4 ms·

Many who have had chicken pox still have the virus living dormant in their neurons. The virus can randomly reactivate and causes a painful skin lesions called s

by rcme 4y ago

Many who have had chicken pox still have the virus living dormant in their neurons. The virus can randomly reactivate and causes a painful skin lesions called shingles.

timr 4y ago
Yes, but "living in neurons" != "living in the brain" != "causes neurodegenerative disease", which seems to be the implication being drawn here.
- meindnoch 4y ago
  Herpesviruses (which includes VZV, the chickenpox virus) sometimes cause recurring meningitis and encephalitis. They do get into the brain. We just don’t know how.
  - timr 4y ago
    > Herpesviruses (which includes VZV, the chickenpox virus) sometimes cause recurring meningitis and encephalitis. They do get into the brain. We just don’t know how. So does MMR (Paramyxoviridae, Matonaviridae) and Influenza. So does Zika and Dengue and Yellow Fever (Flaviviridae) and Chikungunya (Togaviridae) and Adeonvirus, which all have very different tissue specificity, and aren't associated with long-term dormancy. In the case of meningitis, it's not an infection of the brain, but the membrane around the brain. It's caused by lots of bacteria, as well as enteroviruses, which are most commonly associated with the digestive tract. Malaria (which is a eukaryotic parasite) causes both meningitis and encephalitis. All of these things "get into the brain". Point being: it's not even remotely the same thing. You cannot extrapolate from "inflammation of the brain" to "neurodegeneration". It's like extrapolating from "fever" to "risk of dementia", and just because herpes viruses happen to infect neurons and cause inflammation doesn't imply a causal relationship with neural degeneration.
    - meindnoch 4y ago
      >just because herpes viruses happen to infect neurons and cause inflammation doesn't imply a causal relationship with neural degeneration Herpesviruses infect neurons and cause lifelong infections by changing the expression of a variety of proteins in infected cells, thereby evading detection by the immune system. I don’t think we should brush off the possibility of such an infection having long-term neurodegenerative effects (most likely combined with other necessary factors).
      - timr 4y ago
        > Herpesviruses infect neurons and cause lifelong infections No, you're abusing terminology to exaggerate. Herpes viruses establish dormancy, which is not the same thing as an active infection. Are the viruses in the cells, somewhere, in low numbers? We don't actually know (your claim about protein expression change and hiding from the immune system is a hypothesis, not a fact). We know that viruses in the family go dormant -- stop causing visible symptoms -- and periodically recur. There's a huge leap from that to "causes long-term neural cell death and disability". > I don’t think we should brush off the possibility of such an infection having long-term neurodegenerative effects (most likely combined with other necessary factors). I'm not saying we should "brush off the possibility". I'm saying that it's a hypothesis, and it needs to be shown to be true before insinuating that it is a known fact.

by rcme 4y ago

Many who have had chicken pox still have the virus living dormant in their neurons. The virus can randomly reactivate and causes a painful skin lesions called shingles.

timr 4y ago

Yes, but "living in neurons" != "living in the brain" != "causes neurodegenerative disease", which seems to be the implication being drawn here.

meindnoch 4y ago
Herpesviruses (which includes VZV, the chickenpox virus) sometimes cause recurring meningitis and encephalitis. They do get into the brain. We just don’t know how.
- timr 4y ago
  > Herpesviruses (which includes VZV, the chickenpox virus) sometimes cause recurring meningitis and encephalitis. They do get into the brain. We just don’t know how. So does MMR (Paramyxoviridae, Matonaviridae) and Influenza. So does Zika and Dengue and Yellow Fever (Flaviviridae) and Chikungunya (Togaviridae) and Adeonvirus, which all have very different tissue specificity, and aren't associated with long-term dormancy. In the case of meningitis, it's not an infection of the brain, but the membrane around the brain. It's caused by lots of bacteria, as well as enteroviruses, which are most commonly associated with the digestive tract. Malaria (which is a eukaryotic parasite) causes both meningitis and encephalitis. All of these things "get into the brain". Point being: it's not even remotely the same thing. You cannot extrapolate from "inflammation of the brain" to "neurodegeneration". It's like extrapolating from "fever" to "risk of dementia", and just because herpes viruses happen to infect neurons and cause inflammation doesn't imply a causal relationship with neural degeneration.
  - meindnoch 4y ago
    >just because herpes viruses happen to infect neurons and cause inflammation doesn't imply a causal relationship with neural degeneration Herpesviruses infect neurons and cause lifelong infections by changing the expression of a variety of proteins in infected cells, thereby evading detection by the immune system. I don’t think we should brush off the possibility of such an infection having long-term neurodegenerative effects (most likely combined with other necessary factors).
    - timr 4y ago
      > Herpesviruses infect neurons and cause lifelong infections No, you're abusing terminology to exaggerate. Herpes viruses establish dormancy, which is not the same thing as an active infection. Are the viruses in the cells, somewhere, in low numbers? We don't actually know (your claim about protein expression change and hiding from the immune system is a hypothesis, not a fact). We know that viruses in the family go dormant -- stop causing visible symptoms -- and periodically recur. There's a huge leap from that to "causes long-term neural cell death and disability". > I don’t think we should brush off the possibility of such an infection having long-term neurodegenerative effects (most likely combined with other necessary factors). I'm not saying we should "brush off the possibility". I'm saying that it's a hypothesis, and it needs to be shown to be true before insinuating that it is a known fact.