Importance of and Approach to Taking a History of Exposures to Occupational Respiratory Hazards.

Occupational respiratory diseases are caused by exposure to respiratory hazards at work. It is important to document those exposures and whether they are causing or exacerbating disease because these determinations can have important impacts on diagnosis, treatment, job restrictions, and eligibility for benefits. Without investigation, it is easy to miss clinically relevant exposures, especially in those with chronic diseases that can have work and nonwork causes. The first and most important step in identifying exposures to respiratory hazards at work is to take an appropriate history. For efficiency, this is a two-step process. An initial quick screening history is done by asking only a few questions. Follow-up questions are asked if there are positive responses to the screening questions or if an occupational etiology is suspected based on the clinical presentation. Electronic health records have promise for facilitating this process. Follow-up to the screening history may include additional questions, evaluating additional sources of information about workplace exposures, and medical testing. Radiographic findings or tests conducted on noninvasive samples or lung tissue can be used as biomarkers. Online resources can be used to learn more about exposures associated with occupations and industries and to see if investigations evaluating exposures were performed in the patient's own workplace. It is important to adhere to the patient's wishes about contacting the employer. With patient consent, the employer can be an important source of information about exposures and, if a problem exists, has an important role in taking corrective action. Consultation for challenging cases is available from a variety of professional and governmental entities. If a clinician identifies a significant public health issue, such as an occupational disease outbreak, it is important to notify relevant public health authorities so that steps can be taken to prevent additional exposures and appropriately care for those already exposed.

Influence of Preseason Antibodies Against Influenza Virus on Risk of Influenza Infection Among Healthcare Personnel.

BACKGROUND: The association of hemagglutination inhibition (HAI) antibodies with protection from influenza among healthcare personnel (HCP) with occupational exposure to influenza viruses has not been well-described. METHODS: The Respiratory Protection Effectiveness Clinical Trial was a cluster-randomized, multisite study that compared medical masks to N95 respirators in preventing viral respiratory infections among HCP in outpatient healthcare settings for 5180 participant-seasons. Serum HAI antibody titers before each influenza season and influenza virus infection confirmed by polymerase chain reaction were studied over 4 study years. RESULTS: In univariate models, the risk of influenza A(H3N2) and B virus infections was associated with HAI titers to each virus, study year, and site. HAI titers were strongly associated with vaccination. Within multivariate models, each log base 2 increase in titer was associated with 15%, 26% and 33%-35% reductions in the hazard of influenza A(H3N2), A(H1N1), and B infections, respectively. Best models included preseason antibody titers and study year, but not other variables. CONCLUSIONS: HAI titers were associated with protection from influenza among HCP with routine exposure to patients with respiratory illness and influenza season contributed to risk. HCP can be reassured about receiving influenza vaccination to stimulate immunity.

Cardiovascular responses to physical activity during work and leisure.

OBJECTIVES: Recent evidence suggests that occupational physical activity (OPA) is associated with adverse cardiovascular health, whereas leisure time physical activity is protective. This study explored explanatory physiological mechanisms. METHODS: Nineteen males (68% white, age=46.6±7.9 years, body mass index=27.9±5.1 kg/m2) with high self-reported OPA wore activity (ActiGraph and activPAL) and heart rate (HR) monitors for 7 days and an ambulatory blood pressure (BP) monitor on one workday and one non-workday. Mixed effects models compared cardiovascular variables (24-hour, nocturnal, waking and non-work time HR and BP) and nocturnal HR variability (HRV) on workdays versus non-workdays. Additional models examined associations of daily activity (steps, light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA)) with cardiovascular variables. Workday by daily activity interactions were examined. RESULTS: 24-hour and waking HR and diastolic BP as well as non-work diastolic BP were significantly higher on workdays versus non-workdays (p<0.05 for all). However, no difference in systolic BP or nocturnal HR or BP was observed between work and non-workdays (p>0.05 for all). Low-frequency and high-frequency power indices of nocturnal HRV were lower on workdays (p<0.05 for both). Daily steps and LPA were positively associated with 24-hour and waking HR on work and non-workdays. Significant interactions suggested MVPA increases HR and lowers nocturnal HRV during workdays, with the opposite effect on non-workdays. CONCLUSIONS: Cardiovascular load was higher on workdays versus non-workdays with no compensatory hypotensive response following workdays. Daily MVPA may differentially affect ambulatory cardiovascular load and nocturnal HRV on workdays versus non-workdays, supporting the physical activity health paradox hypothesis.

