Staff to staff transmission as a driver of healthcare worker infections with COVID-19

Assessing ventilation through ambient carbon dioxide concentrations across multiple healthcare levels in Ghana

Infection prevention and control (IPC) measures safeguard primary healthcare systems, especially as the infectious disease landscape evolves due to climate and environmental change, increased global mobility, and vaccine hesitancy and inequity, which can introduce unexpected pathogens. This study explores the importance of an "always-on," low-cost IPC approach, focusing on the role of natural ventilation in health facilities, particularly in low-resource settings. Ambient carbon dioxide (CO2) levels are increasingly used as a measure of ventilation effectiveness allowing for spot checks and targeted ventilation improvements. Data were collected through purposive sampling in Northern Ghana over a three-month period. Levels of CO2 ppm (parts per million) were measured by a handheld device in various healthcare settings, including Community-Based Health Planning and Services (CHPS) facilities, municipal and teaching hospitals, and community settings to assess ventilation effectiveness. Analyses compared CO2 readings in community and hospital settings as well as in those settings with and without natural ventilation. A total of 40 facilities were evaluated in this study; 90% were healthcare facilities and 75% had natural ventilation (with an open window, door or wall). Facilities that relied on natural ventilation were mostly community health centers (60% vs 0%) and more commonly had patients present (83% vs 40%) compared with facilities without natural ventilation. Facilities with natural ventilation had significantly lower CO2 concentrations (CO2 ppm: 663 vs 1378, p = 0.0043) and were more likely to meet international thresholds of CO2 < 800 ppm (87% vs 10%, p = <0.0001) and CO2 < 1000 ppm (97% vs 20%, p = <0.0001). The adjusted odds ratio of low CO2 in the natural facilities compared with non-natural were: odds ratios, OR (95% CI): 21.7 (1.89, 247) for CO2 < 800 ppm, and 16.8 (1.55, 183) for CO2 < 1000 ppm. Natural ventilation in these facilities was consistently significantly associated with higher likelihood of low CO2 concentrations. Improved ventilation represents one cost-effective layer of IPC. This study highlights the continuing role natural ventilation can play in health facility design in community health care clinics. Most health facilities met standard CO2 thresholds, particularly in community health facilities. Further research is needed to optimize the use of natural ventilation. The use of a handheld devices to track a simple metric, CO2 levels, could improve appreciation of ventilation among healthcare workers and public health professionals and allow for them to target improvements. This study highlights potential lessons in the built environment of community primary health facilities as a blueprint for low-cost, integrated multi-layer IPC measures to mitigate respiratory illness and anticipate future outbreaks.

Employee investigation and contact tracing program in a pediatric cancer hospital to mitigate the spread of COVID-19 among the workforce, patients, and caregivers

Background

Case investigations and contact tracing are essential disease control measures used by health departments. Early in the pandemic, they were seen as a key strategy to stop COVID-19 spread. The CDC urged rapid action to scale up and train a large workforce and collaborate across public and private agencies to halt COVID-19 transmission.

Methods

We developed a program for case investigation and contact tracing that followed CDC and local health guidelines, compliant with the Occupational Safety and Health Administration (OSHA) regulations and tailored to the needs and resources of our institution. Program staff were trained and assessed for competency before joining the program.

Results

From March 2020 to May 2021, we performed 838 COVID-19 case investigations, which led to 136 contacts. Most employees reported a known SARS-CoV-2 exposure from the community (n = 435) or household (n = 343). Only seven (5.1%) employees were determined as more likely than not to have SARS-CoV-2 infection related to workplace exposure, and when so, lapses in following the masking recommendations were identified. Between June 2021-February 2022, our program adjusted to the demand of the different waves, particularly omicron, by significantly reducing the amount of data collected. No transmission from employees to patients or caregivers was observed during this period.

Conclusion

Prompt implementation of case investigation and contact tracing is possible, and it effectively reduces workplace exposures. This approach can be adapted to suit the specific needs and requirements of various healthcare settings, particularly those serving the most vulnerable patient populations.

Evaluating the impact of testing strategies for the detection of nosocomial COVID-19 in English hospitals through data-driven modeling

Introduction

During the first wave of the COVID-19 pandemic 293,204 inpatients in England tested positive for SARS-CoV-2. It is estimated that 1% of these cases were hospital-associated using European centre for disease prevention and control (ECDC) and Public Health England (PHE) definitions. Guidelines for preventing the spread of SARS-CoV-2 in hospitals have developed over time but the effectiveness and efficiency of testing strategies for preventing nosocomial transmission has not been explored.

