SARS-CoV-2 Droplet and Airborne Transmission Heterogeneity
The spread dynamics of the SARS-CoV-2 virus have not yet been fully understood after two years of the pandemic. The virus’s global spread represented a unique scenario for advancing infectious disease research. Consequently, mechanistic epidemiological theories were quickly dismissed, and more atten...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-05-01
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| Series: | Journal of Clinical Medicine |
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| Online Access: | https://www.mdpi.com/2077-0383/11/9/2607 |
| _version_ | 1797504138403119104 |
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| author | Marta Baselga Antonio Güemes Juan J. Alba Alberto J. Schuhmacher |
| author_facet | Marta Baselga Antonio Güemes Juan J. Alba Alberto J. Schuhmacher |
| author_sort | Marta Baselga |
| collection | DOAJ |
| description | The spread dynamics of the SARS-CoV-2 virus have not yet been fully understood after two years of the pandemic. The virus’s global spread represented a unique scenario for advancing infectious disease research. Consequently, mechanistic epidemiological theories were quickly dismissed, and more attention was paid to other approaches that considered heterogeneity in the spread. One of the most critical advances in aerial pathogens transmission was the global acceptance of the airborne model, where the airway is presented as the epicenter of the spread of the disease. Although the aerodynamics and persistence of the SARS-CoV-2 virus in the air have been extensively studied, the actual probability of contagion is still unknown. In this work, the individual heterogeneity in the transmission of 22 patients infected with COVID-19 was analyzed by close contact (cough samples) and air (environmental samples). Viral RNA was detected in 2/19 cough samples from patient subgroups, with a mean Ct (Cycle Threshold in Quantitative Polymerase Chain Reaction analysis) of 25.7 ± 7.0. Nevertheless, viral RNA was only detected in air samples from 1/8 patients, with an average Ct of 25.0 ± 4.0. Viral load in cough samples ranged from 7.3 × 10<sup>5</sup> to 8.7 × 10<sup>8</sup> copies/mL among patients, while concentrations between 1.1–4.8 copies/m<sup>3</sup> were found in air, consistent with other reports in the literature. In patients undergoing follow-up, no viral load was found (neither in coughs nor in the air) after the third day of symptoms, which could help define quarantine periods in infected individuals. In addition, it was found that the patient’s Ct should not be considered an indicator of infectiousness, since it could not be correlated with the viral load disseminated. The results of this work are in line with proposed hypotheses of superspreaders, which can attribute part of the heterogeneity of the spread to the oversized emission of a small percentage of infected people. |
| first_indexed | 2024-03-10T04:00:24Z |
| format | Article |
| id | doaj.art-550fbe29c89f48efa6392ff492369636 |
| institution | Directory Open Access Journal |
| issn | 2077-0383 |
| language | English |
| last_indexed | 2024-03-10T04:00:24Z |
| publishDate | 2022-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Journal of Clinical Medicine |
| spelling | doaj.art-550fbe29c89f48efa6392ff4923696362023-11-23T08:34:48ZengMDPI AGJournal of Clinical Medicine2077-03832022-05-01119260710.3390/jcm11092607SARS-CoV-2 Droplet and Airborne Transmission HeterogeneityMarta Baselga0Antonio Güemes1Juan J. Alba2Alberto J. Schuhmacher3Institute for Health Research Aragon (IIS Aragón), 50009 Zaragoza, SpainInstitute for Health Research Aragon (IIS Aragón), 50009 Zaragoza, SpainInstitute for Health Research Aragon (IIS Aragón), 50009 Zaragoza, SpainInstitute for Health Research Aragon (IIS Aragón), 50009 Zaragoza, SpainThe spread dynamics of the SARS-CoV-2 virus have not yet been fully understood after two years of the pandemic. The virus’s global spread represented a unique scenario for advancing infectious disease research. Consequently, mechanistic epidemiological theories were quickly dismissed, and more attention was paid to other approaches that considered heterogeneity in the spread. One of the most critical advances in aerial pathogens transmission was the global acceptance of the airborne model, where the airway is presented as the epicenter of the spread of the disease. Although the aerodynamics and persistence of the SARS-CoV-2 virus in the air have been extensively studied, the actual probability of contagion is still unknown. In this work, the individual heterogeneity in the transmission of 22 patients infected with COVID-19 was analyzed by close contact (cough samples) and air (environmental samples). Viral RNA was detected in 2/19 cough samples from patient subgroups, with a mean Ct (Cycle Threshold in Quantitative Polymerase Chain Reaction analysis) of 25.7 ± 7.0. Nevertheless, viral RNA was only detected in air samples from 1/8 patients, with an average Ct of 25.0 ± 4.0. Viral load in cough samples ranged from 7.3 × 10<sup>5</sup> to 8.7 × 10<sup>8</sup> copies/mL among patients, while concentrations between 1.1–4.8 copies/m<sup>3</sup> were found in air, consistent with other reports in the literature. In patients undergoing follow-up, no viral load was found (neither in coughs nor in the air) after the third day of symptoms, which could help define quarantine periods in infected individuals. In addition, it was found that the patient’s Ct should not be considered an indicator of infectiousness, since it could not be correlated with the viral load disseminated. The results of this work are in line with proposed hypotheses of superspreaders, which can attribute part of the heterogeneity of the spread to the oversized emission of a small percentage of infected people.https://www.mdpi.com/2077-0383/11/9/2607COVID-19bioaerosolsinfectious diseasescoughairbornesuperspreaders |
| spellingShingle | Marta Baselga Antonio Güemes Juan J. Alba Alberto J. Schuhmacher SARS-CoV-2 Droplet and Airborne Transmission Heterogeneity Journal of Clinical Medicine COVID-19 bioaerosols infectious diseases cough airborne superspreaders |
| title | SARS-CoV-2 Droplet and Airborne Transmission Heterogeneity |
| title_full | SARS-CoV-2 Droplet and Airborne Transmission Heterogeneity |
| title_fullStr | SARS-CoV-2 Droplet and Airborne Transmission Heterogeneity |
| title_full_unstemmed | SARS-CoV-2 Droplet and Airborne Transmission Heterogeneity |
| title_short | SARS-CoV-2 Droplet and Airborne Transmission Heterogeneity |
| title_sort | sars cov 2 droplet and airborne transmission heterogeneity |
| topic | COVID-19 bioaerosols infectious diseases cough airborne superspreaders |
| url | https://www.mdpi.com/2077-0383/11/9/2607 |
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