Covid-19: four fifths of cases are asymptomatic, China figures indicate
BMJ 2020; 369 doi: https://doi.org/10.1136/bmj.m1375 (Published 02 April 2020) Cite this as: BMJ 2020;369:m1375Read our latest coverage of the coronavirus outbreak
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Dear Editor
I cannot get the words of Tom Jefferson and Carl Heneghan out of my head: “Lockdown is going to bankrupt all of us and our descendants and is unlikely at this point to slow or halt viral circulation as the genie is out of the bottle.” (Day, BMJ 2020;369:m1375, April 2) Seven months later their opinion was unchanged: “…lockdowns do not work in the long run; they just kick the can down the road. Meanwhile, ever-increasing restrictions will destroy lives and livelihoods.” (dailymail.co.uk, Oct 31) Their opinion is not isolated; it is shared by other distinguished experts, but is invisible amidst the cacophony of headlines about “waves…surges…spikes…deaths…variants…” Now the headlines are promising salvation in the form of vaccines produced by Pfizer and Moderna. In the US we are being told to hold on until the vaccines are widely distributed: 100 million…200 million…300 million people vaccinated to achieve herd immunity. Is this really the way to go? Here are some questions:
1) How effective are the vaccines? We do not know. Peter Doshi has been a real bird-dog about this. His recent review indicates that Pfizer’s vaccine may be only 19% effective, instead of the “95% effective” so widely publicized. (Doshi, blogs.bmj.com, 4 Jan 2021) Furthermore, there is no evidence that the vaccines save lives or interrupt virus transmission. (Doshi, BMJ 2020;371:m4037, Oct 21)
2) How does Covid-19 vaccine immunity compare with natural immunity from the infection? Again, we do not know. How long will immunity last? How broad will it be? Remember that annual influenza vaccination has been a double-edged sword because it subverts the broad and lasting protection provided by the infection. (Bodewes et al, Lancet Inf Dis 2009;9:784. J Virol 2011;85:11995) Are we now headed for annual Covid-19 shots? Els Torreele may have had flu shots in mind when he warned that we were setting the bar for Covid-19 vaccines too low and were redefining the concept of vaccines from long term public health tools to population-wide suboptimal chronic treatments, good for business but bad for public health. (Torreele, BMJ 2020;370:m3209, Aug 18) The unfortunate history of influenza vaccines should give us pause before we get stampeded into universal Covid-19 vaccination. (https://www.bmj.com/content/371/bmj.m4037/rr-3)
3) What is the real Herd Immunity Threshold/HIT? 60-70% population immunity to halt the pandemic is the figure most frequently publicized, but in the US experts like Anthony Fauci have been quietly increasing the figure to 75…80…85…90%. (McNeil, NYTimes, 12/27/20) Other experts suggest the HIT may be as low as 10%. (https://doi.org/10.1101/2020.07.23.20160762) (https://medrxiv.org/content/10.1101/2020.09.26.20202267) (reason.com/2020/09/29/) The appearance of the B.1.1.7 variant may change things, but our CDC offers no HIT estimate and says that “experts do not know.” (NYT 12/27/20) Anthony Fauci has been criticized for “moving the herd immunity goal post to promote policy goals.” (Vinay Prasad. Op-Ed: Why Did Fauci Move the Herd Immunity Goal Posts? Dec 29, 2020)
4) What about symptom-free but test-positive individuals? Is their quarantining an example of overkill? Household transmission by such individuals is only 0.7% in the US. (Madewell et al, JAMA Network Open.2020;3(12):e2031756, Dec 14) In a study from Wuhan no viable viruses were found in any of 300 such individuals and there was no evidence of asymptomatic transmission. (Cao et al, Nat Commun 2020;11:5917. Griffin, BMJ 2020;371:m4695, Dec 1. Pollock & Lancaster, BMJ 2020;371m4851,Dec 21)
5) Is a positive PCR sufficient to diagnose a case of Covid-19? It is in the US (CSTE, 4/5/20. CDC, National Covid-19 Case Surveillance, 8/28/20), yet the overwhelming majority of positive PCRs are found in individuals who harbor no live viruses. (https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaa1764/60...) A large group of international experts has demanded the retraction of a prominent article supporting the use of PCR for Covid-19 diagnosis, citing 10 fatal flaws. (Review report Corman-Drosten et al. Eurosurveillance 2020, submitted 27 November 2020)....PCR massively amplifies dead fragments of viral RNA; it is exquisitely sensitive and subject to contamination, leading to vast numbers of false positives, massive over-diagnosis of Covid-19 illness, and unnecessary quarantine of millions of healthy people. (Yeadon, lockdownsceptics.org, 11/30/20. Andrews, www.rt.com, 11/27/20)….Covid-19 is most contagious in the first 5 days after symptom onset, but beyond day 9 of the illness live viruses are not recovered. However, PCR tests remain positive for as long as 12 weeks in respiratory secretions and 18 weeks in stool. (Cevik et al, Lancet Microbe 2020, Nov 19. BMJ 2020;371:m3862, Oct 23)