Methods

Using an individual-based model, parameterised using multiple datasets, we simulated the transmission of SARS-CoV-2 to patients and healthcare workers between March and August 2020 and evaluated the efficacy of different testing strategies. These strategies were: 0) Testing only symptomatic patients on admission; 1) Testing all patients on admission; 2) Testing all patients on admission and again between days 5 and 7, and 3) Testing all patients on admission, and again at days 3, and 5-7. In addition to admissions testing, patients that develop a symptomatic infection while in hospital were tested under all strategies. We evaluated the impact of testing strategy, test characteristics and hospital-related factors on the number of nosocomial patient infections.

Results

Modelling suggests that 84.6% (95% CI: 84.3, 84.7) of community-acquired and 40.8% (40.3, 41.3) of hospital-associated SARS-CoV-2 infections are detectable before a patient is discharged from hospital. Testing all patients on admission and retesting after 3 or 5 days increases the proportion of nosocomial cases detected by 9.2%. Adding discharge testing increases detection by a further 1.5% (relative increase). Increasing occupancy rates, number of beds per bay, or the proportion of admissions wrongly suspected of having COVID-19 on admission and therefore incorrectly cohorted with COVID-19 patients, increases the rate of nosocomial transmission. Over 30,000 patients in England could have been discharged while incubating a non-detected SARS-CoV-2 infection during the first wave of the COVID-19 pandemic, of which 3.3% could have been identified by discharge screening. There was no significant difference in the rates of nosocomial transmission between testing strategies or when the turnaround time of the test was increased.

Discussion

This study provides insight into the efficacy of testing strategies in a period unbiased by vaccines and variants. The findings are relevant as testing programs for SARS-CoV-2 are scaled back, and possibly if a new vaccine escaping variant emerges.

Experiences of redeployment by haemodialysis nurses during the COVID-19 pandemic: a hermeneutic phenomenological approach

BACKGROUND

Redeployment of healthcare workers is one of the strategies that has been successfully used to manage increased workload and shortage of staff during the COVID-19 pandemic. However, little is known about how best to do this in the pandemic and beyond. The purpose of this study was to explore the lived experiences of haemodialysis nurses who were redeployed across five haemodialysis units affiliated with a large metropolitan teaching hospital in Australia during the COVID-19 pandemic.

DESIGN

Qualitative design utilizing a hermeneutic (interpretive) phenomenology approach.

METHODS

Interviews were conducted in March 2022 among nurses who had been redeployed to other haemodialysis units during the COVID-19 pandemic (N = 16). Audiotaped interviews were transcribed verbatim and analysed independently by two researchers following specific steps of hermeneutic phenomenological analysis.

RESULTS

Five themes were derived from the analyses. These were: (1) Nurses' immediate reaction; (2) Barriers to redeployment; (3) Benefits of redeployment; (4) Local and organisational support and (5) Opportunities for improvement.

CONCLUSIONS

Redeployment of nurses across different haemodialysis units is associated with personal and organisational benefits and number of barriers that need to be addressed. Future studies should explore the long-term effects of redeployment due to the COVID-19 pandemic on haemodialysis nurses and other healthcare workers.

The Role of Medication Beliefs in COVID-19 Vaccine and Booster Uptake in Healthcare Workers: An Exploratory Study

Illness and medication beliefs have shown to predict COVID-19 vaccination behaviour in the general population, but this relationship has yet to be demonstrated in healthcare staff. This research aimed to explore the potential explanatory value of illness and medication beliefs on the COVID-19 vaccination uptake of a sample of patient-facing healthcare workers (HCWs). A web-based questionnaire-measuring beliefs about vaccinations (the BMQ), perceptions of COVID-19 (the BIPQ), vaccine hesitancy, and vaccine uptake-was targeted to HCWs via social media platforms between May-July 2022. Open text responses allowed participants to provide explanations for any delay in vaccine uptake. A total of 91 participants completed the questionnaire. Most respondents (77.1%, n = 64) had received three doses of the COVID-19 vaccination, and vaccination uptake (number of doses received) was predicted by Vaccine Concerns, Vaccine Hesitancy, and their Necessity-Concerns Differential score. Vaccine Hesitancy was predicted by Necessity, Concerns, and Overuse scores, as well as Necessity-Concerns Differential scores. Delay in Vaccine Uptake could only be predicted for Dose 3 (Booster). Qualitative data revealed that hesitant respondents were "unable to take time off work" for vaccination and that some had concerns over vaccine safety. In conclusion, illness and medication beliefs have potential value in predicting vaccine hesitancy and uptake in healthcare workers. Interventions to improve vaccination uptake in this population should address concerns about vaccine safety and releasing staff for vaccination booster appointments should be prioritised. Future research should further investigate the relationship between illness and medication beliefs and COVID-19 vaccine uptake in a larger sample of healthcare workers.