Risk Factors for Healthcare Personnel Infection With Endemic Coronaviruses (HKU1, OC43, NL63, 229E): Results from the Respiratory Protection Effectiveness Clinical Trial (ResPECT).

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) presents a large risk to healthcare personnel (HCP). Quantifying the risk of coronavirus infection associated with workplace activities is an urgent need. METHODS: We assessed the association of worker characteristics, occupational roles and behaviors, and participation in procedures with the risk of endemic coronavirus infection among HCP who participated in the Respiratory Protection Effectiveness Clinical Trial (ResPECT), a cluster randomized trial to assess personal protective equipment to prevent respiratory infections and illness conducted from 2011 to 2016. RESULTS: Among 4689 HCP seasons, we detected coronavirus infection in 387 (8%). HCP who participated in an aerosol-generating procedure (AGP) at least once during the viral respiratory season were 105% (95% confidence interval, 21%-240%) more likely to be diagnosed with a laboratory-confirmed coronavirus infection. Younger individuals, those who saw pediatric patients, and those with household members <5 years of age were at increased risk of coronavirus infection. CONCLUSIONS: Our analysis suggests that the risk of HCP becoming infected with an endemic coronavirus increases approximately 2-fold with exposures to AGPs. Our findings may be relevant to the coronavirus disease 2019 (COVID-19) pandemic; however, SARS-CoV-2, the virus that causes COVID-19, may differ from endemic coronaviruses in important ways. CLINICAL TRIALS REGISTRATION: NCT01249625.

N95 Respirators vs Medical Masks for Preventing Influenza Among Health Care Personnel: A Randomized Clinical Trial.

Importance: Clinical studies have been inconclusive about the effectiveness of N95 respirators and medical masks in preventing health care personnel (HCP) from acquiring workplace viral respiratory infections. Objective: To compare the effect of N95 respirators vs medical masks for prevention of influenza and other viral respiratory infections among HCP. Design, Setting, and Participants: A cluster randomized pragmatic effectiveness study conducted at 137 outpatient study sites at 7 US medical centers between September 2011 and May 2015, with final follow-up in June 2016. Each year for 4 years, during the 12-week period of peak viral respiratory illness, pairs of outpatient sites (clusters) within each center were matched and randomly assigned to the N95 respirator or medical mask groups. Interventions: Overall, 1993 participants in 189 clusters were randomly assigned to wear N95 respirators (2512 HCP-seasons of observation) and 2058 in 191 clusters were randomly assigned to wear medical masks (2668 HCP-seasons) when near patients with respiratory illness. Main Outcomes and Measures: The primary outcome was the incidence of laboratory-confirmed influenza. Secondary outcomes included incidence of acute respiratory illness, laboratory-detected respiratory infections, laboratory-confirmed respiratory illness, and influenzalike illness. Adherence to interventions was assessed. Results: Among 2862 randomized participants (mean [SD] age, 43 [11.5] years; 2369 [82.8%]) women), 2371 completed the study and accounted for 5180 HCP-seasons. There were 207 laboratory-confirmed influenza infection events (8.2% of HCP-seasons) in the N95 respirator group and 193 (7.2% of HCP-seasons) in the medical mask group (difference, 1.0%, [95% CI, -0.5% to 2.5%]; P = .18) (adjusted odds ratio [OR], 1.18 [95% CI, 0.95-1.45]). There were 1556 acute respiratory illness events in the respirator group vs 1711 in the mask group (difference, -21.9 per 1000 HCP-seasons [95% CI, -48.2 to 4.4]; P = .10); 679 laboratory-detected respiratory infections in the respirator group vs 745 in the mask group (difference, -8.9 per 1000 HCP-seasons, [95% CI, -33.3 to 15.4]; P = .47); 371 laboratory-confirmed respiratory illness events in the respirator group vs 417 in the mask group (difference, -8.6 per 1000 HCP-seasons [95% CI, -28.2 to 10.9]; P = .39); and 128 influenzalike illness events in the respirator group vs 166 in the mask group (difference, -11.3 per 1000 HCP-seasons [95% CI, -23.8 to 1.3]; P = .08). In the respirator group, 89.4% of participants reported "always" or "sometimes" wearing their assigned devices vs 90.2% in the mask group. Conclusions and Relevance: Among outpatient health care personnel, N95 respirators vs medical masks as worn by participants in this trial resulted in no significant difference in the incidence of laboratory-confirmed influenza. Trial Registration: ClinicalTrials.gov Identifier: NCT01249625.

