Occurrence and transmission potential of asymptomatic and presymptomatic SARS-CoV-2 infections: A living systematic review and meta-analysis

Autoři: Diana Buitrago-Garcia aff001;  Dianne Egli-Gany aff001;  Michel J. Counotte aff001;  Stefanie Hossmann aff001;  Hira Imeri aff001;  Aziz Mert Ipekci aff001;  Georgia Salanti aff001;  Nicola Low aff001
Působiště autorů: Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland aff001;  Graduate School of Health Sciences, University of Bern, Bern, Switzerland aff002
Vyšlo v časopise: Occurrence and transmission potential of asymptomatic and presymptomatic SARS-CoV-2 infections: A living systematic review and meta-analysis. PLoS Med 17(9): e32767. doi:10.1371/journal.pmed.1003346
Kategorie: Research Article
doi: 10.1371/journal.pmed.1003346



There is disagreement about the level of asymptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We conducted a living systematic review and meta-analysis to address three questions: (1) Amongst people who become infected with SARS-CoV-2, what proportion does not experience symptoms at all during their infection? (2) Amongst people with SARS-CoV-2 infection who are asymptomatic when diagnosed, what proportion will develop symptoms later? (3) What proportion of SARS-CoV-2 transmission is accounted for by people who are either asymptomatic throughout infection or presymptomatic?

Methods and findings

We searched PubMed, Embase, bioRxiv, and medRxiv using a database of SARS-CoV-2 literature that is updated daily, on 25 March 2020, 20 April 2020, and 10 June 2020. Studies of people with SARS-CoV-2 diagnosed by reverse transcriptase PCR (RT-PCR) that documented follow-up and symptom status at the beginning and end of follow-up or modelling studies were included. One reviewer extracted data and a second verified the extraction, with disagreement resolved by discussion or a third reviewer. Risk of bias in empirical studies was assessed with an adapted checklist for case series, and the relevance and credibility of modelling studies were assessed using a published checklist. We included a total of 94 studies. The overall estimate of the proportion of people who become infected with SARS-CoV-2 and remain asymptomatic throughout infection was 20% (95% confidence interval [CI] 17–25) with a prediction interval of 3%–67% in 79 studies that addressed this review question. There was some evidence that biases in the selection of participants influence the estimate. In seven studies of defined populations screened for SARS-CoV-2 and then followed, 31% (95% CI 26%–37%, prediction interval 24%–38%) remained asymptomatic. The proportion of people that is presymptomatic could not be summarised, owing to heterogeneity. The secondary attack rate was lower in contacts of people with asymptomatic infection than those with symptomatic infection (relative risk 0.35, 95% CI 0.10–1.27). Modelling studies fit to data found a higher proportion of all SARS-CoV-2 infections resulting from transmission from presymptomatic individuals than from asymptomatic individuals. Limitations of the review include that most included studies were not designed to estimate the proportion of asymptomatic SARS-CoV-2 infections and were at risk of selection biases; we did not consider the possible impact of false negative RT-PCR results, which would underestimate the proportion of asymptomatic infections; and the database does not include all sources.


The findings of this living systematic review suggest that most people who become infected with SARS-CoV-2 will not remain asymptomatic throughout the course of the infection. The contribution of presymptomatic and asymptomatic infections to overall SARS-CoV-2 transmission means that combination prevention measures, with enhanced hand hygiene, masks, testing tracing, and isolation strategies and social distancing, will continue to be needed.

Klíčová slova:

COVID 19 – Database searching – China – Medical risk factors – Respiratory infections – Reverse transcriptase-polymerase chain reaction – SARS CoV 2 – Virus testing


1. Oran DP, Topol EJ. Prevalence of Asymptomatic Sars-Cov-2 Infection: A Narrative Review. Ann Intern Med. 2020. Epub 2020/06/04. doi: 10.7326/M20-3012 32491919.

2. World Health Organization. Coronavirus Disease 2019 (Covid-19) Situation Report—73. Geneva: 2020.

3. Lipsitch M, Swerdlow DL, Finelli L. Defining the Epidemiology of Covid-19—Studies Needed. N Engl J Med. 2020. Epub 2020/02/20. doi: 10.1056/NEJMp2002125 32074416.

4. Elliott JH, Turner T, Clavisi O, Thomas J, Higgins JP, Mavergames C, et al. Living Systematic Reviews: An Emerging Opportunity to Narrow the Evidence-Practice Gap. PLoS Med. 2014;11(2):e1001603. doi: 10.1371/journal.pmed.1001603 24558353; PubMed Central PMCID: PMC3928029.

5. Thomas J, Noel-Storr A, Marshall I, Wallace B, McDonald S, Mavergames C, et al. Living Systematic Reviews: 2. Combining Human and Machine Effort. J Clin Epidemiol. 2017;91:31–7. Epub 2017/09/16. doi: 10.1016/j.jclinepi.2017.08.011 28912003.

6. Rapid Reviews to Strengthen Health Policy and Systems: A Practical Guide. Geneva: World Health Organization; 2017 [cited 2020 Jul 27]. Available from: https://apps.who.int/iris/bitstream/handle/10665/258698/9789241512763-eng.pdf;sequence=1.

