Ch32-33 Corona- picorna- arbo Flashcards
describe coronaviruses
- positive strand RNA viruses
- enveloped
what is the agent of COVID 19
SARS-CoV-2
what is MERS and what is the mortality rate
- middle east respiratory syndrome
- viral respiratory illness
- 30-40% mortality rate
what is the coronavirus life cycle
- 1st phase of translation: includes an RNA dependent RNA polymerase
- 2ns phase of translation
- acquire viral envelope by budding of nucleocapsid into the ER
what are the clinical presentations of people with SARS CoV 2
-asymptomatic
- mild illness
- moderate illness
- severe illness: less than 94% O2, PaO2/FiO2 less than 300 mmHg, less than 30 breaths per minute
- critical illness: respiratory failure, septic shock, multiple organ dysfunction
explain the viral entry mechanism of SARS coV 2
RBD of spike protein binds to ACE2
what does ACE2 do
lowers BP
what does TMPRSS2 do
transmembrane protease, serine 2 cleaves spike protein
what are the proposed mechanisms of COVID 19 infection
- direct cytotoxic effect
- dysregulatino of RAAS
- endothelial cell damage and thromboinflammation
- dysregulated immune response
describe picornaviruses
- positive stranded RNA viruses
- do not have envelope
what is the habitat of enteroviruses and what are they types
- GI tract
- poliovirus and coxsackievirus
what are the types of picornaviridae
- enterovirus
- hepatovirus
- parechovirus
- rhinovirus
what are the types of enteroviruses
- coxsackievirus A
- cocksackievirus B
- echovirus
- enterovirus
- poliovirus
what is the habitat for rhinoviruses
respiratory epithelium
describe enteroviruses
- very stable in food and water
- stable at pH3 (stomach)
describe rhinoviruses
- sensitive to acidic pH
- replicate poorly above 33 C
describe organ involvement for enteroviruses
- only occurs if viremia persists
what are the 3 types of polioviruses and what are the differences between the types
- PV1, PV2 and PV3
capsid differences
what is the transmission of poilioviruses
fecal-oral