RNA Viruses 2 Flashcards
What are the defining features of the Rotavirus?
reovirus
dsRNA
segmented
naked icosahedron
What are the defining features of the Influenza Virus?
orthomoxyvirus
(–) ssRNA
segmented
enveloped
What are the defining features of HIV?
retrovirus
(+) ssRNA
2 copies
enveloped
What does the Rotavirus cause? what are the symptoms and affected age groups?
severe gastroenteritis
adults - usually asymptomatic
children - profuse diarrhea, dehydration, maladsorption
Where do rotavirus virions assemble? What happens next?
cytoplasm
then but into rough ER
How does rotavirus egress occur?
exocytosis or cell lysis
Where do rotavirus virions mature? What do they do next?
in gut lumen
either infect other enterocytes or are shed in diarrhea
What are the diagnosis, treatment, and prevention of rotavirus?
diagnosis: often not needed
treatment: rehydration
prevention: vaccine
What characterizes uncomplicated influenza?
upper and/or lower resp tract
fever, headache, myalgia, weakness
What characterizes complicated influenza?
Primary pneumonia caused by flu
secondary bacterial pneumonia
mixed viral and bacterial pneumonia
muscle involvement (myositis - pain, rhabdomyelitis - breakdown)
Where do txn and replication of influenza happen?
nucleus
How do influenza virions egress?
budding
In influenza, _________ (N antigen) releases virions form ______ on cell surface
neuraminidase
sialic acid
How are influenza virions shed?
droplets - cough, sneeze
How is the flu treated and prevented?
antiviral drugs for treatment
vaccines for prevention
How is the flu vaccine characterized?
TRIVALENT inactivated vaccine
live attenuated vaccine
How is the AIDS stage characterized?
CD4 count < 200mm^m
How is the advanced HIV infection characterized?
CD4 count < 50mm^3
What are the stages of HIV disease?
Exposure/Transmission Primary HIV infection - acute Seroconversion Latent Early symptomatic HIV AIDS Advanced HIV
How does the HIV virus cause immunodeficiency? To what does it bind?
Binds CD4 and chemokine receptors on T cells and machrophages
depletes these cells –> extreme immune activation –> immunodeficiency
What are the top 10 AIDS defining conditions?
P. carnii pneumonia esophageal candidiasis wasting Kaposi's sarcoma Disseminated M. avium infection TB Cytomegalovirus disease HIV-associated dementia recurrent bacterial pneumonia toxoplasmosis
After the HIV virion fuses with the host PM, what happens?
Reverse transcriptase converts (+) ssRNA genomes into dsDNA
Once synthesized, what do HIV dsDNA genomes do?
integrate into host genome for life
How are the dsDNA HIV genomes, which have integrated into the host cell, transcribed?
Host RNA Pol II
What is the egress of the HIV virus?
Viral proteins and 2 genomes (+ssRNA and dsDNA) bud from the PM
Where does virion maturation occur for the HIV virus? What triggers maturation?
outside the cell
viral protease cleaves capsid proteins –> final trapezoidal shape
What is the diagnosis for HIV?
serologic assays for antibodies
nucleic acid assays for viral load
CD4 T cell count
What is the prevention of HIV?
risk avoidance
community awareness
public health measures
antiviral drugs (chemoprophylaxis)
What is the treatment of HIV?
antiretroviral therapy (ART) combined drugs to avoid resistance
What are 5 types of HIV drugs?
Nucleoside reverse transcriptase inhibitors (NRTI)
Non-nucleoside reverse transcriptase inhibitors (NNRTI)
Protease inhibitors (PI)
Integrase strand transfer inhibitors (INSTI)
CCR5 antagonists
What are 5 goals of HIV treatment?
Durable suppression of HIV viral load Restoration of immune function Prevention of transmission Prevention of drug resistance Improvement of quality of life