7. Buitrago-Garcia D, Egli-Gany D, Counotte M, Hossmann S, Imeri H, Salanti G, et al. The Role of Asymptomatic Sars-Cov-2 Infections: Rapid Living Systematic Review and Meta-Analysis. Version 1. medRxiv [Preprint]. 2020 [cited 2020 Jul 27]. Available from: https://doi.org/10.1101/2020.04.25.20079103

8. Buitrago-Garcia D, Egli-Gany D, Counotte M, Hossmann S, Imeri H, Salanti G, et al. The Role of Asymptomatic Sars-Cov-2 Infections: Rapid Living Systematic Review and Meta-Analysis. Version 2. medRxiv [Preprint]. 2020 [cited 2020 Jul 27]. Available from: https://doi.org/10.1101/2020.04.25.20079103

9. Liberati A, Altman DG, Tetzlaff J, Mulrow C, Gotzsche PC, Ioannidis JP, et al. The Prisma Statement for Reporting Systematic Reviews and Meta-Analyses of Studies That Evaluate Health Care Interventions: Explanation and Elaboration. PLoS Med. 2009;6(7):e1000100. doi: 10.1371/journal.pmed.1000100 19621070

10. Counotte M, Imeri H, Ipekci M, Low N. Covid-19 Living Evidence. Bern: Institute of Social and Preventive Medicine, University of Bern; 2020 [cited 2020 May 9]. Available from: https://ispmbern.github.io/covid-19/living-review/

11. Joanna Briggs Institute. The Joanna Briggs Institute Critical Appraisal Tools for Use in JBI Systematic Reviews–Checklist for Case Series. 2017 [cited 2020 Aug 31]. Available from: https://joannabriggs.org/sites/default/files/2019-05/JBI_Critical_Appraisal-Checklist_for_Case_Series2017_0.pdf

12. Boyle MH. Guidelines for Evaluating Prevalence Studies. Evid Based Ment Health. 1998;1(2):37–40.

13. Jaime Caro J, Eddy DM, Kan H, Kaltz C, Patel B, Eldessouki R, et al. Questionnaire to Assess Relevance and Credibility of Modeling Studies for Informing Health Care Decision Making: An Ispor-Amcp-Npc Good Practice Task Force Report. Value Health. 2014;17(2):174–82. doi: 10.1016/j.jval.2014.01.003 24636375.

14. Balduzzi S, Rucker G, Schwarzer G. How to Perform a Meta-Analysis with R: A Practical Tutorial. Evid Based Ment Health. 2019;22(4):153–60. Epub 2019/09/30. doi: 10.1136/ebmental-2019-300117 31563865.

15. Newcombe RG. Two-Sided Confidence Intervals for the Single Proportion: Comparison of Seven Methods. Stat Med. 1998;17(8):857–72. doi: 10.1002/(sici)1097-0258(19980430)17:8<857::aid-sim777>3.0.co;2-e 9595616

16. Riley RD, Higgins JP, Deeks JJ. Interpretation of Random Effects Meta-Analyses. BMJ. 2011;342:d549. doi: 10.1136/bmj.d549 21310794

17. Bai Y, Yao L, Wei T, Tian F, Jin DY, Chen L, et al. Presumed Asymptomatic Carrier Transmission of Covid-19. JAMA. 2020;54(0):E017. doi: 10.1001/jama.2020.2565 32083643

18. Chan JF, Yuan S, Kok KH, To KK, Chu H, Yang J, 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. 2020;395(10223):514–23. Epub 2020/01/28. doi: 10.1016/S0140-6736(20)30154-9 31986261; PubMed Central PMCID: 7159286.

19. Ferretti L, Wymant C, Kendall M, Zhao L, Nurtay A, Abeler-Dorner L, et al. Quantifying Sars-Cov-2 Transmission Suggests Epidemic Control with Digital Contact Tracing. Science. 2020;368(6491):2020.03.08.20032946. Epub 2020/04/03. doi: 10.1126/science.abb6936 32234805; PubMed Central PMCID: 7164555.

20. Ganyani T, Kremer C, Chen D, Torneri A, Faes C, Wallinga J, et al. Estimating the Generation Interval for Coronavirus Disease (Covid-19) Based on Symptom Onset Data, March 2020. Euro Surveill. 2020;25(17):2020.03.05.20031815. Epub 2020/05/07. doi: 10.2807/1560-7917.ES.2020.25.17.2000257 32372755; PubMed Central PMCID: 7201952.

21. Hu Z, Song C, Xu C, Jin G, Chen Y, Xu X, et al. Clinical Characteristics of 24 Asymptomatic Infections with Covid-19 Screened among Close Contacts in Nanjing, China. Sci China Life Sci. 2020;63(5):706–11. Epub 2020/03/09. doi: 10.1007/s11427-020-1661-4 32146694; PubMed Central PMCID: 7088568.

22. Liao J, Fan S, Chen J, Wu J, Xu S, Guo Y, et al. Epidemiological and Clinical Characteristics of Covid-19 in Adolescents and Young Adults. medRxiv [Preprint]. 2020. Available from: https://www.medrxiv.org/content/10.1101/2020.03.10.20032136v1

23. Luo SH, Liu W, Liu ZJ, Zheng XY, Hong CX, Liu ZR, et al. A Confirmed Asymptomatic Carrier of 2019 Novel Coronavirus. Chin Med J (Engl). 2020;133(9):1123–5. Epub 2020/03/10. doi: 10.1097/CM9.0000000000000798 32149768.

24. 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. 2020;25(10). Epub 2020/03/19. doi: 10.2807/1560-7917.ES.2020.25.10.2000180 32183930; PubMed Central PMCID: 7078829.