6) How many deaths have been certifiably caused by Covid-19? We do not know. At one time case reports of infections in medical journals required certification by a positive culture or a rise in antibody titers, but these criteria are not the basis for case numbers reported in today’s headlines. Without such specifics we can only guess at causes of death….For weeks 8 through 49 in 2020 there were 2,620,553 US deaths reported from all causes, an excess of 389,054 deaths compared with the three-year average for the same period in 2017-19. For weeks 8 through 49 286,597 Covid-19 deaths were reported. (CDC, Covidview, 12/30/20. NCHS weekly mortality surveillance data 2013-19)….How many deaths from heart attacks or pneumonia were labelled Covid-19 deaths because of false-positive PCRs? How many of the excess deaths resulted from delays in medical care and societal disruption forced by lockdowns? Have we ignored cases and deaths associated with other respiratory viruses? Last March in California 26.1% of nasal swabs in patients with acute respiratory symptoms tested positive for non-Covid viruses and just 9.5% had Covid-19. (Kim et al, JAMA, 4/15/20)
THIS IS WHAT WE NOW MUST DO: Open up society and focus protection on the truly vulnerable. Offer the vaccines to healthcare workers, to the elderly and other high-risk individuals. Our knowledge of vaccine safety and effectiveness is limited, so we should closely monitor the recipients. Do not vaccinate healthy young and middle-aged individuals, but allow the gradual acquisition of lasting population immunity from an infection that is generally mild. Skip the flu shot. We are seeing very little influenza, and the vaccine increases the risk of illness from non-influenza respiratory viruses, probably including Covid-19. (https://www.bmj.com/content/370/bmj.m3720/rr) ….I can’t get the words of Tom Jefferson, Carl Heneghan, Els Torreele, Peter Doshi and others out of my head.
ALLAN S. CUNNINGHAM 11 January 2021
Competing interests: No competing interests
Dear Editor,
This recent finding that four-fifths of COVID-19 cases are asymptomatic from Chinese authority is contradictory to an earlier Report by the WHO-China Joint Mission on Coronavirus Disease 2019 (COVID-19) which indicated “the proportion of truly asymptomatic infections is unclear but appears to be relatively rare and does not appear to be a major driver of transmission.” [1].
This is frustrating information since asymptomatic infection, if as high as four-fifths of the SARS-CoV-2 infection, should have been found in Feb in Wuhan, when it was mainly still a local epidemic.
Asymptomatic infection is one of the most important transmission dynamics that would have changed how we should have responded to the outbreak. Unfortunately, now the Chinese authorities confirmed this from a few imported cases in April. One can't stop but wonder, why they did not find out asymptomatic infection of SARS-CoV-19 in Jan and Feb with more than 70,000 cases in Hubei?
International Health Regulation is an international health treaty that mandates a country to report outbreaks within 24 hours. It was negotiated after the turbulent and hectic response to the 2003 SARS endemic and was implanted in 2005. We urge WHO to be transparent on all early communications with the Chinese national authority, and we recommend an independent investigation into 1) the dates of notification of the initial outbreak in December 2019, with a focus on 2) how human-to-human transmission was initially dismissed and confirmation of the outbreak was delayed, and 3) the information on asymptomatic transmission confirmation.
Transparency is the key to effective endemic control. The world will undoubtedly continue to face emerging infectious diseases. We must learn from our mistakes since transparency is the key to prevailing in the fight against epidemics and pandemics.
References
1. WHO-China Joint Mission Members. Report of the WHO-China Joint Mission on Coronavirus Disease 2019 (COVID-19). World Health Organization 2020.
