RNA Viruses of Animals

Viral Classification Taxonomy Order (-viridae) Family (-viridae) Subfamily (-virinae) Genus (-virus) Species Group III (ds) IV (+ss) V (-ss)

RNA Virions Cytoplasm: Helical capsid Most enveloped with spikes NA Replication Biosynthesis Helical capsid Most enveloped with spikes NA Double sense Single sense (+ / -) 2 single sense (+)

Viral Entry into Cells

Group III: dsRNA Reoviridae

REOVIRIDAE REO=Respiratory Enteric Orphan Virus Non-enveloped Icosahedral RNA ds Segmented Human Diseases Rotavirus Coltivirus

Rotavirus World wide infection Fecal-oral spread Incubation: 1-3 days Diarrhea Children Diagnosis ELISA Latex Agglutination Prevention Hygiene Water sanitation

Coltivirus Colorado Tick Fever Disease Tick vector Rodent reservoir Acute Myalgia Photophobia Rash Hemorrhage Tick vector Rodent reservoir

RNA ss (+); (-); & retro-

Group IV: +ssRNA nonenveloped Picornavirus Rhinovirus Enterovirus Hepatovirus Calicivirus Astrovirus Hepevirus

Hepevirus (formerly calcivirus) +ss RNA nonenveloped Icosahedral Fecal-oral Domestic pig reservoir Developing countries/sanitation Hepatitis E (enteric hepatitis)

ASTROVIRIDAE Astro = Star Nonenveloped +ssRNA 7 Human Serotypes Diarrhea Treatment Supportive

CALICIVIRIDAE Calicus Non-enveloped Icosahedral Linear ss + RNA Cup shaped Indentations Non-enveloped Icosahedral Linear ss + RNA Human Diseases Norwalk Virus (Norovirus)

Calicivirus Norwalk Virus Summer diarrhea Epidemic Gastroenteritis V/D Institutions ID virus in stool 90% of viral diarrheas

PICORNAVIRIDAE Pico = small Nonenveloped Icosahedral RNA + ss Human Diseases Enterovirus Polio Coxsackie A , B ECHO Rhinovirus Hepatovirus

Rhinovirus Common cold virus: 50% Transmission: inhalation Incubation: 1-3 days Symptoms Sore throat Mucopurulent nasal discharge Complications predispose to secondary bacterial infections

Hepatovirus: Hepatitis A Infectious Hepatitis Milder disease than Hepatitis B No chronic form Fecal-oral Incubation: 2-5 weeks Virus excreted in stool Resistant to disinfection Dx: IgM

Enterovirus Disease Groups Fecal-oral Cytolytic Poliovirus Coxsackie A, B Echovirus Fecal-oral Cytolytic GI mucosa Lymphatic tissue

Echovirus ECHO= Enteric Cytopathic Human Orphan Fecal-oral route Disease Meningitis Paralysis URTI Myocarditis Fever Rashes Orchitis

Coxsackie A and B Fecal-oral Disease Coxsackie A Coxsackie B Skin Rashes Herpangina Mouth Pharynx Hand/Foot/Mouth Conjunctivitis +/- DM Type I cause Coxsackie B Myocarditis Meningitis URTI Paralysis

Poliomyelitis 3 serotypes (Type 1 disease) Transmission: fecal-oral Throat ->LN->Ileum->Blood-> CNS Phases Asymptomatic: 90% Minor Polio Non-paralytic Paralytic: 2-3%, causes 75% of paralysis Dx: virus in feces, secretions Prevention: Vaccine Salk (IPV, killed) Sabin (OPV, modified live)

Poliovirus Bulbar Poliomyelitis Post Polio syndrome

Group IV:+ssRNA enveloped Togavirus Flavivirus Coronavirus

CORONAVIRIDAE Corona = crown Enveloped Helical Linear RNA + ss Respiratory droplet Human Diseases Common cold (20%) SARS

Severe Acute Respiratory Syndrome (SARS) Respiratory Droplet Direct Indirect 2-10 day incubation Cough->Pneumonia Stable in environment for days Dx: PCR Tx: supportive Prevention avoid contact disinfect