25. Nishiura H, Kobayashi T, Suzuki A, Jung SM, Hayashi K, Kinoshita R, et al. Estimation of the Asymptomatic Ratio of Novel Coronavirus Infections (Covid-19). Int J Infect Dis. 2020. doi: 10.1016/j.ijid.2020.03.020 32179137

26. Qian G, Yang N, Ma AHY, Wang L, Li G, Chen X, et al. A Covid-19 Transmission within a Family Cluster by Presymptomatic Infectors in China. Clin Infect Dis. 2020;71(15):861–862. doi: 10.1093/cid/ciaa316 32201889

27. Tabata S, Imai K, Kawano S, Ikeda M, Kodama T, Miyoshi K, et al. Non-Severe Vs Severe Symptomatic Covid-19: 104 Cases from the Outbreak on the Cruise Ship 'Diamond Princess' in Japan. medRxiv [Preprint]. 2020 [cited 2020 Jul 27]. doi: 10.1101/2020.03.18.20038125

28. Arima Y, Shimada T, Suzuki M, Suzuki T, Kobayashi Y, Tsuchihashi Y, et al. Severe Acute Respiratory Syndrome Coronavirus 2 Infection among Returnees to Japan from Wuhan, China, 2020. Emerg Infect Dis. 2020;26(7). Epub 2020/04/11. doi: 10.3201/eid2607.200994 32275498.

29. Breslin N, Baptiste C, Gyamfi-Bannerman C, Miller R, Martinez R, Bernstein K, et al. Covid-19 Infection among Asymptomatic and Symptomatic Pregnant Women: Two Weeks of Confirmed Presentations to an Affiliated Pair of New York City Hospitals. Am J Obstet Gynecol MFM. 2020:100118. Epub 2020/04/16. doi: 10.1016/j.ajogmf.2020.100118 32292903; PubMed Central PMCID: PMC7144599.

30. Le TQM, Takemura T, Moi ML, Nabeshima T, Nguyen LKH, Hoang VMP, et al. Severe Acute Respiratory Syndrome Coronavirus 2 Shedding by Travelers, Vietnam, 2020. Emerg Infect Dis. 2020. doi: 10.3201/eid2607.200591 32240079

31. Chang L, Zhao L, Gong H, Wang L, Wang L. Severe Acute Respiratory Syndrome Coronavirus 2 Rna Detected in Blood Donations. Emerg Infect Dis. 2020;26(7). Epub 2020/04/04. doi: 10.3201/eid2607.200839 32243255.

32. Danis K, Epaulard O, Benet T, Gaymard A, Campoy S, Bothelo-Nevers E, et al. Cluster of Coronavirus Disease 2019 (Covid-19) in the French Alps, 2020. Clin Infect Dis. 2020. Epub 2020/04/12. doi: 10.1093/cid/ciaa424 32277759; PubMed Central PMCID: 7184384.

33. He X, Lau EHY, Wu P, Deng X, Wang J, Hao X, et al. Temporal Dynamics in Viral Shedding and Transmissibility of Covid-19. Nat Med. 2020. Epub 2020/04/17. doi: 10.1038/s41591-020-0869-5 32296168.

34. Hoehl S, Rabenau H, Berger A, Kortenbusch M, Cinatl J, Bojkova D, et al. Evidence of Sars-Cov-2 Infection in Returning Travelers from Wuhan, China. N Engl J Med. 2020;382(13):1278–80. Epub 2020/02/19. doi: 10.1056/NEJMc2001899 32069388; PubMed Central PMCID: 7121749.

35. Kimball A, Hatfield KM, Arons M, James A, Taylor J, Spicer K, et al. Asymptomatic and Presymptomatic Sars-Cov-2 Infections in Residents of a Long-Term Care Skilled Nursing Facility—King County, Washington, March 2020. MMWR Morb Mortal Wkly Rep. 2020;69(13):377–81. Epub 2020/04/03. doi: 10.15585/mmwr.mm6913e1 32240128; PubMed Central PMCID: PMC7119514

36. Luo L, Liu D, Liao X-l, Wu X-b, Jing Q-l, Zheng J-z, et al. Modes of Contact and Risk of Transmission in Covid-19 among Close Contacts. bioRxiv [Preprint]. 2020 [cited 2020 Jul 27]. Available from: https://www.medrxiv.org/content/10.1101/2020.03.24.20042606v1

37. Lytras T, Dellis G, Flountzi A, Hatzianastasiou S, Nikolopoulou G, Tsekou K, et al. High Prevalence of Sars-Cov-2 Infection in Repatriation Flights to Greece from Three European Countries. J Travel Med. 2020. Epub 2020/04/17. doi: 10.1093/jtm/taaa054 32297940; PubMed Central PMCID: 7184451.

38. Meng H, Xiong R, He R, Lin W, Hao B, Zhang L, et al. Ct Imaging and Clinical Course of Asymptomatic Cases with Covid-19 Pneumonia at Admission in Wuhan, China. J Infect. 2020. Epub 2020/04/16. doi: 10.1016/j.jinf.2020.04.004 32294504; PubMed Central PMCID: 7152865.

39. Pongpirul WA, Mott JA, Woodring JV, Uyeki TM, MacArthur JR, Vachiraphan A, et al. Clinical Characteristics of Patients Hospitalized with Coronavirus Disease, Thailand. Emerg Infect Dis. 2020;26(7). Epub 2020/04/09. doi: 10.3201/eid2607.200598 32267826.

40. Qiu H, Wu J, Hong L, Luo Y, Song Q, Chen D. Clinical and Epidemiological Features of 36 Children with Coronavirus Disease 2019 (Covid-19) in Zhejiang, China: An Observational Cohort Study. Lancet Infect Dis. 2020. Epub 2020/03/30. doi: 10.1016/S1473-3099(20)30198-5 32220650; PubMed Central PMCID: PMC7158906.

41. See KC, Liew SM, Ng DCE, Chew EL, Khoo EM, Sam CH, et al. Covid-19: Four Paediatric Cases in Malaysia. Int J Infect Dis. 2020;94:125–7. Epub 2020/04/19. doi: 10.1016/j.ijid.2020.03.049 32304822; PubMed Central PMCID: PMC7158792.

