Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Clinical presentations, laboratory and radiological findings, and treatments for 11,028 COVID-19 patients: a systematic review and meta-analysis

Abstract

This systematic review and meta-analysis investigated the comorbidities, symptoms, clinical characteristics and treatment of COVID-19 patients. Epidemiological studies published in 2020 (from January–March) on the clinical presentation, laboratory findings and treatments of COVID-19 patients were identified from PubMed/MEDLINE and Embase databases. Studies published in English by 27th March, 2020 with original data were included. Primary outcomes included comorbidities of COVID-19 patients, their symptoms presented on hospital admission, laboratory results, radiological outcomes, and pharmacological and in-patient treatments. 76 studies were included in this meta-analysis, accounting for a total of 11,028 COVID-19 patients in multiple countries. A random-effects model was used to aggregate estimates across eligible studies and produce meta-analytic estimates. The most common comorbidities were hypertension (18.1%, 95% CI 15.4–20.8%). The most frequently identified symptoms were fever (72.4%, 95% CI 67.2–77.7%) and cough (55.5%, 95% CI 50.7–60.3%). For pharmacological treatment, 63.9% (95% CI 52.5–75.3%), 62.4% (95% CI 47.9–76.8%) and 29.7% (95% CI 21.8–37.6%) of patients were given antibiotics, antiviral, and corticosteroid, respectively. Notably, 62.6% (95% CI 39.9–85.4%) and 20.2% (95% CI 14.6–25.9%) of in-patients received oxygen therapy and non-invasive mechanical ventilation, respectively. This meta-analysis informed healthcare providers about the timely status of characteristics and treatments of COVID-19 patients across different countries.

PROSPERO Registration Number: CRD42020176589

Introduction

Following the possible patient zero of coronavirus infection identified in early December 20191, the Coronavirus Disease 2019 (COVID-19) has been recognized as a pandemic in mid-March 20202, after the increasing global attention to the exponential growth of confirmed cases3. As on 29th March, 2020, around 690 thousand persons were confirmed infected, affecting 199 countries and territories around the world, in addition to 2 international conveyances: the Diamond Princess cruise ship harbored in Yokohama, Japan, and the Holland America's MS Zaandam cruise ship. Overall, more than 32 thousand died and about 146 thousand have recovered4.

A novel bat-origin virus, 2019 novel coronavirus, was identified by means of deep sequencing analysis. SARS-CoV-2 was closely related (with 88% identity) to two bat-derived severe acute respiratory syndrome (SARS)-like coronaviruses, bat-SL-CoVZC45 and bat-SL-CoVZXC21, but were more distant from SARS-CoV (about 79%) and MERS-CoV (about 50%)5, both of which were respectively responsible for two zoonotic human coronavirus epidemics in the early twenty-first century. Following a few initial human infections6, the disease could easily be transmitted to a substantial number of individuals with increased social gathering7 and population mobility during holidays in December and January8. An early report has described its high infectivity9 even before the infected becomes symptomatic10. These natural and social factors have potentially influenced the general progression and trajectory of the COVID-19 epidemiology.

By the end of March 2020, there have been approximately 3000 reports about COVID-1911. The number of COVID-19-related reports keeps growing everyday, yet it is still far from a clear picture on the spectrum of clinical conditions, transmissibility and mortality, alongside the limitation of medical reports associated with reporting in real time the evolution of an emerging pathogen in its early phase. Previous reports covered mostly the COVID-19 patients in China. With the spread of the virus to other continents, there is an imminent need to review the current knowledge on the clinical features and outcomes of the early patients, so that further research and measures on epidemic control could be developed in this epoch of the pandemic.

Methods

Search strategy and selection criteria

The systematic review was conducted according to the protocol registered in the PROSPERO database (CRD42020176589). Following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guideline throughout this review, data were identified by searches of MEDLINE, Embase and references from relevant articles using the search terms "COVID", “SARS-CoV-2”, and “novel coronavirus” (Supplementary material 1). Articles published in English up to 27th March, 2020 were included. National containment measures have been implemented at many countries, irrespective of lockdown, curfew, or stay-at-home orders, since the mid of March 202012, except for China where imposed Hubei province lockdown at 23th January 2020, Studies with original data including original articles, short and brief communication, letters, correspondences were included. Editorials, viewpoints, infographics, commentaries, reviews, or studies without original data were excluded. Studies were also excluded if they were animal studies, modelling studies, or did not measure symptoms presentation, laboratory findings, treatment and therapeutics during hospitalization.

After the removal of duplicate records, two reviewers (CW and CHA) independently screened the eligibility criteria of study titles, abstracts and full-texts, and reference lists of the studies retrieved by the literature search. Disagreements regarding the procedures of database search, study selection and eligibility were resolved by discussion. The second and the last authors (JW and AW) verified the eligibility of included studies.

Outcomes definitions

Signs and symptoms were defined as the presentation of fever, cough, sore throat, headache, dyspnea, muscle pain, diarrhea, rhinorrhea, anosmia, and ageusia at the hospital admission13.

Laboratory findings included a complete blood count (white blood count, neutrophil, lymphocyte, platelet count), procalcitonin, prothrombin time, urea, and serum biochemical measurements (including electrolytes, renal-function and liver-function values, creatine kinase, lactate dehydrogenase, C-reactive protein, Erythrocyte sedimentation rate), and treatment measures (i.e. antiviral therapy, antibiotics, corticosteroid therapy, mechanical ventilation, intubation, respiratory support, and renal replacement therapy). Radiological outcomes included bilateral involvement identified and pneumonia identified by chest radiograph.

Comorbidities of patients evaluated in this study were hypertension, diabetes, chronic obstructive pulmonary disease (COPD), cardiovascular disease, chronic kidney disease, liver disease and cancer.

In-patient treatment included intensive care unit admission, oxygen therapy, non-invasive ventilation, mechanical ventilation, Extracorporeal membrane oxygenation (ECMO), renal replacement therapy, and pharmacological treatment. Use of antiviral and interferon drugs (Lopinavir/ritonavir, Ribavirin, Umifenovir, Interferon-alpha, or Interferon-beta), antibiotic drugs, corticosteroid, and inotropes (Nor-adrenaline, Adrenaline, Vasopressin, Phenylephrine, Dopamine, or Dobutamine) were considered.

