Ronald E Shaffer’s research while affiliated with Pennsylvania Institute of Technology and other places

RESUMEN Las mascarillas respiratorias autofiltrantes (filtering facepiece respirators, FFR) N95 certificadas por el Instituto Nacional de Seguridad y Salud Laborales (National Institute for Occupational Safety and Health, NIOSH) se utilizan en los centros de atención sanatoria como medida de control para mitigar las exposiciones a partículas atmosféricas infecciosas. Cuando la superficie externa de una FFR se contamina, supone un riesgo de transmisión para el usuario. La guía de los Centros para el Control y Prevención de Enfermedades (Centers for Disease Control and Prevention, CDC) recomienda que el personal sanitario retire las FFR agarrando las tiras en la parte posterior de la cabeza para evitar el contacto con la superficie posiblemente contaminada. Al parecer, la adherencia a la técnica de retirada adecuada es baja, debido a numerosos factores que incluyen la dificultad para ubicar y agarrar las tiras. En este estudio se compara el impacto de lengüetas ubicadas en las tiras de la FFR con el de mascarillas comparativas (sin lengüetas) sobre la retirada adecuada, la facilidad de uso, la comodidad y la reducción de la transmisión de la contaminación al usuario. El uso de un agente fluorescente como rastreador de contactos para explorar la contaminación de las FFR en manos y áreas de la cabeza de 20 sujetos humanos demostró que no hubo diferencia entre las tiras de la FFR con lengüetas y las mascarillas comparativas en el sentido de estimular la retirada adecuada de las mismas (p = 0.48), pero la hizo más fácil (p = 0.04), según indican siete de ocho sujetos que usaron las lengüetas. Siete de 20 sujetos opinaron que las FFR con lengüetas son más fáciles de retirar, mientras que solo dos de 20 sujetos indicaron que las FFR sin lengüetas son más fáciles de retirar. La incomodidad no fue un factor relevante para ninguno de los tipos de tiras de las FFR. Al retirar una FFR con las manos contaminadas, el uso de lengüetas redujo de forma importante la cantidad del rastreador de contactos transferida en comparación con las tiras sin lengüetas (p = 0.012). Las FFR con lengüetas en las tiras están asociadas con la facilidad de la retirada y una transferencia notablemente menor del rastreador de contactos fluorescente.

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.

Introduction Healthcare personnel are at high risk for exposure to influenza by direct and indirect contact, droplets and aerosols, and by aerosol generating procedures. Information on air and surface influenza contamination is needed to assist in developing guidance for proper prevention and control strategies. To understand the vulnerabilities of healthcare personnel, we measured influenza in the breathing zone of healthcare personnel, in air and on surfaces within a healthcare setting, and on filtering facepiece respirators worn by healthcare personnel when conducting patient care. Methods Thirty participants were recruited from an adult emergency department during the 2015 influenza season. Participants wore personal bioaerosol samplers for six hours of their work shift, submitted used filtering facepiece respirators and medical masks and completed questionnaires to assess frequency and types of interactions with potentially infected patients. Room air samples were collected using bioaerosol samplers, and surface swabs were collected from high-contact surfaces within the adult emergency department. Personal and room bioaerosol samples, surface swabs, and filtering facepiece respirators were analyzed for influenza A by polymerase chain reaction. Results Influenza was identified in 42% (53/125) of personal bioaerosol samples, 43% (28/ 96) of room bioaerosol samples, 76% (23/30) of pooled surface samples, and 25% (3/12) of the filtering facepiece respirators analyzed. Influenza copy numbers were greater in personal bioaerosol samples (17 to 631 copies) compared to room bioaerosol samples (16 to 323 copies). Regression analysis suggested that the amount of influenza in personal samples was approximately 2.3 times the amount in room samples (Wald χ2 = 16.21, p<0.001). Conclusions Healthcare personnel may encounter increased concentrations of influenza virus when in close proximity to patients. Occupations that require contact with patients are at an increased risk for influenza exposure, which may occur throughout the influenza season. Filtering facepiece respirators may become contaminated with influenza when used during patient care.

