Thread by @abledoc

"Social Distancing" is a term coined by (math inclined) epidemic modellers and misunderstood by public & even by most public health "experts"
So what does it mean. 1/n
Lets start with the factors affecting R0 (Basic Reproductive Rate) that critically determines an outbreak...

https://twitter.com/OwenJones84/status/1241853523245125632

R0 (Basic Reproductive Rate)
= (Avge number of people one meets in a day) * (Probability of Transmission) * (Number of Infective days)
Thus R0 is not a fixed number but influenced & modified by behaviour.
Meeting & interacting with fewer people reduces R0 (Social Distancing) 2/n

Keeping 2m/6 feet distance distance reduces droplet transmission (Probability of Transmission, 2nd term), physical distancing is confused as Social distancing
Masks, Vaccination etc all reduce the second factor in R0
@s_harley1 @PriyankaPulla @JoyAnnReid
3/n

Droplet transmission operate similarly in indoor & outdoor spaces & is easily stopped by any kind of mask and physical distancing. (Hand washing & fomite precautions also target droplets. Hence in practice airborne transmission is responsible for the bulk of COVID19 cases. 4/n

During festivals, & social functions (marriage, conferences), the number of people one meets goes skyrockets, sending R0 through the roof. Thus R0 can go up by 10 or even a hundred times becoming superspreading events when these are in closed spaces or crowd density is high 5/n

Indeed Superspreading during social occasions is a characteristic trade mark of airborne pathogens such as SARS & COVID19.
Contact tracing data would reveal wide dispersion of secondary attack rates (very obvious early on during the COVID19 outbreak) 6/n

Thus the most important public health measures to stop airborne pathogens like SARS-Cov2 is to meet fewer people & avoid social functions & crowds. Keeping 2m distance won't stop superspreading in indoor crowded spaces.
Hence COVID19 loves festivals 7/n

Talking Loud and singing also increase aerosol generation and airborne spread. Hence people removing masks to speak and sing is a dangerous activity unless special air bubble is created using enclosures and HEPA filters. 8/n

Thus a consequence of this dispersion is that 90% of transmission is by less than 10% or fewer sources. (intimately related to the fact that aerosol transmission is sensitive to viral load, ventilation (size of the closed space, air replacement rate and duration of exposure.