Evaluation of an Online Training Program on COVID-19 for Health Workers in Papua New Guinea

BACKGROUND

Health worker training is an important component of a holistic outbreak response, and travel restrictions resulting from the COVID-19 pandemic have highlighted the potential of virtual training. Evaluation of training activities is essential for understanding the effectiveness of a training program on knowledge and clinical practice. We conducted an evaluation of the online COVID-19 Healthcare E-Learning Platform (CoHELP) in Papua New Guinea (PNG) to assess its effectiveness, measure engagement and completion rates, and determine barriers and enablers to implementation, in order to inform policy and practice for future training in resource-limited settings.

METHODS

The evaluation team conducted a mixed methods evaluation consisting of pre- and post-knowledge quizzes; quantification of engagement with the online platform; post-training surveys; qualitative interviews with training participants, non-participants, and key informants; and audits of six health facilities.

RESULTS

A total of 364 participants from PNG signed up to participate in the CoHELP online training platform, with 41% (147/360) completing at least one module. Of the 24 participants who completed the post-training survey, 92% (22/24) would recommend the program to others and 79% (19/24) had used the knowledge or skills gained through CoHELP in their clinical practice. Qualitative interviews found that a lack of time and infrastructural challenges were common barriers to accessing online training, and participants appreciated the flexibility of online, self-paced learning.

CONCLUSIONS

Initially high registration numbers did not translate to ongoing engagement with the CoHELP online platform, particularly for completion of evaluation activities. Overall, the CoHELP program received positive feedback from participants involved in the evaluation, highlighting the potential for further online training courses in PNG.

Combining epidemiological data and whole genome sequencing to understand SARS-CoV-2 transmission dynamics in a large tertiary care hospital during the first COVID-19 wave in The Netherlands focusing on healthcare workers

BACKGROUND

Healthcare facilities have been challenged by the risk of SARS-CoV-2 transmission between healthcare workers (HCW) and patients. During the first wave of the COVID-19 pandemic, infections among HCW were observed, questioning infection prevention and control (IPC) measures implemented at that time.

AIM

This study aimed to identify nosocomial transmission routes of SARS-CoV-2 between HCW and patients in a tertiary care hospital.

METHODS

All SARS-CoV-2 PCR positive HCW and patients identified between 1 March and 19 May 2020, were included in the analysis. Epidemiological data were collected from patient files and HCW contact tracing interviews. Whole genome sequences of SARS-CoV-2 were generated using Nanopore sequencing (WGS). Epidemiological clusters were identified, whereafter WGS and epidemiological data were combined for re-evaluation of epidemiological clusters and identification of potential transmission clusters. HCW infections were further classified into categories based on the likelihood that the infection was acquired via nosocomial transmission. Secondary cases were defined as COVID-19 cases in our hospital, part of a transmission cluster, of which the index case was either a patient or HCW from our hospital.

FINDINGS

The study population consisted of 293 HCW and 245 patients. Epidemiological data revealed 36 potential epidemiological clusters, with an estimated 222 (75.7%) HCW as secondary cases. WGS results were available for 195 HCW (88.2%) and 20 patients (12.8%) who belonged to an epidemiological cluster. Re-evaluation of the epidemiological clusters, with the available WGS data identified 31 transmission clusters with 65 (29.4%) HCW as secondary cases. Transmission clusters were all part of 18 (50.0%) previously determined epidemiological clusters, demonstrating that several larger outbreaks actually consisted, of several smaller transmission clusters. A total of 21 (7.2%) HCW infections were classified as from confirmed nosocomial, of which 18 were acquired from another HCW and 3 from a patient.

