Aerosol and surface contamination of SARS-CoV-2 observed in quarantine and isolation care
Authors: James V Lawler
Danielle N Rivera
Hannah M Creager
St Patrick Reid
David M Brett-Major
M Jana Broadhurst
John J Lowe
Joshua L Santarpia
Elizabeth R Schnaubelt
Vicki L Herrera
M Jane Morwitzer
George W Santarpia
Kevin K Crown
Journal: Scientific Reports (2020)
Discipline: Multidisciplinary
Keywords: SARS-CoV-2; COVID-19; pandemic; global spread; public health emergency
Affiliations: University of Nebraska Medical Center, Omaha, NE, USA. ., National Strategic Research Institute, Omaha, NE, USA. ., National Strategic Research Institute, Omaha, NE, USA., University of Nebraska Medical Center, Omaha, NE, USA., United States Air Force School of Aerospace Medicine, San Antonio, TX, USA.

Abstract:  The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) originated in Wuhan, China in late 2019, and its resulting coronavirus disease, COVID-19, was declared a pandemic by the World Health Organization on March 11, 2020. The rapid global spread of COVID-19 represents perhaps the most significant public health emergency in a century. As the pandemic progressed, a continued paucity of evidence on routes of SARS-CoV-2 transmission has resulted in shifting infection prevention and control guidelines between classically-defined airborne and droplet precautions. During the initial isolation of 13 individuals with COVID-19 at the University of Nebraska Medical Center, we collected air and surface samples to examine viral shedding from isolated individuals. We detected viral contamination among all samples, supporting the use of airborne isolation precautions when caring for COVID-19 patients. 

Retracted: No

PubPeer comments:
 Comments on the preprint (I think): https: pubpeer.com publications 01779AEDF93AEA3736DB5C923760C9 , 
 Figure 2, panels A and B are supposed to be of cell cultures exposed to two different environmental samples. These images look identical to me. ![file] , 
 #2 Yes, clearly , 
 You can indeed read my comments on the preprint at https: pubpeer.com publications 01779AEDF93AEA3736DB5C923760C9 . Some additional remarks: - Happy that the authors calculated their standard curve starting with known copies u00b5L. Question is, how did they quantify their standard? - As all qPCR values are so low, maybe a standard curve with smaller dilutions in the lower range would have been of added value. (Also, at those low ranges, you get subsampling effects). A lot of data are flirting (or below) with the LOD. - Do they mean triplicates or 3 PCR runs? (all on the same RNA extraction???) - From the previous version I understood that a fixed threshold instead of a calibrator or standard curve on each plate was used. Looking at the formula, I do have the impression that this problem was not fixed. This can definitely have an impact on the small differences observed here. F. e.  a mean concentration of 0.22 copies u00b5L is your detection limit. - Considering Figure 2C: ![file] - taking supernatant away for analysis should not result in lower virus , as your concentration per u00b5L does not directly change. (It is even more likely to increase, as you are concentrating the supernatant and production is theoretically ongoing ...) - If you want to do a decent experiment, wash away the virus after several hours or a day (depending on the kinetics), and follow up production then. - Claiming an increase requires statistics. The same is through for the claims that are made about  differences in the discussion on the data presented in table S1. (If you look at differences, use by preference a method like dCq or ddCq and perform the correct statistical tests.) - It remains a pity that the viruses detected with TEM were not quantified (and maybe checked and quantified for maturation etc). - There is a small mistake in the legend (Fig 2F) of the TEM image:  TEM images of the lysates from the windowsill culture . I hope this were fixed cells and not lysed cells. - CPE is a strong word for the observation made in Figure 2A. Was the picture from the control taken the same day? (From the figure, I guess not.) This might just be from keeping your cells X days in culture if not. - Figure 2E. I am a bit surprised that all cells seem infected, in particular due to the low viral RNA copy numbers. - The fact that the personnel samplers showed higher viral loads: couldn t this be a result of the fact that they come closer to the patients and talk to them? , 
 #2 Indeed. You are correct. We submitted a corrected image to the journal about a week ago, and the correction should be published soon. , 
 #4 I did analyze the data in Figure 2C a bit deeper. Firstly, the error bars are not described (and not 2-sided). Based on estimates I do estimate the following values for Day 2, 3 4: - Day 2: mean: 0.15 (below the limit of detection), SD5(?): 0.3: (so, 2 out of 3 technical biological ... replicates did not show anything) - Day 3: mean 0.75, SD 0.7 - Day 4: mean 0.95, SD 0.9 Do you see the problem? Now, if you calculate this back to Cq with the formula you do get: Day 2: mean + SD: 37.32 - mean: 39.93 ( LOD) - mean -Cq??? This is a Cq STDEV 2 Cq Day 3: mean + SD: 34.54 - mean: 36.11 - mean-Cq: 42.5 (??) This is a Cq STDEV 2 Cq Day 4: mean + SD: mean: 34.5 + 35.5 - mean-Cq: 42.5 (??) This is again a large Cq STDev The problem even becomes bigger, if you assume that each time at least one sample was 0... This is just to show you the problem, as I cannot retrieve the exact values. I would suggest that the authors would publish their Cq values (and maybe their amplification plots as well), so we could do proper calculations and statistics and make this a better publication. , 
 September 22, 2020 Correction to: Scientific Reports https: doi.org 10.1038 s41598-020-69286-3, published online 29 July 2020 This Article contains an error. As a result of an error during figure assembly, NQU A Windowsill Day 5 image in Fig 2B duplicates NQU Hallway Air Day 8 image in Fig 2A. The correct image for NQU A Windowsill Day 5 is shown below as Figure 1. ![file] ,