Interstitial Lung Diseases in the U.S. Mining Industry: Using MSHA Data to Examine Trends and the Prevention Effects of Compliance with Health Regulations, 1996-2015.

Given the recent increase in dust-induced lung disease among U.S. coal miners and the respiratory hazards encountered across the U.S. mining industry, it is important to enhance an understanding of lung disease trends and the organizational contexts that precede these events. In addition to exploring overall trends reported to the Mine Safety and Health Administration (MSHA), the current study uses MSHA's enforcement database to examine whether or not compliance with health regulations resulted in fewer mine-level counts of these diseases over time. The findings suggest that interstitial lung diseases were more prevalent in coal mines compared to other mining commodities, in Appalachian coal mines compared to the rest of the United States, and in underground compared to surface coal mines. Mines that followed a relevant subset of MSHA's health regulations were less likely to report a lung disease over time. The findings are discussed from a lung disease prevention strategy perspective.

The Respiratory Protection Effectiveness Clinical Trial (ResPECT): a cluster-randomized comparison of respirator and medical mask effectiveness against respiratory infections in healthcare personnel.

BACKGROUND: Although N95 filtering facepiece respirators and medical masks are commonly used for protection against respiratory infections in healthcare settings, more clinical evidence is needed to understand the optimal settings and exposure circumstances for healthcare personnel to use these devices. A lack of clinically germane research has led to equivocal, and occasionally conflicting, healthcare respiratory protection recommendations from public health organizations, professional societies, and experts. METHODS: The Respiratory Protection Effectiveness Clinical Trial (ResPECT) is a prospective comparison of respiratory protective equipment to be conducted at multiple U.S. study sites. Healthcare personnel who work in outpatient settings will be cluster-randomized to wear N95 respirators or medical masks for protection against infections during respiratory virus season. Outcome measures will include laboratory-confirmed viral respiratory infections, acute respiratory illness, and influenza-like illness. Participant exposures to patients, coworkers, and others with symptoms and signs of respiratory infection, both within and beyond the workplace, will be recorded in daily diaries. Adherence to study protocols will be monitored by the study team. DISCUSSION: ResPECT is designed to better understand the extent to which N95s and MMs reduce clinical illness among healthcare personnel. A fully successful study would produce clinically relevant results that help clinician-leaders make reasoned decisions about protection of healthcare personnel against occupationally acquired respiratory infections and prevention of spread within healthcare systems. TRIAL REGISTRATION: The trial is registered at clinicaltrials.gov, number NCT01249625 (11/29/2010).

Potential airborne pathogen transmission in a hospital with and without surge control ventilation system modifications.

To better understand the transport of airborne particulate matter (PM) in hospital environments when surge control strategies are implemented, tests were conducted in a recently decommissioned hospital during a one-week period. An aerosol was released within a patient room and concentrations measured in the room and hallway with and without surge control ventilation system modifications. The average hallway protection efficiencies were high (>98%) both for the baseline ventilation configuration and when the ventilation system was modified for whole floor negative pressure, indicating very little PM reached the hallway. During entry/exit events through the patient room door into the hallway, the average minimum hallway protection efficiencies were lower during the modified ventilation operation (93-94%) than for the baseline operation (98-99%). These lower hallway protection efficiencies may be explained by the 52% reduction in the outdoor air ventilation being supplied to the hallway during the modified operation mode. This suggests that patient room doors should remain closed to control PM movement into the hallway. In addition, if there is concern about airborne infection transmission, an anteroom may be used to further reduce the transport of particles from the patient rooms to the hallways of the ward.

Triggering interventions for influenza: the ALERT algorithm.