CONCLUSION

The majority of SARS-CoV-2 infections among HCW could be attributed to community-acquired infection. Infections among HCW that could be classified as due to nosocomial transmission, were mainly caused by HCW-to-HCW transmission rather than patient-to-HCW transmission. It is important to recognize the uncertainties of cluster analyses based solely on epidemiological data.

Infection control strategies for healthcare workers during COVID-19 pandemic in German hospitals: A cross-sectional study in march-april 2021

Background

Healthcare workers (HCW) are at risk of getting infected with COVID-19 at work. To prevent such incidents and provide a safe environment in hospitals, comprehensive infection control strategies are necessary. We aimed to collect information on COVID-19 infection control strategies regarding personal protective equipment (PPE), regulations during breaks for HCW and dissemination of pandemic-related information.

Methods

We invited infection control practitioners from 987 randomly selected German hospitals in March-April 2021 to participate in our cross-sectional online survey. We categorized the hospital based on bed capacity (≤499 beds = small; ≥500 beds = large). Fisher's exact test was performed and p < 0.05 defined as statistically significant.

Findings

100 participants completed the questionnaire. Small hospitals were more directive about requiring FFP2 respirators (63%), whereas larger hospitals more often gave their HCW a choice between these and medical masks (67%). For the care of COVID-19 and suspected COVID-19 cases, >90% of the participants recommended the use of gloves. Notably, gloves were recommended beyond COVID-19 in 30% of the hospitals. During meal breaks various strategies were followed.

Conclusion

Recommendations for PPE varied across hospital sizes, which could be due to different assessments of necessity and safety. Regulations during breaks varied strongly which illustrates the need for clear official guidelines.

Sources of exposure and risk among employees infected with severe acute respiratory coronavirus virus 2 (SARS-CoV-2) in a large, urban, tertiary-care hospital in the United States

Objective

Hospital employees are at risk of SARS-CoV-2 infection through transmission in 3 settings: (1) the community, (2) within the hospital from patient care, and (3) within the hospital from other employees. We evaluated probable sources of infection among hospital employees based on reported exposures before infection.

Design

A structured survey was distributed to participants to evaluate presumed COVID-19 exposures (ie, close contacts with people with known or probable COVID-19) and mask usage. Participants were stratified into high, medium, low, and unknown risk categories based on exposure characteristics and personal protective equipment.

Setting

Tertiary-care hospital in Boston, Massachusetts.

Participants

Hospital employees with a positive SARS-CoV-2 PCR test result between March 2020 and January 2021. During this period, 573 employees tested positive, of whom 187 (31.5%) participated.

Results

We did not detect a statistically significant difference in the proportion of employees who reported any exposure (ie, close contacts at any risk level) in the community compared with any exposure in the hospital, from either patients or employees. In total, 131 participants (70.0%) reported no known high-risk exposure (ie, unmasked close contacts) in any setting. Among those who could identify a high-risk exposure, employees were more likely to have had a high-risk exposure in the community than in both hospital settings combined (odds ratio, 1.89; P = .03).

Conclusions

Hospital employees experienced exposure risks in both community and hospital settings. Most employees were unable to identify high-risk exposures prior to infection. When respondents identified high-risk exposures, they were more likely to have occurred in the community.

Risk categorization and outcomes among healthcare workers exposed to COVID-19: A cohort study from a Thai tertiary-care center

BACKGROUND

A risk categorization tool for healthcare workers (HCWs) exposed to COVID-19 is crucial for preventing COVID-19 transmission and requires validation and modification according to local context.

METHODS

From January to December 2021, a prospective cohort study was conducted among Thai HCWs to evaluate the performance of the specifically-created risk categorization tool, which classified HCWs into low-risk (LR), intermediate-risk (IR), and high-risk (HR) groups based on types of activities, duration of exposure, and protective methods used during exposure. Subsequent measures were determined for the HCWs based on the risk categories.

RESULTS

1891 HCWs were included; 52%, 25% and 23% were LR, IR, and HR, respectively. COVID-19 was diagnosed in 1.3%, 5.1% and 27.3% of LR, IR and HR HCWs, respectively (P <0.001). Independent factors associated with COVID-19 were household or community exposure [adjusted odds ratio (aOR), 1588.68; P <0.001), being HR (aOR, 11.94; P <0.001), working at outpatient departments (aOR, 2.54; P <0.001), and no history of COVID-19 vaccination (aOR, 2.05; P = 0.01). The monthly rates of COVID-19 among LR, IR, and HR HCWs significantly decreased after the incremental rate of full vaccination. In-hospital transmission between HCWs occurred in 8% and was mainly due to eating at the same table.