Competing interests: No competing interests
Dear Editor
Please see the press release from Mount Sinai in New York: "Mount Sinai Study Finds COVID-19 May Be Driven by Pulmonary Thrombi and Pulmonary Endothelial Dysfunction" [1].
It should be clear now that, instead of watchful waiting - perhaps till death? - the patients should be considered for LOW MOLECULAR HEPARIN as soon as possible. There is no way you can forecast who will develop thrombotic phenomena.
Reference
1 Mount Sinai. Press release 13 April 2020. Mount Sinai Study Finds COVID-19 May Be Driven by Pulmonary Thrombi and Pulmonary Endothelial Dysfunction
https://www.mountsinai.org/about/newsroom/2020/mount-sinai-study-finds-c...
Competing interests: No competing interests
Dear Editor
An interesting thing happened on the English website of the World Health Organization（WHO）between March 7th and 8th, 2020：among the measures that are ineffective and potentially harmful to the treatment of COVID-19, they included "Taking traditional herbal remedies", but this content has been deleted from the website on March 8. (1）However, on the WHO Chinese website, there has never been any content that traditional herbs are “ineffective and potentially harmful”. (2）
The use of herbal medicine is exactly the representative part of the core value of traditional Chinese medicine（TCM), which is not displayed on the Chinese website to indicate that WHO does not want to offend Beijing in this case, who has long regarded TCM as a symbol of China's traditional values that are different from those of the West. China's propaganda of TCM was unprecedented in this battle against the outbreak.
Zhang Boli, a member of the Chinese Academy of Engineering, said that his team compared the clinical data of 34 cases of COVID-19 in the integrated Chinese and Western medicine treatment group with 18 cases in the Western medicine group, and the overall efficacy of the former was significantly better than that of pure Western medicine treatment under the measurement of various inspection indicators. （3）
However, judging from the number of confirmed cases in China that have exceeded 80,000, the conclusion that Academician Zhang Boli relied on dozens of cases does not seem to give any confidence that TCM plays an active role in the treatment of COVID-19.
TCM has a long history, and the early basic theories came from an ancient book called “The Inner Canon of the Yellow Emperor” two thousand years ago. The treatment methods of TCM preached in the book were based on the Yin-yang and Five-element Thought, which has not changed for thousands of years, and is still the core part of the current theory of TCM. Its principle cannot be demonstrated experimentally to prove its correctness, nor can it restore the treatment process and evidence in an evidence-based way.
The medicine used by traditional Chinese pharmacy is very extensive, and a variety of naturally occurring substances can be included in the scope. In the current COVID-19 spreading around the world, there is evidence to show a close relationship with the use of Chinese medicine. The scholars from the South China Agricultural University have found that the virus strains isolated in pangolins are 99% similar to covid-19 virus strain in the infected. （4）TCM treats a large number of animal organs as medicine raw materials. For pangolins, TCM thinks that eating pangolins can make breastfeeding women lactate smoothly, which is based on the fact that the pangolin's hard shell can penetrate hard objects to gain access. According to statistics, China consumes 300,000 pangolins each year.
The major drawback of TCM is the use of untested prescriptions to prescribe medicines for patients. The toxic side effects, contraindications, and adverse reactions of these medicines have not been proven through clinical trials. On October 27, 2017, in the list of carcinogens released by the WHO's International Cancer Research Agency, aristolochic acid and plants containing aristolochic acid belonged to the first class of carcinogens; （5）however, there are six types of Chinese medicinal materials that have clearly contained aristolochic acid in the 2000 Chinese Pharmacopoeia.
China's economy has developed rapidly in the past three decades, and its GDP has become the world's second-largest country after the United States. Compared with the tragic situation of poverty and persistent insults in the country more than 100 years ago, China is now becoming stronger and more confident than ever before, and it is very urgent to publicize and project this strength and confidence. High-speed railways, communication networks, and manufacturing capabilities are typical examples of China's external display of its economic strength, a sign of hard power. In addition, China has also promoted the superiority of its soft power to the world, that is, traditional culture, but there are not many choices worthy of external publicity. And TCM that has been widely used in China for thousands of years has been selected as a typical representative.
Although TCM has various problems that contradict modern medicine, it has survived and developed stubbornly in China, which has a huge relationship with the government's vigorous efforts to support it. In the composition of all levels of government in China, there are government agencies such as the Administration of Traditional Chinese Medicine to support TCM, and every year a large amount of scientific research funds are used to study how to promote the development of TCM.
