New coronavirus: Preliminary CFR, incubation period
Scott McPherson
in coronavirus, influenza and infectious diseases
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The only thing that kept the SARS epidemic from going full tilt pandemic in 2003 was its incubation period. SARS was a coronavirus, whose incubation periods are usually 2 to 7 days. People didn't transmit the disease until the incubation period was over. Public health officials were actually able to get in front of the disease and beat it back. Line of sight. Good thing too, because for every 100 people who contracted it, around fifteen died, according to the WHO. That number was impacted by the usual issues of age, general health, and so on. The dreaded 1918 Spanish Flu (H1N1) haad a Case Fatality Rate, or CFR, of 2.5.
Now we don't really know a helluva lot about this new coronavirus, but we suspect it is not as lethal as SARS. At least, not yet. It does currently have a CFR of 3, meaning it appears to be as lethal as the 1918 flu. We are also being treated to conflicting theories as to how transmissible it is (it appears to be quite good at that), and how long the incubation period is.
From The Hill:
"Chinese health officials are warning that the deadly coronavirus could be much more contagious than initially thought, as infected patients can spread the flu-like illness before showing any symptoms.
China’s National Health Commissioner Minister Ma Xiaowei announced during a press conference Sunday the virus is infectious during its incubation period of one to 14 days and its ability to spread is increasing.
The official said authorities have limited knowledge on the new virus, and are unclear on the risks posed by the mutations of the virus.
A longtime adviser to the U.S. Centers for Disease Control and Prevention, Dr. William Schaffner, told CNN the new development means “the infection is much more contagious than we originally thought.”
Schaffner called it a game changer, and warned current preventative methods won’t be enough to fight off the outbreak since tracking down the contacts a patient had before experience symptoms complicates the situation."
The general rule is that viruses get along to go along. They gain nothing by killing their hosts. Their goal is coexistence. But it is also true that as a virus mutates, it can gain some nasty attributes. The second wave of the 1918 flu (fall 1918) was the REAL killer, where most of the 50 to 100 million worldwide deaths occurred.
It is way too early to know what this new coronavirus will mutate into. But we have a virus that is getting easier and easier to catch and transmit, or might have been fron the get-go. And we also have a virus which is not nearly as lethal as SARS or its current cousin MERS (with a CFR nearing 35%). But 3% is what we worried about during bird flu planning assumptions. This concern is real and increasing.
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