BACKGROUND: Early, accurate predictions of the onset of influenza season enable targeted implementation of control efforts. Our objective was to develop a tool to assist public health practitioners, researchers, and clinicians in defining the community-level onset of seasonal influenza epidemics. METHODS: Using recent surveillance data on virologically confirmed infections of influenza, we developed the Above Local Elevated Respiratory Illness Threshold (ALERT) algorithm, a method to identify the period of highest seasonal influenza activity. We used data from 2 large hospitals that serve Baltimore, Maryland and Denver, Colorado, and the surrounding geographic areas. The data used by ALERT are routinely collected surveillance data: weekly case counts of laboratory-confirmed influenza A virus. The main outcome is the percentage of prospective seasonal influenza cases identified by the ALERT algorithm. RESULTS: When ALERT thresholds designed to capture 90% of all cases were applied prospectively to the 2011-2012 and 2012-2013 influenza seasons in both hospitals, 71%-91% of all reported cases fell within the ALERT period. CONCLUSIONS: The ALERT algorithm provides a simple, robust, and accurate metric for determining the onset of elevated influenza activity at the community level. This new algorithm provides valuable information that can impact infection prevention recommendations, public health practice, and healthcare delivery.

Guidance on Mitigating the Risk of Transmitting Respiratory Infections During Nebulization by the COPD Foundation Nebulizer Consortium.

BACKGROUND: Nebulizers are used commonly for inhaled drug delivery. Because they deliver medication through aerosol generation, clarification is needed on what constitutes safe aerosol delivery in infectious respiratory disease settings. The COVID-19 pandemic highlighted the importance of understanding the safety and potential risks of aerosol-generating procedures. However, evidence supporting the increased risk of disease transmission with nebulized treatments is inconclusive, and inconsistent guidelines and differing opinions have left uncertainty regarding their use. Many clinicians opt for alternative devices, but this practice could impact outcomes negatively, especially for patients who may not derive full treatment benefit from handheld inhalers. Therefore, it is prudent to develop strategies that can be used during nebulized treatment to minimize the emission of fugitive aerosols, these comprising bioaerosols exhaled by infected individuals and medical aerosols generated by the device that also may be contaminated. This is particularly relevant for patient care in the context of a highly transmissible virus. RESEARCH QUESTION: How can potential risks of infections during nebulization be mitigated? STUDY DESIGN AND METHODS: The COPD Foundation Nebulizer Consortium (CNC) was formed in 2020 to address uncertainties surrounding administration of nebulized medication. The CNC is an international, multidisciplinary collaboration of patient advocates, pulmonary physicians, critical care physicians, respiratory therapists, clinical scientists, and pharmacists from research centers, medical centers, professional societies, industry, and government agencies. The CNC developed this expert guidance to inform the safe use of nebulized therapies for patients and providers and to answer key questions surrounding medication delivery with nebulizers during pandemics or when exposure to common respiratory pathogens is anticipated. RESULTS: CNC members reviewed literature and guidelines regarding nebulization and developed two sets of guidance statements: one for the health care setting and one for the home environment. INTERPRETATION: Future studies need to explore the risk of disease transmission with fugitive aerosols associated with different nebulizer types in real patient care situations and to evaluate the effectiveness of mitigation strategies.

Healthcare workers' infection risk perceptions of aerosol-generating procedures and affective response.

Objective: To understand healthcare worker (HCW) perceptions of infection risk associated with aerosol-generating procedures (AGPs) and their affective response to performing AGPs. Design: Systematic review. Methods: Systematic searches of PubMed, CINHAL Plus, and Scopus were conducted using combinations of selected keywords and synonyms. To reduce bias, titles and abstracts were screened for eligibility by 2 independent reviewers. Also, 2 independent reviewers extracted data from each eligible record. Discrepancies were discussed until consensus was reached. Results: In total, 16 reports from across the globe were included in this review. Findings suggest that AGPs are generally perceived to place HCWs at high risk of becoming infected with respiratory pathogens and that this perception stimulates a negative affective response and hesitancy to participate in the procedures. Conclusions: AGP risk perception are complex and context dependent but have important influences on HCW infection control practices, decision to participate in AGPs, emotional welfare, and workplace satisfaction. New and unfamiliar hazards paired with uncertainty lead to fear and anxiety about personal and others' safety. These fears may create a psychological burden conducive to burnout. Empirical research is needed to thoroughly understand the interplay between HCW risk perceptions of distinct AGPs, their affective responses to conducting these procedures under various conditions, and their resulting decision to participate in these procedures. Results from such studies are essential for advancing clinical practice; they point to methods for mitigating provider distress and better recommendations for when and how to conduct AGPs.