42. Tan YP, Tan BY, Pan J, Wu J, Zeng SZ, Wei HY. Epidemiologic and Clinical Characteristics of 10 Children with Coronavirus Disease 2019 in Changsha, China. J Clin Virol. 2020;127(NA):104353. Epub 2020/04/18. doi: 10.1016/j.jcv.2020.104353 32302953; PubMed Central PMCID: PMC7195108.

43. Tian S, Wu M, Chang Z, Wang Y, Zhou G, Zhang W, et al. Epidemiological Investigation and Intergenerational Clinical Characteristics of 24 Covid-19 Patients Associated with Supermarket Cluster. bioRxiv [Preprint]. 2020 [cited 2020 Jul 27]. doi: 10.1101/2020.04.11.20058891

44. Tong ZD, Tang A, Li KF, Li P, Wang HL, Yi JP, et al. Potential Presymptomatic Transmission of Sars-Cov-2, Zhejiang Province, China, 2020. Emerg Infect Dis. 2020;26(5):1052–4. Epub 2020/02/25. doi: 10.3201/eid2605.200198 32091386; PubMed Central PMCID: PMC7181913.

45. Wang X, Fang J, Zhu Y, Chen L, Ding F, Zhou R, et al. Clinical Characteristics of Non-Critically Ill Patients with Novel Coronavirus Infection (Covid-19) in a Fangcang Hospital. Clin Microbiol Infect. 2020. Epub 2020/04/07. doi: 10.1016/j.cmi.2020.03.032 PubMed Central PMCID: PMC7195539. 32251842

46. Wang Y, Liu Y, Liu L, Wang X, Luo N, Ling L. Clinical Outcome of 55 Asymptomatic Cases at the Time of Hospital Admission Infected with Sars-Coronavirus-2 in Shenzhen, China. J Infect Dis. 2020. Epub 2020/03/18. doi: 10.1093/infdis/jiaa119 32179910; PubMed Central PMCID: PMC7184401.

47. Wang Z, Ma W, Zheng X, Wu G, Zhang R. Household Transmission of Sars-Cov-2. J Infect. 2020. Epub 2020/04/14. doi: 10.1016/j.jinf.2020.03.040 32283139; PubMed Central PMCID: PMC7151261.

48. Yang N, Shen Y, Shi C, Ma AHY, Zhang X, Jian X, et al. In-Flight Transmission Cluster of Covid-19: A Retrospective Case Series. bioRxiv [Preprint]. 2020 [cited 2020 Jul 27]. doi: 10.1101/2020.03.28.20040097

49. Ye F, Xu S, Rong Z, Xu R, Liu X, Deng P, et al. Delivery of Infection from Asymptomatic Carriers of Covid-19 in a Familial Cluster. Int J Infect Dis. 2020;94:133–8. Epub 2020/04/06. doi: 10.1016/j.ijid.2020.03.042 32247826; PubMed Central PMCID: PMC7129961.

50. Zhang J, Tian S, Lou J, Chen Y. Familial Cluster of Covid-19 Infection from an Asymptomatic. Crit Care. 2020. doi: 10.1186/s13054-020-2817-7 32220236

51. Zhang W. Estimating the Presymptomatic Transmission of Covid19 Using Incubation Period and Serial Interval Data. bioRxiv [Preprint]. 2020 [cited 2020 Jul 27]. doi: 10.1101/2020.04.02.20051318

52. Zhou X, Li Y, Li T, Zhang W. Follow-up of Asymptomatic Patients with Sars-Cov-2 Infection. Clin Microbiol Infect. 2020. Epub 2020/04/03. doi: 10.1016/j.cmi.2020.03.024 32234453.

53. Zou L, Ruan F, Huang M, Liang L, Huang H, Hong Z, et al. Sars-Cov-2 Viral Load in Upper Respiratory Specimens of Infected Patients. N Engl J Med. 2020;382(12):1177–9. Epub 2020/02/20. doi: 10.1056/NEJMc2001737 32074444; PubMed Central PMCID: PMC7121626.

54. Alshami AA, Alattas RA, Anan HF, Al Qahtani HS, Al Mulhim MA, Alahilmi AA, et al. Silent Disease and Loss of Taste and Smell Are Common Manifestations of Sars-Cov-2 Infection in a Quarantine Facility: First Report from Saudi Arabia. medRxiv [Preprint]. 2020 [cited 2020 Jul 27]. doi: 10.1101/2020.05.13.20100222

55. Al-Shamsi HO, Coomes EA, Alrawi S. Screening for Covid-19 in Asymptomatic Patients with Cancer in a Hospital in the United Arab Emirates. JAMA Oncol. 2020. doi: 10.1001/jamaoncol.2020.2548 32459297

56. Andrikopoulou M, Madden N, Wen T, Aubey JJ, Aziz A, Baptiste CD, et al. Symptoms and Critical Illness among Obstetric Patients with Coronavirus Disease 2019 (Covid-19) Infection. Obstet Gynecol. 2020. doi: 10.1097/AOG.0000000000003996 32459701

57. Angelo Vaira L, Hopkins C, Salzano G, Petrocelli M, Melis A, Cucurullo M, et al. Olfactory and Gustatory Function Impairment in Covid-19 Patients: Italian Objective Multicenter-Study. Head Neck. 2020. doi: 10.1002/hed.26269 32437022

58. Arons MM, Hatfield KM, Reddy SC, Kimball A, James A, Jacobs JR, et al. Presymptomatic Sars-Cov-2 Infections and Transmission in a Skilled Nursing Facility. N Engl J Med. 2020. doi: 10.1056/NEJMoa2008457 32329971

59. Bai K, Liu W, Liu C, Fu Y, Hu J, Qin Y, et al. Clinical Analysis of 25 Novel Coronavirus Infections in Children. Pediatr Infect Dis J. 2020. doi: 10.1097/INF.0000000000002740 32520888

60. Bi Q, Wu Y, Mei S, Ye C, Zou X, Zhang Z, et al. Epidemiology and Transmission of Covid-19 in 391 Cases and 1286 of Their Close Contacts in Shenzhen, China: A Retrospective Cohort Study. Lancet Infect Dis. 2020. Epub 2020/05/01. doi: 10.1016/S1473-3099(20)30287-5 32353347; PubMed Central PMCID: PMC7185944.

