Air surveillance of SARS-CoV-2 and different respiratory pathogens

Post date:



A current research posted to the medRxiv* preprint server reported extreme acute respiratory syndrome coronavirus-2 (SARS-CoV-2) detection in air samples from real-world congregate settings.

Two years for the reason that coronavirus illness 2019 (COVID-19) pandemic, SARS-CoV-2 surveillance has been difficult in the USA (US). Polymerase chain response (PCR) assays had been deployed slowly, and the huge demand for PCR-based analysis constrained laboratories and provide chains. Whereas point-of-care antigen assessments had been out there by late 2020, their software was not widespread till the emergence of the SARS-CoV-2 Omicron variant.

The US recorded greater than 1.3 million instances on January 10, 2022, the very best ever single-day surge, with a seven-day common being 3 times greater than the earlier peak. Because of this, laboratory testing was overwhelmed by the huge, unprecedented enhance of COVID-19 instances. Subsequently, there’s a urgent have to diversify and discover novel viral testing methods to evaluate the transmission threat of SARS-CoV-2.

Study: SARS-CoV-2 and other respiratory pathogens are detected in continuous air samples from congregate settings. Image Credit: Kateryna Kon / ShutterstockResearch: SARS-CoV-2 and different respiratory pathogens are detected in steady air samples from congregate settings. Picture Credit score: Kateryna Kon / Shutterstock

The research and findings

Within the current research, researchers examined if lively air samplers could possibly be employed for potential air surveillance of SARS-CoV-2.

The analysis group deployed steady air samplers in lots of public locations between July 19, 2021, and February 9, 2022, for surveying SARS-CoV-2 at websites which might be flagged as excessive threat for indoor transmission and close-contact.

Thermo Fisher Scientific’s aerosol sense samplers had been used for weekly and day by day surveillance. Transcription-mediated amplification (TMA) and quantitative reverse transcription PCR (RT-qPCR) had been carried out on the examined samples for the extraction of SARS-CoV-2 ribonucleic acid (RNA). The testing places all through Wisconsin and Minnesota coated a hospital, workplace, two preschools, cafeteria, brewery taproom, campus espresso store, athletic coaching facility, bar, two shelters, and 4 Okay-12 colleges.

About 527 air samples had been collected from 15 places, with a majority (88.4%) from Dane County, Wisconsin. The authors detected 106 SARS-CoV-2-positive air samples, and 52 others had been deemed inconclusive.

Regardless of the intensive implementation of threat mitigation measures, air cartridges had been constructive for SARS-CoV-2 at 14 surveillance places. Since, by means of this technique, it was not possible to find out the COVID-19 standing of each particular person vicinal to air samplers, a retrospective correlation with air surveillance knowledge was estimated with reported COVID-19 an infection instances at one of many websites.

Air sample testing workflow.

Air pattern testing workflow.

(A) Overview of air pattern assortment, processing, and testing. (B) Air pattern knowledge assortment and administration. People in control of altering air cartridges at surveillance websites use the iOS and Android Askidd cellular app to gather metadata on air samples when cartridges are inserted and eliminated. Knowledge are compiled in Labkey database and exhibited to surveillance websites within the Askidd cellular app. Created with

The primary documented case was from a quarantining particular person who took the check after creating signs. These current in the identical room needed to quarantine, however none had been constructive on the time. Three shut contacts examined constructive with antigen assessments. Subsequently, a number of others examined constructive, leading to an outbreak of 20 confirmed infections. Air samples collected a minimum of seven days earlier than the primary documented case of COVID-19 had been constructive.

Subsequent, the researchers examined the feasibility of extending the interval of sampling. For 5 weeks, two samplers had been deployed to seize specimens weekly or day by day. The group famous that both weekly or day by day sampling could possibly be utilized in congregate settings with a stability between turnaround time and value. Moreover, the air samples collected between October 25, 2021, and February 9, 2022, from eight places in Wisconsin had been examined for the presence of different respiratory pathogens (micro organism, fungi, and viruses). Throughout this era, 16 different respiratory pathogens had been detected. Commensals or transiently commensal respiratory microbes, together with Klebsiella pneumoniae, Moraxella catarrhalis, and Staphylococcus aureus, had been recognized steadily. Pathogens resembling adenovirus, cytomegalovirus, Epstein-Barr virus, influenza, and parainfluenza, amongst others, inflicting sickness in school-aged youngsters had been additionally detected. The nucleic acids of influenza A virus (IAV) had been detected in air specimens on the College of Wisconsin-Madison campus ranging from November 10, 2021, by means of January 2022. One of many two samplers positioned within the campus espresso store offered damaging air samples starting the week of December 22, 2021, till January 12, 2022, coinciding with the autumn break.

Lastly, SARS-CoV-2 genomic sequencing was carried out on 11 air samples with low cycle threshold (Ct) values collected from websites the place individuals had been typically unmasked to eat or drink. Utilizing two sequencing methods, partial or near-full size genome sequences had been obtained. Samples collected between December 30, 2021, and January 25, 2021, contained the attribute mutations of the SARS-CoV-2 Omicron BA.1 lineage, coincident with the arrival of the Omicron variant within the area.


The research findings demonstrated the applicability of lively air samplers for surveillance of SARS-CoV-2 and different respiratory pathogens along with current mitigation methods. Air surveillance would possibly assist establish pathogenic aerosols in congregate settings to evaluate the transmission threat. It’s noteworthy that RT-qPCR testing doesn’t distinguish between an infectious virus or the genetic materials. The researchers didn’t isolate SARS-CoV-2 or different pathogens from constructive samples by means of cultures.

Air surveillance could possibly be a scalable, cost-effective technique and show a high-throughput substitute for particular person testing to detect SARS-CoV-2 and different respiratory pathogens in congregate settings. Thus, establishing an air surveillance community just like the wastewater surveillance system would possibly supply extra safeguards and enhance resilience to future threats of respiratory problems.

*Necessary discover

medRxiv publishes preliminary scientific experiences that aren’t peer-reviewed and, due to this fact, shouldn’t be considered conclusive, information scientific observe/health-related conduct, or handled as established info.

Journal reference:

  • SARS-CoV-2 and different respiratory pathogens are detected in steady air samples from congregate settings, Mitchell D Ramuta, Christina M Newman, Savannah F Brakefield, Miranda R Stauss, Roger W Wiseman, Amanda Kita-Yarbro, Eli J O’Connor, Neeti Dahal, Ailam Lim, Keith P Poulsen, Nasia Safdar, John A Marx, Molly A Accola, William M Rehrauer, Julia A Zimmer, Manjeet Khubbar, Lucas J Beversdorf, Emma C Boehm, David Castaneda, Clayton Rushford, Devon Arch Gregory, Joseph D Yao, Sanjib Bhattacharyya, Marc C Johnson, Matthew T Aliota, Thomas Friedrich, David O’Connor, Shelby L O’Connor, medRxiv preprint 2022, DOI:, material/10.1101/2022.03.29.22272716v1




%d bloggers like this: