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This is a very serious disease for many of the infected when left untreated: it causes pneumonia (inflammation of the lungs/airways) which makes people’s respir

This is a very serious disease for many of the infected when left untreated: it causes pneumonia (inflammation of the lungs/airways) which makes people’s respiratory system less effective, leading their blood oxygen levels to drop and potentially leading to death, especially in the elderly and people with pre-existing conditions like cardiovascular problems, obesity, diabetes, compromised immune systems, asthma, other chronic respiratory issues, .... A significant proportion of people over 60, a non-negligible proportion of people ages 40–60, and still some proportion of people aged 20–40 need to be hospitalized and put on supplemental oxygen. In severe cases people need support from a mechanical respirator. In the WHO report from China 20% of positive cases needed hospitalization. This might be a substantial overestimate if there are many mild cases not caught by tests, but even if that estimate is off by a factor of 5 or 10, if there are many cases this can overwhelm hospital capacity. When treated aggressively by a capable healthcare system (caught early before severe symptoms start, treated with antiviral meds, patients put on supplemental oxygen as soon as blood oxygen starts to dip, hospitals have enough respirators for severely affected patients) so that people don’t die while waiting for their immune systems to fight the virus off, many fatalities can be avoided, as is happening in Singapore or some wealthier provinces in China. But this depends on social distancing in the community, widespread testing, aggressive isolation and contact tracing of infected people, and efficient triage of cases. If cases are not caught early and treated aggressively or if medical systems get overwhelmed, it is bad news. If this virus is not checked and spreads throughout the world quickly, the death toll could be in the millions. Beyond being very dangerous to a substantial proportion of infected people, it is also extremely contagious, and has been spreading very rapidly. It is contagious even among pre-symptomatic or asymptomatic people. Perhaps most dangerously, its early symptoms are close enough to ordinary cold/flu symptoms (and some of the infected seem to not advance to the more serious stage) that people who are shedding the virus continue to go about their everyday lives without realizing they are infected with novel coronavirus instead of a typical cold or flu.

zaroth 7y ago
To be clear, at this time we only the “CFR” - known case fatality rate. Likewise, we only know the known case hospitalization rate. What we do not know, and can only estimate, is the “IFR” or the overall infection fatality rate, and the overall infection hospitalization rate. Imagine the flu was a brand new virus which we didn’t have any test for. In 3 months we would see 100,000 hospitalizations and 10,000 deaths from this new virus. Only after testing became inexpensive and widespread would we come to realize that actually 32 million people were infected with this virus, but only 200,000 per year went to the hospital, about 20,000 of which end up dying. My point is, we do not know the infection hospitalization rate, nor the infection fatality rate of COVID-19, but its upper bound is the CFR and it’s reasonable to suspect the actual value is at least an order of magnitude lower than the current CFR data might indicate. It’s not reasonable to state anything definitively about the overall hospitalization rate of COVID at this time without the qualifier that it’s based on only known cases and therefore overstated by some unknown amount. You may find this letter (written March 4th) from doctors specializing in Emergency Medicine more compelling than my own summary: https://www.bmj.com/content/368/bmj.m606/rr-5 https://www.bmj.com/content/368/bmj.m606/rr-5
- jacobolus 7y ago
  Edit: I was basing my comment on a 2018 newspaper story, but thanks for tracking down a peer-reviewed model estimate. I deleted my comment as it didn’t make a grounded comparison. We can only wait and see how many people die from ncov-19 in Italy or anywhere else.
  - zaroth 7y ago
    > “We estimated excess deaths of 7,027, 20,259, 15,801 and 24,981 attributable to influenza epidemics in the 2013/14, 2014/15, 2015/16 and 2016/17, respectively, using the Goldstein index. The average annual mortality excess rate per 100,000 ranged from 11.6 to 41.2 with most of the influenza-associated deaths per year registered among the elderly.” > “In the winter seasons from 2013/14 to 2016/17, an estimated average of 5,290,000 ILI cases occurred in Italy, corresponding to an incidence of 9%. More than 68,000 deaths attributable to flu epidemics were estimated in the study period.” (Edited) The wording here is confusing. It’s an average of 5.2 million cases per year for 4 years resulting in a total of 68,000 deaths over 4 years. Meaning an average of 0.325% IFR due to Flu (ILI - “influenza-like illness” in Italy. That’s a high confidence IFR based on a well established surveillance network and widespread testing. Meaning it is likely not being overstated. Versus COVID’s know case fatality rate, which is an upper bound on the IFR and known to be missing a significant number of mild cases in the general population from the denominator. I agree that it remains to be seen how bad this will be in Italy and elsewhere, but putting it in perspective to the flu (which we do not generally “fear”) is useful. [1] - https://www.sciencedirect.com/science/article/pii/S1201971219303285 https://www.sciencedirect.com/science/article/pii/S120197121...
    - jacobolus 7y ago
      Consider the chain of reasoning in https://threadreaderapp.com/thread/1236095180459003909.html https://threadreaderapp.com/thread/1236095180459003909.html
      - zaroth 7y ago
        This is just dark fiction, not science. If any of this were true, China would already be totally overrun. Instead they are reported fewer than 150 new cases per day and closing their temporary hospitals. My prediction is that we will see the same thing happening in Italy and South Korea in two/three weeks time.

