As of right now (17:30 UTC-8, 26 January 2020) the 2019 novel coronavirus (2019-nCoV) has an infectivity rate, or R0 (pronounced R-zero or R-nought) of 2.6 and appears to be accelerating. (For comparison, the flu pandemic of 1918 had an R0 = 2, and ordinary seasonal flu = 1-2.)
The 2019-nCoV fatality rate (the number of people infected who subsequently die of the virus) = 4%. (1918 flu pandemic = 2%, seasonal flu = <0.1%.)
The 2019-nCoV incubation period (the time from when a person comes into contact with the virus and begins to show symptoms) = 1-14 days, averaging about 10. (Seasonal flu = 1-4 days, average about 2, 1918 pandemic = unknown, though if it’s similar to H1N1 of a few years ago, around 5 days.) And there are indications that, like flu, those who have contracted the virus are infectious even before showing symptoms. This is Bad News: infected people will be spreading the virus without knowing they’re even infected, and they’ll be doing it five times longer than those with seasonal flu and twice as long as the 1918 pandemic.
So, to recap, this new virus is more infectious than the H1N1 strain of flu that killed 50-100 million people a century ago, it is much more deadly, and it will be spread farther and wider by asymptomatic people. It makes ordinary, seasonal flu (that killed about 80,000 people in the US alone in the 2018 flu season) look like a startled sneeze.
These are preliminary figures; the data we have is so sketchy as to be mostly useless. We simply have no idea what the real picture is; it’s entirely possible that things aren’t nearly as bad as they seem. On the other hand, they could be worse. I think we’ll know a lot more in 10-14 days. Meanwhile, expect those numbers to vary enormously as other regions begin to track cases with varying degrees of accuracy and transparency. If R0 and fatality numbers go up, I’ll be stocking up on masks and gloves and dry goods and batteries and wine (oh, lots of wine), and not letting anyone in the house without a mask. If the numbers start to go down, well, I’ll still stock up—masks and water don’t go bad, and lithium ion batteries and wine last a while—but I’ll be a lot more relaxed about it.
Am I being alarmist? No doubt. But I’m a big fan to planning for the worst and hoping for the best. Your response, of course, may vary.
8 thoughts on “2019-nCoV: the new coronavirus”
!!! masks added to shopping list!! sharing
Whoa. An R-naught of 2.6? That is scary. Every infected person would be estimated to pass it on to 2.6 people (there are variables, of course). The ebola virus has an R-naught of 1.5 – 2.5. Measles has an R-naught of 12-18. Of course, ebola is transmitted by bodily fluids, which ideally makes it more amenable to being starved out by isolation or quarantine. Measles is airborne, so it’s virapalooza. The 1918 influenza pandemic had an R-naught of 2-3 (as an airborne droplet). I’m assuming (i.e., guessing) that this n-corona virus is transmitted by airborne droplets? Maybe we don’t know yet.
I’m sitting up and paying closer attention.
Maggie, yes. Spread by airborne droplets and by contact. The virus is large, though, so won’t stay aerosolised for a long time.
I have MS and live in a basement suite and share heat through vents from the furnace. Do I need to be worried? A nurse plus 3 kids live up there.
Most HVAC systems these days are fitted with HEPA filters that will catch particles <0.3 microns in diameter. While the novel corona virus from Wuhan is 0.06 – 0.14 in size, when coughed or sneezed out it’s coated in droplets that make it about 0.5 microns—too big to get through the filter. If you are worried, though, go buy an anti-viral surgical mask from your local pharmacy. They are cheap and very effective.
“The virus is large…” Good clue-age. I know next to nothing about viruses, so with this information I’m like a kid who’s gotten into the cookie-making ingredients, i.e., I might not end up with actual cookies.
But I read this: “…As an RNA virus, 2019-nCoV still has the inherent feature of a high mutation rate, although like other coronaviruses the mutation rate might be somewhat lower than other RNA viruses because of its genome-encoded exonuclease….”
So, in the story, we might have someone in charge of capturing viruses in the wild, then tweaking them for maximum lethality. Is “goddamnit, the genome-encoded exonuclease is still TOO BIG! Work the problem, people” a viable development if you want to hurry up a virus mutation rate that is kinda sluggish? I mean, in the wild, the virus will mutate or not, but would a diabolical actor see viral size as a workable tweak?
I know this is a serious subject and also, maybe nobody wants to play with what-ifs, so everyone please ignore me if this is too obnoxious. My feelings won’t be hurt.
Maggielle, the virus isn’t large, but the droplet it’s contained in is. And I’m not sure there’s much you can do about droplet size. So if I were writing this story, my weaponisation team who be looking to maximise virus viability—so that after it falls onto surfaces it stays alive and infectious for days rather than couple of hours…
I need to read up on how the heck we count the number of infected people in order to calculate the fatality rate. Sure, we can count the number of people who test positive for the virus or correlative antibodies and how many of them die of the disease, but that’s necessarily some fraction of the people actually infected. The only folks we test are those sick enough to seek or require medical care, those who are diagnosed posthumously, close contacts of the above, and presumably a number of apparently unaffected people who happen to work in a sensitive nexus such as a hospital or transportation hub and are tested as a precaution. But with the incubation period as long as two weeks, how much sheer guesswork is in the calculation of how many people are infected but not yet discovered and diagnosed?
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