TOGAVIRIDAE Toga = coat Spiked envelope Icosahedral Linear ss+RNA ~Arthropod vector Human diseases Encephalitis (VEE, WEE, EEE) Rubella

Encephalitis: VEE, WEE, EEE all Rodent: VEE

Togavirus: Rubella Rubivirus Rubella German Measles Respiratory Droplet 2-3 week incubation Rash: 3 days Facial Spreads to body Changes hourly Complications Adults Arthritis Encephalitis Congenital defects Nervous Heart Blindness Prevention: MMR Rubivirus

FLAVIVIRIDAE Flavus = yellow Enveloped Helical Linear RNA ss + Human Diseases Hepatitis Encephalitis Hemorrhagic Fever

Flavivirus Hepatitis C Endemic Parental 6-8 week incubation Mild form HCV Non A non B Endemic Parental Blood Needles Organs 6-8 week incubation Mild form Chronic Cancer Liver failure Dx:IgG, PCR Tx: Interferon

Flaviviridae Hepatitis Yellow Fever Hepatitis G Acute Persistent Liver / GI Kidneys Heart Hepatitis G Acute Persistent Co-infection with Hepatitis C Parental: blood Encephalitis Japanese Complex Russian spring/summer St. Louis Acute Inflammatory Vector: mosquito 4-21 days incubation

Flavivirus Encephalitis

Flavivirus West Nile Virus Acute Febrile Hemorrhagic Vector: mosquito 3-14 days incubation Dx: IgM, ELISA Tx: Supportive

Flavivirus: Dengue Fever Tropical Aedes mosquito Disease syndromes Breakbone fever Rash Myalgia Hemorrhagic fever Reinfection Hyperimmune response

Group V: -ssRNA enveloped, segmented Bunyvirus Orthomyxovirus Arenavirus

ARENAVIRIDAE Arenosus = sand (ribosomes) Enveloped Helical Segmented linear ss- RNA Rodent reservoir Human Disease Hemorrhagic fever Old world Lassa Sabia Junin Lymphocytic choriomenigitis (LCM) New world arenavirus

Arenavirus Hepatitis D Delta Agent Defective Incomplete ss RNA Viroid Co-infection with HepB Satellite virus Enveloped Body fluid spread

BUNYAVIRIDAE Named after location of first viral isolation Spiked, enveloped Helical Circular ss-RNA Human Disease Arborvirus Encephalitis Respiratory Hemorrhagic Fever Rodent Hanta Virus

Bunyavirus Hanta virus Adult Respiratory Disease 1-3 weeks incubation Transmission: deer mice Symptoms SOB N/V pain Tx: supportive Prevention: rodent control, disinfect

ORTHOMYXOVIRIDAE Myxo = mucus Spiked envelope Helical capsid HA hemaggluttinin attach Antigen number NA neuraminidase through mucus antigen number Helical capsid 8 Segmented linear ss-RNA Human Diseases Influenza A Influenza B

-ssRNA

Orthomyxovirus Influenza Influenza Treatments Inhibit Neuraminidase Range of symptoms from mild to severe Droplet Direct Indirect 1-3 days incubation Reservoir: Humans Treatments Vaccination Drugs Complications Recombinant due to segmented RNA Secondary bacterial infections Viral super infection with Adenovirus Influenza Treatments Inhibit Neuraminidase Relenza (IN) Tamiflu (PO)

Antigenic drift: HA/NA mutations Antigenic shift: genetic reassortment

Influenza Pandemics

Group V: -ssRNA enveloped, nonsegmented Paramyxovirus Morbillivirus Parainfluenza Rubella RSV Nipahavirus Rhabdovirus Filovirus

PARAMYXOVIRIDAE Similar to Orthomyxoviruses Spiked Envelope Helical HA NA Fusion (F protein) Helical Segmented linear ss – RNA Human Diseases Respiratory Epithelial

Paramyxovirus : Respiratory Parainfluenza 4 types (HPIV) Pediatric infection Symptoms Fever Coryza Barking cough (Croup) Airway obstruction Droplet Tx: supportive

