Is there good epidemiological data that estimates how many disease transmissions have insufficient hand hygiene as an important/necessary vector?
As opposed to what? Direct airborne transmission via breathing in droplets?
My model of the spread of colds and flu and so forth is that it is primarily down to bad hand hygiene. I’d predict (with pretty low confidence) that more people get infected through getting virus on their hands and then onto their face / into their mouth than by breathing in virus directly. I’ll look into this more when I get the chance, though, since lots of people are asking about this.
Droplets don’t usually float around very long. It seems most transmission would still require something going into a person’s mouth. A small portion of these droplets hang around in the air and can be breathed in, but poor hygiene seems like a far bigger issue given how often people touch their face, mouth, and food.
Also worth noting that, depending on the virus, particles outside a host can often survive for hours or sometimes days. To get infected by direct inhalation you’d need to be fairly close to a sick person when they were shedding virus into the air – i.e. to be very close to them in both space and time. To get infected through surface contamination the time requirement is much less stringent: you only need to be where an infected person was fairly recently. If you don’t have good hand/face/mouth hygiene, they can infect you without your ever seeing them or knowing they were there.
As opposed to what? Direct airborne transmission via breathing in droplets?
My model of the spread of colds and flu and so forth is that it is primarily down to bad hand hygiene. I’d predict (with pretty low confidence) that more people get infected through getting virus on their hands and then onto their face / into their mouth than by breathing in virus directly. I’ll look into this more when I get the chance, though, since lots of people are asking about this.
Droplets would be number one on my list of transmission vectors for people other than the hand hygiene intensive cases I mentioned, yes.
Droplets don’t usually float around very long. It seems most transmission would still require something going into a person’s mouth. A small portion of these droplets hang around in the air and can be breathed in, but poor hygiene seems like a far bigger issue given how often people touch their face, mouth, and food.
Also worth noting that, depending on the virus, particles outside a host can often survive for hours or sometimes days. To get infected by direct inhalation you’d need to be fairly close to a sick person when they were shedding virus into the air – i.e. to be very close to them in both space and time. To get infected through surface contamination the time requirement is much less stringent: you only need to be where an infected person was fairly recently. If you don’t have good hand/face/mouth hygiene, they can infect you without your ever seeing them or knowing they were there.