zaroth 7y ago

To be clear, at this time we only the “CFR” - known case fatality rate. Likewise, we only know the known case hospitalization rate. What we do not know, and can only estimate, is the “IFR” or the overall infection fatality rate, and the overall infection hospitalization rate. Imagine the flu was a brand new virus which we didn’t have any test for. In 3 months we would see 100,000 hospitalizations and 10,000 deaths from this new virus. Only after testing became inexpensive and widespread would we come to realize that actually 32 million people were infected with this virus, but only 200,000 per year went to the hospital, about 20,000 of which end up dying. My point is, we do not know the infection hospitalization rate, nor the infection fatality rate of COVID-19, but its upper bound is the CFR and it’s reasonable to suspect the actual value is at least an order of magnitude lower than the current CFR data might indicate. It’s not reasonable to state anything definitively about the overall hospitalization rate of COVID at this time without the qualifier that it’s based on only known cases and therefore overstated by some unknown amount. You may find this letter (written March 4th) from doctors specializing in Emergency Medicine more compelling than my own summary: https://www.bmj.com/content/368/bmj.m606/rr-5 https://www.bmj.com/content/368/bmj.m606/rr-5

jacobolus 7y ago
Edit: I was basing my comment on a 2018 newspaper story, but thanks for tracking down a peer-reviewed model estimate. I deleted my comment as it didn’t make a grounded comparison. We can only wait and see how many people die from ncov-19 in Italy or anywhere else.
- zaroth 7y ago
  > “We estimated excess deaths of 7,027, 20,259, 15,801 and 24,981 attributable to influenza epidemics in the 2013/14, 2014/15, 2015/16 and 2016/17, respectively, using the Goldstein index. The average annual mortality excess rate per 100,000 ranged from 11.6 to 41.2 with most of the influenza-associated deaths per year registered among the elderly.” > “In the winter seasons from 2013/14 to 2016/17, an estimated average of 5,290,000 ILI cases occurred in Italy, corresponding to an incidence of 9%. More than 68,000 deaths attributable to flu epidemics were estimated in the study period.” (Edited) The wording here is confusing. It’s an average of 5.2 million cases per year for 4 years resulting in a total of 68,000 deaths over 4 years. Meaning an average of 0.325% IFR due to Flu (ILI - “influenza-like illness” in Italy. That’s a high confidence IFR based on a well established surveillance network and widespread testing. Meaning it is likely not being overstated. Versus COVID’s know case fatality rate, which is an upper bound on the IFR and known to be missing a significant number of mild cases in the general population from the denominator. I agree that it remains to be seen how bad this will be in Italy and elsewhere, but putting it in perspective to the flu (which we do not generally “fear”) is useful. [1] - https://www.sciencedirect.com/science/article/pii/S1201971219303285 https://www.sciencedirect.com/science/article/pii/S120197121...
  - jacobolus 7y ago
    Consider the chain of reasoning in https://threadreaderapp.com/thread/1236095180459003909.html https://threadreaderapp.com/thread/1236095180459003909.html
    - zaroth 7y ago
      This is just dark fiction, not science. If any of this were true, China would already be totally overrun. Instead they are reported fewer than 150 new cases per day and closing their temporary hospitals. My prediction is that we will see the same thing happening in Italy and South Korea in two/three weeks time.