Data analysis

Three authors (CW, EHMT and CHA) extracted data using a standardized spreadsheet to record the article type, country of origin, surname of first author, year of publications, sample size, demographics, comorbidities, symptoms, laboratory and radiology results, pharmacological and non-pharmacological treatments.

We aggregated estimates across 90 eligible studies to produce meta-analytic estimates using a random-effects model. For dichotomous outcomes, we estimated the proportion and its respective 95% confidence interval. For laboratory parameters as continuous outcomes, we estimated the mean and standard deviation from the median and interquartile range if the mean and standard deviation were not available from the study14, and calculated the mean and its respective 95% confidence intervals. Random-effect models on DerSimonian and Laird method were adopted due to the significant heterogeneity, checked by the I2 statistics and the p values. I2 statistic of < 25%, 25–75% and ≥ 75% is considered as low, moderate, high likelihood of heterogeneity. Pooled estimates were calculated and presented by using forest plots. Publication bias was estimated by Egger’s regression test. Funnel plots of outcomes were also presented to assess publication bias.

All statistical analyses were conducted using the STATA Version 13.0 (Statacorp, College Station, TX). The random effects model was generated by the Stata packages ‘Metaprop’ for proportions15 and ‘Metan’ for continuous variables16.

Results

The selection and screen process are presented in Fig. 1. A total of 241 studies were found by our searching strategy (71 in PubMed and 170 in Embase). 46 records were excluded due to duplication. After screening the abstracts and titles, 100 English studies were with original data and included in full-text screening. By further excluding 10 studies with not reporting symptoms presentation, laboratory findings, treatment and therapeutics, 90 studies17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,102,103,104,105,106 and 76 studies with more than one COVID-19 case17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,34,35,36,37,38,39,42,43,44,45,49,50,51,53,57,58,59,60,61,62,63,64,67,69,70,72,73,74,75,76,77,78,79,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,98,100,101,102,103,104,105 were included in the current systematic review and meta-analysis respectively. 73.3%66 studies were conducted in China. Newcastle–Ottawa Quality Assessment Scale has been used to assess study quality of each included cohort study107. 30% (27/90) of included studies had satisfactory or good quality. The summary of the included study is shown in Table 1.

Figure 1
figure1

PRISMA flowchart reporting identification, searching and selection processes.

Table 1 Summary of 90 reviewed studies.

Of those 90 eligible studies, 11,028 COVID-19 patients were identified and included in the systematic review. More than half of patients (6336, 57.5%) were from mainland China. The pooled mean age was 45.8 (95% CI 38.6–52.5) years and 49.3% (pooled 95% CI 45.6–53.0%) of them were male.

For specific comorbidity status, the most prevalent comorbidity was hypertension (18.1%, 95% CI 15.4–20.8%), followed by cardiovascular disease (11.8%, 95% CI 9.4–14.2%) and diabetes (10.4%, 95% CI 8.7–12.1%). The pooled prevalence (95% CI) of COPD, chronic kidney disease, liver disease and cancer were 2.0% (1.3–2.7%), 5.2% (1.7–8.8%), 2.5% (1.7–3.4%) and 2.1% (1.3–2.8%) respectively. Moderate to substantial heterogeneity between reviewed studies were found, with I2 statistics ranging from 39.4 to 95.9% (p values between < 0.001–0.041), except for liver disease (I2 statistics: 1.7%, p = 0.433). Detailed results for comorbidity status are displayed in Fig. 2.

Figure 2
figure2

Random-effects meta-analytic estimates for comorbidities. (A) Diabetes mellitus, (B) Hypertension, (C) Cardiovascular disease, (D) Chronic obstructive pulmonary disease, (E) Chronic kidney disease, (F) Cancer.

Regarding the symptoms presented at hospital admission, the most frequent symptoms were fever (pooled prevalence: 72.4%, 95% CI 67.2–77.7%) and cough (pooled prevalence: 55.5%, 95% CI 50.7–60.3%). Sore throat (pooled prevalence: 16.2%, 95% CI 12.7–19.7%), dyspnoea (pooled prevalence: 18.8%, 95% CI 14.7–22.8%) and muscle pain (pooled prevalence: 22.1%, 95% CI 18.6–25.5%) were also common symptoms found in COVID-19 patients, but headache (pooled prevalence: 10.5%, 95% CI 8.7–12.4%), diarrhoea (pooled prevalence: 7.9%, 95% CI 6.3–9.6%), rhinorrhoea (pooled prevalence: 9.2%, 95% CI 5.6–12.8%) were less common. However, none of the included papers reported prevalence of anosmia and ageusia. The I2 statistics varied from 68.5 to 97.1% (all p values < 0.001), indicating a high heterogeneity exists across studies. Figure 3 shows the pooled proportion of symptoms of patients presented at hospital.

Figure 3
figure3

Random-effects meta-analytic estimates for presenting symptoms. (A) Fever, (B) Cough, (C) Dyspnoea, (D) Sore throat, (E) Muscle pain, (F) Headache.

For laboratory parameters, white blood cell (pooled mean: 5.31 × 109/L, 95% CI 5.03–5.58 × 109/L), neutrophil (pooled mean: 3.60 × 109/L, 95% CI 3.31–3.89 × 109/L), lymphocyte (pooled mean: 1.11 × 109/L, 95% CI 1.04–1.17 × 109/L), platelet count (pooled mean: 179.5 U/L, 95% CI 172.6–186.3 U/L), aspartate aminotransferase (pooled mean: 30.3 U/L, 95% CI 27.9–32.7 U/L), alanine aminotransferase (pooled mean: 27.0 U/L, 95% CI 24.4–29.6 U/L) and C-reactive protein (CRP) (pooled mean: 22.0 mg/L, 95% CI 18.3–25.8 mg/L) and D-dimer (0.93 mg/L, 95% CI 0.68–1.18 mg/L) were the common laboratory test taken for COVID-19 patients. Above results and other clinical factors are depicted in Fig. 4. Same with the comorbidity status and symptoms, high likelihood of heterogeneity was detected by I2 statistics for a majority of clinical parameters.

Figure 4
figure4

Random-effects meta-analytic estimates for laboratory parameters. (A) White blood cell, (B) Lymphocyte, (C) Neutrophil, (D) C-creative protein, (E) D-dimer, (F) Lactate dehydrogenase.