Job titles and job descriptions. (DOCX)

Participants’ daily survey. (DOCX)

Increased understanding of influenza transmission is critical for pandemic planning and selecting appropriate controls for healthcare personnel safety and health. The goals of this pilot study were to assess environmental contamination in different areas and at two time periods in the influenza season and to determine the feasibility of using surgical mask contamination to evaluate potential exposure to influenza virus. Bioaerosol samples were collected over 12 days (two 6-day sessions) at 12 locations within a student health center using portable two-stage bioaerosol samplers operating 8 hours each day. Surface samples were collected each morning and afternoon from common high-contact non-porous hard surfaces from rooms and locations where bioaerosol samplers were located. Surgical masks worn by participants while in contact with patients with influenza-like illness were collected. A questionnaire administered to each of the 12 participants at the end of each workday and another at the end of each workweek assessed influenza-like illness symptoms, estimated the number of influenza-like illness patient contacts, hand hygiene, and surgical mask usage. All samples were analyzed using qPCR. Over the 12 days of the study, three of the 127 (2.4%) bioaerosol samples, two of 483 (0.41%) surface samples, and zero of 54 surgical masks were positive for influenza virus. For the duration of contact that occurred with an influenza patient on any of the 12 days, nurse practitioners and physicians reported contacts with influenza-like illness patients > 60 minutes, medical assistants reported 15–44 minutes, and administrative staff reported < 30 minutes. Given the limited number of bioaerosol and surface samples positive for influenza virus in the bioaerosol and surface samples, the absence of influenza virus on the surgical masks provides inconclusive evidence for the potential to use surgical masks to assess exposure to influenza viruses. Further studies are needed to determine feasibility of this approach in assessing healthcare personnel exposures. Information learned in this study can inform future field studies on influenza transmission.

Healthcare workers (HCWs) are at significantly higher risk of exposure to influenza virus during seasonal epidemics and global pandemics. During the 2009 influenza pandemic, some healthcare organizations recommended that HCWs wear respiratory protection such as filtering facepiece respirators, while others indicated that facemasks such as surgical masks (SMs) were sufficient. To assess the level of exposure a HCW may possibly encounter, the aim of this study was to (1.) evaluate if SMs and N95 respirators can serve as "personal bioaerosol samplers" for influenza virus and (2.) determine if SMs and N95 respirators contaminated by influenza laden aerosols can serve as a source of infectious virus for indirect contact transmission. This effort is part of a National Institute for Occupational Safety and Health 5-year multidisciplinary study to determine the routes of influenza transmission in healthcare settings. A coughing simulator was programmed to cough aerosol particles containing influenza virus over a wide concentration range into an aerosol exposure simulation chamber virus/L of exam room air), and a breathing simulator was used to collect virus on either a SM or N95 respirator. Extraction buffers containing nonionic and anionic detergents as well as various protein additives were used to recover influenza virus from the masks and respirators. The inclusion of 0.1% SDS resulted in maximal influenza RNA recovery (41.3%) but with a complete loss of infectivity whereas inclusion of 0.1% bovine serum albumin resulted in reduced RNA recovery (6.8%) but maximal retention of virus infectivity (17.9%). Our results show that a HCW's potential exposure to airborne influenza virus can be assessed in part through analysis of their SMs and N95 respirators, which can effectively serve as personal bioaerosol samplers.

Machine and human subject testing of four prototype filtering facepiece respirators (FFR) and two commercial FFR was carried out utilizing recently proposed respirator test criteria that address healthcare worker-identified comfort and tolerance issues. Overall, two FFR (one prototype, one commercial model) were able to pass all eight criteria and three FFR (two prototypes, one commercial model) were able to pass seven of eight criteria. One prototype FFR was not tested against the criteria due to an inability to obtain satisfactory results on human subject quantitative respirator fit testing. Future studies, testing different models and styles of FFR against the proposed criteria, will be required to gauge the overall utility and effectiveness of the criteria in determining FFR comfort and tolerance issues that may impact user compliance and, by extension, protection.

