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.

Viral epidemiology and SARS-CoV-2 coinfections with other respiratory viruses during the first COVID-19 wave in Paris, France (preprint)

Abstract: Objectives: Our work assessed the prevalence of co-infections in patients with SARS-CoV-2. Methods: All patients hospitalized in a Parisian hospital during the first wave of COVID-19 were tested by mPCR if they presented ILI symptoms. Results: A total of 806 patients (21%) were positive for SARS-CoV-2, 755 (20%) were positive for other respiratory viruses. Among the SARS-CoV-2 positive patients, 49 (6%) had viral co-infections. They presented similar age, symptoms, except for fever (p=0.013) and headaches (p=0.048), than single SARS-CoV-2 infections. Conclusions: SARS-CoV-2 infected patients presenting viral co-infections had similar clinical characteristics and prognosis than patients solely infected with SARS-CoV-2.

Learning from Public Health and Hospital Resilience to the SARS-CoV-2 Pandemic: Protocol for a Multiple Case Study (Brazil, Canada, China, France, Japan, and Mali). (preprint)

Background: All prevention efforts currently being implemented for COVID-19 are aimed at reducing the burden on strained health systems and human resources. There has been little research conducted to understand how SARS-CoV-2 has affected healthcare systems and professionals in terms of their work. Finding effective ways to share the knowledge and insight between countries, including lessons learned, is paramount to the international containment and management of the COVID-19 pandemic. The aim of this project is to compare the pandemic response to COVID-19 in Brazil, Canada, China, France, Japan, and Mali. This comparison will be used to identify strengths and weaknesses in the response, including challenges for health professionals and health systems.Methods:  We will use a multiple case study approach with multiple levels of nested analysis. We chose these countries as they represent different continents and different stages of the pandemic. We will focus on several major hospitals and two public health interventions (contact tracing and testing). It is a multidisciplinary research approach that will use qualitative data through observations, document analysis, and interviews, as well as quantitative data based on disease surveillance data and other publicly available data. Given that the methodological approaches of the project are largely qualitative, the ethical risks are minimal. For the quantitative component, the data being used are publicly available.Discussion: We will deliver lessons learned based on a rigorous process and on strong evidence to enable operational-level insight for national and international stakeholders.

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.

High-risk exposure without personal protective equipment and infection with SARS-CoV-2 in healthcare workers: results of the CoV-CONTACT prospective cohort (preprint)

Objective: We aimed to estimate the risk of infection in Healthcare workers (HCWs) following a high-risk exposure without personal protective equipment (PPE). Methods: We conducted a prospective cohort in HCWs who had a high-risk exposure to SARS-CoV-2-infected subject without PPE. Daily symptoms were self-reported for 30 days, nasopharyngeal swabs for SARS-CoV-2 RT-PCR were performed at inclusion and at days 3, 5, 7 and 12, SARS-CoV-2 serology was assessed at inclusion and at day 30. Confirmed infection was defined by positive RT-PCR or seroconversion, and possible infection by one general and one specific symptom for two consecutive days. Results: Between February 5th and May 30th, 2020, 154 HCWs were enrolled within 14 days following one high-risk exposure to either a hospital patient (70/154; 46.1%) and/or a colleague (95/154; 62.5%). At day 30, 25.0% had a confirmed infection (37/148; 95%CI, 18.4%; 32.9%), and 43.9% (65/148; 95%CI, 35.9%; 52.3%) had a confirmed or possible infection. Factors independently associated with confirmed or possible SARS-CoV-2 infection were being a pharmacist or administrative assistant rather than being from medical staff (adjusted OR (aOR)=3.8, CI95%=1.3;11.2, p=0.01), and exposure to a SARS-CoV-2-infected patient rather than exposure to a SARS-CoV-2-infected colleague (aOR=2.6, CI95%=1.2;5.9, p=0.02). Among the 26 HCWs with a SARS-CoV-2-positive nasopharyngeal swab, 7 (26.9%) had no symptom at the time of the RT-PCR positivity. Conclusions: The proportion of HCWs with confirmed or possible SARS-CoV-2 infection was high. There were less occurrences of high-risk exposure with patients than with colleagues, but those were associated with an increased risk of infection.

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.