The result now is that not only has TCM failed to develop abroad, it has also been increasingly controversial and questioned at home, and the Chinese are increasingly rejecting TCM as the primary treatment option.
In 2010, the number of Chinese people receiving medical services about was 2.396 billion, of which 613 million were TCM services, accounting for about 30.04%; however, in 2018, the number of medical services was 8.308 billion, of which 108 million were TCM services, accounting for 12.90%, a decrease of 17.14 percentage points. （6） It can be seen from the trend of the change in numbers that the efficacy of traditional Chinese medicine is unsatisfactory. More and more Chinese accept Western medicine services and give up TCM services, the number of patients receiving TCM services only a small proportion.
According to the current trend, if TCM still cannot solve the pathological and pharmacological problems through experimental and evidence-based methods, and continue to use similar methods of witch doctors such as "Heaven and Man Unity" and " Yin-yang and Five-element Thought " without scientific explanation to prove to the world the rationality of TCM, and the therapeutic effect of TCM cannot be fully recognized by patients, TCM will be abandoned by everyone sooner or later, regardless of whether the government is still willing to spend huge amounts of money to support it.
References:
（1）Q&A on coronaviruses (COVID-19), https://www.who.int/news-room/q-a-detail/q-a-coronaviruses
（2）https://www.who.int/zh/news-room/q-a-detail/q-a-coronaviruses
（3）http://dz.jjckb.cn/www/pages/webpage2009/html/2020-02/26/content_61837.htm
（4）http://finance.chinanews.com/sh/2020/02-07/9082215.shtml
（5）Zhao Chong, Liu Zhongyang. Research progress on the influence of benzene series in the paint coatings on the health status of the exposed personnel, Occupation and Health, May 2019, 1286-1289. DOI:10.13329/j.cnki.zyyjk.2019.0339
（6）Data from the 2019 China Health Statistics Yearbook, Page3,119 and 195.
Competing interests: No competing interests
Dear Editor,
Do the Chinese data lead to over or underestimations of the total number of infected people? Let’s assume that the Chinese estimate of “four in five coronavirus infections caused no illness” is correct. This is a fair assumption as other case studies have shown similar shares between symptomatic and asymptomatic cases (also reported in the BMJ article). If this assumption is sound, would it be correct to estimate the total number of infections as the number of symptomatic persons times five? Only if all individuals in the population are tested, which we know is not the case. In fact, it is easy to show that the proportion of undetected cases is much higher than the 80% suggested by the Chinese study.
Imagine to split a country's population into those who have been tested and those who have not. Then divide further the population into Susceptible, Infected symptomatic, Infected asymptomatic, Recovered and Dead (SIIRD). Naturally, if you have tested positive you will either be infected or dead, and if you have tested negative is because you remain susceptible to the infection or have recovered from the infection (we leave aside the question of whether infected people can result negative to the test). Similarly, if you are not tested, you still can belong to any of these five categories. With this simple categorization, you can divide the population into 10 groups, five SIIRD tested groups and five SIIRD non-tested groups. This simply shows that the symptomatic and asymptomatic can also be found in the non-tested category.
Now, apply this categorization to real data from Italy (April 12th, 2020, official data downloaded from https://github.com/). Italy is one of the countries in the world that performed more tests with a total of more than 1 m tests performed by April 12th. It is also a country with good health statistics and it was easy to find the information for all the five categories of tested people (with the exception of the symptomatic/asymptomatic shares which we assume being 4 to 1).
But what about the number of people who have not been tested? We know the number overall as a difference between the population and the number of tested people, which is a very large number (98.33% of the population). In fact, this share is larger since some tests are performed on the same person multiple times. Unfortunately, we know nothing about the five categories that make up the non-tested group. In fact, the group that has been tested is not representative of the group that has not been tested, or the population overall. In other words, we cannot infer from the statistics on the tested group the statistics on the non-tested group.