Paramyxovirus :Respiratory Respiratory Syncytial Virus (RSV) Infants Pneumonia lower airways Alveoli damaged Symptoms Cold like Fever Coryza Cough Wheeze Dsypnea Droplet Tx: supportive

Paramyxovirus: Epithelial Mumps Glandular (Parotiditis) Droplet transmission 21 day incubation Inflammation Complications Encephalitis Orchitis Nephritis Pancreatitis Arthritis IgM Tx: symptomatic Prevention: MMR Rubulavirus

Mumps Pathogenesis

Paramyxovirus: Epithelial Measles (Rubeola) Epithelial mucosal linings Skin -> rash Respiratory GI Complications Panencephalitis Conjunctivitis Droplet transmission 10-12 days incubation Desquamation Highly infectious Tx: symptomatic Prevention: MMR Morbillivirus

RHABDOVIRIDAE Rhabdo = rod like Spiked, enveloped Helical -ssRNA Hemagglutin Helical -ssRNA Human Disease Vesicular Stomatitis Rabies

Rhabdovirus Lyssa virus Tx: IgG Prevention: vaccination Rabies Encephalitis Direct 3-8 weeks incubation Replication Local CNS Salivary Reservoir Bats K-9 / coyotes / foxes Racoons Skunks Clinical Furious Dumb Tx: IgG Prevention: vaccination

FILOVIRIDAE Filo = filamentous Spiked, enveloped Helical Linear ss – RNA Pleomorphic shape Filament, branched, U-shape, Circular Gp epithelial receptors Human Disease Acute Hemorrhagic fevers Marburg Virus Ebola Virus

Marburg Fruit bat/green monkey Africa (Germany isolated Body fluid spread 3-9 day incubation Course Rash Gi inflammation Liver failure Pancreatitis Hemorrhageshock MODSDeath

Ebola virus Africa Direct contact Acute hemorrhagic fever 4-16 day incubation Symptoms Fever V/D Rash Hemorrhage from all open body cavities Death due to shock from fluid and blood loss

RETROVIRIDAE Retro = reverse RNA dependent DNA polymerase (RT) Spiked envelope polyhedral 2 linear +ssRNA (diploid virus) Enzymes Reverse transcriptase Protease Integrase Human Diseases Deltaretrovirus HTLV: leukemia Lentivirus HIV: AIDS

Retroviridae Human T-Lymphocytic Virus (HTLV-1) Adult T cell Leukemia Aggressive Tumor Latent Infiltrates Skin brain Transmission Horizontal Blood Sexual Intercourse Vertical Breast milk

Retroviridae Human T-Lymphocytic Virus (HTLV-2) B-Lymphocytes Hairy cell leukemia Slow growing Middle aged men Type of CLL Signs Bruising/bleeding Swollen LN Fatigue Fevers

Human Immunodeficiency Virus

Ecological Groups Oncoviruses Arboviruses Cancer causing DNA related Arthropod borne viruses Transmitted by Insects Mites Ticks Lice Viral Families Togavirus Bunyaviridae Rhabdovirus (some) Arenavirus (some) Reovirus (some) Oncoviruses Cancer causing DNA related Viral Families Papovirus Adenovirus Parvovirus Herpesvirus Retrovirus

Zoonoses Disease that humans can acquire from animals Viral examples Marburg (monkeys) Pox (cow pox, pseudo-cowpox, monkey pox) Rabies (warm blooded mammals) Influenza A Lassa (rodents, bats) Hanta virus: pulmonary (rodents)

Viral Vaccines Live / Attenuated Killed / Viral Protein Measles Mumps Rubella Polio (oral) Yellow Fever VZV Killed / Viral Protein Hepatitis A Hepatitis B Rabies Polio (Salk)

Antiviral Chemotherapy Inhibits Viral DNA-dependent DNA polymerase Herpes Inhibits DNA replication and transcription Interferes with penetration or viral uncoating Influenza A Inhibits translation of late mRNA Smallpox Inhibits reverse transcriptase Aids Inhibits Protein synthesis Genital Warts

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