5 ms·

Rabies is generally fatal and is not new or genetically novel, and like the article linked, is a CNS infection that travels the peripheral nervous system. Firs

Rabies is generally fatal and is not new or genetically novel, and like the article linked, is a CNS infection that travels the peripheral nervous system. First recorded case was 4000 years ago, suggesting it’s likely ancient through pre-history.

kevviiinn 4y ago
AFAIK is also isn't super contagious, less opportunity for it to evolve
- fnordpiglet 4y ago
  It’s super contagious in the reservoir species. But it’s not in humans. The point made above was about age if the pathogen not infectiousness.
  - kevviiinn 4y ago
    But it isn't very lethal in that species, is it? In the species that it spreads rapidly in, it likely won't be very lethal which was the point
echelon 4y ago
How many humans get rabies per year versus how many that get influenza?
- fnordpiglet 4y ago
  I’m not sure that’s relevant? I didn’t see anything stated about rates of infection. Absolutely if influenza were as fatal as rabies we would be extinct. But we also wouldn’t be posting on hacker news about it either. The statement was about longevity of the pathogen and fatality.
  - echelon 4y ago
    > Absolutely if influenza were as fatal as rabies we would be extinct. The chance that it would evolve to be as infectious would be greatly reduced. They teach this in first semester immunology.
    - unsupp0rted 4y ago
      Not necessarily. What would be reduced is the likelihood of showing any symptoms while still being infectious.
    - fnordpiglet 4y ago
      I don’t see why you think that’s true - if infections are latent long enough to spread and it’s virulent enough, with a fatal outcome, it could rapidly wipe out most people. There’s no reason to believe a viral infection that mutates from an animal infection to human wouldn’t be both easily transmitted and highly lethal. It’s not a great evolutionary adaptation for the long term, but transitory effects can often be sub optimal and catastrophic. COVID is a perfect example. It could easily have been significantly more lethal and it was very infectious in its first blush with humanity. What process other than luck prevented it from being both highly lethal and highly contagious rather than moderately lethal and highly contagious? If you have a reference to a first semester immunology text that supports this supposition I’m very interested to read the justification. Otherwise this feels like a big of an appeal to authority.
- pvaldes 4y ago
  Is not really designed for surviving outside. Very long filaments are fragile out of vascular systems.
ramraj07 4y ago
Viruses like rabies are interesting because they are actually not as serious in the species they evolved to infect; just turns out they rapidly kill some other species (us) that they don’t care about. Make no mistake, rabies virus also has multiple immune evading mechanisms that are unluckily supercharged in humans.
- fnordpiglet 4y ago
  Yeah I expect that’s the case - the bubonic plague spread via the reservoir fleas and rats, etc.
  - alexvoda 4y ago
    That may actually have not been the case: https://theconversation.com/the-black-death-may-not-have-been-spread-by-rats-after-all-196521 https://theconversation.com/the-black-death-may-not-have-bee...
- hnick 4y ago
  Sounds a little like funnel web spider venom - just an evolutionary accident it's so potent to humans, at no evolutionary drawback for its main role.
- acyou 4y ago
  Thought rabies usually killed dogs? https://www.cdc.gov/mmwr/volumes/68/wr/mm6823e1.htm#:~:text=Rabies%20virus%20infection%2C%20regardless%20of,2%20weeks%20of%20symptom%20onset https://www.cdc.gov/mmwr/volumes/68/wr/mm6823e1.htm#:~:text=.... CDC says it kills 99% regardless. Why would it evolve this way?
  - EEBio 4y ago
    I doubt that rabies has evolutionary developed to target dogs. It’s just a “happy” accident that dogs are so plentiful and can infect many other animals (until recently at least). If I had to guess I’d say rabies had evolutionarily targeted species that today are largely asymptomatic and can easily survive a rabies infection, like bats or birds.
pvaldes 4y ago
Rabies most probably evolved from a virus from plants so is very "alien" to animals. As long as can hide in their main host, it does not care about killing everybody else (if accidentally ends in the wrong place). This can be also and advantage and selected by evolution in some cases ("enemy of my host is my enemy" situations).
RobotToaster 4y ago
Tuberculosis is likewise at least 5000 years old, and kills around 50% of those infected.
- meindnoch 4y ago
  >Roughly one-quarter of the world's population has been infected with M. tuberculosis, with new infections occurring in about 1% of the population each year. However, most infections with M. tuberculosis do not cause disease, and 90–95% of infections remain asymptomatic. https://en.wikipedia.org/wiki/Tuberculosis#Epidemiology https://en.wikipedia.org/wiki/Tuberculosis#Epidemiology
- ramraj07 4y ago
  5000 years is literally a blip in evolutionary timescales.
  - thelittleone 4y ago
    Is that an imperial or metric blip?

