ID - viruses Flashcards
Reassortment
Segmented viruses (e.g. flu) exchanging segments. Cause of pandemics
Complementation
1 of 2 viruses infecting same cell has non-functioning mutation. Other virus “complements” by making protein that serves both
Phenotypic mixing
Simultaneous infxn of cell with 2 viruses. Genotype A partially or completely coated with surface proteins of B. proteins determine tropism, but infect with A’s genome
Recombinant vaccines
HBV (HBsAg), HPV (6, 11, 16, 18)
RNA viral genomes mnemonic
All RNA viruses are ssRNA except reovirus.All replicate in cytoplasm except flu and retrovirus.(+) stranded RNA viruses are…I went to a retro (retrovirus) toga (togavirus) party, where I drank flavored (flavivirus) Corona (coronavirus) and ate hippy (hepevirus) California (calicivirus) pickles (picornavirus)
Naked viruses and nuclear membrane virus
Naked: Papillomavirus, Adeno, picorna, polyoma, calcivirus, parvovirus, reovirus, hepevirusGive PAPP smears and CPR to a naked Heppy. All enveloped viruses are from plasma membrane, except herpesvirus (nuclear)
DNA virus rules
HHAPPPPy viruses – Hepadna (HBV), Herpes, Adeno, Pox, Parvo, Papilloma, Polyoma. Parvo is only ssDNA. papilloma and polyoma are circular, supercoiled. Hepadna is circular, incomplete. All others are linear. Pox is complex, all others are icosahedralPox replicated in cytoplasm (has own DNA-dependente RNApol). All others in nucleus
Herpesvirus family
dsDNA, linearenveloped ( nuclear membrane)HSV-1: oral/genital, keratoconjunctivits, temporal lobe encephalitisHSV-2: genital/oralVZV (HHV-3): chickenpox, zosterEBV (HHV-4): mono, Burkitt’s lymphoma, Hodgkin’s lymphoma, nasopharyngeal carcinoma. Latent in B Cells. Positive Monospot. Atypical lymphos with “hugging” of RBCs.CMV (HHV-5): infxn in AIDS/transplant (retinitis), congenital defects, mono with negative monospot. “owl’s eye” inclusions. latent in monocytes.HHV-6: roseolaHHV-7: roseola (less common)HHV-8: Kaposi’s sarcoma
Adenovirus
dsDNA, linear non-enveloped Febrile pharyngitis, acute hemorrhagic cystitis, PNA, conjunctivitis
Parvovirus B19
ssDNA, linear, negative strand (smaller DNA virus)non-envelopedSCD kids: aplastic crisiskids: slapped cheek rash, fetus: hydrops fetalis, aduls: adults: pure RBC aplasia and RA-like Sx
HPV
PapillomavirusdsDNA – circularNon-envelopedwarts (1, 2, 6, 11) CIN, cancer (16, 18)
polyomaviruses
dsDNA, circularnon-envelopedJC – PML in HIVBK – transplant pts, kidney
poxvirus
dsDNA, linear (largest)envelopedSmallpoxVaccinia – cowpox molluscum contagiosum
Reovirus family
dsRNA linearnon envelopedicosahedral capsidColtivirus – colorado tick fever (arbovirus)Rotaviurs – #1 cause of fatal diarrhea in kids. Day-care, winter, kindergarten. Villous destruction –> decreased Na/K absorption. Routine Vaccination
picornavirus
ssRNA linear, (+)non-envelopedicosahedralRNA makes 1 large polypeptide that is cleaved by proteases into functional proteins. All are enteroviruses except rhinoPERCH:Poliovirus – Salk IPV, Sabin OPVEchovirus – aseptic meningitisRhinovirus – common cold. >100 types. acid labileCoxsackievirus – aseptic meningitis, herpangina (mouth blisters, fever), hand/foot/mouth dz, myocarditisHAV– fecal-oral, short incubation, asymptomatic/acute, no carriers
HEV
hepevirusssRNA, linear (+)nonenvelopedicosahedralfecal-oral, especially waterborne epidemicsshort incubation, high mortality in pregnant women(Enteric, Epidemic, Expectant moms)no carrier state
Norovirus
CalicivirusssRNA linear (+)non-envelopedicosahedralviral gastroenteritis
Flaviviruses
ssRNA, linear (+)icosahedralEnvelopedHCV – carrier state, long incubation, cirrhosis, HCC (chronic inflammation)Yellow Fever - arbovirus, Aedes mosquito. monkey or human reservoir. high fever, black vomitus, jaundice (yellow)Dengue – arboSt louis encephalitis – arboWest nile – arbo
Togavirus
ssRNA, linear (+)envelopedicosahedralRubella – (german measles) fever, post-auricular LAD, arthralgias, fine rash starting on head and moving down. One of the TORCHS infxnsEEE – arboWEE – arbo
Retrovirus family
ssRNA, linear (+)envelopedhave reverse transcriptaseHTLV (icosahedral) causes T cell leukemiaHIV
Coronavirus
ssRNA, linear (+)envelopedhelicalcommon cold, SARS
Influenza
orthomyxovirusssRNA, linear (-), segmentedhelicalhemagglutinin – viral entryneuraminidiase – progeny releaseGenetic shift – pandemicsGenetic drift – epidemics
Paramyxoviruses
ssRNA, linear (-), nonsegmentedenvelopedhelicalall contain F (fusion) protein, which causes respiratory epithelial cells to fuse and form multinucleated cells.Parainfluenza – croupRSV – bronchiolitis Tx with ribavirin. Palivizumab (anti-F) prevents PNA in premiesMeasles – Cough, Coryza, Conjunctivitis, Koplik spots, descenting maculopapular rash. SSPE (years later), encephalitis, giant cell PNA. Rash includes hands and feet (contrast rubella)Mumps – Parotitis, Orchitis, aseptic Meningitis. Can cause sterility
Rabies
rhabdovirusssRNA, linear (-)envelopedhelicalBullet-shaped viron. Negri bodies (cytoplasmic inclusions in neurons). Purkinje cells of cerebellum.Long incubationPost-exposure Tx: cleansing and vaccination +/- rabies IgRetrograde migration up nerve axonsFever, malaise –> agitation, photophobia, hydrophobia –> paralysis, coma –> death
Ebola
filovirusssRNA, linear (-)envelopedhelical
Arenaviruses
ssRNA, circular (-) 2 segmentsenvelopedhelicalLCMV – lymphocytic choriomeningitisLassa fever encephalitis – spread by mice
Bunyaviruses
ssRNA, (-), circular 3 segmentsEnvelopedHelicalCalifornia encephalitis – arboSandfly/Rift Valley fever – arboCrimean/Congo hemmorhagic fever – arboHantavirus – hemorrhagic fever, PNA
HDV
deltavirusssRNA, circular (-)Requires HBV co-infection –> worse prognosis
env gene
envelope proteins formed by cleavage of gp160gp120 – attach to host CD4+ T cell. crosses placenta causing false (+) tests in babies born to HIV+ momsgp41 – fusion and entry
gag gene
p24 – capsid protein
pol gene
reverse transcriptase, aspart protease, integrase
