Environmental contamination and evaluation of healthcare-associated SARS-CoV-2 transmission risk in temporary isolation wards during the COVID-19 pandemic

Background Temporary isolation wards have been introduced to meet demands for airborne-infection-isolation-rooms (AIIRs) during the COVID-19 pandemic. Environmental sampling and outbreak investigation was conducted in temporary isolation wards converted from general wards and/or prefabricated containers, in order to evaluate the ability of such temporary isolation wards to safely manage COVID-19 cases over a period of sustained use. Methods Environmental sampling for SARS-CoV-2 RNA was conducted in temporary isolation ward rooms constructed from pre-fabricated containers (N = 20) or converted from normal-pressure general wards (N = 47). Whole genome sequencing (WGS) was utilized to ascertain health care-associated transmission when clusters were reported amongst HCWs working in isolation areas from July 2020 to December 2021. Results A total of 355 environmental swabs were collected;22.4% (15/67) of patients had at least one positive environmental sample. Patients housed in temporary isolation ward rooms constructed from pre-fabricated containers (adjusted-odds-ratio, aOR = 10.46, 95% CI = 3.89-58.91, P = .008) had greater odds of detectable environmental contamination, with positive environmental samples obtained from the toilet area (60.0%, 12/20) and patient equipment, including electronic devices used for patient communication (8/20, 40.0%). A single HCW cluster was reported amongst staff working in the temporary isolation ward constructed from pre-fabricated containers;however, health care-associated transmission was deemed unlikely based on WGS and/or epidemiological investigations. Conclusion Environmental contamination with SARS-CoV-2 RNA was observed in temporary isolation wards, particularly from the toilet area and smartphones used for patient communication. However, despite intensive surveillance, no healthcare-associated transmission was detected in temporary isolation wards over 18 months of prolonged usage, demonstrating their capacity for sustained use during succeeding pandemic waves.

Linking sporadic hospital clusters during a community surge of the severe acute respiratory coronavirus virus 2 (SARS-CoV-2) B.1.617.2 delta variant: The utility of whole-genome sequencing.

Sporadic clusters of healthcare-associated coronavirus disease 2019 (COVID-19) occurred despite intense rostered routine surveillance and a highly vaccinated healthcare worker (HCW) population, during a community surge of the severe acute respiratory coronavirus virus 2 (SARS-CoV-2) B.1.617.2 δ (delta) variant. Genomic analysis facilitated timely cluster detection and uncovered additional linkages via HCWs moving between clinical areas and among HCWs sharing a common lunch area, enabling early intervention.

Unintended consequences of infection prevention and control measures during COVID-19 pandemic.

BACKGROUND: In the current COVID-19 pandemic, aggressive Infection Prevention and Control (IPC) measures have been adopted to prevent health care-associated transmission of COVID-19. We evaluated the impact of a multimodal IPC strategy originally designed for the containment of COVID-19 on the rates of other hospital-acquired-infections (HAIs). METHODOLOGY: From February-August 2020, a multimodal IPC strategy was implemented across a large health care campus in Singapore, comprising improved segregation of patients with respiratory symptoms, universal masking and heightened adherence to Standard Precautions. The following rates of HAI were compared pre- and postpandemic: health care-associated respiratory-viral-infection (HA-RVI), methicillin-resistant Staphylococcus aureus, and CP-CRE acquisition rates, health care-facility-associated C difficile infections and device-associated HAIs. RESULTS: Enhanced IPC measures introduced to contain COVID-19 had the unintended positive consequence of containing HA-RVI. The cumulative incidence of HA-RVI decreased from 9.69 cases per 10,000 patient-days to 0.83 cases per 10,000 patient-days (incidence-rate-ratio = 0.08; 95% confidence interval [CI] = 0.05-0.13, P< .05). Hospital-wide MRSA acquisition rates declined significantly during the pandemic (incidence-rate-ratio = 0.54, 95% CI = 0.46-0.64, P< .05), together with central-line-associated-bloodstream infection rates (incidence-rate-ratio = 0.24, 95% CI = 0.07-0.57, P< .05); likely due to increased compliance with Standard Precautions. Despite the disruption caused by the pandemic, there was no increase in CP-CRE acquisition, and rates of other HAIs remained stable. CONCLUSIONS: Multimodal IPC strategies can be implemented at scale to successfully mitigate health care-associated transmission of RVIs. Good adherence to personal-protective-equipment and hand hygiene kept other HAI rates stable even during an ongoing pandemic where respiratory infections were prioritized for interventions.

