2020-02-01

Good News: Case Growth Drops, Chinese Quarantine Working

Data out of China shows quarantine efforts are bearing fruit. Yesterday, I posted Coronavirus Spreading as Fast in China as Outside. The data through January 31 shows case growth starting to turn outside of Hubei, indicating Chinese efforts are working. However, there is no sign of relief yet because a second-wave of infections is possible. Additionally, given the incubation period and the timing of quarantine efforts, it will take a few more days of data to be sure of a trend shift.

This chart shows the daily case growth outside of Hubei. On January 31, it stopped growing altogether. If this holds, it means China's quarantine worked and they have contained the coronavirus outside of Hubei.
This next chart shows cases in Wuhan (blue) and the rest of Hubei (orange). It is not as encouraging:
I don't want to extrapolate off this small set, but the very initial takeaway is that there is a small window for stopping the spread of coronavirus. The good news is it can be stopped with "crude" measures such as quarantining cities, but the bad news is this requires a powerful and competent government. The bad news is Wuhan and Hubei could be in bad shape even with quarantine measures. Huanggang (which borders Wuhan) is now under full lockdown. Caixin: Reporters’ Notebook: There Shouldn’t Be a Second Wuhan
Among them, Wuhan has 2,639 confirmed cases, of which 159 people have died. Huanggang has confirmed 573 cases, of which 12 have died. However, Huanggang’s situation may be much worse than its numbers suggest, as the city may have more than 1,000 cases when taking into account suspected but unconfirmed infections as of Wednesday, according to Governor Wang.
Many patients are simply waiting for the tests needed to confirm whether their symptoms come from the new virus, but resources are either prioritized for Wuhan, or still in transit. Traffic lockdowns and logistics blockages are among the factors that leading to near-total exhaustion of medical supplies in cities like Huanggang.
Too many sanguine reports on the coronavirus fail to appreciate how quickly logistics break down in a pandemic. Short of a major pandemic that hits everywhere simultaneously, the biggest risk from the coronavirus is a disruption in the economy. Leaving aside all the debt and fragility created by governments and central banks, global and national supply chains are also fragile. Just-in-time inventory is highly efficient because the great coordination between companies makes the global and national economy function like a single body. However, if one important part of the supply chain goes down or there is a great demand shock somewhere, it causes a shock to the entire system. It looks like China has a handle on the virus outside of Hubei, but if they lose one more major city to the coronavirus, the demand shock will be incredible. Imagine a nation that lacks the manufacturing base of China or its logistics system, how would that nation respond to a similar outbreak?

Back to the good news. This next chart also shows the case growth slowing in all of China, inclusive of Hubei province.
These charts (save the first) came from: 新型肺炎(2019-nCoV)非湖北新增病例首次下降，拐点还会远吗？ (New pneumonia (2019-nCoV) non-Hubei new cases drop for the first time, Is the inflection point far away?)
Decrease in new cases is one of the signs of the turning point in the epidemic, New cases have declined in Hubei non-Wuhan and non-Hubei provinces. Xiaobian expects within three days, new diagnoses nationwide will also decline.

One thing to worry about is, new cases in Wuhan increased sharply on the 31st, the possibility of a second wave of outbreaks cannot be ruled out.
Some experts are more cautious and expect a peak in cases in Wuhan and Hubei may not arrive until late February or March. 武汉肺炎的拐点可能要拖到二月下旬？
Two outcomes: Will the inflection point of new cases be delayed until the end of March?

Combining all the data and information I know, I think there are two endings to the epidemic:

1: If the three-generation infectious index is low and the severity of the disease is reduced, coupled with the concerted efforts of the people across the country to isolate, prevent, and prevent most of the transmission routes, the highest point of new cases will appear inflection point in mid-late February.

2: If the three-generation infectious index and the level of disease remain high, coupled with factors such as the return of employees to work in the market in early February after the year, the disease will erupt at the end of February and may spread across the globe. In the end, the inflection point of the new cases will be delayed until the end of March if nothing unexpected happens. If so, the actual number of people infected will exceed one million, or even higher. Of course, the counted number will be much lower than this number.
I've heard many people in the U.S. compare the coronavirus to the flu. The article plainly states why this is wrong:
4. Wuhan Pneumonia and Influenza Viruses Can't Be Equaled

Recently, some people have suggested that the flu kills thousands in the United States every year and tens of thousands of lives in China. Therefore, it is believed that there are currently 10,000 cases of infection in 2019-nCoV, and the death of two hundred people is a piece of cake. Don't forget that the genes of influenza viruses are relatively stable and regular, and we have vaccines that can cause tens of thousands of deaths each year without additional isolation and precautions (case fatality rate is about 0.1%).

If a new virus, all of our human bodies do not have any immunity, and a mortality rate of 3% (current forecast of the virus by Lancet Jan 2020) , assuming that 10% of Chinese people are infected and 1.4 billion Chinese people will have More than 4 million deaths. The resulting social unrest and economic losses will be a huge disaster. This is why the WHO and other countries around the world are so anxious about this issue.
There's also concern it could be transmitted back to animals:
5. The possibility of infection and transmission of Wuhan pneumonia cannot be ruled out in pets and other animals

There may be many unknown possibilities that really determine the next step. Some people recently emphasized that pets and other animals will not infect and spread 2019-nCoV. In the absence of evidence, no possibility of transmission can be ruled out. There are currently no reports of pets getting sick from 2019-nCoV. But several coronaviruses have been found to infect animals and in some cases make them sick. Therefore, the U.S. Centers for Disease Control and Prevention recommends avoiding contact with pets and wearing a mask if you are sick. Researchers reported in the 2003 issue of Nature that cats may be infected with the SARS virus and spread it to other cats in the same cage, but they did not show any symptoms.
Going back to my post yesterday, Coronavirus Spreading as Fast in China as Outside, that showed the case growth was the same inside and outside of China. If China has gotten a handle on the coronavirus inside China, concern will quickly shift outside of China where other governments have been late to declare emergencies or take similarly strong measures.

To summarize: Wuhan and Hubei are not out of the woods. These remain the areas of highest concern. Case growth outside of Hubei may peak in the coming days. China outside of Hubei may breathe a sign of relief as early as next week. While China is starting to look good, the rest of the world remains a concern. Case growth through January 31 was growing at the same pace inside and outside of China. Even if China has success, it is unknown if foreign governments have or will be able to match China's response. Even if they stop an outbreak, the economic impact could be substantial. Still, the turn in Chinese data is a reason for cautious optimism, at least for China.

Finally, here is a good thread from Erik Townsend which explains why we need to take the data with a big grain of salt, but comes to similar conclusion that ex-China is more important now.











Finally, here's my projection for case growth assuming the January 31 growth rate holds. If there is no change, there will be 1 billion infections outside of China by March 20.
Posted by at 10:12 AM
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