SARS-CoV-2 Exposures of Healthcare Workers from Primary Care, Long-Term Care Facilities and Hospitals: A Nationwide Matched Case-Control Study (preprint)

ABSTRACT Objectives Healthcare workers (HCWs) are at higher risk of contracting coronavirus disease-19 (COVID-19) than the general population. This study assessed the roles of various exposures and personal protective equipment (PPE) use on that risk for HCWs working in primary care, long-term-care facilities (LTCFs) or hospitals. Methods We conducted a matched case-control (1:1) study (10 April–9 July 2021). Cases (HCWs with confirmed COVID-19) and controls (HCWs without any COVID-19-positive test or symptoms) recruited by email were invited to complete an online questionnaire on their exposures and PPE use. Questions covered the 10 days preceding symptom onset for cases (or testing if asymptomatic) or inclusion for controls. Results A total of 4152 matched cases and controls were included. The multivariable conditional logistic regression analysis retained exposure to an infected person outside work (adjusted odds ratio, 19.9 [95% confidence intervaI, 12.4–31.9]), an infected colleague (2.26 [1.53–3.33]) or COVID-19 patients (2.37 [1.66–3.40]), as independent predictors of COVID-19 in HCWs, while partial or complete immunization was protective. Eye protection (0.57 [0.37–0.87]) and wearing a gown (0.58 [0.34–0.97]) during COVID-19 patient care were protective, while wearing an apron slightly increased the risk of infection (1.47 [1.00–2.18]). N95-respirator protection was comparable to that of surgical masks. Results were consistent across healthcare-facility categories. Conclusions HCWs were more likely to get COVID-19 in their personal sphere than during occupational activities. Our results suggest that eye protection for HCWs during patient care should be actively promoted.

Macro Level Influences on Strategic Responses to the COVID-19 Pandemic - A Tool for National Assessments (preprint)

Background: Variation in the approaches taken to contain the SARS-CoV-2 (COVID-19) pandemic at country level has been shaped by economic and political considerations, technical capacity, and assumptions about public behaviours. To address the limited application of learning from previous pandemics, this study aimed to analyse perceived facilitators and inhibitors during the pandemic and to inform the development of an assessment tool for pandemic response planning.Methods: A cross-sectional electronic survey of health and non-healthcare professionals (5 May - 5 June 2020) in six languages, with respondents recruited via email, social media and website posting. Participants were asked to score inhibitors (-10 to 0) or facilitators (0 to +10) impacting country response to COVID-19 from the following domains – Political, Economic, Sociological, Technological, Ecological, Legislative, and wider Industry (the PESTELI framework). Participants were then asked to explain their responses using free text. Descriptive and thematic analysis was followed by triangulation with the literature and expert validation to develop the assessment tool, which was then compared with four existing pandemic planning frameworks.Findings: 928 respondents from 66 countries (57% healthcare professionals) participated. Political and economic influences were consistently perceived as powerful negative forces and technology as a facilitator across high- and low-income countries. The 103-item tool developed for guiding rapid situational assessment for pandemic planning is comprehensive when compared to existing tools and highlights the interconnectedness of the 7 domains.Interpretation: The tool developed and proposed addresses the problems associated with decision making in disciplinary silos and offers a means to refine future use of epidemic modelling.Funding Statement: This study did not receive any external funding.Declaration of Interests: None to declare. Ethics Approval Statement: The study was approved by the Joint Research Compliance Office, Imperial College London (ICREC reference: 20IC5947).

How do the general population behave with facemasks to prevent COVID-19 in the community? (preprint)

IMPORTANCE The appropriate use of facemasks, recommended or mandated by authorities, is critical to protect the community and prevent the spread of COVID-19. OBJECTIVE To evaluate the frequency and quality of facemask use in general populations of different socio-spatial backgrounds. DESIGN A multi-site observational study carried out from 25 June 2020 to 21 July 2020. SETTING The observations were carried out in 43 different locations in a region in the west of France, representing various areas: rural and urban, indoor and outdoor, and in areas where masks were mandated or not. An observer was positioned at a predetermined place, facing a landmark, and collected information about the use of facemasks and socio-demographic data. PARTICIPANTS All individual passing between the observer and the landmark were included. EXPOSURE The observer collected information on whether a mask was worn, the type of mask used, the quality of the positioning, gender, and the age category of each individual. MAIN OUTCOMES AND MEASURES The main outcomes were the use of a facemask and the quality of the positioning. Factors associated with these outcomes were identified. RESULTS A total of 3354 observations were recorded. A facemask was worn by 56.4% (n=1892) of individuals, varying from 49% (n=1359) in non-mandatory areas and 91.7% (n=533) in mandatory areas, including surgical facemasks (56.8%, n=1075) and cloth masks (43.2%, n=817). The facemask was correctly positioned in 75.2% (n=1422) of cases. The factors independently associated with wearing a facemask were being indoors (adjusted odds ratio [aOR], 0.37; 95% confidence interval [CI], 0.31-0.44), being in a mandatory area (aOR, 0.14; 95%CI, 0.10-0.20), female gender (aOR, 0.57; 95%CI, 0.49-0.66), and age >40 years (aOR, 0.54; 95%CI, 0.46-0.63). The factors independently associated with correct mask position were rural location (aOR, 0.76; 95%CI, 0.97-0.98), being in an indoor area (aOR, 0.49; 95%CI, 0.38-0.65), use of a cloth mask (aOR, 0.65; 95%CI, 0.52-0.81), and age >40 years (aOR, 0.61; 95%CI 0.49-0.76). CONCLUSIONS AND RELEVANCE Information campaigns should promote the use of cloth masks. Young people in general and men in particular are the priority targets. Simplifying the rules to require universal mandatory masking seems to be the best approach for health authorities.

