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

Hiroki Kitagawa; Toshihito Nomura; Yuki Kaiki; Masaki Kakimoto; Tanuza Nazmul; Keitaro Omori; Norifumi Shigemoto; Takemasa Sakaguchi; Hiroki Ohge

doi:10.1016/j.ijid.2022.11.003

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

Int J Infect Dis. 2023 Jan:126:73-78. doi: 10.1016/j.ijid.2022.11.003. Epub 2022 Nov 8.

Authors

Hiroki Kitagawa¹, Toshihito Nomura², Yuki Kaiki³, Masaki Kakimoto⁴, Tanuza Nazmul⁵, Keitaro Omori⁶, Norifumi Shigemoto⁷, Takemasa Sakaguchi⁵, Hiroki Ohge⁶

Affiliations

¹ Department of Infectious Diseases, Hiroshima University Hospital, Hiroshima, Japan; Department of Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan. Electronic address: hkitaga@hiroshima-u.ac.jp.
² Department of Infectious Diseases, Hiroshima University Hospital, Hiroshima, Japan; Department of Virology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
³ Department of Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
⁴ Department of General Internal Medicine, Hiroshima University Hospital, Hiroshima, Japan.
⁵ Department of Virology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
⁶ Department of Infectious Diseases, Hiroshima University Hospital, Hiroshima, Japan.
⁷ Department of Infectious Diseases, Hiroshima University Hospital, Hiroshima, Japan; Department of Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan; Translational Research Center, Hiroshima University, Hiroshima, Japan.

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.

MeSH terms

COVID-19* / diagnosis
Hospitalization
Hospitals
Humans
RNA, Viral / genetics
SARS-CoV-2 / genetics

Substances

RNA, Viral