Reducing airborne transmissible diseases in perioperative environments.

The COVID-19 pandemic has transformed our understanding of aerosol transmissible disease and the measures required to minimise transmission. Anaesthesia providers are often in close proximity to patients and other hospital staff for prolonged periods while working in operating and procedure rooms. Although enhanced ventilation provides some protection from aerosol transmissible disease in these work areas, close proximity and long duration of exposure have the opposite effect. Surgical masks provide only minimal additional protection. Surgical patients are also at risk from viral and bacterial aerosols. Despite having recently experienced the most significant pandemic in 100 yr, we continue to lack adequate understanding of the true risks encountered from aerosol transmissible diseases in the operating room, and the best course of action to protect patients and healthcare workers from them in the future. Nevertheless, hospitals can take specific actions now by providing respirators for routine use, encouraging staff to utilise respirators routinely, establishing triggers for situations that require respirator use, educating staff concerning the prevention of aerosol transmissible diseases, and providing portable air purifiers for perioperative spaces with low levels of ventilation.

Criticism of Workplace Protection Barrier Face Covering Article Mischaracterizes ASTM Standard and its Potential Utility.

Editor's Note: This is a response to "Why a Workplace Barrier Face Covering is a Bad Idea" by Mark Nicas. DOI: 10.1177/10482911231193771.

Preventing Aerosol-Transmissible Diseases in Healthcare Settings: The Need for Protective Guidelines and Standards-Workshop Report.

There is an urgent need for stronger protection from aerosol-transmissible diseases in healthcare settings-for workers, patients, volunteers, and visitors. Concerned that the Centers for Disease Control and Prevention (CDC) Healthcare Infection Control Practices Advisory Committee (HICPAC) lacks diversity in expertise and experience and has not consulted widely with all concerned parties regarding a planned update to the 2007 Guideline for Isolation Precautions, a workshop was developed to consider the science and lessons learned before and during the COVID-19 pandemic. Sponsored by the New York/New Jersey Occupational Safety and Health Center, Preventing Aerosol-Transmissible Diseases in Healthcare Settings: The Need for Protective Guidelines and Standards was held on October 13, 2023, with these goals: describe current CDC/HICPAC infection prevention guidelines, review current scientific understanding of aerosol-transmissible pathogens, and consider perspectives from a wide range of groups currently excluded from the CDC HICPAC process.

Public Health Experts Ask CDC Director to Broaden Input on Revisions to Key Infection Control Guidelines.

On July 20, 2023 a letter was sent to the Director of the Centers for Disease Control and Prevention requesting the agency's Healthcare Infection Control Practice Advisory Committee seek input from more stakeholders and the public, recognize the importance of infectious disease transmission by inhalation of human-generated aerosols, and ensure the application of interventions from all levels of the control hierarchy.

Health and Safety Regulations for COVID-19: A Policy Analysis.

The COVID-19 pandemic spurred some regulators in the USA to require occupational health and safety programs to prevent COVID-19 transmission in workplaces. The objective of this study was to describe such state and federal regulations enacted between January 2020 and January 2022. Regulations, including emergency temporary standards (ETS) and permanent standards, were identified through a search of Nexis Uni and Bloomberg Law and review of US OSHA websites and the Federal Register. Full texts were reviewed for regulatory scope, hazard and exposure definitions, determination of exposure or risk levels, and control strategies. Four state (California, Michigan, Virginia, and Oregon) and two federal regulations were identified. All regulations described respiratory aerosols as the primary source of SARS-CoV-2 and recognized person-to-person transmission by droplet, airborne, and contact routes. Only the US OSHA ETS for healthcare explicitly stated that inhalation of respiratory particles was the most likely method of COVID-19 transmission. The Virginia, Michigan, and Oregon regulations described different categories of risk defined by exposure frequency and duration or specific workplace activities. California described exposure as places and times when employees come into contact or congregate with other people. The US OSHA ETS for healthcare described exposure as involving close contact with suspected or confirmed COVID-19 patients. While all of the state regulations required strategies from across the hierarchy, only the Virginia regulations specifically incorporated the hierarchy of controls. Only the California and Virginia regulations explicitly linked control strategies to the transmission route, while Virginia demarcated control strategies by risk level. Oregon linked risk level to occupancy levels and physical distancing requirements and referred to the use of a layered approach for transmission control. The US OSHA ETS for healthcare defined droplet and airborne precautions but made no mention of the hierarchy of controls or risk levels. Respirators were discussed in most of the regulations. The first Michigan regulation explicitly required respirators appropriate to exposure risk. The California regulations noted that respirators protect the wearer while face coverings protect people around the wearer. These regulations offer insights for a permanent US OSHA infectious disease regulation, such as the need to consider a range of transmission modes including near- and far-range aerosol inhalation, endemic and novel pathogens, workplaces beyond healthcare settings, factors that contribute to exposure and risk, the hierarchy of controls, the role of vaccination, and the importance of written exposure assessment and infection prevention plans.

Simulated workplace protection factor study of a quarter-facepiece elastomeric respirator.