Figure 5 presents the distribution of the pharmacological treatments received for COVID-19 patients. 10.6% of patients admitted to intensive care units (pooled 95% CI 8.1–13.2%). For drug treatment, 63.9% (pooled 95% CI 52.5–75.3%), 62.4% (pooled 95% CI 47.9–76.8%) and 29.7% (pooled 95% CI 21.8–37.6%) patients used antibiotics, antiviral, and corticosteroid, respectively. 41.3% (pooled 95% CI 14.3–68.3%) and 50.7% (pooled 95% CI 9.2–92.3%) reported using Lopinavir/Ritonavir and interferon-alpha as antiviral drug treatment, respectively. Among 14 studies reporting proportion of corticosteroid used, 7 studies (50%) specified the formulation of corticosteroid as systemic corticosteroid. The remaining one specified the use of methylprednisolone. No reviewed studies reported the proportion of patients receiving Ribavirin, Interferon-beta, or inotropes.

Figure 5
figure5

Random-effects meta-analytic estimates for pharmacological treatments and intensive unit care at hospital. (A) Antiviral or interferon drugs, (B) Lopinavir/Ritonavir, (C) Interferon alpha (IFN-α), (D) Antibiotic drugs, (E) Corticosteroid, (F) Admission to Intensive care unit.

The prevalence of radiological outcomes and non-pharmacological treatments were presented in Fig. 6. Radiology findings detected chest X-ray abnormalities, with 74.4% (95% CI 67.6–81.1%) of patients with bilateral involvement and 74.9% (95% CI 68.0–81.8%) of patients with viral pneumonia. 62.6% (pooled 95% CI 39.9–85.4%), 20.2% (pooled 95% CI 14.6–25.9%), 15.3% (pooled 95% CI 11.0–19.7%), 1.1% (pooled 95% CI 0.4–1.8%) and 4.7% (pooled 95% CI 2.1–7.4%) took oxygen therapy, non-invasive ventilation, mechanical ventilation, ECMO and dialysis respectively.

Figure 6
figure6

Random-effects meta-analytic estimates for radiological findings and non-pharmacological treatments at hospital. (A) Bilateral involvement, (B) Pneumonia, (C) Oxygen therapy, (D) Non-invasive ventilation, (E) Extracorporeal membrane oxygenation (ECMO), (F) Dialysis.

The funnel plots and results Egger’s test of comorbidity status, symptoms presented, laboratory test and treatment were presented in eFigure 1S5 in the Supplement. 63% (19/30) of the funnel plots (eFigure 1S5) showed significance in the Egger’s test for asymmetry, suggesting the possibility of publication bias or small-study effects caused by clinical heterogeneity.

Discussion

This meta-analysis reveals the condition of global medical community responding to COVID-19 in the early phase. During the past 4 months, a new major epidemic focus of COVID-19, some without traceable origin, has been identified. Following its first identification in Wuhan, China, the virus has been rapidly spreading to Europe, North America, Asia, and the Middle East, in addition to African and Latin American countries. Three months since Wuhan CDC admitted that there was a cluster of unknown pneumonia cases related to Huanan Seafood Market and a new coronavirus was identified as the cause of the pneumonia108, as on 1 April, 2020, there have been 858,371 persons confirmed infected with COVID-19, affecting 202 countries and territories around the world. Although this rapid review is limited by the domination of reports from patients in China, and the patient population is of relative male dominance reflecting the gender imbalance of the Chinese population109, it provides essential information.

In this review, the pooled mean age was 45.8 years. Similar to the MERS-CoV pandemic110, middle-aged adults were the at-risk group for COVID-19 infections in the initial phase, which was different from the H1N1 influenza pandemic where children and adolescents were more frequently affected111. Biological differences may affect the clinical presentations of infections; however, in this review, studies examining the asymptomatic COVID-19 infections or reporting any previous infections were not included. It is suggested that another systematic review should be conducted to compare the age-specific incidence rates between the pre-pandemic and post-pandemic periods, so as to understand the pattern and spread of the disease, and tailor specific strategies in infection control.

Both sexes exhibited clinical presentations similar in symptomatology and frequency to those noted in other severe acute respiratory infections, namely influenza A H1N1112 and SARS113,114. These generally included fever, new onset or exacerbation of cough, breathing difficulty, sore throat and muscle pain. Among critically ill patients usually presented with dyspnoea and chest tightness22,29,39,72, 141 (4.6%) of them with persistent or progressive hypoxia resulted in the requirement of intubation and mechanical ventilation115, while 194 (6.4%) of them required non-invasive ventilation, yielding a total of 11% of patients requiring ventilatory support, which was similar to SARS116.

The major comorbidities identified in this review included hypertension, cardiovascular diseases and diabetes mellitus. Meanwhile, the percentages of patients with chronic renal diseases and cancer were relatively low. These chronic conditions influencing the severity of COVID-19 had also been noted to have similar effects in other respiratory illnesses such as SARS, MERS-CoV and influenza117,118. Higher mortality had been observed among older patients and those with comorbidities.

Early diagnosis of COVID-19 was based on recognition of epidemiological linkages; the presence of typical clinical, laboratory, and radiographic features; and the exclusion of other respiratory pathogens. The case definition had initially been narrow, but was gradually broadened to allow for the detection of more cases, as milder cases and those without epidemiological links to Wuhan or other known cases had been identified119,120. Laboratory investigations among COVID-19 patients did not reveal specific characteristics—lymphopenia and elevated inflammatory markers such as CRP are some of the most common haematological and biochemical abnormalities, which had also been noticed in SARS121. None of these features were specific to COVID-19. Therefore, diagnosis should be confirmed by SARS-CoV–2 specific microbiological and serological studies, although initial management will continue to be based on a clinical and epidemiological assessment of the likelihood of a COVID-19 infection.

Radiology imaging often plays an important role in evaluating patients with acute respiratory distress; however, in this review, radiological findings of SARS-CoV-2 pneumonia were non-specific. Despite chest radiograph usually revealed bilateral involvement and Computed Tomography usually showed bilateral multiple ground-glass opacities or consolidation, there were also patients with normal chest radiograph, implying that chest radiograph might not have high specificity to rule out pneumonia in COVID-19.

Limited clinical data were available for asymptomatic COVID-19 infected persons. Nevertheless, asymptomatic infection could be unknowingly contagious122. From some of the official figures, 6.4% of 150 non-travel-related COVID-19 infections in Singapore123, 39.9% of cases from the Diamond Princess cruise ship in Japan124, and up to 78% of cases in China as extracted on April 1st, 2020, were found to be asymptomatic122. 76% (68/90) studies based on hospital setting which provided care and disease management to symptomatic patients had limited number of asymptomatic cases of COVID-19 infection. This review calls for further studies about clinical data of asymptomatic cases. Asymptomatic infection intensifies the challenges of isolation measures. More global reports are crucially needed to give a better picture of the spectrum of presentations among all COVID-19 infected persons. Also, public health policies including social and physical distancing, monitoring and surveillance, as well as contact tracing, are necessary to reduce the spread of COVID-19.

