key: cord-0783003-pgc7hw4z
authors: Wee, Liang En; Venkatachalam, Indumathi; Jean Sim, Xiang Ying; Boon-Kiat Tan, Kenneth; Wen, Ruan; Tham, Chee Kian; Gan, Wee Hoe; Karrie Ko, Kwan Ki; Ho, Wan Qi; Teck Cheng, Grace Kwek; Conceicao, Edwin Philip; Edwin Sng, Chong Yu; Jorin Ng, Xin Hui; Ong, Jie Yi; Chiang, Juat Lan; Chua, Ying Ying; Ling, Moi Lin; Tan, Thuan Tong; Wijaya, Limin
title: Containment of COVID-19 and reduction in healthcare-associated respiratory viral infections through a multi-tiered infection control strategy
date: 2020-11-16
journal: Infect Dis Health
DOI: 10.1016/j.idh.2020.11.004
sha: 0e0eddf47a912e2c0f2dabb7b0e102cbeab26168
doc_id: 783003
cord_uid: pgc7hw4z

BACKGROUND: During the ongoing COVID-19 pandemic, healthcare-associated transmission of respiratory viral infections (RVI) is a concern. To reduce the impact of SARS-CoV-2 and other respiratory viruses on patients and healthcare workers (HCWs) we devised and evaluated a multi-tiered infection control strategy with the goal of preventing nosocomial transmission of SARS-CoV2 and other RVIs across a large healthcare campus. METHODOLOGY: From January-June 2020, a multi-tiered infection control strategy was implemented across a healthcare campus in Singapore, comprising the largest acute tertiary hospital as well as four other subspecialty centres, with more than 10,000 HCWs. Drawing on our institution’s experience with an outbreak of Severe Acute Respiratory Syndrome (SARS) in 2003, this strategy included improved patient segregation and distancing, and heightened infection prevention and control (IPC) measures including universal masking. All symptomatic patients were tested for COVID-19 and common RVIs. RESULTS: A total of 16,162 admissions campus-wide were screened; 7.% (1155/16162) tested positive for COVID-19. Less than 5% of COVID-19 cases (39/1155) were initially detected outside of isolation wards in multi-bedded cohorted wards. Improved distancing and enhanced IPC measures successfully mitigated onward spread even amongst COVID-19 cases detected outside of isolation. COVID-19 rates amongst HCWs were kept low (0.13%, 17/13066) and reflected community acquisition rather than nosocomial spread. Rates of healthcare-associated-RVI amongst inpatients fell to zero and this decrease was sustained even after the lifting of visitor restrictions. CONCLUSION: This multi-tiered infection control strategies can be implemented at-scale to successfully mitigate healthcare-associated transmission of respiratory viral pathogens.

During the ongoing COVID-19 pandemic, healthcare-associated transmission of respiratory viral 5 infections (RVI) is a concern. To reduce the impact of SARS-CoV-2 and other respiratory viruses on 6 patients and healthcare workers (HCWs) we devised and evaluated a multi-tiered infection control 7

strategy with the goal of preventing nosocomial transmission of SARS-CoV2 and other RVIs across a 8 large healthcare campus. 9

From January-June 2020, a multi-tiered infection control strategy was implemented across a healthcare 11 campus in Singapore, comprising the largest acute tertiary hospital as well as four other subspecialty 12 centres, with more than 10,000 HCWs. Drawing on our institution's experience with an outbreak of 13

Severe Acute Respiratory Syndrome (SARS) in 2003, this strategy included improved patient segregation 14

and distancing, and heightened infection prevention and control (IPC) measures including universal 15

masking. All symptomatic patients were tested for COVID-19 and common RVIs. 16

A total of 16,162 admissions campus-wide were screened; 7.% (1155/16162) tested positive for 19. Less than 5% of COVID-19 cases (39/1155) were initially detected outside of isolation wards in 19 multi-bedded cohorted wards. Improved distancing and enhanced IPC measures successfully mitigated 20 onward spread even amongst COVID-19 cases detected outside of isolation. COVID-19 rates amongst 21

HCWs were kept low (0.13%, 17/13066) and reflected community acquisition rather than nosocomial 22

spread. Rates of healthcare-associated-RVI amongst inpatients fell to zero and this decrease was sustained 23 even after the lifting of visitor restrictions. 24

