Week 3 Day 4 Covid Flashcards
What helps SARS-CoV-2 resist mutations that could weaken it?
Genomic proof reading mechanism
What is a virulence factor that helps SARS CoV 2?
Recombination with other coronaviruses that give it mutations to allow it to infect new cell type
Can move species
What protein on its surface does it use to bind and what receptor does it bind to?
S- Spike protein binds to ACE2/angiotensin converting Enzyme 2 receptors
After binding to a cell what enzyme activates the S protein causing fusion allowing viral entry into the cell?
TMPRSS2- a serine protease
Could TMPRSS2 be a potential drug target?
Yes- TMPRSS2 inhibitors have been shown to block viral entry
What host enzyme that is abundant in respiratory tracts does CoV 2 use to cleave S proteins and escape the cell after replication?
Furin
How does SARS-CoV-2 cause damage in lungs?
Infects and destroys alveoli- inflammation response/leaky vessels which causes
WBCs to plug the airway and block RBCs from picking up Oxygen
Triggers immune system into overdrive causing cytokine storm and tissue damage
Sometimes permanent lung damage
Can SARS CoV 2 be carried in blood?
Yes it is how it reaches so many parts of the body
What happens in some Cytokine storms?
Multiple Organ failure and Death
What are most variants a result of?
AA sub on spike protein which causes conformational change and increases binding to ACE which increases viral load
What variant level is Delta classified as?
Variant of concern- more contagious and more serious disease
10 others are being monitored as variant of concern
None have reached the highest level- high consequence where no tx and no vax works
What is major difference in contagiousness and risk of transmission between vaxxed and unvaxxed?
Vax = shorter window of transmission which translates to less time contagious and less transmission
Same levels of virus between two
Less symptoms in vaxxed too
How effective Are US approved vaccines against the Delta variant?
Highly
Other areas of the body that Covid can attack?
Heart Digestive Kidneys Immune and hematology systems Psychology Neurological systems Reproductive
Is the dose of virus needed for infection known?
No
3 known modes of transmission and one that hasn’t been demonstrated?
- Inhalation
- Deposition of virus on micas membranes
- Touching mucous membranes with contaminated hands
Fomite transmission hasn’t been shown to be a thing although virus can live hours to days on surfaces
Still learning
Has Covid been detected in breast milk, urine, stool, and serum?
Yes but no know transmissions
How long has viable virus been shown to stay in air after aerosol generating procedures?
3-16 hours
They found virus after non agps but it wasn’t viable
Dental guidelines?
Pre-questions
PPE
Wait on to for potential positive unless urgent
Technique- 4 hand, high vac, dental dams
Patient placement- Barriers, space and head placement away from air intakes
How soon can viral Covid RNA be detected?
1-3 days prior to symptoms
When are viral loads usually the highest?
Usually day of symptoms onset
Does detection of Covid Rna mean someone is positive?
Nope
What are the three Ws and Ds for preventing transmission?
W
Wash hands
Wear mask
Watch distance
D
Distance
Density
Duration. Greater than 15 minutes increases risk
Why do some people think herd immunity is not possible?
Breakthrough infections
Reinfections
Unknown antibody duration
Variants
3 different types of tests?
PCR- slight chance of false neg is viral count is low- most specific and sensitive
Antigen- looks for capsid N protein antigens- not super sensitive higher chance of false negatives but very specific and if viral loads are high very reliable
Antibody- looks for spike or N antibodies- evidence of past infection only can’t conduct too early
If hospitalized what is the current recommended treatment?
Remdesivir
Dexamethasone
Blood thinners