Preschool-Aged Household Contacts as a Risk Factor for Viral Respiratory Infections in Healthcare Personnel.

Background: Viral respiratory infections (VRIs) are common and are occupational risks for healthcare personnel (HCP). VRIs can also be acquired at home and other settings among HCPs. We sought to determine if preschool-aged household contacts are a risk factor for VRIs among HCPs working in outpatient settings. Methods: We conducted a secondary analysis of data from a cluster randomized trial at 7 medical centers in the United States over 4 influenza seasons from 2011-2012 to 2014-2015. Adult HCPs who routinely came within 6 feet of patients with respiratory infections were included. Participants were tested for respiratory viruses whenever symptomatic and at 2 random times each season when asymptomatic. The exposure of interest was the number of household contacts 0-5 years old (preschool-aged) at the beginning of each HCP-season. The primary outcome was the rate of polymerase chain reaction-detected VRIs, regardless of symptoms. The VRI incidence rate ratio (IRR) was calculated using a mixed-effects Poisson regression model that accounted for clustering at the clinic level. Results: Among the 4476 HCP-seasons, most HCPs were female (85.4%) and between 30 and 49 years of age (54.6%). The overall VRI rate was 2.04 per 100 person-weeks. In the adjusted analysis, HCPs having 1 (IRR, 1.22 [95% confidence interval {CI}, 1.05-1.43]) and ≥2 (IRR, 1.35 [95% CI, 1.09-1.67]) preschool-aged household contacts had higher VRI rates than those with zero preschool-aged household contacts. Conclusions: Preschool-aged household contacts are a risk factor for developing VRIs among HCPs working in outpatient settings.

Aerosol susceptibility of influenza virus to UV-C light.

The person-to-person transmission of influenza virus, especially in the event of a pandemic caused by a highly virulent strain of influenza, such as H5N1 avian influenza, is of great concern due to widespread mortality and morbidity. The consequences of seasonal influenza are also substantial. Because airborne transmission appears to play a role in the spread of influenza, public health interventions should focus on preventing or interrupting this process. Air disinfection via upper-room 254-nm germicidal UV (UV-C) light in public buildings may be able to reduce influenza transmission via the airborne route. We characterized the susceptibility of influenza A virus (H1N1, PR-8) aerosols to UV-C light using a benchtop chamber equipped with a UVC exposure window. We evaluated virus susceptibility to UV-C doses ranging from 4 to 12 J/m(2) at three relative humidity levels (25, 50, and 75%). Our data show that the Z values (susceptibility factors) were higher (more susceptible) to UV-C than what has been reported previously. Furthermore, dose-response plots showed that influenza virus susceptibility increases with decreasing relative humidity. This work provides an essential scientific basis for designing and utilizing effective upper-room UV-C light installations for the prevention of the airborne transmission of influenza by characterizing its susceptibility to UV-C.

Discomfort and exertion associated with prolonged wear of respiratory protection in a health care setting.

The nature of discomfort and level of exertion associated with wearing respiratory protection in the health care workplace are not well understood. Although a few studies have assessed these topics in a laboratory setting, little is known about the magnitude of discomfort and the level of exertion experienced by workers while they deliver health care to patients for prolonged periods. The purpose of this study was to determine the magnitude of discomfort and level of exertion experienced by health care workers while wearing respiratory protection for periods up to 8 hr when performing their typical occupational duties. This project was a multiple cross-over field trial of 27 health care workers, aged 24-65, performing their typical, hospital-based occupational duties. Each participant served as his/her own control and wore one of seven respirators or a medical mask for 8 hr (or as long as tolerable) with interposed doffing periods every 2 hr. Self-perceived discomfort and exertion were quantified before each doffing: self-perceived level of discomfort using a visual analog scale, and self-perceived level of exertion using a Borg scale. Overall, and as would be expected, discomfort increased over time with continual respirator use over an 8-hr period. Interestingly, exertion increased only marginally over the same time period. The relatively low level of exertion associated with eight respiratory protective devices, including models commonly used in the U.S. health care workplace, is not likely to substantially influence workers' tolerability or occupational productivity. However, the magnitude of discomfort does appear to increase significantly over time with prolonged wear. These results suggest that respirator-related discomfort, but not exertion, negatively influences respirator tolerance over prolonged periods. Discomfort may also interfere with the occupational duties of workers.