kevviiinn 4y ago

AFAIK is also isn't super contagious, less opportunity for it to evolve

fnordpiglet 4y ago
It’s super contagious in the reservoir species. But it’s not in humans. The point made above was about age if the pathogen not infectiousness.
- kevviiinn 4y ago
  But it isn't very lethal in that species, is it? In the species that it spreads rapidly in, it likely won't be very lethal which was the point

echelon 4y ago

How many humans get rabies per year versus how many that get influenza?

fnordpiglet 4y ago
I’m not sure that’s relevant? I didn’t see anything stated about rates of infection. Absolutely if influenza were as fatal as rabies we would be extinct. But we also wouldn’t be posting on hacker news about it either. The statement was about longevity of the pathogen and fatality.
- echelon 4y ago
  > Absolutely if influenza were as fatal as rabies we would be extinct. The chance that it would evolve to be as infectious would be greatly reduced. They teach this in first semester immunology.
  - unsupp0rted 4y ago
    Not necessarily. What would be reduced is the likelihood of showing any symptoms while still being infectious.
  - fnordpiglet 4y ago
    I don’t see why you think that’s true - if infections are latent long enough to spread and it’s virulent enough, with a fatal outcome, it could rapidly wipe out most people. There’s no reason to believe a viral infection that mutates from an animal infection to human wouldn’t be both easily transmitted and highly lethal. It’s not a great evolutionary adaptation for the long term, but transitory effects can often be sub optimal and catastrophic. COVID is a perfect example. It could easily have been significantly more lethal and it was very infectious in its first blush with humanity. What process other than luck prevented it from being both highly lethal and highly contagious rather than moderately lethal and highly contagious? If you have a reference to a first semester immunology text that supports this supposition I’m very interested to read the justification. Otherwise this feels like a big of an appeal to authority.
pvaldes 4y ago
Is not really designed for surviving outside. Very long filaments are fragile out of vascular systems.

ramraj07 4y ago

Viruses like rabies are interesting because they are actually not as serious in the species they evolved to infect; just turns out they rapidly kill some other species (us) that they don’t care about. Make no mistake, rabies virus also has multiple immune evading mechanisms that are unluckily supercharged in humans.

fnordpiglet 4y ago
Yeah I expect that’s the case - the bubonic plague spread via the reservoir fleas and rats, etc.
- alexvoda 4y ago
  That may actually have not been the case: https://theconversation.com/the-black-death-may-not-have-been-spread-by-rats-after-all-196521 https://theconversation.com/the-black-death-may-not-have-bee...
hnick 4y ago
Sounds a little like funnel web spider venom - just an evolutionary accident it's so potent to humans, at no evolutionary drawback for its main role.
acyou 4y ago
Thought rabies usually killed dogs? https://www.cdc.gov/mmwr/volumes/68/wr/mm6823e1.htm#:~:text=Rabies%20virus%20infection%2C%20regardless%20of,2%20weeks%20of%20symptom%20onset https://www.cdc.gov/mmwr/volumes/68/wr/mm6823e1.htm#:~:text=.... CDC says it kills 99% regardless. Why would it evolve this way?
- EEBio 4y ago
  I doubt that rabies has evolutionary developed to target dogs. It’s just a “happy” accident that dogs are so plentiful and can infect many other animals (until recently at least). If I had to guess I’d say rabies had evolutionarily targeted species that today are largely asymptomatic and can easily survive a rabies infection, like bats or birds.

pvaldes 4y ago

Rabies most probably evolved from a virus from plants so is very "alien" to animals. As long as can hide in their main host, it does not care about killing everybody else (if accidentally ends in the wrong place). This can be also and advantage and selected by evolution in some cases ("enemy of my host is my enemy" situations).

RobotToaster 4y ago

Tuberculosis is likewise at least 5000 years old, and kills around 50% of those infected.

meindnoch 4y ago
>Roughly one-quarter of the world's population has been infected with M. tuberculosis, with new infections occurring in about 1% of the population each year. However, most infections with M. tuberculosis do not cause disease, and 90–95% of infections remain asymptomatic. https://en.wikipedia.org/wiki/Tuberculosis#Epidemiology https://en.wikipedia.org/wiki/Tuberculosis#Epidemiology
ramraj07 4y ago
5000 years is literally a blip in evolutionary timescales.
- thelittleone 4y ago
  Is that an imperial or metric blip?