key: cord-0845900-ozry96of
authors: Chow, Angela; Guo, Huiling; Kyaw, Win Mar; Li, Anthony Lianjie; Lim, Rachel Hui Fen; Ang, Brenda
title: Rostered routine testing for severe acute respiratory coronavirus virus 2 (SARS-CoV-2) infection among healthcare personnel—Is there a role in a tertiary-care hospital with enhanced infection prevention and control measures and robust sickness-surveillance systems?
date: 2021-06-02
journal: Infection control and hospital epidemiology
DOI: 10.1017/ice.2021.268
sha: 7508e63da5bf582fa1a5a58a7182044a08cc6c2c
doc_id: 845900
cord_uid: ozry96of

nan

Upon detection of the cluster on April 28, 2021, the affected ward was locked down and contact tracing was initiated. HCP close contacts were defined as those who had interacted with a confirmed COVID-19 patient or HCP for a cumulative duration of ≥15 minutes within a distance of 2 m, or ward-based HCP. Close contacts were placed on quarantine and were screened for SARS-CoV-2 infection via polymerase chain reaction (PCR) test on entry to quarantine and at 7, 14, and 21 days from the date of last exposure to the confirmed case or to the ward. Furthermore, HCP who had visited the affected ward between April 20 and 28, 2021, for a cumulative duration of ≥15 minutes were also identified, placed on quarantine, and screened for SARS-CoV-2 infection on entry to quarantine and at 7, 14, and 21 days from the date of last exposure to the affected ward. The first patient identified with COVID-19 was admitted to the ward on April 20, and the ward was locked down on April 28. Additionally, all asymptomatic HCP working in the hospital underwent weekly SARS-CoV-2 PCR testing until the affected ward reopened on May 22.

Among 416 HCP close contacts who were placed under quarantine, 1 HCP was detected with SARS-CoV-2 infection via quarantine on-entry test 1 day prior to ARI symptom onset, and 2 were detected when they developed ARI symptoms within first 4 days of quarantine (Table 1) . Among the 634 HCP who had visited the affected ward for ≥15 minutes, 1 HCP was positive 2 days prior to symptom onset.

Of 11,004 asymptomatic staff who had undergone 2 rounds of weekly SARS-CoV-2 PCR testing, none was confirmed with COVID-19. However, 10 were identified to have equivocal results, with high cycle threshold values ranging from 37.42 to 43.30. For these HCP with equivocal results, subsequent 2 swabs taken 24 hours apart yielded negative results by the hospital's laboratory and the national reference laboratory. All except 1 HCP had nonreactive serology test results; that HCP was a returned traveler from India who was diagnosed with COVID-19 on arrival to Singapore in March 2021. Each HCP with an equivocal test result was placed on leave of absence (LOA) and was advised to self-isolate at home except for returning to the hospital for tests. Coworkers identified to be close contacts of the HCP were also placed on LOA until the repeated tests returned negative. An average of 7 HCP close contacts (maximum, 18) per HCP with equivocal test results were placed on LOA from work for a mean duration of 3.5 days (maximum, 5).

Although the screening of presymptomatic and symptomatic HCP close contacts and HCP who had visited the affected ward yielded a SARS-CoV-2 detection rate of 0.7% and 0.2% respectively, hospital-wide weekly screening of other asymptomatic HCP did not detect any SARS-CoV-2 infections. Instead, the hospital-wide screening resulted in a loss of productivity of 292 HCPworkdays, with a mean of 3.5 work days lost per HCP placed on LOA. For the HCP (a cook in the hospital) with the greatest number of HCP close contacts (n = 18) placed on LOA, response to the equivocal test result caused a reduction in food choices and compromised the nutritional services available to patients.

Even in the wake of a ward cluster due to a highly transmissible SARS-CoV-2 variant strain, the extensive hospital-wide testing of asymptomatic HCP did not uncover any covert infections. With the hospital's robust infection prevention and control measures and HCP ARI surveillance system, the implementation of RRT may yield limited benefits and paradoxically exacerbate strained manpower and laboratory resources that could be conserved to manage community SARS-CoV-2 infections. Other HCP 11,004 0 10 10,994 0 a Had an interaction with a confirmed COVID-19 patient or HCP for a cumulative total duration of ≥15 min within a distance of 2 m, or were ward-based HCP. b Visited the affected ward between April 20 and 28, 2021, for a cumulative total duration of ≥15 min.

Frequency of routine testing for coronavirus disease 2019 (COVID-19) in high-risk healthcare environments to reduce outbreaks

Routine surveillance of asymptomatic healthcare personnel for severe acute respiratory coronavirus virus 2 (SARS-CoV-2): not a prevention strategy

Asymptomatic health-care worker screening during the COVID-19 pandemic

Responding to the COVID-19 outbreak in Singapore: staff protection and staff temperature and sickness surveillance systems

Dancing with COVID-19 after the hammer is lifted: enhancing healthcare worker surveillance

Healthcare worker acute respiratory illness cluster in 2020: could it be from COVID-19?

Healthcare workers as 'canaries' for acute respiratory infections and pathogens during the COVID-19 pandemic

Far from out of the woods': how a COVID-19 variant put Singapore back in defensive mode. South China Morning Post website

Acknowledgments. We thank colleagues from TTSH's human resource (Serene Tan and her team) and hospital operations (Michael Leow and his team), departments that worked tirelessly to collate the data on HCP on quarantine and weekly SARS-CoV-2 PCR testing.Financial support. No financial support was provided relevant to this article.Conflicts of interest. All authors report no conflicts of interest relevant to this article.