RNA Virus 2 Flashcards
What are the basic characteristics of Rotavirus?
reovirus, dsRNA, segmented, naked icosahedron
What are the basic characteristics of influenza virus?
orthomyxovirus, (-) ssRNA, segmented, enveloped
What are the basic characteristics of HIV?
retrovirus, (+) ssRNA, 2 copies, enveloped
What is the presentation of rotavirus?
Causes severe gastroenteritis–>profuse watery diarrhea, dehydration, maladsorption
Who does rotavirus typically affect? When is it’s peak incidence?
infants, and children, though adults are ususally asymptomatic but can be affected as well
How many deaths are casued by rotavirus?
more than 600k per year, mostly in developing countries
Don’t forget to study the image of rotavirus life cycle
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What are the key features of the rotavirus life cycle?
genome is segmented, one gene each
RDRP in the virion first transcribes mRNA
are viral proteins translated, new virions and genome segments are synthesized in the cytoplasm
virions assemble then bud into rough EE
Egress is via exocytosis or by cell lysis
Virions mature in gut lumen, then infect more enterocytes or are shed in profuse diarrhea
how is rotavirus diagnosed, treated, and prevented?
diagnosis: not required in most cases
treatment: oral rehydration solutions
prevented: live-attenuated vaccines
What are the rotavirus vaccines?
rotatrix and rotateq
What is influenza?
Acute respiratory illness, mainly during the winter
Describe the difference between complicated and uncomplicated flu virus.
Uncomplicated: upper and lower respiratory tract involvement, feverr headache myalgia and weakness
Complicated: pneumonia caused by influenza or bacterial pneumonia; you can have mixed viral and bacterial pneumonia; can have muscle involvement: myositis (pain) and rhabdomyelitis (muscle breakdown)
What are the key features of influenza virus replication
- genome is segmented, (-) ssRNA
- genome segments traffic into the nucleus for transcription and replication by RDRP
- viral proteins and genome segments accumulate at the plasma membrane
- virions assemble and egress by budding
- neuraminidase (N antigen) releases virions from sialic acid on cell surface
- virions shed by respiratory droplets
What are the major flu treatments?
Antiviral drugs: oseltamivir (Influenza A and B), zanamivir (influenza A and B)
amantadine and rimantadine: Influenza A only
Describe the Vaccines for flu.
Fluzone and many others, trivalent inactivated vaccine
FluMist live attentuated vaccines
what is a trivalent vaccine?
Vaccine that has 3 different flu strains in it
Describe the trends of HIV infections and AIDS related deaths?
both have been slowly declining after they peaked
What are the stages of HIV infection?
exposure to virus (transmission) primary HIV infection seroconversion latent period early symptomatic HIV infection AIDS (CD4 count under 200/mm^3) Advanced HIV infection (CD4 count under 50/ mm^3)
What is HIV cell tropism?
Only humans can be infected, virus binds to CD4 and chemokine receptors on T cells and macrophages
depletion of these cells and chronic immune activation cause immunodeficiency
What are the top 10 AIDS defining conditions?
- P. carinii pneumonia
- esophageal candidiasis
- wasting
- kaposi’s sarcoma
- diseeminated M. avium infection
- tuberculosis
- cytomegalovirus
- HIV-associated dementia
- recurrent bacterial pneumonia
- Toxoplasmosis
What are the key features of the HIV life cycle?
after the virion fuses with the plasma membrane, the RT enzyme converts the (+) ssRNA to dsDNA
dsDNA genomes integrate into the host chromosome for life
Host RNA Pol II transcribes the mRNA from the integrated genome, serves as the genome that is packaged into new virions
viral proteins and 2 genomes but from the plasma membrane
virion maturaturation occurs outside the cell when the viral protease cleaves the capsid proteins, forming the final trapezoid shape
How is HIV diagnosed?
Serologic assays for antibodies, nucleic acid assays for viral load, and CD4 T cell count
What is HIV prevention?
risk avoidance, community awareness, public health measures, antivirals drugs (chemoprophylaxis)
How is HIV treated?
ART (antiretroviral therapy)
must combine a bunch of drugs to avoid resistance
