RNA Virus Table (+) Strand RNA Virus Disease Treatment or Vaccine Picornavirus Picornavirus Picornavirus Poliovirus Paralytic poliomyelitis (paralysis) Aseptic meningitis Post-polio syndrome Sabin vaccine (live) SalK vaccine (Killed) Rhinovirus Common cold (most common cause) No specific treatment Coxsackievirus Aseptic meningitis Carditis Hand, foot, and mouth disease Herpangia Pleurodynia Bornholm disease (Devil's grip) No specific treatment Echovirus Aseptic meningitis Hepatitis A virus Mild acute hepatitis Killed vaccine Serum globulin Calicivirus Calicivirus Calicivirus Norwalk virus Acute gastroenteritis (schoolchildren) No specific treatment Togavirus Togavirus Togavirus Rubella virus Rubella (German measles) Congenital rubella Live attenuated vaccine (MMR) Eastern equine encephalitis - Killed vaccine Western equine encephalitis - Killed vaccine Flavivirus Flavivirus Flavivirus Yellow fever virus Yellow fever Live attenuated vaccine Dengue Dengue ("break bone fever") Supportive only Hepatitis C virus Chronic hepatitis IFN Ribavirin West Nile virus Aseptic meningitis Encephalitis Paralysis Supportive only St. Louis encephalitis Encephalitis Supportive only Coronavirus Coronavirus Coronavirus Coronavirus Common cold SARS Self-limiting Retrovirus Retrovirus Retrovirus HIV AIDS HAART Human T cell leukemia virus T-cell leukemia - Hepevirus Hepevirus Hepevirus Hepatitis E virus Mild acute hepatitis (fatal when prEgnant) Self-limiting (-) Strand RNA Bunyavirus Bunyavirus Bunyavirus Hantavirus Hantavirus pulmonary syndrome (50% mortality) Supportive only CA Encephalitis virus Encephalitis - Orthomyxovirus Orthomyxovirus Orthomyxovirus Influenza virus Flu Zanamivir/oseltamivir Paramyxovirus Paramyxovirus Paramyxovirus Rubeola Measles Live attenuated vaccine (MMR) Mumps virus Mumps Live attenuated vaccine (MMR) RSV Pneumonia (infants) Palivizumab Parainfluenza Croup Bronchiolitis Pneumonia Supportive only Rhabdovirus Rhabdovirus Rhabdovirus Rabies virus Rabies hRIG Arenavirus Arenavirus Arenavirus Lassa fever virus Hemorrhagic fever (50% mortality) Ribavirin Lymphocytic choriomeningitis virus (LCMV) Meningitis - Filovirus Filovirus Filovirus Ebola and marburg viruses Hemorrhagic fever (up to 90% mortality) Supportive only Double-Stranded (ds) RNA Reovirus Reovirus Reovirus Reovirus Common cold Gastroenteritis Self-limiting Rotavirus Gastroenteritis (infants) Self-limiting Colorado tick fever virus Flu-like Supportive only Virus Overview Viruses are obligate intracellular infectious agents with the following basic components DNA or RNA never both capsid a protein coat that surrounds the genetic material icosahedral or helical symmetry made of capsomers polypeptide chains organized into a globular subunit in helical symmetry, capsomers are bound to RNA and coiled forms a helical nucleoprotein capsid sometimes an envelope Viruses are classified by nucleic acid DNA or RNA double stranded or single stranded (+) or (-) stranded RNA single or segmented pieces of nucleic acid complexity of genome capsid icosahedral or helical envelope naked DNA or RNA + capsomers and other structural proteins = nucleocapsid enveloped nucleocapsid + host membrane with viral-specified glycoproteins = enveloped virus size diameter or number of capsomers ploidy all viruses are haploid (1 copy of DNA or RNA) except retroviruses retroviruses have 2 identical copies of their ssRNA, approximating diploidy infectivity of purified nucleic acid purified nucleic acid that is intrinsically infectious dsDNA from most viruses except poxviridae except HBV (+) strand ssRNA from most viruses (+) linear, nonsegmented ssRNA can be translated immediately into a large protein by host machinery virus must carry protease to cleave the 1 large protein product that will be generated by the host machinery purified nucleic acid that is NOT intrinsically infectious (-) ssRNA viruses must carry an RNA-dependent RNA polymerase to generate mRNA the host machinery can read dsRNA they require enzymes contained in the complete virion for infectivity RNA Viruses Most RNA viruses are single-stranded (ssRNA, like human mRNA) have helical symmetry replicate in the cytoplasm are enveloped Exceptions double-stranded (dsRNA) reo icosahedral reo picorna toga flavi calici replicate in nucleus retro orthomyxo non-enveloped picorna calici reo hepe