Hey #MedTwitter
As promised, taking this thread further, I'll highlight a few more aspects about #COVID19.
A) TRANSMISSION and SPECIFIC PRECAUTIONS
B) WHAT IS SUPER-SPREADING?
C) WHAT IS R0?
1/n https://twitter.com/HaryaxPathak/status/1330803873980801025
As promised, taking this thread further, I'll highlight a few more aspects about #COVID19.
A) TRANSMISSION and SPECIFIC PRECAUTIONS
B) WHAT IS SUPER-SPREADING?
C) WHAT IS R0?
1/n https://twitter.com/HaryaxPathak/status/1330803873980801025
A) TRANSMISSION and SPECIFIC PRECAUTIONS
So, what are the various mechanisms of COVID-19 transmission?
As defined by the @CDCgov, these are the 3 mechanisms of COVID-19 spread:
Fomites (least important)
Droplet Spread
Aerosol
https://www.cdc.gov/coronavirus/2019-ncov/faq.html#Spread
2/n
So, what are the various mechanisms of COVID-19 transmission?
As defined by the @CDCgov, these are the 3 mechanisms of COVID-19 spread:



https://www.cdc.gov/coronavirus/2019-ncov/faq.html#Spread
2/n

Fomites are objects or materials which are likely to carry infection, such as clothes, utensils, and furniture.
They were thought to transmit COVID19 as well, but @CDCgov has said that COVID transmission through fomites is minimal.
3/n

"Droplet transmission is an infection spread through exposure to virus-containing respiratory droplets (i.e., larger and smaller droplets and particles) exhaled by an infectious person." - @CDCgov
Talking, coughing, sneezing, shouting produce droplets.
5/n
Respiratory droplets can be of varying sizes - larger ones descend to the ground earlier; smaller ones can travel further - up to a distance of 6ft or 2m.
So, a healthy person within 6ft or 2m of an infected person can get infected by the droplets of the infected person.
6/n
So, a healthy person within 6ft or 2m of an infected person can get infected by the droplets of the infected person.
6/n

> Personal Hygiene - cover the face while coughing/sneezing to prevent dispersion of droplets.
> Avoid Direct Contact
> Masks
> Social Distancing
7/n
> Masks
Simply put, Masks reduce the dispersion of droplets to a great extent.
As shown in the image, Masks reduce the risk of contracting the infection if everyone masks up, irrespective of whether infected or healthy.
The next tweet explains WHY MASKS?
8/n
Simply put, Masks reduce the dispersion of droplets to a great extent.
As shown in the image, Masks reduce the risk of contracting the infection if everyone masks up, irrespective of whether infected or healthy.
The next tweet explains WHY MASKS?
8/n
Thermal plumes produced by a person.
In (a–c) no mask is worn, in (d–f) a non-surgical three-ply disposable mask is worn.
(a,d) sitting quietly breathing through their nose
(b,e) saying ‘also’ when speaking at a conversational volume
(c,f) laughing
https://bit.ly/3fyZFRk
9/n
In (a–c) no mask is worn, in (d–f) a non-surgical three-ply disposable mask is worn.
(a,d) sitting quietly breathing through their nose
(b,e) saying ‘also’ when speaking at a conversational volume
(c,f) laughing
https://bit.ly/3fyZFRk
9/n
> Social Distancing
As mentioned above, droplets can travel up to 2 metres in the air.
That is precisely the reason for practicing Social Distancing - to keep yourself out of the range of droplet dispersion from a possibly infected person.
10/n
As mentioned above, droplets can travel up to 2 metres in the air.
That is precisely the reason for practicing Social Distancing - to keep yourself out of the range of droplet dispersion from a possibly infected person.
10/n

