Virology Lectures 2023 #12: Infection basics

In the second half of this course we shift from studying virus infection in cell culture to infection of animal hosts. In this lecture we discuss infection basics: how viruses enter hosts, spread to and infect different tissues, are transmitted to new hosts, and how geography and season may affect virus infections.

[jsweezey]

THANK YOU COLUMBIA U! If only I had VR as my professor... I would have tried to stay the course back in college & the "fun" 4 hour labs in zoonotic diseases; hematology; parasitology, etc.! Thank you VR & Columbia for teaching us. (I'm glad I dropped out & didn't go into this field...) I was better at drawing the little buggers under the microscope than identifying them... plus I was always somehow cross-contaminating myself... :)

[anatolyl]

1:05:30
Seasonality. The main factor is ventilation. In winter most people stay inside with bad ventilation. The infection rates go up. Rh is a small factor. Ventilation is by far the major factor... The argument about temperatures in Winter etc is not relevant since the vast majority of transmissions happen inside and not outside. We have similar temperatures in Summer and in Winter inside. doi:10.1038/1951129a0

[jsweezey]

And a big "salute tribute" to good old professor of organic chemistry, Dr. Fuchs... 🤭who scared the sheet out of me (and usually half his class) before the day was out in his chemistry lab... (Most of his students all agreed he must have been a stand-in double for Pete Cushing's character in Star Wars: A New Hope)🤫 I seem to recall he got a "sadistic kick" out of "announcing" (during active lab classes) that there might be a sudden explosion due to someone's idiocy of mishandling stored chemicals & we were to drop what we were doing & evacuate the lab as fast as possible... before we got blown to smithereens (or worse, failed his class)... Ah! The joyous trauma of lab technology! I'll never forget those good old days... (Although sucking human blood of unknown origins via a glass pipette in hematology lab runs a close second place...)

[anatolyl]

1:00:19
Some info regarding droplets is not accurate. It is mostly physics rather than biology.
1. The virion of respiratory viruses travels attached to a droplet only. Otherwise it disintegrates.
2. The virion of measles is not smaller than SARS-Cov2. They are similar in size. The info that the virus can travel 150 feet is unreliable. The virus can travel a distance the droplet can travel and not more. The droplet can travel a distance based on the laws of physics (depends on the airflow, Rh, temperature, etc). It is not an intrinsic feature of the virus.
3. The majority of transmission of SARS-Cov2 is via speaking and aerosol-size droplets which spread in repetitive plumes.

[tag_of_frank]

West Nile slide just shows that most people don't go to the doctor for a cold right? It does not mean that 80% show no symptoms.

[gingerbiscuits]

In the UK our government defined an arbitrary Covid Alert Level as 1-5 (1 is good, 5 is bad) and then defined this Covid Alert Level = R + number of infections. (!) Watching this lecture reminded me of that mathematical monstrosity and this seems likes the kind of place that would appreciate that little fact :p

In defence of UK science, this was just some guff tweeted by Boris Johnson and I assume it had nothing to do with actual public health advice/decisions ...

[jsweezey]

For the record, my fond "lab memories" were NOT at Columbia University...

[kxo]

The media is back to saying “Lab Leak” suspected. How many microbiologists would work on biowarfare projects?