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The Natural History and Transmission Potential of Asymptomatic Severe Acute Respiratory Syndrome Coronavirus 2 Infection.

Authors :
Van Vinh Chau N
Lam VT
Dung NT
Yen LM
Minh NNQ
Hung LM
Ngoc NM
Dung NT
Man DNH
Nguyet LA
Nhat LTH
Nhu LNT
Ny NTH
Hong NTT
Kestelyn E
Dung NTP
Xuan TC
Hien TT
Phong NT
Tu TNH
Geskus RB
Thanh TT
Truong NT
Binh NT
Thuong TC
Thwaites G
Van Tan L
Source :
Clinical infectious diseases : an official publication of the Infectious Diseases Society of America [Clin Infect Dis] 2020 Dec 17; Vol. 71 (10), pp. 2679-2687.
Publication Year :
2020

Abstract

Background: Little is known about the natural history of asymptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.<br />Methods: We conducted a prospective study at a quarantine center for coronavirus disease 2019 in Ho Chi Minh City, Vietnam. We enrolled quarantined people with reverse-transcription polymerase chain reaction (RT-PCR)-confirmed SARS-CoV-2 infection, collecting clinical data, travel and contact history, and saliva at enrollment and daily nasopharyngeal/throat swabs (NTSs) for RT-PCR testing. We compared the natural history and transmission potential of asymptomatic and symptomatic individuals.<br />Results: Between 10 March and 4 April 2020, 14 000 quarantined people were tested for SARS-CoV-2; 49 were positive. Of these, 30 participated in the study: 13 (43%) never had symptoms and 17 (57%) were symptomatic. Seventeen (57%) participants imported cases. Compared with symptomatic individuals, asymptomatic people were less likely to have detectable SARS-CoV-2 in NTS collected at enrollment (8/13 [62%] vs 17/17 [100%]; P = .02). SARS-CoV-2 RNA was detected in 20 of 27 (74%) available saliva samples (7 of 11 [64%] in the asymptomatic group and 13 of 16 [81%] in the symptomatic group; P = .56). Analysis of RT-PCR positivity probability showed that asymptomatic participants had faster viral clearance than symptomatic participants (P < .001 for difference over the first 19 days). This difference was most pronounced during the first week of follow-up. Two of the asymptomatic individuals appeared to transmit SARS-CoV-2 to 4 contacts.<br />Conclusions: Asymptomatic SARS-CoV-2 infection is common and can be detected by analysis of saliva or NTSs. The NTS viral loads fall faster in asymptomatic individuals, but these individuals appear able to transmit the virus to others.<br /> (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America.)

Details

Language :
English
ISSN :
1537-6591
Volume :
71
Issue :
10
Database :
MEDLINE
Journal :
Clinical infectious diseases : an official publication of the Infectious Diseases Society of America
Publication Type :
Academic Journal
Accession number :
32497212
Full Text :
https://doi.org/10.1093/cid/ciaa711