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nbme24/Block 3/Question#25

An investigator is studying a new virus isolated ...

Coronavirus

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submitted by tea-cats-biscuits(69),

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. +  
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. +7  
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. +1  
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) +1  




 +2  upvote downvote
submitted by drdoom(192),

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