61. Bohmer MM, Buchholz U, Corman VM, Hoch M, Katz K, Marosevic DV, et al. Investigation of a Covid-19 Outbreak in Germany Resulting from a Single Travel-Associated Primary Case: A Case Series. Lancet Infect Dis. 2020. Epub 2020/05/19. doi: 10.1016/S1473-3099(20)30314-5 32422201; PubMed Central PMCID: PMC7228725.

62. Brandstetter S, Roth S, Harner S, Buntrock-Döpke H, Toncheva A, Borchers N, et al. Symptoms and Immunoglobulin Development in Hospital Staff Exposed to a Sars-Cov-2 Outbreak. Pediatr Allergy Immunol. 2020. doi: 10.1111/pai.13278 32413201

63. Casey M, Griffin J, McAloon CG, Byrne AW, Madden JM, McEvoy D, et al. Estimating Pre-Symptomatic Transmission of Covid-19: A Secondary Analysis Using Published Data. medRxiv [Preprint]. 2020 [cited 2020 Jul 27]. doi: 10.1101/2020.05.08.20094870

64. Chang MC, Hur J, Park D. Chest Computed Tomography Findings in Asymptomatic Patients with Covid-19. medRxiv [Preprint]. 2020 [cited 2020 Jul 27]. doi: 10.1101/2020.05.09.20096370

65. Chaw L, Koh WC, Jamaludin SA, Naing L, Alikhan MF, Wong J. Sars-Cov-2 Transmission in Different Settings: Analysis of Cases and Close Contacts from the Tablighi Cluster in Brunei Darussalam. medRxiv [Preprint]. 2020 [cited 2020 Jul 27]. doi: 10.1101/2020.05.04.20090043

66. Cheng HY, Jian SW, Liu DP, Ng TC, Huang WT, Lin HH, et al. Contact Tracing Assessment of Covid-19 Transmission Dynamics in Taiwan and Risk at Different Exposure Periods before and after Symptom Onset. JAMA Intern Med. 2020. Epub 2020/05/02. doi: 10.1001/jamainternmed.2020.2020 32356867; PubMed Central PMCID: PMC7195694.

67. Choe PG, Kang EK, Lee SY, Oh B, Im D, Lee HY, et al. Selecting Coronavirus Disease 2019 Patients with Negligible Risk of Progression: Early Experience from Non-Hospital Isolation Facility in Korea. Korean J Intern Med. 2020. doi: 10.3904/kjim.2020.159 32460457

68. Dora AV, Winnett A, Jatt LP, Davar K, Watanabe M, Sohn L, et al. Universal and Serial Laboratory Testing for Sars-Cov-2 at a Long-Term Care Skilled Nursing Facility for Veterans—Los Angeles, California, 2020. MMWR Morb Mortal Wkly Rep. 2020. doi: 10.15585/mmwr.mm6921e1 32463809

69. Emery JC, Russel TW, Liu Y, Hellewell J, Pearson CA, group Cnw, et al. The Contribution of Asymptomatic Sars-Cov-2 Infections to Transmission—a Model-Based Analysis of the Diamond Princess Outbreak. medRxiv [Preprint]. 2020 [cited 2020 Jul 27]. doi: 10.1101/2020.05.07.20093849

70. Gao Y, Shi C, Chen Y, Shi P, Liu J, Xiao Y, et al. A Cluster of the Corona Virus Disease 2019 Caused by Incubation Period Transmission in Wuxi, China. J Infect. 2020. doi: 10.1016/j.jinf.2020.03.042 32283165

71. Graham N, Junghans C, Downes R, Sendall C, Lai H, McKirdy A, et al. Sars-Cov-2 Infection, Clinical Features and Outcome of Covid-19 in United Kingdom Nursing Homes. J Infect. 2020. doi: 10.1016/j.jinf.2020.05.073 32504743

72. Hijnen D, Marzano AV, Eyerich K, GeurtsvanKessel C, Giménez-Arnau AM, Joly P, et al. Sars-Cov-2 Transmission from Presymptomatic Meeting Attendee, Germany. Emerg Infect Dis. 2020. doi: 10.3201/eid2608.201235 32392125

73. Huang L, Jiang J, Li X, Zhou Y, Xu M, Zhou J. Initial Ct Imaging Characters of an Imported Family Cluster of Covid-19. Clin Imaging. 2020. doi: 10.1016/j.clinimag.2020.04.010 32361413

74. Huang R, Zhao H, Wang J, Yan X, Shao H, Wu C. A Family Cluster of Covid-19 Involving an Asymptomatic Case with Persistently Positive Sars-Cov-2 in Anal Swabs. Travel Med Infect Dis. 2020. doi: 10.1016/j.tmaid.2020.101745 32425697

75. Jiang X, Luo M, Zou Z, Wang X, Chen C, Qiu J. Asymptomatic Sars-Cov-2 Infected Case with Viral Detection Positive in Stool but Negative in Nasopharyngeal Samples Lasts for 42 Days. J Med Virol. 2020. doi: 10.1002/jmv.25941 32330309

76. Jiang XL, Zhang XL, Zhao XN, Li CB, Lei J, Kou ZQ, et al. Transmission Potential of Asymptomatic and Paucisymptomatic Sars-Cov-2 Infections: A Three-Family Cluster Study in China. J Infect Dis. 2020. doi: 10.1093/infdis/jiaa206 32319519