Physical Activity in the Workplace: Does Just Working Meet Activity Recommendations?

Background: The physical activity (PA) health paradox hypothesizes that occupational physical activity (OPA) and leisure time PA have differential cardiovascular health effects due to increased cardiovascular load without adequate recovery; however, research describing worker PA lacks high-quality objective OPA measurement. This study aimed to objectively describe PA profiles of men reporting high OPA and make comparisons to aerobic PA and OPA recommendations. Methods: Male food service, material moving, health care, or maintenance workers wore activity (ActiGraph® and activPAL®) and heart rate monitors for 7 days. Participants recorded work, non-work, and sleep times in a diary. PA was operationalized as time spent in sedentary behavior, upright time, light, moderate, vigorous, and moderate-to-vigorous PA during work and non-work hours. PA profiles were described and compared with Centers for Disease Control and Prevention aerobic PA guidelines (≥21.4 minute/day) and OPA recommendations (<30 minute/hour upright and intensity of <30% heart rate reserve). Findings: Nineteen male workers (68% White, age = 46.6±7.9 years) were more active on workdays than non-workdays (sedentary: 492.3 vs. 629.7 minute/day; upright: 462.4 vs. 325.2 minute/day; moderate-to-vigorous PA: 72.4 vs. 41.5 minute/day, respectively; all p < .05). Most participants (17/19) achieved aerobic PA guidelines across all days with more achieving on workdays (19/19) than non-workdays (13/19). OPA often exceeded recommended limits with participants accumulating 39.6±12.2 minutes/work hour upright and 30.3±25.9% of working time >30% heart rate reserve. Conclusions/Application to Practice: Male workers reporting high OPA typically met aerobic PA guidelines but exceeded recommended OPA limits. The long-term health implications of such activity profiles should be investigated.

Impact of mandatory vaccination of healthcare personnel on rates of influenza and other viral respiratory pathogens.

OBJECTIVE: The implementation of mandatory influenza vaccination policies among healthcare personnel (HCP) is controversial. Thus, we examined the affect of mandatory influenza vaccination policies among HCP working in outpatient settings. SETTING: Four Veterans' Affairs (VA) health systems and three non-VA medical centers. METHODS: We analyzed rates of influenza and other viral causes of respiratory infections among HCP working in outpatient sites at 4 VA health systems without mandatory influenza vaccination policies and 3 non-VA health systems with mandatory influenza vaccination policies. RESULTS: Influenza vaccination was associated with a decreased risk of influenza (odds ratio, 0.17; 95% confidence interval [CI], 0.13-0.22) but an increased risk of other respiratory viral infections (incidence rate ratio, 1.26; 95% CI, 1.02-1.57). CONCLUSIONS: Our fitted regression models suggest that if influenza vaccination rates in clinics where vaccination was not mandated had equalled those where vaccine was mandated, HCP influenza infections would have been reduced by 52.1% (95% CI, 51.3%-53.0%). These observations, their possible causes, and additional strategies to reduce influenza and other viral respiratory illnesses among HCP working in ambulatory clinics warrant further investigation.

Considerations for Pooled Testing of Employees for SARS-CoV-2.

OBJECTIVES: To identify important background information on pooled tested of employees that employers workers, and health authorities should consider. METHODS: This paper is a commentary based on the review by the authors of pertinent literature generally from preprints in medrixiv.org prior to August 2020. RESULTS/CONCLUSIONS: Pooled testing may be particularly useful to employers in communities with low prevalence of COVID-19. It can be used to reduce the number of tests and associated financial costs. For effective and efficient pooled testing employers should consider it as part of a broader, more comprehensive workplace COVID-19 prevention and control program. Pooled testing of asymptomatic employees can prevent transmission of SARS-CoV-2 and help assure employers and customers that employees are not infectious.