I can’t find the source anymore but I remember being fairly convinced (70%?) that rhinovirus is probably spread primarily via formites, fwiw.
The main thing is that snot can carry a lot more viruses than aerosols. It’s also suggestive to me that covid restrictions often had major effects on influenza and RSV, but probably much less so on rhinoviruses.
I also don’t think we should necessarily overindex on viral respiratory diseases/pandemics, even though I agree they’re the scariest.
rhinovirus is probably spread primarily via formites
Until the COVID19 pandemic, nearly everyone thought that most infectious respiratory diseases were transmitted via fomites and droplets, but unfortunately, this was based on shockingly poor evidence and assumptions. The material you’ve seen is based on this outdated consensus.
As I pointed out before, there are mechanistic reasons to doubt that pandemics can arise from fomite transmission.
However, if I squint hard enough, I can kinda, sorta see how young children in daycare might be infected by sharing toys and sticking their fingers up their noses. But stuff like that isn’t going to cause a pandemic.
In fact, the dominant (and most likely only) mode of transmission of rhinovirus is aerosols (at least in adults), not fomites. The same paper claims that fomites were unable to infect adults.
I also don’t think we should necessarily overindex on viral respiratory diseases/pandemics, even though I agree they’re the scariest.
Anything that’s capable of causing a civilization-ending pandemic must be able to rapidly replicate in humans and spread via airborne transmission, and the only thing that can do that is viruses (and perhaps virus-like particles in the future).
The bottom line for me about fomites and surface contamination is that it’s probably a non-issue, and even if there’s something to it (which doesn’t seem too likely), it’s pretty easy to deal with without fancy tech: just wash your hands, disinfect surfaces, and wear a face covering to prevent face-touching.
That Wired article is fantastic. I see this threshold of 5 microns all over the place and it turns out to be completely false and based on a historical accident. It’s crazy how once a couple authorities define the official knowledge (in this case, the first few scientists and public health bodies to look at Ward’s paper), it can last for generations with zero critical engagement and cause maybe thousands of deaths.
I’m confused about the distinction between fomite and droplet transmission. Is droplet transmission a term reserved for all non-inhalation respiratory pathogen transmission (like touching a droplet on a surface and then touching your face, or the droplet landing on your mouth), so it includes some forms of fomite transmission? I’m seeing conflicting sources and a lot that mention the >5 μm rule so don’t seem too trustworthy.
I’m confused about the distinction between fomite and droplet transmission.
From what I’ve read, fomite transmission must involve surface touching, whereas droplet transmission must involve droplets, which are expelled by coughing or sneezing, directly landing (like a bullet) in your mouth, nose, or eyes without any extra contact or touching.
These methods of transmission seem so implausible (how many people actually sneeze or cough directly in someone’s face?) to be major causes of spread that it’s hard to believe that no one seemed to have performed definitive experiments to test these ideas for many decades. On the other hand, even seemingly definitive experiments (like the rhinovirus study) don’t seem able to shift expert opinion. In the case of rhinovirus, maybe one experient isn’t enough, but then the question is why no one seems to have been interested in replicating it.
Yeah, there were two groups that studied how rhinovirus is transmitted. One group was from the University of Virginia and found evidence of only fomite transmission. The study you cited is theirs. The other group was from the University of Wisconsin and found evidence for only airborne transmission. The Wisconsin group ”...argued that the high rate of transmission via the hands in the Virginia experiments might be attributable to intensive contact with fresh wet secretions produced by volunteers who essentially blew their nose into their hand.”
I can’t find the source anymore but I remember being fairly convinced (70%?) that rhinovirus is probably spread primarily via formites, fwiw.
The main thing is that snot can carry a lot more viruses than aerosols. It’s also suggestive to me that covid restrictions often had major effects on influenza and RSV, but probably much less so on rhinoviruses.
I also don’t think we should necessarily overindex on viral respiratory diseases/pandemics, even though I agree they’re the scariest.
Until the COVID19 pandemic, nearly everyone thought that most infectious respiratory diseases were transmitted via fomites and droplets, but unfortunately, this was based on shockingly poor evidence and assumptions. The material you’ve seen is based on this outdated consensus.
As I pointed out before, there are mechanistic reasons to doubt that pandemics can arise from fomite transmission.
However, if I squint hard enough, I can kinda, sorta see how young children in daycare might be infected by sharing toys and sticking their fingers up their noses. But stuff like that isn’t going to cause a pandemic.
In fact, the dominant (and most likely only) mode of transmission of rhinovirus is aerosols (at least in adults), not fomites. The same paper claims that fomites were unable to infect adults.
Anything that’s capable of causing a civilization-ending pandemic must be able to rapidly replicate in humans and spread via airborne transmission, and the only thing that can do that is viruses (and perhaps virus-like particles in the future).
The bottom line for me about fomites and surface contamination is that it’s probably a non-issue, and even if there’s something to it (which doesn’t seem too likely), it’s pretty easy to deal with without fancy tech: just wash your hands, disinfect surfaces, and wear a face covering to prevent face-touching.
That Wired article is fantastic. I see this threshold of 5 microns all over the place and it turns out to be completely false and based on a historical accident. It’s crazy how once a couple authorities define the official knowledge (in this case, the first few scientists and public health bodies to look at Ward’s paper), it can last for generations with zero critical engagement and cause maybe thousands of deaths.
I’m confused about the distinction between fomite and droplet transmission. Is droplet transmission a term reserved for all non-inhalation respiratory pathogen transmission (like touching a droplet on a surface and then touching your face, or the droplet landing on your mouth), so it includes some forms of fomite transmission? I’m seeing conflicting sources and a lot that mention the >5 μm rule so don’t seem too trustworthy.
Don’t you mean millions of deaths?
From what I’ve read, fomite transmission must involve surface touching, whereas droplet transmission must involve droplets, which are expelled by coughing or sneezing, directly landing (like a bullet) in your mouth, nose, or eyes without any extra contact or touching.
These methods of transmission seem so implausible (how many people actually sneeze or cough directly in someone’s face?) to be major causes of spread that it’s hard to believe that no one seemed to have performed definitive experiments to test these ideas for many decades. On the other hand, even seemingly definitive experiments (like the rhinovirus study) don’t seem able to shift expert opinion. In the case of rhinovirus, maybe one experient isn’t enough, but then the question is why no one seems to have been interested in replicating it.
Here’s the study FYI.
Yeah, there were two groups that studied how rhinovirus is transmitted. One group was from the University of Virginia and found evidence of only fomite transmission. The study you cited is theirs. The other group was from the University of Wisconsin and found evidence for only airborne transmission. The Wisconsin group ”...argued that the high rate of transmission via the hands in the Virginia experiments might be attributable to intensive contact with fresh wet secretions produced by volunteers who essentially blew their nose into their hand.”
Oh this is really interesting, thanks!