Concerning potential treatment regime, 62.4% of patients received antivirals or interferons (including oseltamivir, lopinavir-ritonavir, interferon alfa), while 63.9% received antibiotics (such as moxifloxacin, and ceftriaxone). In this review, around one-third of patients were given steroid, suggestive as an adjunct to IFN, or sepsis management. Interferon and antiviral agents such as ribavirin, and lopinavir-ritonavir were used during SARS, and the initial uncontrolled reports then noted resolution of fever and improvement in oxygenation and radiographic appearance113,125,126, without further evidence on its effectiveness. At the time of manuscript preparation, there has been no clear evidence guiding the use of antivirals127. Further research is needed to inform clinicians of the appropriate use of antivirals for specific groups of infected patients.

Limitations of this meta-analysis should be considered. First, a high statistical heterogeneity was found, which could be related to the highly varied sample sizes (9 to 4226 patients) and study designs. Second, variations of follow-up period may miss the event leading to heterogeneity. In fact, some patients were still hospitalized in the included studies. Third, since only a few studies had compared the comorbidities of severe and non-severe patients, sensitivity analysis and subgroup analysis were not conducted. Fourthly, the frequency and severity of signs and symptoms reported in included studies, primarily based on hospitalized COVID-19 patients were over-estimated. Moreover, different cutoffs for abnormal laboratory findings were applied across countries, and counties within the same countries. Lastly, this meta-analysis reviewed only a limited number of reports written in English, with a predominant patient population from China. This review is expected to inform clinicians of the epidemiology of COVID-19 at this early stage. A recent report estimated the number of confirmed cases in China could reach as high as 232,000 (95% CI 161,000, 359,000) with the case definition adopted in 5th Edition. In this connection, further evidence on the epidemiology is in imminent need.

References

  1. 1.

    Oliveira N. Shrimp vendor identified as possible coronavirus ‘patient zero,’ leaked document says. 27 March 2020. New York Daily News. 2020.

  2. 2.

    World Health Organization. Basic protective measures against the new coronavirus (2020). https://www.who.int/emergencies/diseases/novel-coronavirus-2019/advice-for-public. Accessed 7 Oct 2020.

  3. 3.

    Google Trend. When will coronavirus end (2020). https://trends.google.com/trends/explore?date=today%203-m&q=when%20will%20coronavirus%20end,%2Fm%2F01cpyy. Accessed 10 Oct 2020.

  4. 4.

    Worldometer. COVID-19 Coronavirus Pandemic (2020). https://www.worldometers.info/coronavirus/. Accessed 13 Oct 2020.

  5. 5.

    Lu, R. et al. Genomic characterisation and epidemiology of 2019 novel coronavirus: implications for virus origins and receptor binding. Lancet 395(10224), 565–574 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  6. 6.

    Ralph, R. et al. 2019-nCoV (Wuhan virus), a novel Coronavirus: human-to-human transmission, travel-related cases, and vaccine readiness. J. Infect. Dev. Ctries. 14(1), 3–17 (2020).

    CAS  Article  PubMed  Google Scholar 

  7. 7.

    Sun, Z., Thilakavathy, K., Kumar, S. S., He, G. & Liu, S. V. Potential factors influencing repeated SARS outbreaks in China. Int. J. Environ. Res. Public Health 17(5), 1633 (2020).

    CAS  Article  PubMed Central  Google Scholar 

  8. 8.

    Zhao, S. et al. The association between domestic train transportation and novel coronavirus (2019-nCoV) outbreak in China from 2019 to 2020: a data-driven correlational report. Travel Med. Infect. Dis. 33, 101568 (2020).

    Article  PubMed  PubMed Central  Google Scholar 

  9. 9.

    Li, Q. et al. Early transmission dynamics in Wuhan, China, of novel coronavirus-infected pneumonia. N. Engl. J. Med. 382(13), 1199–1207 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  10. 10.

    Chen, J. Pathogenicity and transmissibility of 2019-nCoV-A quick overview and comparison with other emerging viruses. Microbes Infect. 22(2), 69–71 (2020).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  11. 11.

    World Health Organization. Database of publications on coronavirus disease (COVID-19) (2020). https://www.who.int/emergencies/diseases/novel-coronavirus-2019/global-research-on-novel-coronavirus-2019-ncov. Accessed 30 Mar 2020.

  12. 12.

    Wong, C. K. H. et al. Impact of national containment measures on decelerating the increase in daily new cases of COVID-19 in 54 countries and 4 epicenters of the pandemic: comparative observational study. J. Med. Internet Res. 22(7), e19904 (2020).

    Article  PubMed  PubMed Central  Google Scholar 

  13. 13.

    Centers for Disease Control and Prevention. Coronavirus Disease 2019 (COVID-19). Symptoms of Coronavirus (2020).

  14. 14.

    Wan, X., Wang, W., Liu, J. & Tong, T. Estimating the sample mean and standard deviation from the sample size, median, range and/or interquartile range. BMC Med. Res. Methodol. 14(1), 135 (2014).

    Article  PubMed  PubMed Central  Google Scholar 

  15. 15.

    Nyaga, V. N., Arbyn, M. & Aerts, M. Metaprop: a Stata command to perform meta-analysis of binomial data. Arch. Public Health 72(1), 39 (2014).

    Article  PubMed  PubMed Central  Google Scholar 

  16. 16.

    Harris, R. J. et al. metan: fixed- and random-effects meta-analysis. Stata J. 8(1), 3–28 (2008).

    Article  Google Scholar 

  17. 17.

    Xu, X. et al. Imaging and clinical features of patients with 2019 novel coronavirus SARS-CoV-2. Eur. J. Nucl. Med. Mol. Imaging 47(5), 1275–1280 (2020).

    CAS  Article  PubMed  Google Scholar 

  18. 18.

    Cao, J. et al. Clinical features and short-term outcomes of 18 patients with corona virus disease 2019 in intensive care unit. Intensive Care Med. 46(5), 851–853 (2020).

