Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Jan:126:73-78.
doi: 10.1016/j.ijid.2022.11.003. Epub 2022 Nov 8.

Viable SARS-CoV-2 detected in the air of hospital rooms of patients with COVID-19 with an early infection

Hiroki Kitagawa  1 , Toshihito Nomura  2 , Yuki Kaiki  3 , Masaki Kakimoto  4 , Tanuza Nazmul  5 , Keitaro Omori  6 , Norifumi Shigemoto  7 , Takemasa Sakaguchi  5 , Hiroki Ohge  6
Affiliations

Viable SARS-CoV-2 detected in the air of hospital rooms of patients with COVID-19 with an early infection

Hiroki Kitagawa et al. Int J Infect Dis. 2023 Jan.

Abstract

Objectives: This study assessed the concentration of SARS-CoV-2 in the air of hospital rooms occupied by patients with COVID-19 who had viable SARS-CoV-2 in nasopharyngeal (NP) samples in early infection.

Methods: Between July and October 2021, NP swabs were collected from 20 patients with early SARS-CoV-2 infection admitted to a tertiary hospital in Japan. Air samples were collected from their rooms, tested for SARS-CoV-2 RNA, and cultured to determine potential infectivity.

Results: The NP swab samples of 18 patients were positive for viable SARS-CoV-2 (median concentration: 4.0 × 105 tissue culture infectious dose 50/ml). In the air samples, viral RNA (median concentration: 1.1 × 105 copies/m3) was detected in 12/18 (67%) patients, and viable virus (median concentration: 8.9 × 102 tissue culture infectious dose 50/m3) was detected in 5/18 (28%) patients. The median time between illness onset and sampling was 3 days. The RNA concentration was significantly higher in samples wherein viable SARS-CoV-2 was detected than in samples in which viable virus was not detected (P-value = 0.027).

Conclusion: Viable SARS-CoV-2 can be detected in the air surrounding patients with early SARS-CoV-2 infection. Health care workers should pay attention to infection control when caring for patients with early SARS-CoV-2 infection.

Keywords: Aerosol; Air sampling; Airborne transmission; Delta SARS-CoV-2 variant; SARS-CoV-2.

PubMed Disclaimer

Conflict of interest statement

Declaration of competing interest The authors have no competing interests to declare.

Figures

Figure 1
Figure 1
Relationship between SARS-CoV-2 RNA concentration in nasopharyngeal swabs and air samples of 18 participants. TCID50, median tissue culture infectious dose.
Figure 2
Figure 2
Relationship between viable SARS-CoV-2 concentration in nasopharyngeal swabs and SARS-CoV-2 RNA concentration in air samples of 18 participants. TCID50, median tissue culture infectious dose. *This dot includes the data of two samples.
Figure 3
Figure 3
Relationship between SARS-CoV-2 RNA concentration and viable SARS-CoV-2 concentration in air samples of 18 participants. TCID50, median tissue culture infectious dose. *This dot includes the data of three samples.
See this image and copyright information in PMC

References

    1. Adenaiye OO, Lai J, Bueno de Mesquita PJB, Hong F, Youssefi S, German J, et al. Infectious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in exhaled aerosols and efficacy of masks during early mild infection. Clin Infect Dis. 2022;75:e241–e248. - PMC - PubMed
    1. Alsved M, Nygren D, Thuresson S, Medstrand P, Fraenkel CJ, Löndahl J. SARS-CoV-2 in exhaled aerosol particles from COVID-19 cases and its association to household transmission. Clin Infect Dis. 2022;75:e50–e56. - PMC - PubMed
    1. Charlson ME, Pompei P, Ales KL, MacKenzie CR. A new method of classifying prognostic comorbidity in longitudinal studies: development and validation. J Chronic Dis. 1987;40:373–383. - PubMed
    1. Coleman KK, Tay DJW, Tan KS, Ong SWX, Than TS, Koh MH, et al. Viral load of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in respiratory aerosols emitted by patients with coronavirus disease 2019 (COVID-19) while breathing, talking, and singing. Clin Infect Dis. 2022;74:1722–1728. - PMC - PubMed
    1. Dinoi A, Feltracco M, Chirizzi D, Trabucco S, Conte M, Gregoris E, et al. A review on measurements of SARS-CoV-2 genetic material in air in outdoor and indoor environments: implication for airborne transmission. Sci Total Environ. 2022;809 - PMC - PubMed