4 ms·

Asymptomatic carriers are a concept I've always found interesting and honestly a bit confusing. When a pathogen can be present without ever causing symptoms it

Asymptomatic carriers are a concept I've always found interesting and honestly a bit confusing. When a pathogen can be present without ever causing symptoms it becomes much trickier to show causality. This was a lynch pin of sorts in Koch's postulates. We can't properly go through those postulates with viruses like we can with biological pathogens, but it is odd to me that we don't have similar concerns when the presence of a replicable pathogen doesn't cause the symptoms they are expected to cause.

deleted 1y ago
[deleted]
Fomite 1y ago
You can show transmission pathways with a combination of epidemiological evidence and sequencing data.
- _heimdall 1y ago
  Epidemiology can never show causation or evidence, at best it shows correlation that is a useful indicator for future research.
14 1y ago
I am sure it does cause concern to many. I mean how scary is it that you can run into someone seemingly healthy and next thing you know you are sick? I know as a health care worker I actually think about things like this. MRSA is a good example. Most people don't react to exposure but some do. Those that do get long term infections that are hard to get rid of if ever. Most think of this as a hospital issue. But the reality is that there are literally thousands of people with MRSA all over the world and they are carriers of it and they do things like go to the bank machine and touch it, open the door at 7-11, pick up items at the store and then put them back on the shelf and so on and so on. MRSA is literally everywhere. Some people contact it and suffer problems others do not.
- _heimdall 1y ago
  With something like MRSA how do you determine that the virus is cause for disease when, as you said, many will be infected without showing symptoms? That the root of the confusion for me. I haven't wrapped my head around how we can know a specific pathogen causes disease if a large number of people can be found to have that pathogen present without showing symptoms.
  - kijin 1y ago
    Statistics. Not all smokers get lung cancer. But with large enough samples, smokers turn out to be much more likely to get lung cancer than non-smokers. That's why we say that smoking causes lung cancer. It's not as if someone has actually watched a particle of tobacco interact with someone's lung cells to turn them cancerous in real time.
    - jodrellblank 1y ago
      Why doesn't that get dismissed with the usual universal dismissal "correlation != causation"?
      - _heimdall 1y ago
        For one I'd assume its because contagions and physical damage are quite different. That's not to say that correlation between viral presence and disease can't indicate causation, but it is more clear when you are looking at the direct damage to lung tissue from inhaling hot cigarette smoke for years or decades.
    - _heimdall 1y ago
      Smoking isn't a contagious pathogen.
      - sydbarrett74 1y ago
        Second- and third-hand smoke mimic contagion.

deleted 1y ago

[deleted]

Fomite 1y ago

You can show transmission pathways with a combination of epidemiological evidence and sequencing data.

_heimdall 1y ago
Epidemiology can never show causation or evidence, at best it shows correlation that is a useful indicator for future research.

14 1y ago

I am sure it does cause concern to many. I mean how scary is it that you can run into someone seemingly healthy and next thing you know you are sick? I know as a health care worker I actually think about things like this. MRSA is a good example. Most people don't react to exposure but some do. Those that do get long term infections that are hard to get rid of if ever. Most think of this as a hospital issue. But the reality is that there are literally thousands of people with MRSA all over the world and they are carriers of it and they do things like go to the bank machine and touch it, open the door at 7-11, pick up items at the store and then put them back on the shelf and so on and so on. MRSA is literally everywhere. Some people contact it and suffer problems others do not.

_heimdall 1y ago
With something like MRSA how do you determine that the virus is cause for disease when, as you said, many will be infected without showing symptoms? That the root of the confusion for me. I haven't wrapped my head around how we can know a specific pathogen causes disease if a large number of people can be found to have that pathogen present without showing symptoms.
- kijin 1y ago
  Statistics. Not all smokers get lung cancer. But with large enough samples, smokers turn out to be much more likely to get lung cancer than non-smokers. That's why we say that smoking causes lung cancer. It's not as if someone has actually watched a particle of tobacco interact with someone's lung cells to turn them cancerous in real time.
  - jodrellblank 1y ago
    Why doesn't that get dismissed with the usual universal dismissal "correlation != causation"?
    - _heimdall 1y ago
      For one I'd assume its because contagions and physical damage are quite different. That's not to say that correlation between viral presence and disease can't indicate causation, but it is more clear when you are looking at the direct damage to lung tissue from inhaling hot cigarette smoke for years or decades.
  - _heimdall 1y ago
    Smoking isn't a contagious pathogen.
    - sydbarrett74 1y ago
      Second- and third-hand smoke mimic contagion.