That CDC brief on surface transmission is annoying vague about certain things.
Note about your analysis: that's 1 in 10,000 *per surface touched*. If you touch 100 contaminated surfaces per day, the risk would appear to rise to 1% per day! Very few people eat 100 eggs per day. (I know of one toxicologist who did it at least once, but that guy used to do some weird stuff.)
Also, what's a "surface" for this purpose? Each door handle, each light switch, each chair back? You could reach 100 easily, if you're in an area with high incidence of infection.
OTOH, it actually says "less than" 1 in 10,000, so ... did I mention it's annoying vague?
Then again, maybe it doesn't take handwashing into account? It says things like, " Hand hygiene is a barrier to fomite transmission and has been associated with lower risk of infection." and "The risk of fomite transmission can be reduced by wearing masks consistently and correctly, practicing hand hygiene, cleaning, and taking other measures to maintain healthy facilities." It doesn't (as you wrote) make clear if its risk assessment does, or does not, include hand hygiene, but I have to think not. If it did, then would this not imply that it also takes into account mask wearing (How is that relevant to surface transmission), cleaning, and "other measures"? And isn't "other measures" ... annoying vague?
That CDC brief on surface transmission is annoying vague about certain things.
Note about your analysis: that's 1 in 10,000 *per surface touched*. If you touch 100 contaminated surfaces per day, the risk would appear to rise to 1% per day! Very few people eat 100 eggs per day. (I know of one toxicologist who did it at least once, but that guy used to do some weird stuff.)
Also, what's a "surface" for this purpose? Each door handle, each light switch, each chair back? You could reach 100 easily, if you're in an area with high incidence of infection.
OTOH, it actually says "less than" 1 in 10,000, so ... did I mention it's annoying vague?
Then again, maybe it doesn't take handwashing into account? It says things like, " Hand hygiene is a barrier to fomite transmission and has been associated with lower risk of infection." and "The risk of fomite transmission can be reduced by wearing masks consistently and correctly, practicing hand hygiene, cleaning, and taking other measures to maintain healthy facilities." It doesn't (as you wrote) make clear if its risk assessment does, or does not, include hand hygiene, but I have to think not. If it did, then would this not imply that it also takes into account mask wearing (How is that relevant to surface transmission), cleaning, and "other measures"? And isn't "other measures" ... annoying vague?