A scientific study, and a news story

A scientific paper was published (https://www.nature.com/articles/s41564-020-0713-1), which retrospectively investigated the presence of SARS-CoV-2 RNA in the throat swab samples of 640 Wuhan residents with influenza-like illness (ILI) from Oct 6, 2019 to Jan 21, 2020.  Similar studies and blood Ab tests are being conducted in a number of countries, such as China, US, Italy, UK, etc, but this is the first publication with a relatively large sample size trying to answer the question of how prevalent COVID-19 was before widely recognized.  

According to the paper, ILI appeared to be worse this winter than previous ones.  The authors detected 9 cases of COVID-19 out of 640, the first reporting symptoms on Jan 4 and sample taken on Jan 7.  Thus, this paper does not push COVID-19 cases earlier than currently known.  It shows, as expected, that most ILI cases are not COVID-19, pointing to the initial difficulty of COVID-19 detection and diagnosis.  The 9 cases are dispersed around Wuhan, suggesting community transmission early on, although it is unclear if or how the 9 cases are ever related to one another, and their outcomes.

A problem with the study is patient/sample selection or availability: the 9 COVID-19 patients are over 30-year-old.  Out of the 640, 192 are over 30, while 335 are age 9 or under.  It is quite clear now that kids, though more likely to see a doctor for ILI, are less susceptible to COVID-19.  If the authors had examined more adult and elderly samples, they might be able to find more COVID-19.  It is not known how long or well throat swabs can be preserved, e.g., whether samples from previous winters are still available.  But as truism goes, more studies are needed.  There are UK modelers suggesting that Wuhan, Italy or UK has achieved or will soon achieve over 50% infections and hence, herd immunity.  Which is unlikely at this point.  A huge problem of modeling is it has no way of calculating the heterogeneity in human populations and behaviors in large cities or countries.  In any case the models and predictions are not supported by concrete evidence.  

Many countries are seeing the worst passing in early to mid April.  Encouraging signs of reduced daily new confirmations have emerged in Italy, Spain, Germany, France, Austria, and so on.  As the pattern in China suggests, curve of the deaths will come down more slowly, with the death rates in Wuhan increasing steadily since Feb, likely reaching 5.2% eventually.  The recent (sudden) increase in deaths seen in Spain, France, and Germany has been attributed to those in nursing homes, common in developed countries, including the US (e.g., the facilities in Seattle).  China doesn’t have many such congregations, as the elderly usually live with their children. 

While China has successfully contained the first outbreak, its dealing with the global outbreak remains a challenge.  An advantage is obviously a comprehensive system is now in place.  On the other hand, the initial outbreak hit only Wuhan and Hubei hard.  Other provinces were largely OK, especially compared to many other countries right now.  So a concern is what if many provinces were hit simultaneously later this year, considering now we have many potential COVID-19 inputs, not just from Wuhan in Jan 2020?  This would stretch the medical infrastructure greatly, like in other countries.  

While most worldwide attention has been on Wuhan, in hindsight, how Chinese provinces outside Hubei dealt with COVID-19 in Jan-Feb 2020 actually provides an example of how one should have done.  After Wuhan had a lockdown on Jan 23, most cities and provinces in China soon had their own measures, albeit less restrictive, afterward.  The quarantine rules did not distinguish patients of COVID-19 and common cold or flu well, likely leading to an initial waste of energy and resources (my Jan 26 and Feb 9 blogs).  Nevertheless, their subsequent applications and modifications were more targeting, especially outside Hubei.  For example, tracing every case ultimately to Wuhan travel history reduced wasting time on local ILI.  This was doable only because of the very quick action: only 1-3 weeks after the first imports, when there weren’t many transmissions yet.  Also, most people were confined to their communities, checking temperature daily, wearing masks outside, etc.  Unless you had a bad cold, you didn’t go to a hospital.  Thus, efforts were concentrated on COVID-19, not the many more ILI.  Chinese provinces routinely have 50-60 million people, some over 100, but there were only several hundred to 1300 cases each outside Hubei, which were handily managed.  Since Feb 20 the domestic outbreak was practically over outside Hubei.   