77. Kim SE, Jeong HS, Yu Y, Shin SU, Kim S, Oh TH, et al. Viral Kinetics of Sars-Cov-2 in Asymptomatic Carriers and Presymptomatic Patients. Int J Infect Dis. 2020. doi: 10.1016/j.ijid.2020.04.083 32376309

78. Kim Y, Chun JY, Baek G. Transmission Onset Distribution of Covid-19 in South Korea. medRxiv [Preprint]. 2020 [cited 2020 Jul 27]. doi: 10.1101/2020.05.13.20101246

79. Kong W, Wang Y, Hu J, Chughtai A, Pu H. Comparison of Clinical and Epidemiological Characteristics of Asymptomatic and Symptomatic Sars-Cov-2 Infection: A Multi-Center Study in Sichuan Province, China. Travel Med Infect Dis. 2020. doi: 10.1016/j.tmaid.2020.101754 32492485

80. Kumar R, Bhattacharya B, Meena VP, Aggarwal A, Tripathi M, Soneja M, et al. Management of Mild Covid-19: Policy Implications of Initial Experience in India. medRxiv [Preprint]. 2020 [cited 2020 Jul 27]. doi: 10.1101/2020.05.20.20107664

81. Lavezzo E, Franchin E, Ciavarella C, Cuomo-Dannenburg G, Barzon L, Del Vecchio C, et al. Suppression of a Sars-Cov-2 Outbreak in the Italian Municipality of Vo'. Nature. 2020. Epub 2020/07/01. doi: 10.1038/s41586-020-2488-1 32604404.

82. Lombardi A, Consonni D, Carugno M, Bozzi G, Mangioni D, Muscatello A, et al. Characteristics of 1,573 Healthcare Workers Who Underwent Nasopharyngeal Swab for Sars-Cov-2 in Milano, Lombardy, Italy. medRxiv [Preprint]. 2020 [cited 2020 Jul 27]. doi: 10.1101/2020.05.07.20094276

83. London V, McLaren R, Atallah F, Cepeda C, McCalla S, Fisher N, et al. The Relationship between Status at Presentation and Outcomes among Pregnant Women with Covid-19. Am J Perinatol. 2020. doi: 10.1055/s-0040-1712164 32428964

84. Lu Y, Li Y, Deng W, Liu M, He Y, Huang L, et al. Symptomatic Infection Is Associated with Prolonged Duration of Viral Shedding in Mild Coronavirus Disease 2019: A Retrospective Study of 110 Children in Wuhan. Pediatr Infect Dis J. 2020. doi: 10.1097/INF.0000000000002729 32379191

85. Luo Y, Trevathan E, Qian Z, Li Y, Li J, Xiao W, et al. Asymptomatic Sars-Cov-2 Infection in Household Contacts of a Healthcare Provider, Wuhan, China. Emerg Infect Dis. 2020. doi: 10.3201/eid2608.201016 32330112

86. Ma Y, Xu QN, Wang FL, Ma XM, Wang XY, Zhang XG, et al. Characteristics of Asymptomatic Patients with Sars-Cov-2 Infection in Jinan, China. Microbes Infect. 2020. doi: 10.1016/j.micinf.2020.04.011 32387682

87. Melgosa M, Madrid A, Alvárez O, Lumbreras J, Nieto F, Parada E, et al. Sars-Cov-2 Infection in Spanish Children with Chronic Kidney Pathologies. Pediatr Nephrol. 2020. doi: 10.1007/s00467-020-04597-1 32435879

88. Merza MA, Haleem Al Mezori AA, Mohammed HM, Abdulah DM. Covid-19 Outbreak in Iraqi Kurdistan: The First Report Characterizing Epidemiological, Clinical, Laboratory, and Radiological Findings of the Disease. Diabetes Metab Syndr Clin Res Rev. 2020. doi: 10.1016/j.dsx.2020.04.047 32408119

89. Noh JY, Yoon JG, Seong H, Choi WS, Sohn JW, Cheong HJ, et al. Asymptomatic Infection and Atypical Manifestations of Covid-19: Comparison of Viral Shedding Duration. J Infect. 2020. doi: 10.1016/j.jinf.2020.05.035 32445728

90. Park SY, Kim YM, Yi S, Lee S, Na BJ, Kim CB, et al. Coronavirus Disease Outbreak in Call Center, South Korea. Emerg Infect Dis. 2020. doi: 10.3201/eid2608.201274 32324530

91. Peak CM, Kahn R, Grad YH, Childs LM, Li R, Lipsitch M, et al. Individual Quarantine Versus Active Monitoring of Contacts for the Mitigation of Covid-19: A Modelling Study. Lancet Infect Dis. 2020. doi: 10.1016/S1473-3099(20)30361-3 32445710

92. Qiu C, Deng Z, Xiao Q, Shu Y, Deng Y, Wang H, et al. Transmission and Clinical Characteristics of Coronavirus Disease 2019 in 104 Outside-Wuhan Patients, China. J Med Virol. 2020. doi: 10.1002/jmv.25975 32369217

93. Rivett L, Sridhar S, Sparkes D, Routledge M, Jones NK, Forrest S, et al. Screening of Healthcare Workers for Sars-Cov-2 Highlights the Role of Asymptomatic Carriage in Covid-19 Transmission. Elife. 2020;9. Epub 2020/05/12. doi: 10.7554/eLife.58728 32392129.