Early Recognition of Coronavirus 2019 Disease (COVID-19) Infection in Surgical Inpatients: The Importance of a Risk-Stratified Approach for Early Testing and Isolation.

Background: In the ongoing coronavirus disease 2019 (COVID-19) pandemic, resuming provision of surgical services poses a challenge given that patients may have acute surgical pathologies with concurrent COVID-19 infection. We utilized a risk-stratified approach to allow for early recognition and isolation of potential COVID-19 infection in surgical patients, ensuring continuity of surgical services during a COVID-19 outbreak. Patients and Methods: Over a four-month period from January to April 2020, surgical patients admitted with concurrent respiratory symptom, infiltrates on chest imaging, or suspicious travel/epidemiologic history were placed in a dedicated ward in which they were tested for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). If emergency operations were necessary prior to the exclusion of COVID-19, patients were managed as per suspected cases of COVID-19, with appropriate precautions and full personal protective equipment (PPE). Results: From January through April 2020, a total of 8,437 patients were admitted to our surgical department; 5.9% (498/8437) required peri-operative testing for SARS-CoV-2. Because testing was in-house with turnaround within 24 hours, only a small number of emergency operations (n = 10) were conducted for suspected COVID-19 cases prior to results; none tested positive. The testing yield was lower in surgical inpatients compared with medical inpatients (odds ratio [OR] = 0.20, 95% confidence interval [CI], 0.12-0.32, p < 0.001). Three operations were conducted in known COVID-19 cases; all healthcare workers (HCWs) used full PPE. A risk-stratified testing strategy picked up previously unsuspected COVID-19 in six cases; 66.7% (4/6) were asymptomatic at presentation. Although 48 HCWs were exposed to these six cases, delayed diagnosis was averted and no evidence of spread to patients or HCWs was detected. Conclusion: A risk-stratified approach allowed for early recognition, testing, and isolation of potential COVID-19 infection in surgical patients, ensuring continuity of surgical services.

Containing COVID-19 outside the isolation ward: The impact of an infection control bundle on environmental contamination and transmission in a cohorted general ward.

BACKGROUND: During an ongoing outbreak of COVID-19, unsuspected cases may be housed outside of dedicated isolation wards. AIM: At a Singaporean tertiary hospital, individuals with clinical syndromes compatible with COVID-19 but no epidemiologic risk were placed in cohorted general wards for COVID-19 testing. To mitigate risk, an infection control bundle was implemented comprising infrastructural enhancements, improved personal protective equipment, and social distancing. We assessed the impact on environmental contamination and transmission. METHODS: Upon detection of a case of COVID-19 in the dedicated general ward, patients and health care workers (HCWs) contacts were identified. All patient and staff close-contacts were placed on 14-day phone surveillance and followed up for 28 days; symptomatic contacts were tested. Environmental samples were also obtained. FINDINGS: Over a 3-month period, 28 unsuspected cases of COVID-19 were contained in the dedicated general ward. In 5 of the 28 cases, sampling of the patient's environment yielded SARS-CoV-2; index cases who required supplemental oxygen had higher odds of environmental contamination (P = .01). A total of 253 staff close-contacts and 45 patient close-contacts were identified; only 3 HCWs (1.2%, 3/253) required quarantine. On 28-day follow-up, no patient-to-HCW transmission was documented; only 1 symptomatic patient close-contact tested positive. CONCLUSIONS: Our institution successfully implemented an intervention bundle to mitigate COVID-19 transmission in a multibedded cohorted general ward setting.