        

A sound medical system, therefore, was able to limit the fatality rate in most of China to 1% and to further support Wuhan and Hubei, limiting the transmissions as well as fatality rate to 5% in Wuhan.  Otherwise, it is not unreasonable to think Wuhan would have been like Italy and Spain.  At this moment, to suppress COVID-19 China is severely limiting oversea entry and testing and quarantine everybody, but this is not sustainable.  A solution must be for the rest of the world to get better.  This will require a great deal of global cooperation and less finger-pointing.

Much can be learned from a Reuters news story (https://news.yahoo.com/special-report-johnson-listened-scientists-131705700.html) reporting how UK responded to COVID-19 since Jan 2020.  It is the equivalence of the WP story on April 4, 2020, but much better written and rooted in facts and science (my April 4, 2020 blog).  according to the Reuters story, British scientists realized the seriousness of COVID-19 in Jan 20-23 and continued to follow the situation in China and sound the alarm ever since.  The bottleneck, according to the story, however, was that the scientists considered a Wuhan-like lockdown impossible in the UK, and hence were unable to recommend a more suitable or stronger course of actions than the previous plans for flu.  

This story contrasted greatly with a couple of late Mar and April 1 reports that the UK government didn't act earlier because China was hiding COVID-19 case and death figures.  Clearly with the same figures many UK scientists have got the same message as the Chinese.  At the end of a day every country has to decide for themselves what to do with the message, and the Italy lockdown more or less eventually provided UK the cover for doing the similar thing in mid-late March.   But considering what Chinese provinces outside Hubei did.  Most provinces are comparable to the UK in population size but not at the same development level.  And many, many more Wuhan residents (millions) entered these provinces before Jan 23 than the UK.  By acting quickly, with measures less harsh than in Wuhan, all of them limited COVID-19 cases to fewer than 1500.  In other words, the UK could have avoided the current dire situation better than most Chinese provinces, but for one reason or another, a tremendous pity it didn't: not enough test kits, not enough testing facilities, not enough medical supply purchases, late and incomplete social distancing orders, etc, according to Reuters.  Around the world, some countries acted like the UK, but others were much better prepared: South Korea, Germany, just name a couple.  Now that being history, we just need more or most countries to do better and go over the hill.

Note: Serological studies are being conducted in a few countries, some in large scales (millions of people in total as a goal), according to media reports.  There are even reports that 60% of an Italian town were positive, suggesting most were infected, even though only a few were infected based on previous RNA tests.  This result and potentially others must not be considered solid for the simple fact that it has not been established how specific the Ab used in the studies is or are.  For example, it may cross react with other CoVs, known to have circulated for many years. Serological studies alone also don't tell you if you are protected.  The Ab you have might or might not protect you from re-infection.  And a low or no Ab level might can mean anything.  Like you were never infected, infected but didn't produce Ab, infected a long time ago and lost Ab already, or infected and are still protected, as the immune system may have memory: while you no longer have detectable Ab, you may still have a few memory cells that can be quickly reactivated upon new infection.  It is certain more results will appear in the news soon, but unless we know more about the Ab and the disease, nobody can draw a conclusion on how prevalent COVID-19 and herd immunity is. A nice summary can be found here: https://www.the-scientist.com/news-opinion/what-do-antibody-tests-for-sars-cov-2-tell-us-about-immunity--67425?utm_campaign=TS_DAILY%20NEWSLETTER_2020&utm_source=hs_email&utm_medium=email&utm_content=86390471&_hsenc=p2ANqtz-9049a6KgrEHixzj_RIUuoWscyIfqbanKEO2mGn1Tq4k5Wu6qr_jxmoXQhuZGUezReDqc8PNwteQxW0icCbhZcv1CJWCw&_hsmi=86390471.