The assigned protection factor (APF) for quarter-facepiece respirators is currently 5, based on fit test data from the 1970s with models no longer commercially available. The goal of this project was to evaluate the respirator fit capability of a NIOSH-approved N95 quarter-facepiece elastomeric respirator with a gel-based facial seal design (Envo Mask by Sleepnet Corporation). Human subjects were recruited from healthcare and the general population to satisfy a 25-member NIOSH bivariate panel. Subjects were fit tested with a fast fit protocol using a TSI Portacount Model 8038 in the N95 mode. Second-by-second measures of fit were then collected while subjects performed a 30-min series of simulated healthcare activities. Subjects completed a short comfort questionnaire. The median (5th, 95th percentile) fit factor was 188 (48, 201). Simulated workplace protection factors (SWPFs) had a median (5th, 95th percentile) of 181 (94, 199) (data truncated at 200) and 570 (153, 1508) (non-truncated data). Subjects ranked inhalation and exhalation as "easy" with average scores of 5.0/6.0 and 5.2/6.0, respectively. The facepiece was ranked between slightly comfortable and comfortable (4.8/6.0) and the harness as comfortable (5.0/6.0). Most users agreed (5.2/6.0) that the mask was stable on their faces. The 5th percentile SWPF of 95 supports an APF of at least 10 for this quarter-facepiece elastomeric respirator, similar to the APF for half-facepiece respirators. This study supports increasing the APF for quarter-facepiece respirators, a class that has been largely ignored by manufacturers for the past 40 years. A lightweight, low profile, reusable quarter-facepiece respirator is an effective option for healthcare and other worker protection during a pandemic and similar situations.

Feature, Barrier Face Coverings for Workers.

Face coverings have been recommended for the public and workers to prevent person-to-person transmission of COVID-19. Throughout 2020, guidelines for face coverings recommended multiple layers worn tightly against the face with straps or ear loops. This article briefly describes a new ASTM 3502 Standard Specification for Barrier Face Coverings (BFCs) and the development of performance criteria for workplace BFCs ahead of the Occupational Safety and Health Administration (OSHA) COVID-19 Emergency Temporary Standards (ETS). We also describe a method for comparing the effect on the time to receipt of an infectious dose (ID) of BFCs with varying degrees of inward leakage (personal protection) and outward leakage (source control). The role of BFCs in workplace settings during the pandemic and for exposure to infectious respiratory organisms after the pandemic remains in question. It will be important for occupational health and safety professionals to recognize their limitations in contrast with respiratory protection.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Dose, Infection, and Disease Outcomes for Coronavirus Disease 2019 (COVID-19): A Review.

The relationship between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) dose, infection, and coronavirus disease 2019 (COVID-19) outcomes remains poorly understood. This review summarizes the existing literature regarding this issue, identifies gaps in current knowledge, and suggests opportunities for future research. In humans, host characteristics, including age, sex, comorbidities, smoking, and pregnancy, are associated with severe COVID-19. Similarly, in animals, host factors are strong determinants of disease severity, although most animal infection models manifest clinically with mild to moderate respiratory disease. The influence of variants of concern as it relates to infectious dose, consequence of overall pathogenicity, and disease outcome in dose-response remains unknown. Epidemiologic data suggest a dose-response relationship for infection contrasting with limited and inconsistent surrogate-based evidence between dose and disease severity. Recommendations include the design of future infection studies in animal models to investigate inoculating dose on outcomes and the use of better proxies for dose in human epidemiology studies.

Selecting Controls for Minimizing SARS-CoV-2 Aerosol Transmission in Workplaces and Conserving Respiratory Protective Equipment Supplies.

With growing evidence of inhalation of small infectious particles as an important mode of transmission for SARS-CoV-2, workplace risk assessments should focus on eliminating or minimizing such exposures by applying the hierarchy of controls. We adapt a control banding model for aerosol-transmissible infectious disease pandemic planning to encourage the use of source and pathway controls before receptor controls (personal protective equipment). Built on the recognition that aerosol-transmissible organisms are likely to exhibit a dose-response function, such that higher exposures result from longer contact times or higher air concentrations, this control banding model offers a systematic method for identifying a set of source and pathway controls that could eliminate or reduce the need for receptor controls. We describe several examples for workers at high risk of exposure in essential or return to work categories. The goal of using control banding for such workers is to develop effective infection and disease prevention programs and conserve personal protective equipment.

A systematic risk-based strategy to select personal protective equipment for infectious diseases.

