So, we have to wait to see if this "corona virus" continues into summer and if it reaches anything like the 60,000+ dead in the USA alone from a "normal flu" season. Only THEN can we say that it is on par with a NORMAL INFLUENZA virus!
That's pretty much how I think things will play out at this point. We'll see though. Once it runs its course, hopefully we'll be able to get some more reliable stats - but if not, then at least the absolute total number of deaths will tell us something. But I still think it's important to also consider some other issues at play besides total mortality, like transmissibility and the mortality rate, especially while things are still developing.
When it comes to the regular flu, we don't quarantine or lock down cities. We basically let it run rampant every year, millions of people get it, and a very small percentage die. If we can trust the CDC's statistics enough to get a rough picture, then in the the worst flu year in the last decade (
2017-2018), 45 million people got it in the U.S. That's 13-14% of the population. (Average number who get it every year is
3-11%.) 1.8% of those people had to be hospitalized. And 7.5% of those hospitalized died. Overall, 0.14% of those who got the flu died. And that's just the symptomatic cases. Some estimate that the number of people who carry and spread the flu virus without showing any symptoms whatsoever is up to
3x higher than the number of people who end up showing any symptoms, but it could be closer to a
50-50 split. Flu has an R0 of anywhere from 1.5-3 (that's around what the
Spanish flu was, too), meaning on average that's how many people each person with the flu infects. (But that doesn't take into account the presence or absence of 'super spreaders', which can compound the problem.)
A bit
on R0:
In the 1950s,
epidemiologist George MacDonald suggested using it to describe the transmission potential of malaria. He proposed that,
if R0 is less than 1, the disease will die out in a population, because on average an infectious person will transmit to fewer than one other susceptible person. On the other hand, if R0 is greater than 1, the disease will spread.
When public health agencies are figuring out how to deal with an outbreak, they are trying to bring R0 down to less than 1. This is tough for diseases like measles that have a high R0.
It is especially challenging for measles in densely populated regions like India and China, where R0 is higher, compared to places where people are more spread out.
For the
SARS pandemic in 2003, scientists estimated the original R0 to be around 2.75.
A month or two later, the effective R0 dropped below 1, thanks to the tremendous effort that went into intervention strategies, including isolation and quarantine activities.
With any luck, the stats for coronavirus will turn out to be wrong, and not as serious as they look right now. Like Joe mentioned previously, it could be that there are a
lot of asymptomatic cases, or mild cases that haven't been properly recorded. But with the stats that are available, the R0 is either similar, or perhaps greater than flu. From the article Laura posted:
Currently, the R0 for SARS-CoV-2, the virus that causes the disease COVID-19, is estimated at about 2.2, meaning a single infected person will infect about 2.2 others, on average. By comparison, the flu has an R0 of 1.3.
So it's at least
potentially equally or more transmissible than flu. Simply left to its own devices, it could conceivably infect a lot of people, and if the mortality rate really is 15x higher than the flu, then it can also kill a lot of people. I think that at least partially explains China's and other governments' response, with quarantines and lockdowns. If that's what the current numbers suggest - however flawed they may be in reality - it's understandable. Officials just haven't yet been able to know with any certainty, so they opt on the side of caution. Could it be more transmissible than the flu if left unchecked? How much more? And the extra resources spent on hospitalizations and treatments means less resources for uninfected people with OTHER conditions, meaning that lots of those people will die too, even if they never got the virus. At least, that's some of the thinking I think is probably behind some of the official responses we're seeing.
Another bit from the article Laura quoted:
They also admit: "About 81% of people who are infected with the coronavirus have mild cases."
They also say: "About 13.8% report severe illness, meaning they have shortness of breath, or require supplemental oxygen, and about 4.7% are critical, meaning they face respiratory failure, multi-organ failure or septic shock."
That probably means that the number of cases that get counted are this 13.8%. If so, the death rate is WAAAY lower for the infection overall.
That 13.8% figure is from the 'known cases' stats, so it doesn't change the current death rate estimate.
Research so far indicates that COVID-19 spreads more easily and has a higher death rate than the flu.
www.livescience.com
In a more recent study, considered the largest on COVID-19 cases to date, researchers from the Chinese Center for Disease Control and Protection, analyzed
44,672 confirmed cases in China between Dec. 31, 09 and Feb. 11, 2020. Of those cases, 80.9% (or 36,160 cases) were considered mild,
13.8% (6,168 cases) severe and 4.7% (2,087) critical. "Critical cases were those that exhibited respiratory failure, septic shock, and/or multiple organ dysfunction/failure," the researchers wrote in the paper published in
China CDC Weekly.
It's hard to estimate an accurate death rate during an epidemic for
numerous reasons. We're still in a position of not knowing whether the death rate is lower (i.e., there are lots of unreported cases, which means the deaths are a smaller fraction of the whole), or higher, as some of the other methods of calculating at that link might suggest. But one thing we can look at is the hospitalizations. Even if we can't know how many people actually have the virus, we can get a more reasonable idea of how many have to go to the hospital, and how many of those die.
To compare to the flu again: 810,000 people hospitalized, 61,000 died. That's a 7.5% death rate for cases severe enough to require hospitalization. In the study above, a total of 8255 cases were considered serious or severe, and 1023 died. That's a 12.4% death rate for serious cases requiring hospitalization. So, not THAT different from the flu, but still 1.65x higher. (However,
if the total number of cases is close to accurate, then the percentage of people who need to be hospitalized could be much higher than flu too: 18.5% compared to 1.8%.)
Again, that's not to say those figures will end up being accurate - just that as they are, I can understand looking at them and taking precautions to do something about it on the
chance that they're accurate, or on the chance that the situation is worse than they suggest. For example, from the site quoted above on death rates:
A
significant discrepancy in case mortality rate can also be observed when comparing mortality rates as calculated and
reported by China NHC: a CFR of 3.1% in the Hubei province (where Wuhan, with the vast majority of deaths is situated), and a
CFR of 0.16% in other provinces (19 times less).
Finally, we shall remember that while the
2003 SARS epidemic was still ongoing,
the World Health Organization (WHO) reported a fatality rate of 4% (or as low as 3%), whereas the final case fatality rate ended up being 9.6%.
So it might end up being not that much worse than the flu, or several times worse. And if fewer people end up dying than have died this year from the flu, at least part of that could be a result of the containment efforts in China and elsewhere. It will be interesting to see what ends up being the case!