    CAS  Article  PubMed  Google Scholar 

  19. 19.

    Xiong, Y. et al. Clinical and high-resolution CT features of the COVID-19 infection: comparison of the initial and follow-up changes. Invest. Radiol. 55(6), 332–339 (2020).

    CAS  Article  PubMed  Google Scholar 

  20. 20.

    Arentz, M. et al. Characteristics and outcomes of 21 critically ill patients with COVID-19 in Washington state. JAMA 323(16), 1612–1614 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  21. 21.

    Huang, C. et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet 395(10223), 497–506 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  22. 22.

    Guan, W. J. et al. Clinical characteristics of coronavirus disease 2019 in China. N. Engl. J. Med. 382(18), 1708–1720 (2020).

    CAS  Article  PubMed  Google Scholar 

  23. 23.

    Zhao, D. et al. A comparative study on the clinical features of coronavirus 2019 (COVID-19) pneumonia with other pneumonias. Clin. Infect. Dis. 71(15), 756–761 (2020).

    CAS  Article  PubMed  Google Scholar 

  24. 24.

    Xu, X. W. et al. Clinical findings in a group of patients infected with the 2019 novel coronavirus (SARS-Cov-2) outside of Wuhan, China: retrospective case series. BMJ 19(368), m606 (2020).

    Article  Google Scholar 

  25. 25.

    Chan, J. F. et al. A familial cluster of pneumonia associated with the 2019 novel coronavirus indicating person-to-person transmission: a study of a family cluster. Lancet 395(10223), 514–523 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  26. 26.

    Chen, N. et al. Epidemiological and clinical characteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: a descriptive study. Lancet 395(10223), 507–513 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  27. 27.

    Pung, R. et al. Investigation of three clusters of COVID-19 in Singapore: implications for surveillance and response measures. Lancet 395(10229), 1039–1046 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  28. 28.

    Wang, D. et al. Clinical characteristics of 138 hospitalized patients with 2019 novel coronavirus-infected pneumonia in Wuhan, China. JAMA 323(11), 1061–1069 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  29. 29.

    Young, B. E. et al. Epidemiologic features and clinical course of patients infected with SARS-CoV-2 in Singapore. JAMA 323(15), 1488–1494 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  30. 30.

    Chen, H. et al. Clinical characteristics and intrauterine vertical transmission potential of COVID-19 infection in nine pregnant women: a retrospective review of medical records. Lancet 395(10226), 809–815 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  31. 31.

    Huang, W. H. et al. 2019 novel coronavirus disease (COVID-19) in Taiwan: reports of two cases from Wuhan, China. J. Microbiol. Immunol. Infect. 53(3), 481–484 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  32. 32.

    Cheng, S. C. et al. First case of coronavirus disease 2019 (COVID-19) pneumonia in Taiwan. J. Formos. Med. Assoc. 119(3), 747–751 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  33. 33.

    Holshue, M. L. et al. First case of 2019 novel coronavirus in the United States. N. Engl. J. Med. 382(10), 929–936 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  34. 34.

    Wei, M. et al. Novel coronavirus infection in hospitalized infants under 1 year of age in China. JAMA 323(13), 1313–1314 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  35. 35.

    Bernard Stoecklin, S. et al. First cases of coronavirus disease 2019 (COVID-19) in France: surveillance, investigations and control measures, January 2020. Euro Surveill. 25(6), 20–26 (2020).

  36. 36.

    Shi, H. et al. Radiological findings from 81 patients with COVID-19 pneumonia in Wuhan, China: a descriptive study. Lancet Infect. Dis. 20(4), 425–434 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  37. 37.

    Zhu, N. et al. A novel coronavirus from patients with pneumonia in China, 2019. N. Engl. J. Med. 382(8), 727–733 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  38. 38.

    Ghinai, I. et al. First known person-to-person transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the USA. Lancet 395(10230), 1137–1144 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  39. 39.

    Zhou, F. et al. Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study. Lancet 395(10229), 1054–1062 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  40. 40.

    Yang, X. et al. Clinical course and outcomes of critically ill patients with SARS-CoV-2 pneumonia in Wuhan, China: a single-centered, retrospective, observational study. Lancet Respir. Med. 8(5), 475–481 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  41. 41.

    Kim, J. Y. et al. The first case of 2019 novel coronavirus pneumonia imported into Korea from Wuhan, China: implication for infection prevention and control measures. J. Korean Med. Sci. 35(5), e61 (2020).

    Article  PubMed  PubMed Central  Google Scholar 

  42. 42.

    Okada, P. et al. Early transmission patterns of coronavirus disease 2019 (COVID-19) in travellers from Wuhan to Thailand, January 2020. Euro Surveill. 25(8), 6–10 (2020).

  43. 43.

    Arashiro, T., Furukawa, K. & Nakamura, A. COVID-19 in 2 persons with mild upper respiratory tract symptoms on a cruise ship, Japan. Emerg. Infect. Dis. 26(6), 1345–1348 (2020).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  44. 44.

    Lillie, P. J. et al. Novel coronavirus disease (Covid-19): the first two patients in the UK with person to person transmission. J. Infect. 80(5), 578–606 (2020).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  45. 45.

    Tian, S. et al. Pulmonary pathology of early-phase 2019 novel coronavirus (COVID-19) pneumonia in two patients with lung cancer. J. Thorac. Oncol. 15(5), 700–704 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  46. 46.

    Haveri, A. et al. Serological and molecular findings during SARS-CoV-2 infection: the first case study in Finland, January to February 2020. Euro Surveill. 25(11), 16–21 (2020).

  47. 47.

    Nicastri, E. et al. Coronavirus disease (COVID-19) in a paucisymptomatic patient: epidemiological and clinical challenge in settings with limited community transmission, Italy, February 2020. Euro Surveill. 25(11) (2020).

  48. 48.

    Van Cuong, L. et al. The first Vietnamese case of COVID-19 acquired from China. Lancet Infect Dis. 20(4), 408–409 (2020).

    Article  PubMed  PubMed Central  Google Scholar 

  49. 49.

    Spiteri, G. et al. First cases of coronavirus disease 2019 (COVID-19) in the WHO European Region, 24 January to 21 February 2020. Euro Surveill. 25(9), 2–7 (2020).

  50. 50.

    Rothe, C. et al. Transmission of 2019-nCoV infection from an asymptomatic contact in Germany. N. Engl. J. Med. 382(10), 970–971 (2020).