BACKGROUND: Personal protective equipment (PPE) is a primary strategy to protect health care personnel (HCP) from infectious diseases. When transmission-based PPE ensembles are not appropriate, HCP must recognize the transmission pathway of the disease and anticipate the exposures to select PPE. Because guidance for this process is extremely limited, we proposed a systematic, risk-based approach to the selection and evaluation of PPE ensembles to protect HCP against infectious diseases. METHODS: The approach used in this study included the following 4 steps: (1) job hazard analysis, (2) infectious disease hazard analysis, (3) selection of PPE, and (4) evaluation of selected PPE. Selected PPE should protect HCP from exposure, be usable by HCP, and fit for purpose. RESULTS: The approach was demonstrated for the activity of intubation of a patient with methicillin-resistant Staphylococcus aureus or Severe Acute Respiratory Syndrome coronavirus. As expected, the approach led to the selection of different ensembles of PPE for these 2 pathogens. DISCUSSION: A systematic risk-based approach to the selection of PPE will help health care facilities and HCP select PPE when transmission-based precautions are not appropriate. Owing to the complexity of PPE ensemble selection and evaluation, a team with expertise in infectious diseases, occupational health, the health care activity, and related disciplines, such as human factors, should be engaged. CONCLUSIONS: Participation, documentation, and transparency are necessary to ensure the decisions can be communicated, critiqued, and understood by HCP.

Experience of Chicagoland acute care hospitals in preparing for Ebola virus disease, 2014-2015.

During the 2014-2015 Ebola Virus Disease (EVD) outbreak, hospitals in the United States selected personal protective equipment (PPE) and trained healthcare personnel (HCP) in anticipation of receiving EVD patients. To improve future preparations for high-consequence infectious diseases, it was important to understand factors that affected PPE selection and training in the context of the EVD outbreak. Semistructured interviews were conducted with HCP involved with decision-making during EVD preparations at acute care hospitals in the Chicago, IL area to gather information about the PPE selection and training process. HCP who received training were surveyed about elements of training and their perceived impact and overall experience by email invitation. A total of 28 HCP from 15 hospitals were interviewed, and 55 HCP completed the survey. Factors affecting PPE selection included: changing guidance, vendor supply, performance evaluations, and perceived risk and comfort for HCP. Cost did not affect selection. PPE acquisition challenges were mitigated by: sharing within hospital networks, reusing PPE during training, and improvising with existing PPE stock. Selected PPE ensembles were similar across sites. Training included hands-on activities with trained observers, instructional videos, and simulations/drills, which were felt to increase HCP confidence. Many felt refresher training would be helpful. Hands-on training was perceived to be effective, but there is a need to establish the appropriate frequency of refresher training frequency to maintain competence. Lacking confidence in the CDC guidance, interviewed trainers described turning to other sources of information and developing independent PPE evaluation and selection. Response to emerging and/or high consequence infectious diseases would be enhanced by transparent, risk-based guidance for PPE selection and training that addresses protection level, ease of use, ensembles, and availability.

Utilizing the focused conversation method in qualitative public health research: a team-based approach.

BACKGROUND: Qualitative research studies are becoming increasingly necessary to understand the complex challenges in the healthcare setting. Successfully integrating interdisciplinary teams of investigators can be challenging, as investigators inherently view data through their disciplinary lens. Thus, new methods, such as focused conservation, are needed to facilitate qualitative data analysis by interdisciplinary teams. The purpose of this manuscript is to provide a clear description of how we implemented the focused conversation method to facilitate an organized data-driven discussion that responded to our study objectives and ensured participation of our interdisciplinary team. The focused conversation method has not, to our knowledge, been utilized for this purpose to date. METHODS: To better understand the experience of healthcare personnel (HCP) during preparations for the 2014-2015 Ebola Virus Disease (EVD) outbreak, we interviewed HCP who participated in decision making about EVD preparations and training of workers in the use of enhanced personal protective equipment ensembles in the metropolitan Chicagoland area of Illinois to attain a priori research objectives. We identified a systematic method - the focused conversation method - that enabled our interdisciplinary team to interactively contribute to the framing, analysis and interpretation of the data that would enable us to focus on our research objectives. RESULTS: The focused conversation developed to support our a priori research objective about the training of HCP in preparations included objective, reflective, interpretive and decisional questions. These questions grounded the conversation in the data, while leveraging discipline-specific lenses and professional experience in the analysis and interpretation. Insights from the conversation were reviewed later against interview transcripts to ensure validity. The conversation identified areas for future research directions and deficiencies in the interview instrument. CONCLUSIONS: The focused conversation is an efficient, organized method for analysis of qualitative data by an interdisciplinary team.

A Control Banding Framework for Protecting the US Workforce from Aerosol Transmissible Infectious Disease Outbreaks with High Public Health Consequences.

Recent high-profile infectious disease outbreaks illustrate the importance of selecting appropriate control measures to protect a wider range of employees, other than those in healthcare settings. In such settings, where routine exposure risks are often high, control measures may be more available, routinely implemented, and studied for effectiveness. In the absence of evidence-based guidelines or established best practices for selecting appropriate control measures, employers may unduly rely on personal protective equipment (PPE) because of its wide availability and pervasiveness as a control measure, circumventing other effective options for protection. Control banding is one approach that may be used to assign job tasks into risk categories and prioritize the application of controls. This article proposes an initial control banding framework for workers at all levels of risk and incorporates a range of control options, including PPE. Using the National Institutes of Health (NIH) risk groups as a surrogate for toxicity and combining the exposure duration with the exposure likelihood, we can generate the risk of a job task to the worker.