A two-ward acute care hospital outbreak of SARS-CoV-2 delta variant including a point-source outbreak associated with the use of a mobile vital signs cart and sub-optimal doffing of personal protective equipment.

BACKGROUND: The arrival of the Delta variant of SARS-CoV-2 was associated with increased transmissibility and illness of greater severity. Reports of nosocomial outbreaks of Delta variant COVID-19 in acute care hospitals have been described but control measures varied widely. AIM: Epidemiological investigation of a linked two-ward COVID-19 Delta variant outbreak was conducted to elucidate its source, risk factors, and control measures. METHODS: Investigations included epidemiologic analysis, detailed case review serial SARS-CoV-2 reverse transcriptase-polymerase chain reaction (RT-PCR) testing of patients and healthcare workers (HCWs), viral culture, environmental swabbing, HCW-unaware personal protective equipment (PPE) audits, ventilation assessments, and the use of whole genome sequencing (WGS). FINDINGS: This linked two-ward outbreak resulted in 17 patient and 12 HCW cases, despite an 83% vaccination rate. In this setting, suboptimal adherence and compliance to PPE protocols, suboptimal hand hygiene, multi-bedded rooms, and a contaminated vital signs cart with potential fomite or spread via the hands of HCWs were identified as significant risk factors for nosocomial COVID-19 infection. Sudden onset of symptoms, within 72 h, was observed in 79% of all Ward 2 patients, and 93% of all cases (patients and HCWs) on Ward 2 occurred within one incubation period, consistent with a point-source outbreak. RT-PCR assays showed low cycle threshold (CT) values, indicating high viral load from environmental swabs including the vital signs cart. WGS results with ≤3 SNP differences between specimens were observed. CONCLUSION: Outbreaks on both wards settled rapidly, within 3 weeks, using a `back-to-basics' approach without extraordinary measures or changes to standard PPE requirements. Strict adherence to recommended PPE, hand hygiene, education, co-operation from HCWs, including testing and interviews, and additional measures such as limiting movement of patients and staff temporarily were all deemed to have contributed to prompt resolution of the outbreak.

Surveillance of SARS-CoV-2 variants of concern (VOC) in hospital wastewater (WW) and its correlation with hospitalized cases of COVID-19 and the occurrence of outbreaks

Background. WW surveillance enables real time monitoring of SARS-CoV-2 burden in defined sewer catchment areas. Here, we assessed the occurrence of total, Delta and Omicron SARS-CoV-2 RNA in sewage from three tertiary-care hospitals in Calgary, Canada. Methods. Nucleic acid was extracted from hospital (H) WW using the 4S-silica column method. H-1 and H-2 were assessed via a single autosampler whereas H-3 required three separate monitoring devices (a-c). SARS-CoV-2 RNA was quantified using two RT-qPCR approaches targeting the nucleocapsid gene;N1 and N200 assays, and the R203K/G204R and R203M mutations. Assays were positive if Cq< 40. Cross-correlation function analyses (CCF) was performed to determine the timelagged relationships betweenWWsignal and clinical cases. SARS-CoV-2 RNA abundance was compared to total hospitalized cases, nosocomial-acquired cases, and outbreaks. Statistical analyses were conducted using R. Results. Ninety-six percent (188/196) of WW samples collected between Aug/ 21-Jan/22 were positive for SARS-CoV-2. Omicron rapidly supplanted Delta by mid-December and this correlated with lack of Delta-associated H-transmissions during a period of frequent outbreaks. The CCF analysis showed a positive autocorrelation between the RNA concentration and total cases, where the most dominant cross correlations occurred between -3 and 0 lags (weeks) (Cross-correlation values: 0.75, 0.579, 0.608, 0.528 and 0.746 for H-1, H-2, H-3a, H-3b and H-3c;respectively). VOC-specific assessments showed this positive association only to hold true for Omicron across all hospitals (cross-correlation occurred at lags -2 and 0, CFF value range between 0.648 -0.984). We observed a significant difference in median copies/ ml SARS-CoV-2 N-1 between outbreak-free periods vs outbreaks for H-1 (46 [IQR: 11-150] vs 742 [IQR: 162-1176], P< 0.0001), H-2 (24 [IQR: 6-167] vs 214 [IQR: 57-560], P=0.009) and H-3c (2.32 [IQR: 0-19] vs 129 [IQR: 14-274], P=0.001). Conclusion. WWsurveillance is a powerful tool for early detection andmonitoring of circulating SARS-CoV-2VOCs.Total SARS-CoV-2 andVOC-specificWWsignal correlated with hospitalized prevalent cases of COVID-19 and outbreak occurrence.

Viral cultures for assessing fomite transmission of SARS-CoV-2: a systematic review and meta-analysis.

