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NBME 24 Answers

nbme24/Block 3/Question#25
An investigator is studying a new virus ...
Coronavirus🔍

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You know it’s an enveloped virus since it doesn’t hold up to acid or being dried. You know it causes a fever and a cough, while affecting the larynx. Only virus category that fits all that info is the coronavirus (causes SARS) from that list.

zelderonmorningstar  EBV doesn’t cause fever and cough? +  
zelderonmorningstar  Wow, just checked First Aid and it doesn’t list “cough” as a symptom of EBV. +3  
drdoom  EBV is not a “respiratory virus”; it’s a *B cell virus*. Even though you might associate it with the “upper respiratory tract” (=kissing disease), it doesn’t cause respiratory inflammation since that’s not its trope. B cells are its trope! That’s why EBV is implicated in Burkitt Lymphoma, hairy leukoplakia and other blood cancers. (EBV is also known as “lymphocryptovirus” -- it was originally discovered “hiding” in *lymphocytes* of monkeys.) So, EBV = think B cells. +17  
fulminant_life  EBV does cause pharyngeal and laryngeal inflammation along with fever, malaise, and cough and LAD. The only thing that pointed me away from mono and towards coronavirus was the patients age. +4  
nbmehelp  Can someone explain what not holding up to acid or being dried has to do with being enveloped? +  
yb_26  @nbmehelp, the envelope consists of phospholipids and glycoproteins => heat, acid, detergents, drying - all of that can dissolve the lipid bilayer membranes => viruses will loss their infectivity (because they need an envelope for two reasons - to protect them against host immune system, and to attach to host cells surface in order to infect them) +4  
lowyield  @yb_26 does that mean that non-enveloped viruses hold up better to acid/dryness? +  
rina  yes enveloped viruses are easier to kill (see post from drsquarepants: https://www.nbmeanswers.com/exam/nbme23/1161). also i think the "when dried" might refer to the fact that coronavirus is spread by respiratory droplets (don't even need to read first aid can just read the news at this point!) +  



 +5  upvote downvote
submitted by drdoom(460),

EBV is not a “respiratory virus” -- it’s a B cell virus. It infects B cells; not laryngeal cells.

Even though you might associate it with the “upper respiratory tract” (=kissing disease), it doesn’t cause respiratory inflammation since that’s not its trope. B cells are its trope! That’s why EBV is implicated in Burkitt Lymphoma, hairy leukoplakia and other blood cancers. (EBV is also known as “lymphocryptovirus” -- it was originally discovered “hiding” in lymphocytes of monkeys.) So, EBV = think B cells. From the MeSH library:

The type species of LYMPHOCRYPTOVIRUS, subfamily GAMMAHERPESVIRINAE, infecting B-cells in humans. It is thought to be the causative agent of INFECTIOUS MONONUCLEOSIS and is strongly associated with oral hairy leukoplakia (LEUKOPLAKIA, HAIRY;), BURKITT LYMPHOMA; and other malignancies.

https://meshb-prev.nlm.nih.gov/record/ui?name=HERPESVIRUS%204,%20HUMAN




 +1  upvote downvote
submitted by staghorn(1),

too real rn...

thotcandy  right? nbme predicting the future +  



anyone else get this wrong while the current coronavirus "pandemic" (acc to some sources) is happening? feeling reaaallll dumb rn

targetmle  yes because i thought they wont give ques on current coronavirus situation so early!! +  
adamventure  I thought to myself "damn it sure would be fuckin hilarious if Coronavirus was the answer".. turns out it was and it wasn't hilarious since I got it wrong. +3  



 +1  upvote downvote
submitted by 123ojm(1),

Specifically didn't choose coronavirus due to the evidence that COVID-19 is spread fecal-orally. How does it get through the GI tract if it's inactivated by pH < 6? Can someone explain why my thinking is wrong?

hello  ...COVID-19 is transmitted via respiratory droplets. +  
123ojm  Right but some research has come out saying it's also spread fecal-orally. So I'm wondering what I'm missing in this question. +  



Hi there! Predicting some questions on pandemics in STEP1s in the near future. Stay tuned!




 -1  upvote downvote
submitted by madojo(93),

https://www.sketchymedical.com/products/catalog

CORONAVIRUS SKETCHY

positive sense RNA virus, sun crown corona king wearing robe - encapsulated helical virus - spiraling road, helical trees sneezing and blowing king - common cold with bronchiol tree on king pointing to SARS and middle east respiratory syndrome (acute bronchitis)

This virus replicates in the cytoplasm thats why King is outside his castle (nucleus)




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