Overlooking this simple point has very large consequences on the estimation of the true scale of the epidemic. Multiplying the number of tested symptomatic persons by 5 in Italy results in an estimate of 409,019 infected individuals equal to 0.68% of the population on April 12th. The flu alone infects about 9% of the Italian population every year on average, and the peak is reached in February, not April (http://www.iss.it/). This suggests that the total number of true cases in a population cannot be estimated using the ratio between symptomatic and asymptomatic tested people. Such estimate is surely an underestimation of the true number of infected people. Since the Chinese data derive by definition from the tested group and given that the likelihood of catching a symptomatic person is higher among those tested, we should expect the share of asymptomatic to symptomatic persons to be much higher in the population than what is shown by the sample of Chinese data.
Competing interests: No competing interests
Dear Editor,
Scarlet fever was diagnosed in 1488 per 100 000 of children age 1 - 4 years in England. (1)
The nightmare named Covid-19 seems to be more than a virus-infection.
We think it may be a coinfection of corona-virus and group-A-streptococci and streptococcus pneumoniae. With grim effects of non-effective new antibiotics like azithromycin that show failure-rates up to 90%.
We are aware that numerous studies about covid-19 are in progress the world over to study the pathophysiology and possible therapeutic regimens. Also, researchers are going to produce one or more vaccines.
Might we suggest that we look at what is known?
Firstly, there is known to be a very wide variation in the degree of severity. It is suggested that perhaps 95% of those who contract the infection main remain symptomless or so mildly symptomatic that they do not need therapy.
Secondly, we do not know yet, which patients might rapidly develop severe disease leading to multi-organ failure and death.
Thirdly, severe immunological and changes occur; high D-Dimers as a sign of intravascular coagulation are the worst case indicator.
Now some surmises:
Firstly, interstitial pulmonary oedema is a feature of the fatal cases.
Secondly, bacterial invasion must become easy and contributes to the fatal outcome (coinfection, superinfection or secondary infection by commensuals like azithromycin-resistant pneumococci, which become deadly invaders). (2) Azithromycin resistant pneumococci in the USA are 48,4% (3), in China 88,2% (4).
Thirdly, disseminated intravascular coagulation kills in the most severe cases and occurs in many patients.
We suggest therefore that in every recognized case, antibiotic therapy should be instituted. While culture reports are awaited, Penicillin should be commenced. Penicillin is known to kill Streptococci - no resistance has yet been identified.
We also suggest that unfractionated heparin 20.000 - 30.000 IU/day should be started, either s.c. or i.v.. This was the therapy of our old teachers. We recognise that medicine has advanced since we practised. But the gold standards of penicillin and unfractionated heparin have not changed.
"Giving an effective drug like penicillin (...) in 2 days is important for improving outcome" (5)
If there are any flaws in the foregoing, we could appreciate being put right.
1. N N Lynskey, E. Jauneikaite, H K Li, X Zhi, C E Turner, M Mosavic, M Pearson, M Asai, L Lobkowicz, J Y Chow, J Parkhill, T Lamagni, V J Chalker, S Sriskandan: Emergence of toxigenic M1T1 Streptococcus pyogenes clone during increased scarlet fever activity in England: a population-based molecular epidemiological study. Lancet Infect Dis 2019;19:1209-18
2. S Okamoto, S Kawabata, I Nakagawa, Y Okuno, T Goto, K Sano, S Hamada: Influenza A Virus-Infected Hosts Boost an Invasive Type of Streptococcus pyogenes Infection in Mice. J Virology;77:4104-4112
3. D J Farrell, R K Flamm, H S Sader, R N Jones: Results from the Solithromycin International Surveillance Program (2014). Antimicrob Agents Chemoth 2016;60:3662-3668
4. H Wang, YL Liu, MJ Chen, YC Xu, HL Sun, QW Yang, YJ Hu, B Cao, YZ CHu, Y Liu, R Zhang, YS Yu, ZY Sun, C Zhuo, YX Ni, BJ Hu: Antimicrobial susceptibility of community-acquired respiratory tract pathogens isolated from adults in China during 2009 and 2010. Zhonghua Jie He He Hu Xi Za Zhi, 2012;35:113-9
5. H-Y Lee, T-L Wu, L-H Su, H-C Li, RP Janapatla, C-L Chen, C-H Chiu: Invasive pneumococcal disease caused by ceftriaxone-resistant Streptococcus pneumoinae in Taiwan. J Microbiol, Immunol and Infection 2018;51:500-509
Competing interests: No competing interests
Dear Editor
Coronavirus has shown remarkable variability in its effects, ranging all the way from asymptomatic carriers to viral pneumonitis and death.