94. Roxby AC, Greninger AL, Hatfield KM, Lynch JB, Dellit TH, James A, et al. Outbreak Investigation of Covid-19 among Residents and Staff of an Independent and Assisted Living Community for Older Adults in Seattle, Washington. JAMA Intern Med. 2020. doi: 10.1001/jamainternmed.2020.2233 32437547

95. Schwierzeck V, König JC, Kühn J, Mellmann A, Correa-Martínez CL, Omran H, et al. First Reported Nosocomial Outbreak of Severe Acute Respiratory Syndrome Coronavirus 2 (Sars-Cov-2) in a Pediatric Dialysis Unit. Clin Infect Dis. 2020. doi: 10.1093/cid/ciaa491 32337584

96. Sharma AK, Ahmed A, Baig VN, Dhakad P, Dalela G, Kacker S, et al. Characteristics and Outcomes of Hospitalized Young Adults with Mild to Moderate Covid-19 at a University Hospital in India. medRxiv [Preprint]. 2020 [cited 2020 Jul 27]. doi: 10.1101/2020.06.02.20106310

97. Solbach W, Schiffner J, Backhaus I, Burger D, Staiger R, Tiemer B, et al. Antibody Profiling of Covid-19 Patients in an Urban Low-Incidence Region in Northern Germany. medRxiv [Preprint]. 2020 [cited 2020 Jul 27]. doi: 10.1101/2020.05.30.20111393

98. Song W, Li J, Zou N, Guan W, Pan J, Xu W. Clinical Features of Pediatric Patients with Coronavirus Disease (Covid-19). J Clin Virol. 2020. doi: 10.1016/j.jcv.2020.104377 32361323

99. Tan X, Huang J, Zhao F, Zhou Y, Li JQ, Wang XY. [Clinical Features of Children with Sars-Cov-2 Infection: An Analysis of 13 Cases from Changsha, China]. Zhongguo Dang Dai Er Ke Za Zhi. 2020. doi: 10.7499/j.issn.1008-8830.2003199 32312364

100. Pham TQ, Rabaa MA, Duong LH, Dang TQ, Tran QD, Quach HL, et al. The First 100 Days of Sars-Cov-2 Control in Vietnam. medRxiv [Preprint]. 2020 [cited 2020 Jul 27]. doi: 10.1101/2020.05.12.20099242

101. Treibel TA, Manisty C, Burton M, McKnight NA, Lambourne J, Augusto JB, et al. Covid-19: Pcr Screening of Asymptomatic Health-Care Workers at London Hospital. Lancet. 2020. doi: 10.1016/S0140-6736(20)31100-4 32401714

102. Wang Y, Tong J, Qin Y, Xie T, Li J, Li J, et al. Characterization of an Asymptomatic Cohort of Sars-Cov-2 Infected Individuals Outside of Wuhan, China. Clin Infect Dis. 2020. doi: 10.1093/cid/ciaa629 32442265

103. Wong J, Abdul Aziz ABZ, Chaw L, Mahamud A, Griffith MM, Ying-Ru LO, et al. High Proportion of Asymptomatic and Presymptomatic Covid-19 Infections in Travelers and Returning Residents to Brunei. J Travel Med. 2020. doi: 10.1093/jtm/taaa066 32365178

104. Wu HP, Li BF, Chen X, Hu HZ, Jiang SA, Cheng H, et al. Clinical Features of Coronavirus Disease 2019 in Children Aged <18 Years in Jiangxi, China: An Analysis of 23 Cases. Zhongguo Dang Dai Er Ke Za Zhi. 2020;22(5):419–424. doi: 10.7499/j.issn.1008-8830.2003202 32434634

105. Wu J, Huang Y, Tu C, Bi C, Chen Z, Luo L, et al. Household Transmission of Sars-Cov-2, Zhuhai, China, 2020. Clin Infect Dis. 2020. doi: 10.1093/cid/ciaa557 32392331

106. Xu H, Liu E, Xie J, Smyth R, Zhou Q, Zhao R, et al. A Follow-up Study of Children Infected with Sars-Cov-2 from Western China. medRxiv [Preprint]. 2020 [cited 2020 Jul 27]. doi: 10.1101/2020.04.20.20073288

107. Xu T, Huang R, Zhu L, Wang J, Cheng J, Zhang B, et al. Epidemiological and Clinical Features of Asymptomatic Patients with Sars-Cov-2 Infection. J Med Virol. 2020. doi: 10.1002/jmv.25944 32346873

108. Yang R, Gui X, Xiong Y. Comparison of Clinical Characteristics of Patients with Asymptomatic Vs Symptomatic Coronavirus Disease 2019 in Wuhan, China. JAMA Netw Open. 2020. doi: 10.1001/jamanetworkopen.2020.10182 32459353

109. Yongchen Z, Shen H, Wang X, Shi X, Li Y, Yan J, et al. Different Longitudinal Patterns of Nucleic Acid and Serology Testing Results Based on Disease Severity of Covid-19 Patients. Emerg Microbes Infect. 2020. doi: 10.1080/22221751.2020.1756699 32306864

110. Zhang B, Liu S, Dong Y, Zhang L, Zhong Q, Zou Y, et al. Positive Rectal Swabs in Young Patients Recovered from Coronavirus Disease 2019 (Covid-19). J Infect. 2020. doi: 10.1016/j.jinf.2020.04.023 32335176

111. Zhang W, Cheng W, Luo L, Ma Y, Xu C, Qin P, et al. Secondary Transmission of Coronavirus Disease from Presymptomatic Persons, China. Emerg Infect Dis. 2020. doi: 10.3201/eid2608.201142 32453686

112. Zhang W, Long Q, Huang Y, Chen C, Wu J, Hong Y, et al. Asymptomatic Covid-19 Have Longer Treatment Cycle Than Moderate Type of Confirmed Patients. medRxiv [Preprint]. 2020 [cited 2020 Jul 27]. doi: 10.1101/2020.05.16.20103796

113. Zhang Z, Xiao T, Wang Y, Yuan J, Ye H, Wei L, et al. Early Viral Clearance and Antibody Kinetics of Covid-19 among Asymptomatic Carriers. medRxiv [Preprint]. 2020 [cited 2020 Jul 27]. doi: 10.1101/2020.04.28.20083139

114. Zhou R, Li F, Chen F, Liu H, Zheng J, Lei C, et al. Viral Dynamics in Asymptomatic Patients with Covid-19. Int J Infect Dis. 2020. doi: 10.1016/j.ijid.2020.05.030 32437933

115. Savvides C, Siegel R. Asymptomatic and Presymptomatic Transmission of Sars-Cov-2: A Systematic Review. medRxiv [Preprint]. 2020 [cited 2020 Jul 27]. doi: 10.1101/2020.06.11.20129072 32587980.

