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Volume 26, Number 7—July 2020

Online Report

Evidence Supporting Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 While Presymptomatic or Asymptomatic

Nathan W. FurukawaComments to Author , John T. Brooks, and Jeremy Sobel
Author affiliations: Centers for Disease Control and Prevention, Atlanta, Georgia, USA

Main Article

Table 2

Summary of virologic reports supporting transmission of severe acute respiratory syndrome coronavirus 2 while asymptomatic and presymptomatic*

Reference Setting Patient(s), age/sex Laboratory findings Limitations
(23,28)
 Nursing home outbreak in Washington
 24 presymptomatic and 3 asymptomatic
 Mean RT-PCR Ct value 24.2 for presymptomatic and 27.3 for asymptomatic patients. Viral culture identified infectious virus in 7 (64%) of 11 specimens from presymptomatic patients; no virus detected in 1 asymptomatic patient.
 Incomplete viral culture sampling from all presymptomatic and asymptomatic patients.
(24)
 Repatriated to Germany from Wuhan, China
 2 asymptomatic adults
 Patients’ RT-PCR Ct values 24 and 30; infectious virus was detected by viral culture for both.
 No evidence of transmission during evacuation flight.
(25)
 Family cluster in Singapore
 Asymptomatic 6 mo/M
 RT-PCR Ct values 14 at diagnosis and increased to 33 over 9 d.
 No evidence of transmission from the infant to another household member.
(26)
 Cluster in Vietnam related to travel to Wuhan
 Asymptomatic 55 y/M
 RT-PCR Ct values >40 at diagnosis and during 9 d of viral RNA shedding.
 High Ct in the asymptomatic patient suggests minimal infectiousness.
(27) Family cluster in Guangdong, China Asymptomatic, 26 y/M RT-PCR Ct values 22–32 during testing 7–11 d after initial diagnosis. No evidence of transmission to other family members in the cluster.

*Ct, cycle threshold, RT-PCR, reverse transcription PCR.