CONCLUSION

The study risk categorization tool can differentiate risks of COVID-19 among the HCWs. Prevention of COVID-19 should be focused on HCWs with the identified risk factors and behaviors associated with COVID-19 development and encouraging receipt of full vaccination.

Association between COVID-19 vaccination status, time elapsed since the last vaccine dose, morbidity, and absenteeism among healthcare personnel: A prospective, multicenter study

AIM

We assessed the impact of COVID-19 vaccination status and time elapsed since the last vaccine dose on morbidity and absenteeism among healthcare personnel (HCP) in the context of a mandatory vaccination policy.

METHODS

We followed 7592 HCP from November 15, 2021 through April 17, 2022. Full COVID-19 vaccination was defined as a primary vaccination series plus a booster dose at least six months later.

RESULTS

There were 6496 (85.6 %) fully vaccinated, 953 (12.5 %) not fully vaccinated, and 143 (1.9 %) unvaccinated HCP. A total of 2182 absenteeism episodes occurred. Of 2088 absenteeism episodes among vaccinated HCP with known vaccination status, 1971 (94.4 %) concerned fully vaccinated and 117 (5.6 %) not fully vaccinated. Fully vaccinated HCP had 1.6 fewer days of absence compared to those not fully vaccinated (8.1 versus 9.7; p-value < 0.001). Multivariable regression analyses showed that full vaccination was associated with shorter absenteeism compared to not full vaccination (OR: 0.56; 95 % CI: 0.36-0.87; p-value = 0.01). Compared to a history of ≤ 17.1 weeks since the last dose, a history of > 17.1 weeks since the last dose was associated with longer absenteeism (OR: 1.22, 95 % CI:1.02-1.46; p-value = 0.026) and increased risk for febrile episode (OR: 1.33; 95 % CI: 1.09-1.63; p-value = 0.004), influenza-like illness (OR: 1.53, 95 % CI: 1.02-2.30; p-value = 0.038), and COVID-19 (OR: 1.72; 95 % CI: 1.24-2.39; p-value = 0.001).

CONCLUSIONS

The COVID-19 pandemic continues to impose a considerable impact on HCP. The administration of a vaccine dose in less than four months before significantly protected against COVID-19 and absenteeism duration, irrespective of COVID-19 vaccination status. Defining the optimal timing of boosters is imperative.

Targeted reduction of airborne viral transmission risk in long-term residential aged care

COVID-19 has demonstrated the devastating consequences of the rapid spread of an airborne virus in residential aged care. We report the use of CO2-based ventilation assessment to empirically identify potential 'super-spreader' zones within an aged care facility, and determine the efficacy of rapidly implemented, inexpensive, risk reduction measures.

An International Commentary on Dysphagia and Dysphonia During the COVID-19 Pandemic

COVID-19 has had an impact globally with millions infected, high mortality, significant economic ramifications, travel restrictions, national lockdowns, overloaded healthcare systems, effects on healthcare workers' health and well-being, and large amounts of funding diverted into rapid vaccine development and implementation. Patients with COVID-19, especially those who become severely ill, have frequently developed dysphagia and dysphonia. Health professionals working in the field have needed to learn about this new disease while managing these patients with enhanced personal protective equipment. Emerging research suggests differences in the clinical symptoms and journey to recovery for patients with COVID-19 in comparison to other intensive care populations. New insights from outpatient clinics also suggest distinct presentations of dysphagia and dysphonia in people after COVID-19 who were not hospitalized or severely ill. This international expert panel provides commentary on the impact of the pandemic on speech pathologists and our current understanding of dysphagia and dysphonia in patients with COVID-19, from acute illness to long-term recovery. This narrative review provides a unique, comprehensive critical appraisal of published peer-reviewed primary data as well as emerging previously unpublished, original primary data from across the globe, including clinical symptoms, trajectory, and prognosis. We conclude with our international expert opinion on what we have learnt and where we need to go next as this pandemic continues across the globe.

Identifying Contact Risks for SARS-CoV-2 Transmission to Healthcare Workers during Outbreak on COVID-19 Ward

We assessed the risk for different exposures to SARS-CoV-2 during a COVID-19 outbreak among healthcare workers on a hospital ward in late 2020. We found working with isolated COVID-19 patients did not increase the risk of COVID-19 among workers, but working shifts with presymptomatic healthcare coworkers did.

