Evaluación de la eficacia de las lengüetas en las tiras de la mascarilla autofiltrante para mejorar las técnicas de retirada adecuadas al mismo tiempo que se reduce la transmisión por contacto de los patógenos.

RESUMENLas 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.

Transfer of bacteriophage MS2 and fluorescein from N95 filtering facepiece respirators to hands: Measuring fomite potential.

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.

Assessing the efficacy of tabs on filtering facepiece respirator straps to increase proper doffing techniques while reducing contact transmission of pathogens.

NIOSH-certified N95 filtering facepiece respirators (FFRs) are used in healthcare settings as a control measure to mitigate exposures to airborne infectious particles. When the outer surface of an FFR becomes contaminated, it presents a contact transmission risk to the wearer. The Centers for Disease Control and Prevention (CDC) guidance recommends that healthcare workers (HCWs) doff FFRs by grasping the straps at the back of the head to avoid contact with the potentially contaminated surface. Adherence to proper doffing technique is reportedly low due to numerous factors including difficulty in locating and grasping the straps. This study compares the impact of tabs placed on FFR straps to controls (without tabs) on proper doffing, ease of use and comfort, and reduction of transfer of contamination to the wearer. Utilizing a fluorescent agent as a tracer to track contamination from FFRs to hand and head areas of 20 human subjects demonstrated that there was no difference in tabbed FFR straps and controls with respect to promoting proper doffing (p = 0.48), but did make doffing easier (p = 0.04) as indicated by 7 of 8 subjects that used the tabs. Seven of the 20 subjects felt that FFRs with tabs were easier to remove, while only 2 of 20 indicated that FFRs without tabs were easier to remove. Discomfort was not a factor for either FFR strap type. When removing an FFR with contaminated hands, the use of the tabs significantly reduced the amount of tracer transfer compared to straps without tabs (p = 0.012). FFRs with tabs on the straps are associated with ease of doffing and significantly less transfer of the fluorescent tracer.

Assessment of the Angolan (CHERRT) Mobile Laboratory Curriculum for Disaster and Pandemic Response.

INTRODUCTION: As of April 5, 2020, the World Health Organization reported over one million confirmed cases and more than 62,000 confirmed coronavirus (COVID-19) deaths affecting 204 countries/regions. The lack of COVID-19 testing capacity threatens the ability of both the United States (US) and low middle income countries (LMIC) to respond to this growing threat, The purpose of this study was to assess the effectiveness through participant self-assessment of a rapid response team (RRT) mobile laboratory curriculum METHODS: We conducted a pre and post survey for the purpose of a process improvement assessment in Angola, involving 32 individuals. The survey was performed before and after a 14-day training workshop held in Luanda, Angola, in December 2019. A paired t-test was used to identify any significant change on six 7-point Likert scale questions with α< 0.05 (95% confidence interval). RESULTS: All six of the questions - 1) "I feel confident managing a real laboratory sample test for Ebola or other highly contagious sample;" 2) "I feel safe working in the lab environment during a real scenario;" 3) "I feel as if I can appropriately manage a potentially highly contagious laboratory sample;" 4)"I feel that I can interpret a positive or negative sample during a suspected contagious outbreak;" 5) "I understand basic Biobubble/mobile laboratory concepts and procedures;" and 6) "I understand polymerase chain reaction (PCR) principles" - showed statistical significant change pre and post training. Additionally, the final two questions - "I can more effectively perform my role/position because of the training I received during this course;" and "This training was valuable" - received high scores on the Likert scale. CONCLUSION: This Angolan RRT mobile laboratory training curriculum provides the nation of Angola with the confidence to rapidly respond and test at the national level a highly infectious contagion in the region and perform on-scene diagnostics. This mobile RRT laboratory provides a mobile and rapid diagnostic resource when epidemic/pandemic resource allocation may need to be prioritized based on confirmed disease prevalence.

Kikwit Ebola Virus Disease Progression in the Rhesus Monkey Animal Model.

Ongoing Ebola virus disease outbreaks in the Democratic Republic of the Congo follow the largest recorded outbreak in Western Africa (2013-2016). To combat outbreaks, testing of medical countermeasures (therapeutics or vaccines) requires a well-defined, reproducible, animal model. Here we present Ebola virus disease kinetics in 24 Chinese-origin rhesus monkeys exposed intramuscularly to a highly characterized, commercially available Kikwit Ebola virus Filovirus Animal Non-Clinical Group (FANG) stock. Until reaching predetermined clinical disease endpoint criteria, six animals underwent anesthesia for repeated clinical sampling and were compared to six that did not. Groups of three animals were euthanized and necropsied on days 3, 4, 5, and 6 post-exposure, respectively. In addition, three uninfected animals served as controls. Here, we present detailed characterization of clinical and laboratory disease kinetics and complete blood counts, serum chemistries, Ebola virus titers, and disease kinetics for future medical countermeasure (MCM) study design and control data. We measured no statistical difference in hematology, chemistry values, or time to clinical endpoint in animals that were anesthetized for clinical sampling during the acute disease compared to those that were not.

Structures of the fungal dynamin-related protein Vps1 reveal a unique, open helical architecture.

Dynamin-related proteins (DRPs) are large multidomain GTPases required for diverse membrane-remodeling events. DRPs self-assemble into helical structures, but how these structures are tailored to their cellular targets remains unclear. We demonstrate that the fungal DRP Vps1 primarily localizes to and functions at the endosomal compartment. We present crystal structures of a Vps1 GTPase-bundle signaling element (BSE) fusion in different nucleotide states to capture GTP hydrolysis intermediates and concomitant conformational changes. Using cryoEM, we determined the structure of full-length GMPPCP-bound Vps1. The Vps1 helix is more open and flexible than that of dynamin. This is due to further opening of the BSEs away from the GTPase domains. A novel interface between adjacent GTPase domains forms in Vps1 instead of the contacts between the BSE and adjacent stalks and GTPase domains as seen in dynamin. Disruption of this interface abolishes Vps1 function in vivo. Hence, Vps1 exhibits a unique helical architecture, highlighting structural flexibilities of DRP self-assembly.