Main Article

References
  1. 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;jiaa119; Epub ahead of print. DOIPubMedGoogle Scholar
  2. 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;395:514–23. DOIPubMedGoogle Scholar
  3. 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: Epub ahead of print. DOIPubMedGoogle Scholar
  4. Dong  Y, Mo  X, Hu  Y, Qi  X, Jiang  F, Jiang  Z, et al. Epidemiological characteristics of 2143 pediatric patients with 2019 coronavirus disease in China. Pediatrics. 2020; [Epub ahead of print]. DOIGoogle Scholar
  5. 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;25:25; Epub ahead of print. DOIPubMedGoogle Scholar
  6. Roxby  AC, Greninger  AL, Hatfield  KM, Lynch  JB, Dellit  TH, James  A, et al. Detection of SARS-CoV-2 among residents and staff members of an independent and assisted living community for older adults– Seattle, Washington, 2020. MMWR Morb Mortal Wkly Rep. 2020;69:416–8. DOIPubMedGoogle Scholar
  7. Tian  S, Hu  N, Lou  J, Chen  K, Kang  X, Xiang  Z, et al. Characteristics of COVID-19 infection in Beijing. J Infect. 2020;80:401–6. DOIPubMedGoogle Scholar
  8. Ng  O-T, Marimuthu  K, Chia  P-Y, Koh  V, Chiew  CJ, De Wang  L, et al. SARS-CoV-2 infection among travelers returning from Wuhan, China. N Engl J Med. 2020;382:1476–8. DOIPubMedGoogle Scholar
  9. Li  C, Ji  F, Wang  L, Wang  L, Hao  J, Dai  M, et al. Asymptomatic and human-to-human transmission of SARS-CoV-2 in a 2-family cluster, Xuzhou, China. Emerg Infect Dis. 2020 Mar 31 [Epub ahead of print].
  10. 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;26:1052–4. DOIPubMedGoogle Scholar
  11. Yu  P, Zhu  J, Zhang  Z, Han  Y, Huang  L. A familial cluster of infection associated with the 2019 novel coronavirus indicating potential person-to-person transmission during the incubation period. J Infect Dis. 2020;jiaa077; Epub ahead of print. DOIPubMedGoogle Scholar
  12. 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 ahead of print. DOIPubMedGoogle Scholar
  13. Bai  Y, Yao  L, Wei  T, Tian  F, Jin  DY, Chen  L, et al. Presumed asymptomatic carrier transmission of COVID-19. JAMA. 2020;323:1406. DOIPubMedGoogle Scholar
  14. 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;63:706–11. DOIPubMedGoogle Scholar
  15. Zhang  J, Tian  S, Lou  J, Chen  Y. Familial cluster of COVID-19 infection from an asymptomatic. Crit Care. 2020;24:119. DOIPubMedGoogle Scholar
  16. Pan  X, Chen  D, Xia  Y, Wu  X, Li  T, Ou  X, et al. Asymptomatic cases in a family cluster with SARS-CoV-2 infection. Lancet Infect Dis. 2020;20:410–1. DOIPubMedGoogle Scholar
  17. 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;ciaa316; Epub ahead of print. DOIPubMedGoogle Scholar
  18. Rothe  C, Schunk  M, Sothmann  P, Bretzel  G, Froeschl  G, Wallrauch  C, et al. Transmission of 2019-nCoV infection from an asymptomatic contact in Germany. N Engl J Med. 2020;382:970–1. DOIPubMedGoogle Scholar
  19. 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;69:411–5. DOIPubMedGoogle Scholar
  20. Loeffelholz  MJ, Tang  YW. Laboratory diagnosis of emerging human coronavirus infections - the state of the art. Emerg Microbes Infect. 2020;9:747–56. DOIPubMedGoogle Scholar
  21. Corman  VM, Landt  O, Kaiser  M, Molenkamp  R, Meijer  A, Chu  DKW, et al. Detection of 2019 novel coronavirus (2019-nCoV) by real-time RT-PCR. Euro Surveill. 2020;25:25; Epub ahead of print. DOIPubMedGoogle Scholar
  22. Wölfel  R, Corman  VM, Guggemos  W, Seilmaier  M, Zange  S, Müller  MA, et al. Virological assessment of hospitalized patients with COVID-2019. Nature. 2020; Epub ahead of print. DOIPubMedGoogle Scholar
  23. 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;NEJMoa2008457; Epub ahead of print. DOIPubMedGoogle Scholar
  24. 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;382:1278–80. DOIPubMedGoogle Scholar
  25. Kam  KQ, Yung  CF, Cui  L, Lin Tzer Pin  R, Mak  TM, Maiwald  M, et al. A well infant with coronavirus disease 2019 with high viral load. Clin Infect Dis. 2020;ciaa201; Epub ahead of print. DOIPubMedGoogle Scholar
  26. 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;26: Epub ahead of print. DOIPubMedGoogle Scholar
  27. 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;382:1177–9. DOIPubMedGoogle Scholar
  28. Kimball  A, Hatfield  KM, Arons  M, James  A, Taylor  J, Spicer  K, et al.; Public Health – Seattle & King County; CDC COVID-19 Investigation Team. Public Health – Seattle & King County; CDC COVID-19 Investigation Team. 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;69:377–81; Epub ahead of print. DOIPubMedGoogle Scholar
  29. Du  Z, Xu  X, Wu  Y, Wang  L, Cowling  BJ, Meyers  LA. Serial interval of COVID-19 among publicly reported confirmed cases. Emerg Infect Dis. 2020;26: Epub ahead of print. DOIPubMedGoogle Scholar
  30. Nishiura  H, Linton  NM, Akhmetzhanov  AR. Serial interval of novel coronavirus (COVID-19) infections. Int J Infect Dis. 2020;93:284–6. DOIPubMedGoogle Scholar
  31. Lauer  SA, Grantz  KH, Bi  Q, Jones  FK, Zheng  Q, Meredith  HR, et al. The incubation period of coronavirus disease 2019 (COVID-19) from publicly reported confirmed cases: estimation and application. Ann Intern Med. 2020; Epub ahead of print. DOIPubMedGoogle Scholar
  32. Li  R, Pei  S, Chen  B, Song  Y, Zhang  T, Yang  W, et al. Substantial undocumented infection facilitates the rapid dissemination of novel coronavirus (SARS-CoV-2). Science. 2020;368:489–93; Epub ahead of print. DOIPubMedGoogle Scholar
  33. Ferretti  L, Wymant  C, Kendall  M, Zhao  L, Nurtay  A, Abeler-Dörner  L, et al. Quantifying SARS-CoV-2 transmission suggests epidemic control with digital contact tracing. Science. 2020;eabb6936; Epub ahead of print.
  34. Verity  R, Okell  LC, Dorigatti  I, Winskill  P, Whittaker  C, Imai  N, et al. Estimates of the severity of coronavirus disease 2019: a model-based analysis. Lancet Infect Dis. 2020;S1473-3099(20)30243-7; Epub ahead of print. DOIPubMedGoogle Scholar
  35. Wu  JT, Leung  K, Bushman  M, Kishore  N, Niehus  R, de Salazar  PM, et al. Estimating clinical severity of COVID-19 from the transmission dynamics in Wuhan, China. Nat Med. 2020;26:506–10. DOIPubMedGoogle Scholar
  36. Lasry  A, Kidder  D, Hast  M, Poovey  J, Sunshine  G, Winglee  K, et al. Timing of community mitigation and changes in reported covid-19 and community mobility—four US metropolitan areas, February 26–April 1, 2020. MMWR Morb Mortal Wkly Rep. 2020 Apr 13 [Epub ahead of print].
  37. Mahase  E. Covid-19: What is the evidence for cloth masks? BMJ. 2020;369:m1422. DOIPubMedGoogle Scholar
  38. Klompas  M, Morris  CA, Sinclair  J, Pearson  M, Shenoy  ES. Universal masking in hospitals in the COVID-19 era. N Engl J Med. 2020;NEJMp2006372; Epub ahead of print. DOIPubMedGoogle Scholar
  39. 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 ahead of print. DOIPubMedGoogle Scholar
  40. Kissler  SM, Tedijanto  C, Goldstein  E, Grad  YH, Lipsitch  M. Projecting the transmission dynamics of SARS-CoV-2 through the postpandemic period. Science. 2020;eabb5793; Epub ahead of print.

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