    Article  PubMed  PubMed Central  Google Scholar 

  51. 51.

    Tong, Z. D. et al. Potential presymptomatic transmission of SARS-CoV-2, Zhejiang Province, China, 2020. Emerg. Infect. Dis. 26(5), 1052–1054 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  52. 52.

    Bai, Y. et al. Presumed asymptomatic carrier transmission of COVID-19. JAMA 323(14), 1406–1407 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  53. 53.

    Yu, P., Zhu, J., Zhang, Z. & Han, Y. A familial cluster of infection associated with the 2019 novel coronavirus indicating possible person-to-person transmission during the incubation period. J. Infect. Dis. 221(11), 1757–1761 (2020).

    CAS  Article  Google Scholar 

  54. 54.

    Li, P. et al. Transmission of COVID-19 in the terminal stages of the incubation period: a familial cluster. Int. J. Infect. Dis. 96, 452–453 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  55. 55.

    Tang, A. et al. Detection of novel coronavirus by RT-PCR in stool specimen from asymptomatic child, China. Emerg. Infect. Dis. 26(6), 1337–1339 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  56. 56.

    Kam, K. Q. et al. A well infant with coronavirus disease 2019 with high viral load. Clin. Infect. Dis. 71(15), 847–849 (2020).

    CAS  Article  Google Scholar 

  57. 57.

    Zhou, S., Wang, Y., Zhu, T. & Xia, L. CT Features of Coronavirus Disease 2019 (COVID-19) Pneumonia in 62 Patients in Wuhan. China. AJR Am J Roentgenol. 214(6), 1287–1294 (2020).

    Article  Google Scholar 

  58. 58.

    Zhao, W., Zhong, Z., Xie, X., Yu, Q. & Liu, J. Relation between chest CT findings and clinical conditions of coronavirus disease (COVID-19) pneumonia: a multicenter study. AJR Am. J. Roentgenol. 214(5), 1072–1077 (2020).

    Article  Google Scholar 

  59. 59.

    Cheng, Z. et al. Clinical features and chest CT manifestations of coronavirus disease 2019 (COVID-19) in a single-center study in Shanghai, China. AJR Am. J. Roentgenol. 215(1), 121–126 (2020).

    Article  Google Scholar 

  60. 60.

    Chung, M. et al. CT imaging features of 2019 novel coronavirus (2019-nCoV). Radiology 295(1), 202–207 (2020).

    Article  PubMed  Google Scholar 

  61. 61.

    Liu, K. et al. Clinical characteristics of novel coronavirus cases in tertiary hospitals in Hubei Province. Chin Med J (Engl). 133(9), 1025–1031 (2020).

    Article  PubMed  PubMed Central  Google Scholar 

  62. 62.

    Chang, L. M. et al. Epidemiologic and clinical characteristics of novel coronavirus infections involving 13 patients outside Wuhan, China. JAMA 323(11), 1092–1093 (2020).

    Article  PubMed  PubMed Central  Google Scholar 

  63. 63.

    Team C-NIRS. COVID-19, Australia: Epidemiology Report 7 (Reporting week ending 19:00 AEDT 14 March 2020). Commun. Dis. Intell. 44 (2018).

  64. 64.

    Pan, F. et al. Time course of lung changes at chest CT during recovery from coronavirus disease 2019 (COVID-19). Radiology 295(3), 715–721 (2020).

    Article  PubMed  PubMed Central  Google Scholar 

  65. 65.

    Wang, S. et al. A case report of neonatal 2019 coronavirus disease in China. Clin. Infect. Dis. 71(15), 853–857 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  66. 66.

    Bastola, A. et al. The first 2019 novel coronavirus case in Nepal. Lancet Infect. Dis. 20(3), 279–280 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  67. 67.

    Qiu, H. et al. Clinical and epidemiological features of 36 children with coronavirus disease 2019 (COVID-19) in Zhejiang, China: an observational cohort study. Lancet Infect. Dis. 20(6), 689–696 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  68. 68.

    Zhang, J. J. et al. Clinical characteristics of 140 patients infected with SARS-CoV-2 in Wuhan, China. Allergy 75(7), 1730–1741 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  69. 69.

    Ye, G. et al. Clinical characteristics of severe acute respiratory syndrome coronavirus 2 reactivation. J. Infect. 80(5), e14–e17 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  70. 70.

    Liu, Y. et al. Clinical and biochemical indexes from 2019-nCoV infected patients linked to viral loads and lung injury. Sci. China Life Sci. 63(3), 364–374 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  71. 71.

    Chen, T. et al. Clinical characteristics of 113 deceased patients with coronavirus disease 2019: retrospective study. BMJ 26(368), m1091 (2020).

    Article  Google Scholar 

  72. 72.

    Guan, W. J. et al. Comorbidity and its impact on 1590 patients with COVID-19 in China: a nationwide analysis. Eur Respir J. 55(5), 2000547 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  73. 73.

    Wong, H. Y. F. et al. Frequency and Distribution of Chest Radiographic Findings in Patients Positive for COVID-19. Radiology 296(2), E72–E78 (2020).

    Article  PubMed  Google Scholar 

  74. 74.

    Xu, T. et al. Clinical features and dynamics of viral load in imported and non-imported patients with COVID-19. Int J Infect Dis. 94, 68–71 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  75. 75.

    Shen, C. et al. Treatment of 5 critically ill patients with COVID-19 with convalescent plasma. JAMA 323(16), 1582–1589 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  76. 76.

    Kimball, A. et al. Asymptomatic and presymptomatic SARS-CoV-2 infections in residents of a long-term care skilled nursing facility—King County, Washington, March 2020. Morb. Mortal. Wkly. Rep. 69(13), 377–381 (2020).

    CAS  Article  Google Scholar 

  77. 77.

    Team CC-R. Severe outcomes among patients with coronavirus disease 2019 (COVID-19)—United States, February 12-March 16, 2020. Morb. Mortal. Wkly. Rep. 69(12), 343–346 (2020).

    Article  Google Scholar 

  78. 78.

    Wu, J. et al. Clinical characteristics of imported cases of coronavirus disease 2019 (COVID-19) in Jiangsu Province: a multicenter descriptive study. Clin. Infect. Dis. 71(15), 706–712 (2020).

    CAS  Article  PubMed  Google Scholar 

  79. 79.

    Yang, W. et al. Clinical characteristics and imaging manifestations of the 2019 novel coronavirus disease (COVID-19): a multi-center study in Wenzhou city, Zhejiang, China. J. Infect. 80(4), 388–393 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  80. 80.

