I was fortunate to spend time yesterday on a call with a world expert on infectious disease. Some worrying highlights:

-The R0 (R naught) of this disease is probably around 3. Which means if you are infected today you would pass it on to approximately 3 other people. For comparison, influenza is about 1.5. This higher value if you extrapolate makes a massive difference...you infect 3, they infect 3 each = 9, then 27, 81, etc vs for 1.5 the curve is much more shallow. That increase in contagion is massive at the population level

-To understand the current size of the problem, consider Iran. They are not substantially more linked to Wuhan than many other countries in the region, but have had 19 confirmed deaths as of today. It takes about 2-3 weeks to die after being infected, so it is likely these cases had the disease 2-3 weeks ago. The case fatality rate may be around 1%, which means that for every one death there are ~100 who did not die. So there were ~2000 infected in Iran 2-3 weeks ago. We've seen a doubling time of around 7 days, so 2,000 infected 2-3 weeks ago implies roughly 4,000 to 6,000 infected today.

-Iran is not unique; Italy has had 12 deaths, S Korea has had 12 deaths. Who knows what the true numbers are for many surrounding countries with poor reporting. For each of these you can do the same math and estimate that the number infected today is large and worldwide

-This is why many infectious diseases specialists now estimate that 25-40% of the population will get infected. While China has been able to implement aggressive quarantine policies, these are less feasible outside of China due to either 1-poorer countries without technology/resources or 2-wealthier countries that are not dictatorships. Add to this the long period before showing symptoms and the high rate of transmission during the first days of infection before symptoms occur, and you have the potential for very widespread dissemination of this disease

-Vaccines will not be available until at least 2021

-CDC is a mess and US is behind in diagnostic testing

Japan announced today that it is closing schools for a month. Colleagues are suddenly asking me about food storage :). Don't underestimate this and be sure you're prepared for the worst