Corona virus epidemic

January 31, 2020

I keep being asked about the coronavirus, and have been noncommittal about it, because there was not a lot of information to go on.

But now there is more information, so I will say a little.

1.  Anthony Fauci, head of the NIH's infectious disease branch, said the death rate is 1-2% and that this may be compared to an average influenza virus, which has a mortality rate of 0.1%.

If his numbers are based on reported estimates that 100,000 are infected and 1500 have died, his mortality estimate is too low.  You have to look at one whole group that was infected at the same time, then look at the total number of them who died, after the rest have recovered, to estimate mortality.  I am not aware of good stats on this yet.

2.  I heard the R zero number (an estimate of how many people are, on average, infected by a single person with coronavirus) is 3-4.  If so, the coronavirus is less infectious than measles and roughly as infectious as many other infections.

3.  What is the mechanism by which the virus kills?  This needs to be answered in order to devise effective treatments.

A Chinese article published this week suggested that cytokine levels are higher in coronavirus patients than controls.  But are patients dying from cytokine storm?  This was not revealed.

During the 2009 swine flu pandemic, pregnant women in Australia were reported to be dying as a result of thick, infected mucus plugging their airways, preventing gas exchange in the lungs.  (Gas exchange involves carbon dioxide leaving the blood and oxygen entering the blood as it traverses the lungs.)

While there was not much media attention given to the topic, the use of ECMO to temporarily fill in for the lungs, until the body can repair itself, saved a number of lives then.  ECMO stands for extracorporeal membrane oxygenation, in other words, oxygenating the blood using a machine.

There are not many of these machines around, likely only a few in every state.  If patients with good lungs are dying due to temporary respiratory failure, then ECMO might be a lifesaver.

Here is a list of ECMO sites.  822 centers with the devices are listed.


UPDATE Feb 8:  from a Straits Times interview with a doctor of acute medicine at Wuhan University south central hospital:

"How do you treat serious and life-threatening cases?

Peng: For serious and life-threatening cases, our main approach is to provide oxygen, high-volume oxygen. At first noninvasive machine-pumped oxygen, followed by intubated oxygen if conditions worsen. For life-threatening cases, we use Ecmo (extracorporeal membrane oxygenation, or pumping the patient's blood through an artificial lung machine). In four cases, we applied Ecmo to rescue patients from the verge of death."

4.  Is this novel Coronavirus something that escaped from a lab, or perhaps was deliberately released?  You know as much as I do about that one.  If sufficient information is available in the future, I will comment on it then.