    Zhu, L. et al. Successful recovery of COVID-19 pneumonia in a renal transplant recipient with long-term immunosuppression. Am. J. Transplant. 20(7), 1859–1863 (2020).

    CAS  Article  PubMed  Google Scholar 

  81. 81.

    Zhu, W. et al. Initial clinical features of suspected coronavirus disease in two emergency departments outside of Hubei, China. J. Med. Virol. 92, 1525–1532 (2019).

    Article  CAS  Google Scholar 

  82. 82.

    Wu, C. et al. Risk factors associated with acute respiratory distress syndrome and death in patients with coronavirus disease 2019 pneumonia in Wuhan, China. JAMA Intern. Med. 180(7), 934–943 (2020).

    CAS  Article  PubMed  Google Scholar 

  83. 83.

    Wang, Z., Chen, X., Lu, Y., Chen, F. & Zhang, W. Clinical characteristics and therapeutic procedure for four cases with 2019 novel coronavirus pneumonia receiving combined Chinese and Western medicine treatment. Biosci. Trends 14(1), 64–68 (2020).

    CAS  Article  PubMed  Google Scholar 

  84. 84.

    Wang, Y. et al. Clinical outcomes in 55 patients with severe acute respiratory syndrome coronavirus 2 who were asymptomatic at hospital admission in Shenzhen, China. J. Infect. Dis. 221(11), 1770–1774 (2020).

    CAS  Article  PubMed  Google Scholar 

  85. 85.

    Wan, S. et al. Clinical features and treatment of COVID-19 patients in northeast Chongqing. J. Med.. Virol. 92(7), 797–806 (2020).

    CAS  Article  PubMed  Google Scholar 

  86. 86.

    Tian, S. et al. Characteristics of COVID-19 infection in Beijing. J. Infect. 80(4), 401–406 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  87. 87.

    Sun, D. et al. Clinical features of severe pediatric patients with coronavirus disease 2019 in Wuhan: a single center’s observational study. World J. Pediatr. 16(3), 251–259 (2020).

    CAS  Article  PubMed  Google Scholar 

  88. 88.

    Song, F. et al. Emerging 2019 novel coronavirus (2019-nCoV) pneumonia. Radiology 295(1), 210–217 (2020).

    Article  PubMed  Google Scholar 

  89. 89.

    Hu, Z. et al. Clinical characteristics of 24 asymptomatic infections with COVID-19 screened among close contacts in Nanjing, China. Sci. China Life Sci. 63(5), 706–711 (2020).

    CAS  Article  PubMed  Google Scholar 

  90. 90.

    Qu, R. et al. Platelet-to-lymphocyte ratio is associated with prognosis in patients with coronavirus disease-19. J. Med. Virol. 92, 1533–1541 (2020).

    CAS  Article  Google Scholar 

  91. 91.

    Qian, G. Q. et al. Epidemiologic and clinical characteristics of 91 hospitalized patients with COVID-19 in Zhejiang, China: a retrospective, multi-centre case series. QJM 113(7), 474–481 (2020).

    CAS  Article  PubMed  Google Scholar 

  92. 92.

    Mo, P. et al. Clinical characteristics of refractory COVID-19 pneumonia in Wuhan, China. Clin. Infect. Dis. (2020).

  93. 93.

    Liu, W. et al. Analysis of factors associated with disease outcomes in hospitalized patients with 2019 novel coronavirus disease. Chin Med. J. (Engl) 133(9), 1032–1038 (2020).

    Article  Google Scholar 

  94. 94.

    Liu, K., Chen, Y., Lin, R. & Han, K. Clinical features of COVID-19 in elderly patients: A comparison with young and middle-aged patients. J. Infect. 80(6), e14–e18 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  95. 95.

    Liu, F. et al. Patients of COVID-19 may benefit from sustained Lopinavir-combined regimen and the increase of Eosinophil may predict the outcome of COVID-19 progression. Int. J. Infect. Dis. 95, 183–191 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  96. 96.

    Liu, D. et al. Pregnancy and perinatal outcomes of women with coronavirus disease (COVID-19) pneumonia: a preliminary analysis. AJR Am. J. Roentgenol. 215(1), 127–132 (2020).

    Article  PubMed  Google Scholar 

  97. 97.

    Guillen, E. et al. Case report of COVID-19 in a kidney transplant recipient: does immunosuppression alter the clinical presentation?. Am. J. Transplant. 20(7), 1875–1878 (2020).

    CAS  Article  PubMed  Google Scholar 

  98. 98.

    Dong, X. et al. Eleven faces of coronavirus disease 2019. Allergy 75(7), 1699–1709 (2020).

    CAS  Article  PubMed  Google Scholar 

  99. 99.

    Fan, C. et al. Perinatal transmission of COVID-19 associated SARS-CoV-2: should we worry? Clin. Infect. Dis. (2020).

  100. 100.

    Chen, R. et al. Safety and efficacy of different anesthetic regimens for parturients with COVID-19 undergoing Cesarean delivery: a case series of 17 patients. Can. J. Anaesth. 67(6), 655–663 (2020).

    CAS  Article  PubMed  Google Scholar 

  101. 101.

    Chen, L. et al. RNA based mNGS approach identifies a novel human coronavirus from two individual pneumonia cases in 2019 Wuhan outbreak. Emerg. Microbes Infect. 9(1), 313–319 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  102. 102.

    Chen, J. et al. Clinical progression of patients with COVID-19 in Shanghai, China. J. Infect. 80(5), e1–e6 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  103. 103.

    Ding, Q., Lu, P., Fan, Y., Xia, Y. & Liu, M. The clinical characteristics of pneumonia patients coinfected with 2019 novel coronavirus and influenza virus in Wuhan, China. J. Med. Virol. 92, 1549–1555 (2020).

    CAS  Article  Google Scholar 

  104. 104.

    Covid-19 National Emergency Response Center E & Case Management Team KCfDC, Prevention. Early epidemiological and clinical characteristics of 28 cases of coronavirus disease in South Korea. Osong Public Health Res. Perspect. 11(1), 8–14 (2020).

    Article  Google Scholar 

  105. 105.

    Li, Y., Guo, F., Cao, Y., Li, L. & Guo, Y. Insight into COVID-2019 for pediatricians. Pediatr. Pulmonol. 55(5), E1–E4 (2020).