This multi-tiered infection control strategies can be implemented at-scale to successfully mitigate 26

healthcare-associated transmission of respiratory viral pathogens. In the current COVID-19 pandemic, healthcare-associated transmission to healthcare workers (HCWs) 41 and patients has been a major concern.[1-2] However, distinguishing cases of COVID-19 can be difficult, 42

as COVID-19 may manifest with non-specific symptoms. [ Institutional setting and study period 61

The Outram campus hosts the Singapore General Hospital (SGH), the largest tertiary hospital in 62

Singapore with 1785 beds, Outram Community Hospital (OCH), a 545-bed community hospital 63

providing step-down care, and other specialist centres, including the National Heart Centre, Singapore 64

(NHCS), National Cancer Centre, Singapore (NCC), Singapore National Eye Centre (SNEC), and the 65 National Neuroscience Institute (NNI). Almost 13,000 HCWs work on-campus. The study period lasted 66 6 months (7 th January 2020 to 7 th July 2020).

Campus-wide multi-tiered infection control strategy during COVID-19 pandemic 69

A multi-tiered approach was adopted campus-wide to contain COVID-19 amongst HCWs and patients. 70

Recognising the need for a campus-level coordinating platform for emergency preparedness in pre-71 pandemic planning, since 2007, the Outram Campus Command Centre (OCC) was designated the nerve 72 centre for overall campus-wide command-and-control during a disease outbreak situation. As the primary 73 command-and-control centre, the OCC provided instructions and protocols to all identified key hospital 74 command posts for ground implementation and served as the contact-point for external parties (eg. our 75

local Ministry of Health Figure 2a) , and all visitors were required to 98 wear a face covering. From 7 th April 2020 -1 st June 2020, a no-visitor policy was enforced, in-line with 99 the nationwide public lockdown during which all workplaces and schools were closed. The no-visitor 100 policy was lifted from 2 nd June 2020 onwards, in conjunction with the lifting of the nationwide lockdown.

Emergency department: improved segregation during COVID-19 pandemic 103

Our ED's protocols for the safe management of COVID-19 suspects have been previously published 104

elsewhere. [13] [14] [15] We evaluated the success of these protocols in the right-siting of COVID-19 patients. 105

In brief, patients with epidemiologic risk factors and patients presenting with clinical syndromes 106

potentially compatible for COVID-19, were strictly segregated in dedicated 'fever areas' (Supplementary 107 Figure 2b ). In these 'fever areas', improved spacing between ED trolleys (at least 2 metres apart) and 108 patient bays separated by partitions were introduced, and HCWs used full personal-protective-equipment 109

(PPE), including disposable gloves, gowns, eye protection, and N95 respirators. in communal settings, high-risk occupations, contact with known COVID-19 clusters or cases, or travel 116 history to areas with high incidence of COVID-19 were admitted to the purpose-built isolation ward (IW) 117

which was equipped with negative-pressure airborne-infection-isolation-rooms (AIIRs).

[11] All HCWs in 118 IW used disposable gloves, gowns, eye protection, and N95 respirators for protection. 119 120

From February 2020, given ongoing community transmission, lower-risk individuals with clinical 121 syndromes compatible with COVID-19 (eg. respiratory symptoms, infiltrates on chest imaging, or 122 undifferentiated viral fever) who did not have epidemiologic risk factors were segregated in dedicated 123 general wards, termed as "respiratory surveillance wards" (RSWs). [11, 13] . Improved segregation for 124 symptomatic inpatients was hence adopted campus-wide, for general medical and surgical patients in the 125 acute tertiary hospital as well as inpatients of the various specialised centres on campus (cardiology, 126 neurology, and oncology patients). The detailed implementation and specialty-specific protocols have 127 been published elsewhere [11, [16] [17] [18] [19] . In brief, in these converted RSWs, infrastructural enhancements 128

were implemented (half-height partitions between beds and reduced number of beds per cubicle), and 129

HCWs used disposable gloves, gowns, eye protection, and N95 respirators until COVID-19 was excluded. were undiagnosed at the time of presentation. Over the study period, an average of 130 patients-a-day 193

were tested for COVID-19, with a peak of more than 200 patients in April 2020, corresponding to the 194 nationwide surge in cases (Figure 1a) . A total of 16,162 patient admissions campus-wide were screened 195

for COVID-19, with a positive rate of 7.2% (1155/16162) (Figure 1b) . Epidemiological investigations 196 revealed only one potential case of healthcare-associated transmission of SARS-CoV-2 between patients, 197

with potential overlapping contact in a RSW.

