Thread by @President_MU

Ventilation is important, but other factors are equally or more important. SARS-CoV-2 transmits in droplets, fomites (particles, objects and surfaces) and aerosols. We do not know for certain the relative importance of each, so let’s be careful about all of them. 1/8

The best available evidence, and the experience of public health doctors managing outbreaks, strongly suggest that the majority of transmissions occur with close contact, close enough for droplets, and aerosols in high concentration, to transmit the infection. 2/8

We think that transmission via contaminated surfaces is rare, but touching and soiled hands are likely to be important routes of transmission. 3/8

We are, for example, seeing a significant number of transmissions outdoors, when people get too close, most likely transmissions via droplets, spray or soiled hands; a little more distance, not touching or shouting, or better hygiene might have prevented these infections. 4/8

Our own @hpscireland and the are very clear on this, acknowledging that this is a novel virus and we cannot be certain about these things. 5/8

hpsc.ie/a-z/respirator…

cdc.gov/coronavirus/20…

@hpscireland It is bad and potentially dangerous advice to suggest that physical distance, minimising direct contact and hand hygiene are not effective infection prevention and control measures, and that ventilation is somehow more effective or more important. 6/8

@hpscireland This is important. We are depending on people to do everything they can to reduce the risk of transmission, and we need to be clear in our advice, and explain it as best we can. I’m concerned that with the emphasis on ventilation, we forget the basics. 7/8

Vaccination protects, staying home if symptomatic protects, distance protects, masks protect, good respiratory hygiene protects, hand-washing protects, ventilation protects. We need to pay attention to all, and avoid crowding and getting too close, indoors or outdoors. 8/8