{"id":2956,"date":"2021-03-19T09:16:37","date_gmt":"2021-03-19T07:16:37","guid":{"rendered":"https:\/\/halco.gr\/?p=2956"},"modified":"2021-04-14T10:21:05","modified_gmt":"2021-04-14T07:21:05","slug":"aerosol-and-surface-stability-of-sars-cov-2-as-compared-with-sars-cov-1","status":"publish","type":"post","link":"https:\/\/halco.gr\/el\/aerosol-and-surface-stability-of-sars-cov-2-as-compared-with-sars-cov-1\/","title":{"rendered":"Aerosol and surface stability of SARS-CoV-2 and SARS-CoV-1"},"content":{"rendered":"
<\/h6>\n
To the Editor : A novel human coronavirus that is now named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (formerly called
\nHCoV-19) emerged in Wuhan, China, in late 2019\u00a0and is now causing a pandemic.1 We analyzed\u00a0the aerosol and surface stability of SARS-CoV-2
\nand compared it with SARS-CoV-1, the most\u00a0closely related human coronavirus.2
\n<\/span><\/h6>\n
We evaluated the stability of SARS-CoV-2 and\u00a0SARS-CoV-1 in aerosols and on various surfaces\u00a0and estimated their decay rates using a Bayesian
\nregression model (see the Methods section in\u00a0the Supplementary Appendix, available with the\u00a0full text of this letter at NEJM.org). SARS-CoV-2\u00a0nCoV-WA1-2020 (MN985325.1) and SARS-CoV-1Tor2 (AY274119.3) were the strains used. Aerosols\u00a0(<5 \u03bcm) containing SARS-CoV-2 (105.25 50%\u00a0tissue-culture infectious dose [TCID50] per milliliter)\u00a0or SARS-CoV-1 (106.75-7.00 TCID50 per milliliter)\u00a0were generated with the use of a three-jet Collison\u00a0nebulizer and fed into a Goldberg drum to\u00a0create an aerosolized environment. The inoculum\u00a0resulted in cycle-threshold values between 20 and\u00a022, similar to those observed in samples obtained
\nfrom the upper and lower respiratory tract in\u00a0humans.<\/h6>\n