[12] 198

Less than 1% of the campus-wide workforce (0.1%, 17/13066) were diagnosed with COVID-19 ( Figure  199 1b). Over the study period, one-third (34.4%, 4497/13066) of HCWs had been tested for SARS-CoV-2; 200 an average of 30 HCWs were tested for COVID-19 at the Staff Clinic daily. Staff working in high-risk 201 J o u r n a l P r e -p r o o f areas, such as the IW and the ED, did not have higher odds of COVID-19 testing, compared to staff 202 working in other areas (Figure 1b) . Epidemiology investigations indicated that the majority of COVID-203

19 cases in HCWs were linked to known community cases outside of hospital (70.6%, 12/17). Four 204 remaining HCW cases were unlinked, but did not have patient contact in high-risk areas and did not have 205 contact with each other; one HCW shared an office cubicle with a known COVID-19 case.

[10] There was 206 no evidence of patient-HCW transmission.

[10] 207

Infection control measures were also remarkably successful in containing healthcare-associated-RVI 208 across a large healthcare campus. In the six months pre-pandemic, the campus-wide incidence of 209

healthcare-associated-RVI was 7.8 cases per-10,000 patient-days (195 cases; 250,596 patient-days). After 210

introduction of the campus-wide containment strategy, the incidence of healthcare-associated-RVI was 211

1.5 cases per-10,000 patient-days (31 cases; 203,711 patient-days). The incidence-rate-ratio of healthcare-212 associated-RVI per 10,000-patient-days between the two periods (pre-and post-pandemic) was 0.2 (95% 213 confidence interval, 95%CI=0.13-0.29, p<0.001) (Figure 1c) . The marked decrease in healthcare-214 associated-RVI was observed despite increased testing. Prior to the pandemic, an average of 701 RVI-215 panels/month were ordered; during the pandemic, this rose to 970 tests/month. 216 ensured that all HCWs had used a surgical mask, at the minimum, when coming into contact with these 237 unsuspected COVID-19 cases prior to diagnosis. Although one case required intubation and was in a 238 non-isolation ICU room for 10 hours prior to diagnosis, all HCWs performing AGPs had used disposable 239 gloves, gowns, eye protection, and N95 respirators (Figure 3) . To evaluate compliance with enhanced 240

campus-wide IPC measures, comparisons of Staff Clinic attendances for acute respiratory illness and 241

influenza vaccination, as well as consumption of handrub/cleaning wipes and results of hand hygiene and 242 environmental cleaning audits pre-and post-pandemic are provided in Figure 4 . Campus-wide 243 compliance to yearly influenza vaccination was high pre-pandemic, with 81.1% of HCWs receiving 244 influenza vaccination in 2019 (Figure 4a) . During the pandemic, there was an increase in Staff Clinic 245 ARI attendances, likely due to mandatory centralised reporting to facilitate contact tracing as well as staff 246

advisories discouraging presenteeism. Campus-wide consumption of alcohol handrub rose from 1746 247 litres/month in the preceding year (2019) to 2313 litres/month during the pandemic period (Figure 4b) . 248 Similarly, consumption of cleaning wipes rose from 8669 bottles/month pre-pandemic to 10391 249 bottles/month, during the pandemic period (Figure 4b) . Pre-pandemic, campus-wide hand hygiene rates 250

were high (95.0%; min 87.1%, max 100%); during the pandemic period, hand hygiene rates were 251 J o u r n a l P r e -p r o o f maintained at close to 100.0% across all 5 hand hygiene moments audited (Figure 4c) . Standards of 252 environmental cleaning pre-pandemic on regular audit using fluorescent markers (Glogerm) were high, 253

and these standards were maintained throughout the pandemic (Figure 4c) . 254

The key finding of this study is that a multi-tiered infection control strategy was successful in mitigating 256

healthcare-associated transmission of COVID-19 as well as common RVIs across a large healthcare 257 campus, over a sustained duration. Over a 6-month period, no documented patient-HCW transmission of 258 COVID-19 occurred, despite caring for more than 1500 cases of COVID respiratory viral infections throughout a large healthcare system over six months of surveillance. • Despite caring for >1500 COVID-19 cases, no patient-staff transmission occurred.

• Rates of healthcare-associated respiratory viral infections fell to zero over a six-month period.

• Key components of the strategy included improved patient segregation and distancing, and universal masking.

J o u r n a l P r e -p r o o f

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Events/News/Pages/Three-national-level-seroepidemiological-studies-to-determine-level-of-COVID-19-409 infection-in-Singapore