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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: 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 • • • • • 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 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 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 • 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 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 • 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 • 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 HA • hemaggluttinin • attach • Antigen number NA • neuraminidase • through mucus • antigen number Helical capsid 8 Segmented linear ssRNA Human Diseases Influenza A Influenza B -ssRNA Orthomyxovirus Influenza 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 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 Hemagglutin Helical -ssRNA Human Disease Vesicular Stomatitis Rabies Rhabdovirus Lyssa virus Rabies • • • • Encephalitis Direct 3-8 weeks incubation Replication • Local • CNS • Salivary • Reservoir • • • • Tx: IgG Prevention: vaccination Bats K-9 / coyotes / foxes Racoons Skunks • Clinical • Furious • Dumb 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 Hemorrhageshock MODSDeath 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 Arboviruses 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 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 Inhibits DNA replication and transcription Smallpox Inhibits reverse transcriptase Influenza A Inhibits translation of late mRNA Herpes Interferes with penetration or viral uncoating Herpes Aids Inhibits Protein synthesis Genital Warts Questions?