\"\"<\/p>\n

Our data consisted of 10 experimental conditions\u00a0involving two viruses (SARS-CoV-2 and\u00a0SARS-CoV-1) in five environmental conditions\u00a0(aerosols, plastic, stainless steel, copper, and\u00a0cardboard). All experimental measurements are\u00a0reported as means across three replicates.<\/h6>\n
SARS-CoV-2 remained viable in aerosols\u00a0throughout the duration of our experiment\u00a0(3 hours), with a reduction in infectious titer\u00a0from 103.5 to 102.7 TCID50 per liter of air. This\u00a0reduction was similar to that observed with\u00a0SARS-CoV-1, from 104.3 to 103.5 TCID50 per milliliter\u00a0(Fig. 1A).<\/h6>\n
SARS-CoV-2 was more stable on plastic and stainless steel than on copper and cardboard, and viable virus was detected up to 72 hours after application to these surfaces (Fig. 1A), although the virus titer was greatly reduced (from 103.7 to 100.6 TCID50 per milliliter of medium after 72 hours on plastic and from 103.7 to 100.6 TCID50 per milliliter after 48 hours on stainless steel). The stability kinetics of SARS-CoV-1 were similar (from 103.4 to 100.7 TCID50 per milliliter after\u00a072 hours on plastic and from 103.6 to 100.6 TCID50\u00a0per milliliter after 48 hours on stainless steel).<\/h6>\n
On copper, no viable SARS-CoV-2 was measured\u00a0after 4 hours and no viable SARS-CoV-1 was\u00a0measured after 8 hours. On cardboard, no viable
\nSARS-CoV-2 was measured after 24 hours and no\u00a0viable SARS-CoV-1 was measured after 8 hours\u00a0(Fig. 1A).<\/h6>\n
Both viruses had an exponential decay in virus\u00a0titer across all experimental conditions, as indicated\u00a0by a linear decrease in the log10TCID50 per\u00a0liter of air or milliliter of medium over time\u00a0(Fig. 1B). The half-lives of SARS-CoV-2 and\u00a0SARS-CoV-1 were similar in aerosols, with median\u00a0estimates of approximately 1.1 to 1.2 hours\u00a0and 95% credible intervals of 0.64 to 2.64 for\u00a0SARS-CoV-2 and 0.78 to 2.43 for SARS-CoV-1
\n(Fig. 1C, and Table S1 in the Supplementary Appendix).<\/h6>\n
The half-lives of the two viruses were also\u00a0similar on copper. On cardboard, the half-life of\u00a0SARS-CoV-2 was longer than that of SARS-CoV-1.
\nThe longest viability of both viruses was on\u00a0stainless steel and plastic; the estimated median\u00a0half-life of SARS-CoV-2 was approximately 5.6\u00a0hours on stainless steel and 6.8 hours on plastic\u00a0(Fig. 1C). Estimated differences in the half-lives\u00a0of the two viruses were small except for those on\u00a0cardboard (Fig. 1C). Individual replicate data were\u00a0noticeably \u201cnoisier\u201d (i.e., there was more variation\u00a0in the experiment, resulting in a larger\u00a0standard error) for cardboard than for other\u00a0surfaces (Fig. S1 through S5), so we advise caution\u00a0in interpreting this result.<\/h6>\n
We found that the stability of SARS-CoV-2\u00a0was similar to that of SARS-CoV-1 under the\u00a0experimental circumstances tested. This indicates\u00a0that differences in the epidemiologic characteristics\u00a0of these viruses probably arise from other\u00a0factors, including high viral loads in the upper
\nrespiratory tract and the potential for persons\u00a0infected with SARS-CoV-2 to shed and transmit\u00a0the virus while asymptomatic.3,4 Our results indicate\u00a0that aerosol and fomite transmission of\u00a0SARS-CoV-2 is plausible, since the virus can remain\u00a0viable and infectious in aerosols for hours\u00a0and on surfaces up to days (depending on the\u00a0inoculum shed). These findings echo those with\u00a0SARS-CoV-1, in which these forms of transmission\u00a0were associated with nosocomial spread\u00a0and super-spreading events,5 and they provide\u00a0information for pandemic mitigation efforts.<\/h6>\n
Neeltje van Doremalen, Ph.D.<\/strong>
\nTrenton Bushmaker, B.Sc.<\/strong>
\nNational Institute of Allergy and Infectious Diseases
\nHamilton, MT
\nDylan H. Morris, M.Phil.<\/strong>
\nPrinceton University
\nPrinceton, NJ
\nMyndi G. Holbrook, B.Sc.<\/strong>
\nNational Institute of Allergy and Infectious Diseases
\nHamilton, MT
\nAmandine Gamble, Ph.D.<\/strong>
\nUniversity of California, Los Angeles
\nLos Angeles, CA
\nBrandi N. Williamson, M.P.H.<\/strong>
\nNational Institute of Allergy and Infectious Diseases
\nHamilton, MT
\nAzaibi Tamin, Ph.D.<\/strong>
\nJennifer L. Harcourt, Ph.D.<\/strong>
\nNatalie J. Thornburg, Ph.D.<\/strong>
\nSusan I. Gerber, M.D.<\/strong>
\nCenters for Disease Control and Prevention
\nAtlanta, GA
\nJames O. Lloyd-Smith, Ph.D.<\/strong>
\nUniversity of California, Los Angeles
\nLos Angeles, CA
\nBethesda, MD
\nEmmie de Wit, Ph.D.<\/strong>
\nVincent J. Munster, Ph.D.<\/strong>
\nNational Institute of Allergy and Infectious Diseases
\nHamilton, MT
\nvincent.munster@nih.gov<\/h6>\n
Dr. van Doremalen, Mr. Bushmaker, and Mr. Morris contributed<\/strong>
\nequally to this letter.<\/strong>
\nThe findings and conclusions in this letter are those of the\u00a0authors and do not necessarily represent the official position of\u00a0the Centers for Disease Control and Prevention (CDC). Names\u00a0of specific vendors, manufacturers, or products are included for\u00a0public health and informational purposes; inclusion does not\u00a0imply endorsement of the vendors, manufacturers, or products\u00a0by the CDC or the Department of Health and Human Services.<\/h6>\n

