Wuhan figures

Wuhan revised its COVID-19 cases on April 17, 2020 (https://news.sina.com.cn/c/2020-04-17/doc-iircuyvh8285761.shtml).  The original figures on April 16 were 50008 infected, 2579 dead, and about 47k recovered, with over 100 still hospitalized.  The new figures are 50333 infected, 3869 dead, and 46335 recovered.  Revision is the result of verification efforts starting in late March, when the outbreak was over in Wuhan.  The reasons given for the discrepancies are the early crash of Wuhan healthcare system after lockdown, initial focus on treating the sick, human errors resulting in paper trail problems.
 
For infections, from the 50008 number, 217 were duplication, 542 were not previously counted, so the last number is 50008-217+542=50333.  For deaths, 164 were double-counted or not due to COVID-19, 1454 were mis-attributed or not counted previously, so 2579-164+1454=3869.  Since infections change much less than deaths, the recovered cases drop by about 1000.

While revision is nothing unusual-other countries have done it, the big question is where the 1454 came from.  According to in-depth analyses, there are two sources.  First is people who died outside of hospitals.  They could die before getting tested for COVID-19, or were tested positive but couldn’t get admitted, because hospitals were full on Jan 23 and several days afterwards.  Both scenarios have been reported in the media and are not new.  They contributed to most of the 542.   The whole world has the same problem, e.g., counting deaths in nursing homes.  China doesn’t have many nursing homes or senior facilities like the developed countries, otherwise the number would have been higher, pushing fatality rate to 10%.

The second is less expected: the remaining 900-1000 are due to hospital record keeping errors.  In retrospect it reflects how chaotic and fragmented the hospital system was.  Wuhan has many hospitals before COVID-19 and built or set up many more after.  Not every hospital took COVID-19 patients.  Some hospitals treated both mild and severe cases, some only mild cases, others only severe cases.  So if you were tested positive after admission for a different illness, you might be transported to another hospital.  Patients could recover, relapse, recover, relapse, so some might transfer between hospitals once or twice.  Different hospitals might use different systems to trace patients, and 20-30K new medical staff arrived at Wuhan only in Jan and Feb.  Apparently this is where the mixup happened: one person might be transferred, but mislabeled as discharged.  This is not totally unexpected, but surprising there are so many of them, and not corrected earlier.   While a silly mistake, it still doesn’t amount to hiding something.  If one wants to fudge data, he can simply add the 1454 number to both infections and deaths, and call it a day.

Chinese provinces outside Hubei probably didn’t have this kind of problem, with infections rarely over 1000 each.  For other Hubei cities, however, it may be worth doublechecking.  But the new numbers change little regarding COVID-19 in Wuhan.  The total infections hardly move.  Death rate goes from over 5% to almost 8%.  Whether 5% or 8%, it is still higher than the rate in China outside Hubei, and lower than those of countries like Italy.  The purpose of the comparison is not to award a gold medal, but to understand how situations differ among places.

The updated deaths figure should now be very close to the actual number.  A larger uncertainty is infections in Wuhan.  The current 50K number simply shows people who were tested positive, but as in any other country, if you don’t get tested, you are not included in the statistics.  Quite a few studies are looking at this from different angles around the world.  In the first big batch of data reported, Wuhan tested 275K asymptomatic people on April 8-15 (https://news.sina.com.cn/c/2020-04-17/doc-iircuyvh8366932.shtml) and found a positive rate of 0.066%.  Assuming 10 million residents, maybe fewer than 10K are carriers.  While it helps to give 99.9% of the people a certificate of health based on the results, interpreting the data, unfortunately, is hard.  What is really wanted is how many have been infected by April 15.  A simplistic view is 50K+10K=60K, but wrong.  These 10K got infected by others, the latter by others, and so on.  These “others” should get progressively fewer as one goes back in time, assuming a steady level of transmission during.  But it is also possible that many more people were infected initially but recovered, leaving only the 10K now.  The number of deaths keeps an upper limit on infections, although one still doesn’t know the true fatality rate.  Also, the rate is higher among the elderly and gets even higher when the medical system is overwhelmed. 

As the COVID-19 pandemic rages on, a question is, was it inevitable?  This is not as easy to answer as people think.  A common phrase is China caused the pandemic, but did it?   It was first identified in Wuhan, and if pandemic means the whole country, clearly China got it controlled by Feb.  If pandemic means global, more a standard by WHO, it must spread significantly in other countries, which didn't happen until late Feb.  Whether and how much a disease spreads in a country depends on what it does, because only this country can decide what to do within its border, not China or anybody else.   Even if the first cases could be traced to Wuhan in some but not all countries, after one, two, or three transmission cycles, when there were still only a few cases, almost all the infected were local residents already, who could then carry the virus to other countries.  For many countries the cases that caused the actual epidemic were not Chinese.  Not to assign blame here, but any government can shut down the transmission chain and prevent it from going further.   If everybody did his part, it could be shut down, not necessarily leading to a country-wide or global pandemic.  Take Singapore for example, used to be considered a success story.  It has a China travel ban early on, reported its first case on Jan 23, and for almost two months had only 200 cases, by mid March.  Then one month later it has over 5000, due to citizens and residents returning from overseas (not China) and local transmission.  There are many countries like Singapore: few or no cases in early Mar, then shot straight up from mid-late Mar, because of non-Chinese travelers.  Was a pandemic inevitable, or China responsible?  Channeling Bill Clinton, it depends on what the meaning of the word pandemic is.