Its most manifest and serious effects are local and these are at the alveolar level. There are also reports of anosmia and loss of taste https://www.entuk.org/sites/default/files/files/Loss%20of%20sense%20of%2.... I know of a case of unilateral anosmia, demonstrating the local effect of the virus. The case of Ria Lakhani who reports that she needs ‘to remember to breathe’ https://www.bbc.co.uk/news/uk-52204444 suggests a feedback mechanism from damaged alveolar or lower respiratory tract receptors to the respiratory centre, similar to damaged tongue taste buds which can take several weeks to recover.
The three routes of infection are reckoned to be via the mouth, nose and eye mucosa.
Asymptomatic infection
I have not heard of any significant local symptoms associated with infection via the eye mucosa and this route of infection may account for the large proportion of asymptomatic infections. It may also be the route through which the herd immunity that is surely building up in the community has developed. Local eye inoculation may have provoked an immune response before there was significant involvement of the respiratory mucosa.
These different routes of infection may suggest that mouth breathing is more likely to lead to viral pneumonitis than nasal breathing, and that face masks, scarves and bandanas in the community may direct any viral particles towards the eyes rather than the nose and mouth.
Research
Researchers could investigate whether the severe respiratory cases are predominantly mouth-breathers and whether eye inoculation has been the route for asymptomatic infection.
Competing interests: No competing interests
Dear Editor,
We read with great interest the article by Day (2020) commenting on the asymptomatic majority (78%) of those infected with COVID-19 in the Chinese population. (1) Despite many harbouring the infection asymptomatically, we write to highlight that patients may display atypical symptoms - a feature likely under-accounted for by statistics and under-addressed at large by public, healthcare professionals and policy-makers.
COVID-19 exhibits a diverse range of clinical presentations. Whilst classical respiratory symptoms of a dry cough have been underscored, these may be preceded by atypical respiratory symptoms such as haemoptysis. (2) Additionally, progressive gastrointestinal symptoms (diarrhoea, vomiting, abdominal pain) may be the index presentation, even occurring in the absence of other features. (3) Such symptoms have also been described in immunosuppressed patients, highlighting a potential at-risk group. (4) More recently, isolated anosmia or hyposmia has been widely reported as a primary symptom. (5) Ocular manifestations, primarily conjunctivitis, have also been pinpointed in case series, and the possibility of tear transmission has been broached (6). More generally, it is important not to neglect other disease manifestations since they may represent alternative modes of viral dissemination.
In critically ill patients, evidence of raised inflammatory markers suggests that cytokine storm syndrome occurs in COVID-19 and may underlie some atypical presentations. In this context, infected patients presenting solely with cardiac symptoms such as palpitations and chest pain have been reported, often due to underlying virus-induced myocardial injury. (7) Cytokines have also been attributed to certain neurologic symptoms: a patient presenting with fever, cough and altered mental status eventually developed acute necrotising haemorrhagic encephalopathy. (8) Other atypical neurologic presentations include acute cerebrovascular disease and muscle injuries. (9) Notably, the elderly and those with multiple comorbidities are severely affected by COVID-19, and atypical symptoms in these susceptible groups warrant further investigation.
Heightened awareness of these various atypical presentations of COVID-19 has wide-reaching implications. Firstly, the public may be more compelled to undertake precautionary self-isolation, or seek medical attention should concerning symptoms arise. Medical personnel will approach patients with a higher index of suspicion, which is beneficial for both early diagnostic purposes but also for ensuring adequate preventative personal protective equipment (PPE) and hygiene precautions are scrupulously implemented. Furthermore, recognising atypical symptoms allows other screening protocols and biomarkers of disease progression to be investigated. On a national scale, this may facilitate more accurate data collection on confirmed cases which will impact public health policies. The recent development of symptom-tracker applications for mobile phones may assist with this as they allow individuals to rapidly log their symptoms daily, with the objective of collating the information to better characterise the full-spectrum of symptoms that correlate with the disease. (10) Ultimately, by drawing attention to these atypical symptoms, we hope to encourage further investigation, symptom-reporting and awareness of the many guises of COVID-19.