\"\"<\/p>\n

Supported by the Intramural Research Program of the National Institute of Allergy and Infectious Diseases, National Institutes of Health, and by contracts from the Defense Advanced Research Projects Agency (DARPA PREEMPT No. D18AC00031, to Drs. Gamble and Lloyd-Smith), from the National Science Foundation (DEB-1557022, to Dr. Lloyd-Smith), and from the Strategic Environmental Research and Development Program of the Department of Defense (SERDP, RC-2635, to Dr. Lloyd-Smith).<\/h6>\n
Disclosure forms provided by the authors are available with\u00a0the full text of this letter at NEJM.org.<\/h6>\n
This letter was published on March 17, 2020, at NEJM.org.<\/h6>\n
1. Coronavirus disease (COVID-2019) situation reports. Geneva:
\nWorld Health Organization, 2020 (https:\/\/www.who.int\/
\nemergencies\/ diseases\/novel-coronavirus-2019\/situation -reports\/).
\n2. Wu A, Peng Y, Huang B, et al. Genome composition and divergence\u00a0of the novel coronavirus (2019-nCoV) originating in\u00a0China. Cell Host Microbe 2020; 27: 325-8.
\n3. Bai Y, Yao L, Wei T, et al. Presumed asymptomatic carrier transmission
\nof COVID-19. JAMA 2020 February 21 (Epub ahead of print).
\n4. Zou L, Ruan F, Huang M, et al. SARS-CoV-2 viral load in upper
\nrespiratory specimens of infected patients. N Engl J Med\u00a02020; 382:1177-9.
\n5. Chen YC, Huang LM, Chan CC, et al. SARS in hospital emergency\u00a0room. Emerg Infect Dis 2004; 10: 782-8.<\/h6>","protected":false},"excerpt":{"rendered":"

To the Editor : A novel human coronavirus that is now named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (formerly called HCoV-19) emerged in Wuhan, China, in late 2019\u00a0and is now causing a pandemic.1 We analyzed\u00a0the aerosol and surface stability of SARS-CoV-2 and compared it with SARS-CoV-1, the most\u00a0closely related human coronavirus.2 We evaluated the … Continue reading<\/a><\/p>","protected":false},"author":1,"featured_media":2950,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[12],"tags":[],"_links":{"self":[{"href":"https:\/\/halco.gr\/el\/wp-json\/wp\/v2\/posts\/2956"}],"collection":[{"href":"https:\/\/halco.gr\/el\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/halco.gr\/el\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/halco.gr\/el\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/halco.gr\/el\/wp-json\/wp\/v2\/comments?post=2956"}],"version-history":[{"count":5,"href":"https:\/\/halco.gr\/el\/wp-json\/wp\/v2\/posts\/2956\/revisions"}],"predecessor-version":[{"id":3661,"href":"https:\/\/halco.gr\/el\/wp-json\/wp\/v2\/posts\/2956\/revisions\/3661"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/halco.gr\/el\/wp-json\/wp\/v2\/media\/2950"}],"wp:attachment":[{"href":"https:\/\/halco.gr\/el\/wp-json\/wp\/v2\/media?parent=2956"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/halco.gr\/el\/wp-json\/wp\/v2\/categories?post=2956"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/halco.gr\/el\/wp-json\/wp\/v2\/tags?post=2956"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}