Nosocomial COVID-19, a risk illustrated by the first in-hospital transmission of B.1.1.7 variant of SARS-CoV-2 in a French University Hospital

Objectives

In this short report, we describe the first nosocomial spread of B.1.1.7 variant (GR/20I/501Y.V1) in a French hospital, underlining the different aspects of in-hospital transmission of SARS-CoV-2.

Patients and methods

Retrospective study of a SARS-CoV-2 cluster investigation in January 2021. All cases were screened with RT-PCR.

Results

First transmission occurred in a double room with a COVID-19 imported cases, undetected upon admission. Healthcare workers, their relatives and patients’ relatives were screened. Eleven secondary cases were identified within a week, in and out of the hospital (in hospital attack rate: 3.1%). No severe COVID-19 was encountered.

Conclusions

This report highlights several in-hospital chains of transmission involved with COVID-19 with rapid spread.

A Clinician's Obligation to be Vaccinated: Four Arguments that Establish a Duty for Healthcare Professionals to be Vaccinated Against COVID-19

This paper defends four lines of argument that establish an ethical obligation for clinicians to be vaccinated against COVID-19. They are:(1) The obligation to protect patients against COVID-19 spread;(2) The obligation to maintain professional competence and remain available for patients;(3) Clinicians' role and place in society in relation to COVID-19;(4) The obligation to encourage societal vaccination uptake.These arguments stand up well against potential objections and provide a compelling case to consider acceptance of COVID-19 vaccination a duty for all clinicians. This duty brings with it the implication that vaccine refusal amounts to a dereliction of the professional's ethical obligations, which means such clinicians should be subject to disciplinary action. Furthermore, this duty provides grounding for mandatory vaccination policies for clinicians.

Pulmonary function testing during SARS-CoV-2: An ANZSRS/TSANZ position statement

The Thoracic Society of Australia and New Zealand (TSANZ) and the Australian and New Zealand Society of Respiratory Science (ANZSRS) commissioned a joint position paper on pulmonary function testing during coronavirus disease 2019 (COVID-19) in July 2021. A working group was formed via an expression of interest to members of both organizations and commenced work in September 2021. A rapid review of the literature was undertaken, with a 'best evidence synthesis' approach taken to answer the research questions formed. This allowed the working group to accept findings of prior relevant reviews or societal document where appropriate. The advice provided is for providers of pulmonary function tests across all settings. The advice is intended to supplement local infection prevention and state, territory or national directives. The working group's key messages reflect a precautionary approach to protect the safety of both healthcare workers (HCWs) and patients in a rapidly changing environment. The decision on strategies employed may vary depending on local transmission and practice environment. The advice is likely to require review as evidence grows and the COVID-19 pandemic evolves. While this position statement was contextualized specifically to the COVID-19 pandemic, the working group strongly advocates that any changes to clinical/laboratory practice, made in the interest of optimizing the safety and well-being of HCWs and patients involved in pulmonary function testing, are carefully considered in light of their potential for ongoing use to reduce transmission of other droplet and/or aerosol borne diseases.

Masking by health care and public safety workers in non-patient care areas to mitigate SARS-CoV-2 infection: A systematic review

Objectives

Wearing a mask is an important method for reducing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission in health care and public safety settings. We assess the evidence regarding masking in the workplace during the initial months of the COVID-19 pandemic (PROSPERO CRD4202432097).

Methods

We performed a systematic review of published literature from 4 databases and evaluated the quality of evidence with the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework. We searched for observational and experimental research involving public safety and health care workers. We included articles evaluating the use of masks, versus no mask, on the outcome of SARS-CoV-2 infection.

Results

Our search yielded 15,013 records, of which 9 studies were included. Most studies (n = 8; 88.9%) involved infections or outbreaks among health care workers. The majority (88.9%) used in-depth interviews of cases and non-cases to obtain self-reported use of masks during periods of exposure. One of 9 studies quantitatively assessed differences in SARS-CoV-2 infection based on use of masks in non-patient care settings. Use of observational study designs, small sample sizes, inadequate control for confounding, and inadequate measurement of exposure and non-exposure periods with infected coworkers contributed to the quality of evidence being judged as very low.