References
1. Day M. Covid-19: four fifths of cases are asymptomatic, China figures indicate. BMJ [Internet]. 2020 Apr 2 [cited 2020 Apr 5];369. Available from: https://www.bmj.com/content/369/bmj.m1375
2. Shi F, Yu Q, Huang W, Tan C. 2019 Novel Coronavirus (COVID-19) Pneumonia with Hemoptysis as the Initial Symptom: CT and Clinical Features. Korean Journal of Radiology [Internet]. 2020 Feb 26 [cited 2020 Apr 5];21. Available from: https://doi.org/10.3348/kjr.2020.0181
3. Pan L, Mu M, Yang P, Sun Y, Yan J, Li P, et al. Clinical characteristics of COVID-19 patients with digestive symptoms in Hubei, China: a descriptive, cross-sectional, multicenter study. :25.
4. Guillen E, Pineiro GJ, Revuelta I, Rodriguez D, Bodro M, Moreno A, et al. Case report of COVID-19 in a kidney transplant recipient: Does immunosuppression alter the clinical presentation? American Journal of Transplantation [Internet]. [cited 2020 Apr 5];n/a(n/a). Available from: https://onlinelibrary.wiley.com/doi/abs/10.1111/ajt.15874
5. Hopkins C, Kumar N. Loss of sense of smell as marker of COVID-19 infection.pdf [Internet]. ENT UK. 2020 [cited 2020 Apr 5]. Available from: https://templatearchive.com/loss-sense-smell-marker-covid/
6. Wu P, Duan F, Luo C, Liu Q, Qu X, Liang L, et al. Characteristics of Ocular Findings of Patients With Coronavirus Disease 2019 (COVID-19) in Hubei Province, China. JAMA Ophthalmol [Internet]. 2020 Mar 31 [cited 2020 Apr 5]; Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7110919/
7. Clerkin Kevin J., Fried Justin A., Raikhelkar Jayant, Sayer Gabriel, Griffin Jan M., Masoumi Amirali, et al. Coronavirus Disease 2019 (COVID-19) and Cardiovascular Disease. Circulation [Internet]. [cited 2020 Apr 5];0(0). Available from: https://www.ahajournals.org/doi/abs/10.1161/CIRCULATIONAHA.120.046941
8. Poyiadji N, Shahin G, Noujaim D, Stone M, Patel S, Griffith B. COVID-19–associated Acute Hemorrhagic Necrotizing Encephalopathy: CT and MRI Features. Radiology. 2020 Mar 31;201187.
9. Mao L, Wang M, Chen S, He Q, Chang J, Hong C, et al. Neurological Manifestations of Hospitalized Patients with COVID-19 in Wuhan, China: a retrospective case series study. medRxiv. 2020 Feb 25;2020.02.22.20026500.
10. New symptom tracking app aims to slow spread of coronavirus [Internet]. [cited 2020 Apr 5]. Available from: https://www.kcl.ac.uk/news/new-symptom-tracking-app-aims-to-slow-spread-...
Competing interests: No competing interests
Dear Editor
May I draw your attention to the Daily Situation Report of the Robert Koch Institute for 29/03/2020
(https://www.rki.de/DE/Content/InfAZ/N/Neuartiges_Coronavirus/Situationsb...)
In the "Clinical aspects" section it states:-
"Clinical information is available for 37,714 of the notified cases, of which 1,115 cases were reported as not having any symptoms considered significant for COVID-19."
(That is 2.96 %)
Might I also suggest that in the absence of large scale testing using the hospitalisation data from these reports might be a good method of estimating the true number of infections.
Daily Situation Report of the Robert Koch Institute for 04/04/2020 states
(https://www.rki.de/DE/Content/InfAZ/N/Neuartiges_Coronavirus/Situationsb...)
"Hospitalisation was reported for 8,803 (14%) of 63,593 COVID-19 cases with information on hospitalisation available"
Competing interests: No competing interests
Re: Covid-19: four fifths of cases are asymptomatic, China figures indicate
Dear Editor
This is a comment on Dr Allan Cunningham’s Rapid Response.
In any matter of conflicting medical views, I would have expected the government’s spokesmen to speak. But as the readers will recall, the Medical Officers of HMG ignore critical voices. Perhaps they think (like a Prime Minister forty years ago) that opposition should be deprived of “the oxygen of publicity”.
But, please, can the medical teachers at least remember that medical students need to be taught to discuss, debate, the hows, whys, wherefores.
Thank you
Competing interests: Aged 88. Being swept along by a tide.