Contact transmission of pathogens from personal protective equipment is a concern within the healthcare industry. During public health emergency outbreaks, resources become constrained and the reuse of personal protective equipment, such as N95 filtering facepiece respirators, may be needed. This study was designed to characterize the transfer of bacteriophage MS2 and fluorescein between filtering facepiece respirators and the wearer's hands during three simulated use scenarios. Filtering facepiece respirators were contaminated with MS2 and fluorescein in droplets or droplet nuclei. Thirteen test subjects performed filtering facepiece respirator use scenarios including improper doffing, proper doffing and reuse, and improper doffing and reuse. Fluorescein and MS2 contamination transfer were quantified. The average MS2 transfer from filtering facepiece respirators to the subjects' hands ranged from 7.6–15.4% and 2.2–2.7% for droplet and droplet nuclei derived contamination, respectively. Handling filtering facepiece respirators contaminated with droplets resulted in higher levels of MS2 transfer compared to droplet nuclei for all use scenarios (p = 0.007). MS2 transfer from droplet contaminated filtering facepiece respirators during improper doffing and reuse was greater than transfer during improper doffing (p = 0.008) and proper doffing and reuse (p = 0.042). Droplet contamination resulted in higher levels of fluorescein transfer compared to droplet nuclei contaminated filtering facepiece respirators for all use scenarios (p = 0.009). Fluorescein transfer was greater for improper doffing and reuse (p = 0.007) from droplet contaminated masks compared to droplet nuclei contaminated filtering facepiece respirators and for improper doffing and reuse when compared improper doffing (p = 0.017) and proper doffing and reuse (p = 0.018) for droplet contaminated filtering facepiece respirators. For droplet nuclei contaminated filtering facepiece respirators, the difference in MS2 and fluorescein transfer did not reach statistical significance when comparing any of the use scenarios. The findings suggest that the results of fluorescein and MS2 transfer were consistent and highly correlated across the conditions of study. The data supports CDC recommendations for using proper doffing techniques and discarding filtering facepiece respirators that are directly contaminated with secretions from a cough or sneeze.

Objective Cooling devices (CDs) worn under personal protective equipment (PPE) can alleviate some of the heat stress faced by health care workers responding to the Ebola outbreak in West Africa. Methods Six healthy, young individuals were tested while wearing 4 different CDs or no cooling (control) under PPE in an environmental chamber (32°C/92% relative humidity) while walking (3 METs, 2.5 mph, 0% grade) on a treadmill for 60 minutes. Exercise was preceded by a 15-minute stabilization period and a 15-minute donning period. Results The control condition resulted in a significantly higher rectal temperature (T re ) at the end of the exercise than did all CD conditions (CD1, P =0.004; CD2, P =0.01; CD3, P =0.000; CD4, P =0.000) with CD1 and CD2 resulting in a higher T re than CD3 and CD4 ( P <0.05). The control condition resulted in a higher heart rate (HR) at the end of exercise than did the CD3 ( P =0.01) and CD4 ( P =0.009) conditions, whereas the HR of the CD1 and CD2 conditions was higher than that of the CD3 and CD4 conditions ( P <0.05). Weight loss in the control condition was higher than in the CD3 ( P =0.003) and CD4 ( P =0.01) conditions. Significant differences in subjective measurements of thermal stress were found across conditions and time. Conclusions Use of CDs can be advantageous in decreasing the negative physiological and subjective responses to the heat stress encountered by health care workers wearing PPE in hot and humid environments. ( Disaster Med Public Health Preparedness . 2017;page 1 of 7)