Use of serial testing to interrupt a severe acute respiratory coronavirus virus 2 (SARS-CoV-2) outbreak on a hospital medical floor—Minnesota, October–December 2020

Abstract

Objective: Describe a SARS-CoV-2 hospital outbreak and the role of serial testing of patients and healthcare personnel (HCP) in interrupting transmission. Design: Outbreak investigation Setting: Medical floor of a tertiary care center in Minnesota Methods: Serial testing for SARS-CoV-2 and whole genome sequencing (WGS) of positive specimens from HCP and patients was used. An outbreak-associated case was defined as a positive SARS-CoV-2 molecular test in HCP who worked on the floor prior to testing positive or in a patient who was hospitalized on the medical floor during October 27–December 1, 2020. WGS was used to understand potential routes of transmission. Results: The outbreak was detected after a patient hospitalized for 12 days tested positive for SARS-CoV-2. Serial testing of patients and HCP was conducted in response. Overall, 247 HCP and 41 patients participated in serial SARS-CoV-2 testing. Fifty-two (21%) HCP and 19 (46%) hospitalized patients tested positive. One additional HCP tested positive outside of serial testing. WGS of specimens from 27 (51%) HCP and 15 (79%) patients identified three distinct transmission clusters. WGS and epidemiologic evidence suggested intrafacility transmission. The proportion of asymptomatic and pre-symptomatic patients who tested positive (63%) and HCP who worked during their infectious period (75%) highlight the need for serial testing of asymptomatic patients and HCP during outbreaks. Conclusions: Coupled with preventive measures such as personal protective equipment use and physical distancing, serial testing of HCP and patients could help detect and prevent transmission within healthcare facilities during outbreaks and when nosocomial transmission is suspected.

Factors contributing to a coronavirus disease 2019 (COVID-19) outbreak on a mixed medical-surgical unit in a Canadian acute-care hospital

“…In this study, we have shown the benefits of the outbreak investigation of adding WGS analysis. Other reports have highlighted the utility of WGS in outbreak investigation, 3,5,9,12,13,16,18,20,21 including its ability to identify complex outbreaks characterized by introduction of infections by >1 source or refute the original transmission hypothesis. WGS supported this study's hypothesis of the introduction of SARS-CoV-2 onto the unit by 2 patients who presented to the hospital with respiratory symptoms, one of whom was later found to have had community contact with COVID-19.…”

“…Since the beginning of the coronavirus disease 2019 (COVID-19) pandemic, 1 there have been reports of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission to patients and healthcare workers (HCW) within healthcare facilities. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] Factors contributing to these outbreaks have included patient accommodation in multibed rooms or bays, [6][7][8]11,12,17 lack of infection prevention and control precautions due to failure to identify patients admitted with or incubating SARS-CoV-2, [6][7][8][9][10]20 and nosocomial exposure to a patient with COVID-19. [15][16][17][18][19][20] Rhee et al 22 demonstrated that consistent application of infection prevention and control measures can reduce or prevent the spread of SARS-CoV-2 in healthcare settings.…”

Implementation and Adherence to Regular Asymptomatic Testing in a COVID-19 Vaccine Trial

“…This is consistent with other short-term asymptomatic COVID-19 testing schemes in university and hospital settings. 19, 20 For example, in their study of weekly SARS-CoV-2 antigen testing in a university over a 6-week period, Bigouette et al . found weekly adherence ranged between 70·5% and 80·6%.…”

Nosocomial severe acute respiratory coronavirus virus 2 (SARS-CoV-2) transmission arising from a case of N-gene dropout on reverse-transcription polymerase chain reaction (RT-PCR) testing

“…To the Editor— During the coronavirus-disease-2019 (COVID-19) pandemic, in-hospital surveillance via serial severe acute respiratory coronavirus virus 2 (SARS-CoV-2) testing has repeatedly demonstrated its utility in early detection, isolation, and interruption of nosocomial transmission. 1 However, analytical sensitivity of real-time, reverse-transcriptase, polymerase chain reaction (rRT-PCR) testing for SARS-CoV-2 is crucial in ensuring accurate results and early detection of COVID-19 cases and, thus, to mitigate nosocomial COVID-19 outbreaks. The emergence of SARS-CoV-2 variants has been demonstrated to negatively affect analytical sensitivity of rRT-PCR assays.…”

“…The risk of an HCW acquiring COVID-19 from another HCW is reportedly 3 times higher than contracting it from patients. 1 Given that not all infections are detected, it is critically important that during surges, all infection controls (administrative, engineering, and personal protective equipment [PPE]) are optimized to protect patients and HCW colleagues. 2 We report a case in which a highly infectious HCW working with profoundly immunosuppressed patients did not transmit SARS-CoV-2 to patients despite multiple close interactions.…”