    Article  PubMed  PubMed Central  Google Scholar 

  106. 106.

    Ai, J. W., Zhang, Y., Zhang, H. C., Xu, T. & Zhang, W. H. Era of molecular diagnosis for pathogen identification of unexplained pneumonia, lessons to be learned. Emerg Microbes Infect. 9(1), 597–600 (2020).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  107. 107.

    Stang, A. Critical evaluation of the Newcastle-Ottawa scale for the assessment of the quality of nonrandomized studies in meta-analyses. Eur. J. Epidemiol. 25(9), 603–605 (2010).

    Article  PubMed  Google Scholar 

  108. 108.

    Khan N. New virus discovered by Chinese scientists investigating pneumonia outbreak. Wall Street J. (2020).

  109. 109.

    国家统计局 (National Bureau of Statistics). 2019 年国民经济运行总体平稳 发展主要预期目标较好实现 (In 2019, the overall stable development of the national economic operation is expected to achieve the main goals (2020). http://www.stats.gov.cn/tjsj/zxfb/202001/t20200117_1723383.html. Accessed 30 Mar 2020.

  110. 110.

    Park, J. E., Jung, S., Kim, A. & Park, J. E. MERS transmission and risk factors: a systematic review. BMC Public Health 18(1), 574 (2018).

    Article  PubMed  PubMed Central  Google Scholar 

  111. 111.

    Van Kerkhove, M. D. et al. Risk factors for severe outcomes following 2009 influenza A (H1N1) infection: a global pooled analysis. PLoS Med. 8(7), e1001053 (2011).

    Article  PubMed  PubMed Central  Google Scholar 

  112. 112.

    Wang, C. et al. Epidemiological and clinical characteristics of the outbreak of 2009 pandemic influenza A (H1N1) at a middle school in Luoyang, China. Public Health 126(4), 289–294 (2012).

    CAS  Article  PubMed  Google Scholar 

  113. 113.

    Lee, N. et al. A major outbreak of severe acute respiratory syndrome in Hong Kong. N. Engl. J. Med. 348(20), 1986–1994 (2003).

    Article  PubMed  Google Scholar 

  114. 114.

    Booth, C. M. et al. Clinical features and short-term outcomes of 144 patients with SARS in the greater Toronto area. JAMA 289(21), 2801–2809 (2003).

    CAS  Article  PubMed  Google Scholar 

  115. 115.

    Fowler, R. A. et al. Critically ill patients with severe acute respiratory syndrome. JAMA 290(3), 367–373 (2003).

    Article  PubMed  Google Scholar 

  116. 116.

    Christian, M. D., Poutanen, S. M., Loutfy, M. R., Muller, M. P. & Low, D. E. Severe acute respiratory syndrome. Clin Infect Dis. 38(10), 1420–1427 (2004).

    Article  PubMed  PubMed Central  Google Scholar 

  117. 117.

    Mertz, D. et al. Populations at risk for severe or complicated influenza illness: systematic review and meta-analysis. BMJ 23(347), f5061 (2013).

    Article  Google Scholar 

  118. 118.

    Badawi, A. & Ryoo, S. G. Prevalence of comorbidities in the Middle East respiratory syndrome coronavirus (MERS-CoV): a systematic review and meta-analysis. Int. J. Infect. Dis. 49, 129–133 (2016).

    Article  PubMed  PubMed Central  Google Scholar 

  119. 119.

    Tsang, T. K. et al. Effect of changing case definitions for COVID-19 on the epidemic curve and transmission parameters in mainland China: a modelling study. Lancet Public Health. 5(5), e289–e296 (2020).

    Article  PubMed  PubMed Central  Google Scholar 

  120. 120.

    国家卫生健康委办公厅 (Office of National Health Comission). 新型冠状病毒肺炎诊疗方案 (试行第七版) (Clinical Guideline for Novel Coronavirus Pneumonia—Interim 7th Edition) (2020).

  121. 121.

    File, T. M. Jr. & Tsang, K. W. Severe acute respiratory syndrome: pertinent clinical characteristics and therapy. Treat. Respir. Med. 4(2), 95–106 (2005).

    Article  PubMed  PubMed Central  Google Scholar 

  122. 122.

    Day, M. Covid-19: four fifths of cases are asymptomatic, China figures indicate. BMJ 2(369), m1375 (2020).

    Article  Google Scholar 

  123. 123.

    Wei, W. E. et al. Presymptomatic transmission of SARS-CoV-2—Singapore, January 23–March 16, 2020. Morb. Mortal. Wkly. Rep. 69(14), 411–415 (2020).

    CAS  Article  Google Scholar 

  124. 124.

    Mizumoto, K., Kagaya, K., Zarebski, A. & Chowell, G. Estimating the asymptomatic proportion of coronavirus disease 2019 (COVID-19) cases on board the Diamond Princess cruise ship, Yokohama, Japan, 2020. Euro Surveill. 25(10), 2000180 (2020).

    Article  PubMed Central  Google Scholar 

  125. 125.

    Poutanen, S. M. et al. Identification of severe acute respiratory syndrome in Canada. N. Engl. J .Med. 348(20), 1995–2005 (2003).

    Article  PubMed  Google Scholar 

  126. 126.

    Tsang, K. W. et al. A cluster of cases of severe acute respiratory syndrome in Hong Kong. N. Engl. J. Med. 348(20), 1977–1985 (2003).

    Article  PubMed  Google Scholar 

  127. 127.

    Cao, B. et al. A trial of Lopinavir–Ritonavir in adults hospitalized with severe covid-19. N. Engl. J. Med. 382(19), 1787–1799 (2020).

    Article  PubMed  Google Scholar 

Download references

Acknowledgements

None.

Funding

There was no funding source for this study.

Author information

Affiliations

Authors

Contributions

C.W., J.W. and A.W. contributed equally to all aspects of study design, conduct, data interpretation, and the writing of the manuscript. C.W., E.T. and C.H.A. contributed to eligibility screening, data extraction from eligible studies, and data analysis and interpretation.

Corresponding author

Correspondence to Abraham K. C. Wai.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher's note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Wong, C.K.H., Wong, J.Y., Tang, E.H.M. et al. Clinical presentations, laboratory and radiological findings, and treatments for 11,028 COVID-19 patients: a systematic review and meta-analysis. Sci Rep 10, 19765 (2020). https://doi.org/10.1038/s41598-020-74988-9

Download citation

Further reading

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links