5 ms·

Does anyone know if their is a correlation between how contagious a variant is and how lethal it is? For example, MERS has a 35% CFR but wasn't a global health

Does anyone know if their is a correlation between how contagious a variant is and how lethal it is? For example, MERS has a 35% CFR but wasn't a global health disaster because it wasn't highly contagious. Same goes for Ebola, which is even more fatal but even less contagious. My point/question - the more contagious a Covid-19 variant = lower CFR?

wyldfire 5y ago
IIRC pathogenicity has an inverse relationship with virulence.
- YZF 5y ago
  There are no hard rules here. The UK variant is supposedly both more severe and more infectious ( https://www.bmj.com/content/372/bmj.n579 https://www.bmj.com/content/372/bmj.n579 ). The common wisdom there is that something that kills you faster has less chance to transmit but there's nothing precluding something that kills you slowly and is very infectious while it does that.
  - throwawayboise 5y ago
    Yes, Ebola is quite contageous but kills so fast it tends to burn out and not spread. AIDS kills you slowly and is infectious while it does that, so it spreads widely.
    - spfzero 5y ago
      Both are blood-to-blood, rather than respiratory. They are not at all contagious, compared to flus and colds. A lot more deadly, but they can be stopped much more easily. Ebola spread is not stopped so much by it’s deadliness, but by the fact that you can’t get it by just being near someone who has it and is breathing.
guscost 5y ago
It is possible and even likely IMO (at least for respiratory viruses). Look up the “transmission-virulence tradeoff hypothesis” for more info: https://pubmed.ncbi.nlm.nih.gov/30734920/ https://pubmed.ncbi.nlm.nih.gov/30734920/ The “Russian flu” in 1890 may have been the first introduction of the common cold coronavirus OC43: https://en.m.wikipedia.org/wiki/1889–1890_pandemic https://en.m.wikipedia.org/wiki/1889–1890_pandemic https://www.ncbi.nlm.nih.gov/pmc/articles/PMC544107/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC544107/ Also, keep in mind that stress and fear can be very bad for health: https://www.tandfonline.com/doi/abs/10.1080/09540261.2017.1357540?journalCode=iirp20 https://www.tandfonline.com/doi/abs/10.1080/09540261.2017.13... https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1447278/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1447278/
cblconfederate 5y ago
The virus spreads fast long before symptoms appear, so the severity of disease is not necessarily correlated.

wyldfire 5y ago

IIRC pathogenicity has an inverse relationship with virulence.

YZF 5y ago
There are no hard rules here. The UK variant is supposedly both more severe and more infectious ( https://www.bmj.com/content/372/bmj.n579 https://www.bmj.com/content/372/bmj.n579 ). The common wisdom there is that something that kills you faster has less chance to transmit but there's nothing precluding something that kills you slowly and is very infectious while it does that.
- throwawayboise 5y ago
  Yes, Ebola is quite contageous but kills so fast it tends to burn out and not spread. AIDS kills you slowly and is infectious while it does that, so it spreads widely.
  - spfzero 5y ago
    Both are blood-to-blood, rather than respiratory. They are not at all contagious, compared to flus and colds. A lot more deadly, but they can be stopped much more easily. Ebola spread is not stopped so much by it’s deadliness, but by the fact that you can’t get it by just being near someone who has it and is breathing.

guscost 5y ago

It is possible and even likely IMO (at least for respiratory viruses). Look up the “transmission-virulence tradeoff hypothesis” for more info: https://pubmed.ncbi.nlm.nih.gov/30734920/ https://pubmed.ncbi.nlm.nih.gov/30734920/ The “Russian flu” in 1890 may have been the first introduction of the common cold coronavirus OC43: https://en.m.wikipedia.org/wiki/1889–1890_pandemic https://en.m.wikipedia.org/wiki/1889–1890_pandemic https://www.ncbi.nlm.nih.gov/pmc/articles/PMC544107/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC544107/ Also, keep in mind that stress and fear can be very bad for health: https://www.tandfonline.com/doi/abs/10.1080/09540261.2017.1357540?journalCode=iirp20 https://www.tandfonline.com/doi/abs/10.1080/09540261.2017.13... https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1447278/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1447278/

cblconfederate 5y ago

The virus spreads fast long before symptoms appear, so the severity of disease is not necessarily correlated.