Volume 26, Number 7—July 2020
Evidence Supporting Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 While Presymptomatic or Asymptomatic
|Reference||Setting||Patient(s), age/sex||Laboratory findings||Limitations|
||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.
||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.
||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.
||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.
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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].
- 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
- 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
- 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
- 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
- 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
- Zhang J, Tian S, Lou J, Chen Y. Familial cluster of COVID-19 infection from an asymptomatic. Crit Care. 2020;24:119. DOIPubMedGoogle Scholar
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- Nishiura H, Linton NM, Akhmetzhanov AR. Serial interval of novel coronavirus (COVID-19) infections. Int J Infect Dis. 2020;93:284–6. DOIPubMedGoogle Scholar
- 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
- 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
- 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.
- 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
- 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
- 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].
- Mahase E. Covid-19: What is the evidence for cloth masks? BMJ. 2020;369:m1422. DOIPubMedGoogle Scholar
- 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
- 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
- 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.