116. Chau NVV, Thanh Lam V, Thanh Dung N, Yen LM, Minh NNQ, Hung LM, et al. The Natural History and Transmission Potential of Asymptomatic Sars-Cov-2 Infection. Clin Infect Dis. 2020. doi: 10.1093/cid/ciaa711 32497212

117. Kucirka LM, Lauer SA, Laeyendecker O, Boon D, Lessler J. Variation in False-Negative Rate of Reverse Transcriptase Polymerase Chain Reaction-Based Sars-Cov-2 Tests by Time since Exposure. Ann Intern Med. 2020. Epub 2020/05/19. doi: 10.7326/M20-1495 32422057; PubMed Central PMCID: PMC7240870.

118. Heneghan C, Brassey J, Jefferson T. Covid-19: What Proportion Are Asymptomatic? Oxford: Centre for Evidence Based Medicine; 2020 [cited 2020 Jul 27]. Available from: https://www.cebm.net/covid-19/covid-19-what-proportion-are-asymptomatic/.

119. He J, Guo Y, Mao R, Zhang J. Proportion of Asymptomatic Coronavirus Disease 2019 (Covid-19): A Systematic Review and Meta-Analysis. J Med Virol. 2020. Epub 2020/07/22. doi: 10.1002/jmv.26326 32691881.

120. Beale S, Hayward A, Shallcross L, Aldridge RW, Fragaszy E. A Rapid Review of the Asymptomatic Proportion of Pcr-Confirmed Sars-Cov-2 Infections in Community Settings. medRxiv [Preprint]. 2020 [cited 2020 Jul 27]. doi: 10.1101/2020.05.20.20108183

121. Byambasuren O, Cardona M, Bell K, Clark J, McLaws ML, Glasziou P. Estimating the Extent of True Asymptomatic Covid-19 and Its Potential for Community Transmission: Systematic Review and Meta-Analysis. medRxiv [Preprint]. 2020 [cited 2020 Jul 27]. doi: 10.1101/2020.05.10.20097543

122. Day M. Covid-19: Four Fifths of Cases Are Asymptomatic, China Figures Indicate. BMJ. 2020;369:m1375. Epub 2020/04/04. doi: 10.1136/bmj.m1375 32241884.

123. Deeks JJ, Dinnes J, Takwoingi Y, Davenport C, Spijker R, Taylor-Phillips S, et al. Antibody Tests for Identification of Current and Past Infection with Sars-Cov-2. Cochrane Database Syst Rev. 2020;6:CD013652. Epub 2020/06/26. doi: 10.1002/14651858.CD013652 32584464.

124. Wei WE, Li Z, Chiew CJ, Yong SE, Toh MP, Lee VJ. Presymptomatic Transmission of Sars-Cov-2—Singapore, January 23-March 16, 2020. MMWR Morb Mortal Wkly Rep. 2020;69(14):411–5. Epub 2020/04/10. doi: 10.15585/mmwr.mm6914e1 32271722; PubMed Central PMCID: PMC7147908

125. Long QX, Tang XJ, Shi QL, Li Q, Deng HJ, Yuan J, et al. Clinical and Immunological Assessment of Asymptomatic Sars-Cov-2 Infections. Nat Med. 2020. Epub 2020/06/20. doi: 10.1038/s41591-020-0965-6 32555424.

126. Ludvigsson JF. Systematic Review of Covid-19 in Children Shows Milder Cases and a Better Prognosis Than Adults. Acta Paediatr. 2020;109(6):1088–95. Epub 2020/03/24. doi: 10.1111/apa.15270 32202343; PubMed Central PMCID: PMC7228328.

127. von Wyl V, Bonhoeffer S, Bugnion E, Puhan MA, Salathe M, Stadler T, et al. A Research Agenda for Digital Proximity Tracing Apps. Swiss Med Wkly. 2020;150:w20324. Epub 2020/07/17. doi: 10.4414/smw.2020.20324 32672340.

Článek vyšel v časopise

PLOS Medicine

2020 Číslo 9
Nejčtenější tento týden
Nejčtenější v tomto čísle

Zvyšte si kvalifikaci online z pohodlí domova

Třikrát z interní medicíny
nový kurz
Autoři: MUDr. Jana Kubátová

Pokročilá Parkinsonova nemoc − úskalí a možnosti léčby
Autoři: doc. MUDr. Marek Baláž, Ph.D.

Léčba diabetes mellitus 2. typu pomocí GLP- 1 RA

Depresivní porucha a zánětlivé procesy
Autoři: MUDr. Juraj Tkáč

Methotrexát a jeho formy podávání v revmatologii
Autoři: MUDr. Liliana Šedová

Všechny kurzy
Zapomenuté heslo

Zadejte e-mailovou adresu, se kterou jste vytvářel(a) účet, budou Vám na ni zaslány informace k nastavení nového hesla.


Nemáte účet?  Registrujte se