Infectious aerosols are suspensions of pathogens in particles in the air.
They can remain suspended in the air indefinitely; unless they are removed by air current or ventilation.
They can also travel nearly 10m distance.
https://bit.ly/363jk8P
11/n
Droplet vs Aerosol
Droplets are larger in size and travel up to 2m.
Aerosols are far smaller in size (<5microns) and can travel further up to nearly 10m.
12/n
Droplets are larger in size and travel up to 2m.
Aerosols are far smaller in size (<5microns) and can travel further up to nearly 10m.
12/n
This image clearly shows droplet and aerosols production and dispersion.
https://bit.ly/3l8plFn
13/n
https://bit.ly/3l8plFn
13/n

> Masks + Social Distancing - still most important and the primary mode of protection against infection.
> Reduce exposure time: Reduce time spent in proximity to other people as much as possible.
> Ventilation
14/n
> Ventilation
A closed room with no ventilation allows accumulation and concentration of the aerosols which increases the risk of infection.
Adequate ventilation continuously recycles the air in a room and flushes out the aerosols, making them less concentrated.
15/n
A closed room with no ventilation allows accumulation and concentration of the aerosols which increases the risk of infection.
Adequate ventilation continuously recycles the air in a room and flushes out the aerosols, making them less concentrated.
15/n
This here is an extremely helpful, interactive, and graphical representation of how Airborne Transmission works.
Must read and share.
https://english.elpais.com/society/2020-10-28/a-room-a-bar-and-a-class-how-the-coronavirus-is-spread-through-the-air.html?fbclid=IwAR3o-ck_slh21xrGXpK489hQoBC3Zy1gwuMlhz9OL1C5GIiwvu3PH0tEaV4
by @javisalas
16/n
Must read and share.
https://english.elpais.com/society/2020-10-28/a-room-a-bar-and-a-class-how-the-coronavirus-is-spread-through-the-air.html?fbclid=IwAR3o-ck_slh21xrGXpK489hQoBC3Zy1gwuMlhz9OL1C5GIiwvu3PH0tEaV4
by @javisalas
16/n
B) WHAT IS SUPERSPREADING?
It is the disproportionate spread of infection from a single person to a large group of people - who then go on to infect more and more people - leading to an exponential rise in the number of infections.
GIF: https://vis.sciencemag.org/covid-clusters/
17/n
It is the disproportionate spread of infection from a single person to a large group of people - who then go on to infect more and more people - leading to an exponential rise in the number of infections.
GIF: https://vis.sciencemag.org/covid-clusters/
17/n

Any event that leads to an outbreak of COVID, with a majority of the infections/cases tracing back to the said event can be called a Super-spreader event.
Such events cause large outbreaks and can be responsible for 100s to 1000s of cases.
18/n
Super-spreader events can range from a small party or a family get-together to public gatherings like concerts, election rallies, religious gatherings, festivals like Diwali, Eid, Christmas, supermarkets, etc.
So, why does Super-spreading occur?
19/n
So, why does Super-spreading occur?
19/n
C) WHAT IS R0?
A high R0 is the reason for super-spreading.
In simple terms, R0 is the average number of people infected by a single person.
R0 > 1 -->epidemic/pandemic
R0 = 1 -->stable/controlled spread
R0 < 1 -->minimal spread
COVID-19 has an estimated R0 b/w 2-6.
20/n
A high R0 is the reason for super-spreading.
In simple terms, R0 is the average number of people infected by a single person.
R0 > 1 -->epidemic/pandemic
R0 = 1 -->stable/controlled spread
R0 < 1 -->minimal spread
COVID-19 has an estimated R0 b/w 2-6.
20/n
Here is another extremely interesting and interactive article that explains how Super-spreader events occur and how R0 works in real life.
Must share.
https://vis.sciencemag.org/covid-clusters/
21/n
Must share.
https://vis.sciencemag.org/covid-clusters/
21/n

>Avoid crowded places
>Avoid large indoor gatherings
>Ensure maximum natural indoor ventilation
>Avoid mass gatherings, especially during festivals
22/n
To sum up:
Transmission is mainly by droplets and aerosols.
Masks, Distancing, Hygiene, and Ventilation are a must.
To prevent Super-spreading events - avoid crowds and mass gatherings.
Educate yourself and others. Share as much as possible.
23/n




23/n