BACKGROUND: The role of fomites in the transmission of SARS-CoV-2 is unclear. AIM: To assess whether SARS-CoV-2 can be transmitted through fomites, using evidence from viral culture studies. METHODS: Searches were conducted in the World Health Organization COVID-19 Database, PubMed, LitCovid, medRxiv, and Google Scholar to December 31st, 2021. Studies that investigated fomite transmission and performed viral culture to assess the cytopathic effect (CPE) of positive fomite samples and confirmation of SARS-CoV-2 as the cause of the CPE were included. The risk of bias using a checklist modified from the modified Quality Assessment of Diagnostic Accuracy Studies - 2 (QUADAS-2) criteria was assessed. FINDINGS: Twenty-three studies were included. The overall risk of bias was moderate. Five studies demonstrated replication-competent virus from fomite cultures and three used genome sequencing to match fomite samples with human clinical specimens. The mean cycle threshold (CT) of samples with positive viral culture was significantly lower compared with cultured samples that returned negative results (standardized mean difference: -1.45; 95% confidence interval (CI): -2.00 to -0.90; I2 = 0%; P < 0.00001). The likelihood of isolating replication-competent virus was significantly greater when CT was <30 (relative risk: 3.10; 95% CI: 1.32 to 7.31; I2 = 71%; P = 0.01). Infectious specimens were mostly detected within seven days of symptom onset. One study showed possible transmission of SARS-CoV-2 from fomites to humans. CONCLUSION: The evidence from published studies suggests that replication-competent SARS-CoV-2 is present on fomites. Replication-competent SARS-CoV-2 is significantly more likely when the PCR CT for clinical specimens and fomite samples is <30. Further studies should investigate the duration of infectiousness of SARS-CoV-2 and the frequency of transmission from fomites.

Cleaning and disinfecting surfaces in hospitals and long-term care facilities for reducing hospital- and facility-acquired bacterial and viral infections: a systematic review.

BACKGROUND: Multiply drug-resistant organisms (MDROs) in hospitals and long-term care facilities (LTCFs) of particular concern include meticillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococcus, multidrug-resistant Acinetobacter species, and extended-spectrum ß-lactamase-producing organisms. Respiratory viruses include influenza and SARS-CoV-2. AIM: To assess effectiveness of cleaning and disinfecting surfaces in hospitals and LTCFs. METHODS: CINAHL, Cochrane CENTRAL Register of Controlled Trials, Embase, Medline, and Scopus searched inception to June 28th, 2021, no language restrictions, for randomized controlled trials (RCTs), cleaning, disinfection, hospitals, LTCFs. Abstracts and titles were assessed and data abstracted independently by two authors. FINDINGS: Of 14 cluster (c)-RCTs in hospitals and LTCFs, interventions in ten were focused on reducing patient infections of four MDROs and/or healthcare-associated infections (HAIs). In four c-RCTs patient MDRO and/or HAI rates were significantly reduced with cleaning and disinfection strategies including bleach-, quaternary ammonium detergent-, ultraviolet irradiation-, hydrogen peroxide vapour- and copper-treated surfaces or fabrics. Of three c-RCTs focused on reducing MRSA rates, one had significant results and one on Clostridioides difficile had no significant results. Heterogeneity of populations, methods, outcomes and data reporting precluded meta-analysis. Overall risk of bias assessment was low but high for allocation concealment, and GRADE assessment was low risk. No study assessed biofilms. CONCLUSION: Ten c-RCTs focused on reducing multiple MDROs and/or HAIs and four had significant reductions. Three c-RCTs reported only patient MRSA colonization rates (one significant reductions), and one focused on C. difficile (no significant differences). Standardized primary and secondary outcomes are required for future c-RCTs including detailed biofilm cleaning/disinfection interventions.

The use of drones for the delivery of supplies, medical equipment, diagnostic testing, and medical treatments to remote first nations communities in Alberta during COVID-19

Introduction: For members of remote Indigenous communities, accessing healthcare often requires travel to off-reserve locations, which is both burdensome to the individual and increases the risk of contracting COVID-19. Remotely Piloted Aircraft Systems (RPAS), or drones, offer a potentially cost-effective method for reducing that burden and risk by removing geographic barriers and increasing timeliness and accessibility of supplies, equipment, and remote care. Objectives: To demonstrate the potential of RPAS-delivered technology and supplies in diagnosis, evaluation, and treatment, including RPAS-delivered ultrasound (US) machines;to co-develop governance and operating manuals with local Indigenous communities;and to use this work as a scalable model for fully operational RPAS-based medical delivery systems. Methods: Our team is developing and pilot-testing innovative RPASbased medical delivery solutions at the systems, regulatory, technological (software and hardware), and procedural levels. This includes working with Transport Canada for Beyond Visual Line of Sight approval;RPAS fleet development and testing;custom payload system design and fabrication (i.e. refrigerated unit for vaccine delivery);procedural development (i.e. risk and safety assessments);Detect and Avoid System testing and refinement;and pilot-testing COVID-19 test kit fidelity and remote US functionality. Results: We have successfully delivered PPE (gloves, gowns, masks) and COVID-19 test kits. We confirmed that the delivered RNA COVID- 19 test samples contained no decay in signal or testing capabilities. We also delivered a sanitized Tele-mentored Self-Diagnostic US and successfully Tele-mentored a patient in performing a proficient selfadministered US at a remote location. Conclusion: RPAS-based medical delivery models offer an innovative approach to addressing longstanding issues of healthcare access and equity, and are particularly relevant in the context of COVID-19 and preventing pandemic spread.