Airborne contamination of COVID-19 in hospitals: a scoping review of the current evidence. (preprint)

Introduction A controversy remains worldwide regarding the transmission routes of SARS-CoV-2 in hospital settings. We reviewed the current evidence on the air contamination with SARS-CoV-2 in hospital settings, and the factors associated to the contamination including the viral load and the particles size. Methods The MEDLINE, Embase, Web of Science databases were systematically interrogated for original English-language articles detailing COVID-19 air contamination in hospital settings between 1 December 2019 and 21 July 2020. This study was conducted in accordance with the PRISMA-ScR guidelines. The positivity rate of SARS-CoV-2 viral RNA and culture were described and compared according to the setting, clinical context, air ventilation system, and distance from patient. The SARS-CoV-2 RNA concentrations in copies per m3 of air were pooled and their distribution were described by hospital areas. Particle sizes and SARS-CoV-2 RNA concentrations in copies or TCID50 per m3 were analysed after categorization of sizes in <1 micrometers, 1-4 micrometers, and >4 micrometers. Results Among 2,034 records identified, 17 articles were included in the review. Overall, 27.5% (68/247) of air sampled from close patients environment were positive for SARS-CoV-2 RNA, without difference according to the setting (ICU: 27/97, 27.8%; non-ICU: 41/150, 27.3%; p=0.93), the distance from patients (<1 meter: 1/64, 1.5%; 1-5 meters: 4/67, 6%; p=0.4). In other areas, the positivity rate was 23.8% (5/21) in toilets, 9.5% (20/221) in clinical areas, 12.4% (15/121) in staff areas, and 34.1% (14/41) in public areas. A total of 78 viral cultures were performed in three studies, and 3 (4%) were positive, all from close patients environment. The median SARS-CoV-2 RNA concentrations varied from 1.103 copies per m3 (IQR: 0.4.103-9.103) in clinical areas to 9.7.103 (5.1.103-14.3.103) in the air of toilets or bathrooms. The protective equipment removal and patients rooms had high concentrations/titre of SARS-CoV-2 with aerosol size distributions that showed peaks in the <1 micrometers region, and staff offices in the >4 micrometers region. Conclusion In hospital, the air near and away from COVID-19 patients is frequently contaminated with SARS-CoV-2 RNA, with however, rare proofs of their viability. High viral loads found in toilet/bathrooms, staff and public hallways suggests to carefully consider these areas.

Analysis of national and international guidelines on respiratory protection equipment for COVID-19 in healthcare settings. (preprint)

Introduction Consistent guidelines on respiratory protection for healthcare professionals combined with improved global supply chains are critical to protect staff and patients from COVID-19. We summarized and compared the guidelines published by national and international societies/organizations on facemasks and respirators to prevent COVID-19 in healthcare settings. Methods From the 1st January to the 2nd April 2020, guidelines published in four countries (France, Germany, United States, United Kingdom), and two international organizations (US and European Center for Diseases Control, and World Health Organization) were reviewed to analyze the mask and respirators recommended as PPE for the care of patients during the COVID-19 outbreak. Guidelines were eligible for analysis if they (1) included specific guidelines, (2) were written for HCP protection, (3) targeting healthcare settings. The strategy recommended for optimizing supplies and overcoming shortages was collected. Observations The guidelines publication process on respiratory protections varied greatly across countries. Some referred to a unique guide whereas others saw the issue of multiple recommendations by various societies and organization. In term of chronology, most guidelines were published in March with either downgraded (US and European CDC), relatively stable (WHO, Germany, and UK), or a mixing of high and low level equipment (France). The recommendation of respirators was universally recommended for aerosol generating procedures (AGP) across countries, although the type of respirators and what constituted an AGP was variable. Some guidance maintained the use of N95/99 for all contact with confirmed COVID-19 cases (i.e. Germany) whereas others, recommended a surgical mask (i.e. WHO, UK, France). The strategies to overcome shortage of respiratory protection equipment were based on minimizing the need and rationalizing the use, but also prolonging their use, reusing them after cleaning/sterilization, or using cloth masks. Conclusions Stable and consistent guidelines inside and across countries, clearly detailing the respiratory protection type, and the circumstances in which they need to be used may prevent the confusion among frontline staff, and avoid shortage.