Conclusions

The available evidence from the initial months of the pandemic suggests that the use of masks in congregate, non-patient care settings, such as breakrooms, helps to reduce risk of SARS-CoV-2 virus transmission. However, this evidence is limited and is of very low quality. Prospective studies incorporating active observation measures are warranted.

Reducing the rates of household transmission: The impact of COVID-19 vaccination in healthcare workers with a known household exposure

Objective

To determine the impact of COVID-19 vaccination on infection rates in healthcare workers (HCWs) with a household exposure.

Methods

Retrospective cohort study 8410 HCWs (400 fully vaccinated, 1645 partially vaccinated, 6365 unvaccinated), employed by a large integrated healthcare system in the southeastern United States, tested for SARS-CoV-2 between January 1 and February 26, 2021.

Results

Benefit of vaccination persisted even with household exposure, with unvaccinated HCWs being 3.7 to 7.7 times more likely to be infected than partially or fully vaccinated HCW with positive household contacts respectively (partial OR = 3.73, 95% CI 2.17 – 6.47; full OR = 7.67, CI 2.75 – 21.35). Whereas 89.4% of unvaccinated COVID-positive HCWs with known household exposures were symptomatic, 50% of fully vaccinated HCWs had symptoms, reducing risk of secondary spread from and between HCWs.

Conclusions

COVID-19 vaccination provided protection against infection even amongst healthcare workers with close household contact, and after adjusting for community prevalence.

An episode of transmission of COVID-19 from a vaccinated healthcare worker to co-workers

BACKGROUND

Reports of transmission of COVID-19 from a vaccinated healthcare worker (HCW) to vaccinated co-workers are sparse.

METHODS

Index case (IC): After the second dose of the ChAdOx1 nCoV-19 vaccine, a HCW - our IC was diagnosed of COVID-19 by a rapid antigen test (RAT). A reverse transcription-polymerase chain reaction (RT-PCR) test done on the same day showed a cycle threshold (Ct) value of 10.02 (a very high viral load). Contact tracing and findings: The authors traced IC's contacts and seven contacts were identified. Four of those (P 1-4) were tested positive for COVID-19 on day12 after the contact. P1-2 were vaccinated and had slept near the IC in an enclosed 5.5 × 2.7 × 2.4 m room without air change and without masks, while IC was symptomatic. P3 and P4 came in immediately after IC left that room and slept there without masks. We did not find any other exposures of P1-4 within the 14 days (d) before they tested positive.

CONCLUSIONS

P1 and P2 are COVID-19 vaccine breakthrough infections. P3 and P4 contracting infection in the physical absence of IC indicates probable aerosol transmission of COVID-19. The factors that led to this episode, namely, unfamiliarity of breakthrough COVID-19 infections, ignoring the risk of contracting COVID-19 from vaccinated co-workers, hesitancy in seeking medical care soon after the onset of symptoms, poorly ventilated and cramped resting rooms for HCW exists worldwide. This episode reiterates the importance of adhering to basic COVID-19 preventive measures even after vaccination.

Healthcare-acquired clusters of COVID-19 across multiple wards in a Scottish health board

Background

Healthcare-acquired COVID-19 has been an additional burden on hospitals managing increasing numbers of patients with SARS-CoV-2. One acute hospital (W) among three in a Scottish healthboard experienced an unexpected surge of COVID-19 clusters.

Aim

To investigate possible causes of COVID-19 clusters at Hospital W.

Methods

Daily surveillance provided total numbers of patients and staff involved in clusters in three acute hospitals (H, M and W) and care homes across the healthboard. All clusters were investigated and documented, along with patient boarding, community infection rates and outdoor temperatures from October 2020 to March 2021. Selected SARS-CoV-2 strains were genotyped.

Findings

There were 19 COVID-19 clusters on 14 wards at Hospital W during the six-month study period, lasting from two to 42 days (average, five days; median, 14 days) and involving an average of nine patients (range 1–24) and seven staff (range 0–17). COVID-19 clusters in Hospitals H and M reflected community infection rates. An outbreak management team implemented a control package including daily surveillance; ward closures; universal masking; screening; restricting staff and patient movement; enhanced cleaning; and improved ventilation. Forty clusters occurred across all three hospitals before a January window-opening policy, after which there were three during the remainder of the study.

Conclusion

The winter surge of COVID-19 clusters was multi-factorial, but clearly exacerbated by moving trauma patients around the hospital. An extended infection prevention and control package including enhanced natural ventilation helped reduce COVID-19 clusters in acute hospitals.