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Case Reports
. 2021 Sep;42(9):1046-1052.
doi: 10.1017/ice.2020.321. Epub 2020 Jul 3.

Investigation of nosocomial SARS-CoV-2 transmission from two patients to healthcare workers identifies close contact but not airborne transmission events

Derek J Bays  1 , Minh-Vu H Nguyen  1 , Stuart H Cohen  1 , Sarah Waldman  1 , Carla S Martin  2 , George R Thompson  1   3 , Christian Sandrock  4 , Joel Tourtellotte  4 , Janelle Vu Pugashetti  4 , Chinh Phan  4 , Hien H Nguyen  1   5 , Gregory Y Warner #  6 , Bennett H Penn #  1   3
Affiliations
Case Reports

Investigation of nosocomial SARS-CoV-2 transmission from two patients to healthcare workers identifies close contact but not airborne transmission events

Derek J Bays et al. Infect Control Hosp Epidemiol. 2021 Sep.

Abstract

Objective: To describe the pattern of transmission of severe acute respiratory coronavirus virus 2 (SARS-CoV-2) during 2 nosocomial outbreaks of coronavirus disease 2019 (COVID-19) with regard to the possibility of airborne transmission.

Design: Contact investigations with active case finding were used to assess the pattern of spread from 2 COVID-19 index patients.

Setting: A community hospital and university medical center in the United States, in February and March, 2020, early in the COVID-19 pandemic.

Patients: Two index patients and 421 exposed healthcare workers.

Methods: Exposed healthcare workers (HCWs) were identified by analyzing the electronic medical record (EMR) and conducting active case finding in combination with structured interviews. Healthcare coworkers (HCWs) were tested for COVID-19 by obtaining oropharyngeal/nasopharyngeal specimens, and RT-PCR testing was used to detect SARS-CoV-2.

Results: Two separate index patients were admitted in February and March 2020, without initial suspicion for COVID-19 and without contact or droplet precautions in place; both patients underwent several aerosol-generating procedures in this context. In total, 421 HCWs were exposed in total, and the results of the case contact investigations identified 8 secondary infections in HCWs. In all 8 cases, the HCWs had close contact with the index patients without sufficient personal protective equipment. Importantly, despite multiple aerosol-generating procedures, there was no evidence of airborne transmission.

Conclusion: These observations suggest that, at least in a healthcare setting, most SARS-CoV-2 transmission is likely to take place during close contact with infected patients through respiratory droplets, rather than by long-distance airborne transmission.

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Figures

Fig. 1.
Fig. 1.
Stratification of exposed healthcare workers (HCWs) for case 1 at hospital A.
Fig. 2.
Fig. 2.
Description of staff at endotracheal intubation for case 1 at hospital A. Note. Sx+, symptomatic; Sx (−) asymptomatic; PCR +/(−) denotes SARS-CoV-2 test result.
Fig. 3.
Fig. 3.
Stratification of exposed healthcare workers (HCWs) for case 1 at hospital B.
Fig. 4.
Fig. 4.
Stratification of exposed healthcare workers (HCWs) for case 2.
Fig. 5.
Fig. 5.
Description of staff present during intubation of case 2. Note. Sx+, symptomatic; Sx(−) asymptomatic; PCR +/(−) denotes SARS-CoV-2 test result.
See this image and copyright information in PMC

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