfowl, whales, seals
• HA Cell receptor: Sialic acid with specific linkage to glycoprotein

1. Birds: a2,3 linkage
2. Humans: a2,6 linkage
3. Pigs: both = mixing vessel, Cause of epidemics and pandemics

• Current subtypes found in people : H1N1 and H3N2 viruses
• Characterized by continuous changes (drift or shift)
• Vaccine made with Chicken eggs (embryonic)
  

Produces a very different virus not covered by annual vaccine. Typically no cross protection.

Low Pathogenicity Avian Influenza (LPAI)

High pathogenicity avian influenza (HPAI)

• Segmented-negavirales
• Genome: ss(-)RNA, Can be ambisense 13-21 kb
• 3 segments L M S
• Capsid shape? helix
• Enveloped? yes
• "switch" replication
• Replicates in the cytoplasm
• Diseases: Hanta virus/sin nombre virus- Hantavirus spp, Cache Valley virus- Orthobunyavirus, Rift Vallet Fever- Phlebovirus

Bunyaviridae orthobunyavirus

Bunyaviridae Phlebovirus

• Vector-borne disease of wild and domestic ruminants
• Endemic in tropical Africa
• Cyclic epidemics every 5-20 years
• Periods of abnormally heavy rainfalls
• Arthropod vector – mosquito, some sand flies
• OIE List A Disease
• Young animals have a higher death rate
• Bioterorism threat. 3rd most important in US

Bunyaviridae Huntavirus

• Genome: ss(+)RNA
• Capsid shape? Icosohedral
• Enveloped? yes
• Transcription by splicing
• Reverse transcription: ss(+) RNA => dsDNA
• Translation by frameshift and read through
• Replicates in the nucleus and cytoplasm
• Diseases: HIV- Lentivirus

• Nucleotide shift upstream of a stop codon
• Creates a longer protein with the downstream sequences in a different reading frame

• Retroviridae Lentivirus
• ss(+)RNA in 2 copies
• Capsid Shape: Icosohedral
• Enveloped? Yes
• Reverse transcription: ss(+)RNA=>dsDNA=>mRNA
• dsDNA is integrated into host chromosome, active site selected, cell machinery transcribes viral protein
• Multiple protein from one mRNA(frameshift, read through, splicing)
• Complex Retrovirus: Accessory proteins help to control replication
• Zoonotic transmition Monkey=>Human
• Discovered in the 80's

LTR----gag>pro<pol-env----LTR

• LTR= long terminal repeats
• gag=capsid protein
• pro=protease and is between gag and pol and processes the polyproteins
• pol=polymerase complex (RT, RNase H, and integrase)
• env=the precursor to the membrane glycoproteins

• Genome: dsRNA, 10-12 segments
• Capsid shape: Icosahedral, Double or triple capsid
• mRNA synthesis is in a core particle, extruded at 12 vertices
  
• Nonenveloped
• Replicate in cytoplasm
• 16-27kb
• 12 genera: Orthoreviruses, Rotavirus, Orbivirus, Coltivirus...
• Wide host range, Many arboviruses

• "true" reovirus
• Respiratory Enteric Orphan Virus -> REO
• Mild symptoms
• Terminal sequences conserved within genera and are thought to be important for replication and packaging
• Readily reassorts
• 10 segments. 3 large, 3 medium, 4 small. 11 or 12 proteins

 Reoviridae rotavirus

• 11 segments: —2 segments are translated into 2 proteins by  mRNA with overlapping reading frames
• —3 capsids. Outer capsid must be cleaved by enteric enzymes
• Most important single cause of diarrhea
• Young children < 5 years, animals < 1 year
• 300,000-800,000 deaths/year
• 4 important serotypes for humans
• Vaccines available: Rotashield,
  
• Vaccine not used in countries where diarrhea is well taken care of
  

Reoviridae Cultivirus 2 species

Colorado Tick Fever virus (CTF)

• Vector—: Tick (DermacenterAndersoni)
• —12 segments
• —Adult ticks can infect humans

Reoviridae Orbivirus

• Arbovirus=insect vectored
• BTV
• African Horse sickness- sub saharran africa
• EHD-population limiting in proghorn and deer in the US
• August 2012: 9 EHD and 1 BTV cases in cattle in US