scholarly journals Quantitative form and fit of N95 filtering facepiece respirators are retained and coronavirus surrogate is inactivated after heat treatments

2020 ◽  
Author(s):  
Travis Massey ◽  
Monica Borucki ◽  
Samuel Paik ◽  
Kyle Fuhrer ◽  
Mihail Bora ◽  
...  
Keyword(s):  
Thermal Inactivation ◽  
Hepatitis Virus ◽  
Filter Material ◽  
Healthcare Facilities ◽  
Emergency Situations ◽  
Log Reduction ◽  
Quantitative Form ◽  
Dry Conditions ◽  
Dry Heating ◽  
Single Use

SummaryRe-use of filtering facepiece respirators (FFRs, commonly referred to as N95s) normally meant for single use only is becoming common in healthcare facilities due to shortages caused by the COVID19 pandemic. Here we report that mouse hepatitis virus (MHV) initially seeded on FFR filter material is inactivated (6 log reduction as measured by 50% tissue culture infective dose (TCID50)) after dry heating at 75 ºC for 30 minutes. We also find that the quantitative fit of FFRs after heat treatment at this temperature, under dry conditions or at 90% relative humidity, is not affected by single or ten heating cycles. Previous studies have reported that the filtration efficiency of FFR filters is not negatively impacted by these heating conditions. These results suggest that thermal inactivation of coronaviruses is a potentially rapid and widely deployable method to re-use N95 FFRs in emergency situations where re-using FFRs is a necessity and broad-spectrum sterilization is unavailable. However, we also found that a heat source that emits radiation (e.g., an exposed heating element) results in rapid qualitative degradation of the FFR. Finally, we discuss differences in the results reported here and other recent studies investing heat as a means to recycle FFRs and suggest that overall wear time and donning/doffing cycles are important factors that need to be considered.

Surrogates for the Study of Norovirus Stability and Inactivation in the Environment: A Comparison of Murine Norovirus and Feline Calicivirus

2006 ◽  
Vol 69 (11) ◽  
pp. 2761-2765 ◽  
Author(s):  
JENNIFER L. CANNON ◽  
EFSTATHIA PAPAFRAGKOU ◽  
GEUNWOO W. PARK ◽  
JASON OSBORNE ◽  
LEE-ANN JAYKUS ◽  
...  
Keyword(s):  
Cell Culture ◽  
Thermal Inactivation ◽  
Genetic Relatedness ◽  
Mammalian Cell Culture ◽  
Feline Calicivirus ◽  
Murine Norovirus ◽  
Log Reduction ◽  
Culture Model ◽  
Dry Conditions ◽  
Ph Range

Human noroviruses (NoVs) are the leading cause of food- and waterborne outbreaks of acute nonbacterial gastroenteritis worldwide. As a result of the lack of a mammalian cell culture model for these viruses, studies on persistence, inactivation, and transmission have been limited to cultivable viruses, including feline calicivirus (FCV). Recently, reports of the successful cell culture of murine norovirus 1 (MNV-1) have provided investigators with an alternative surrogate for human NoVs. In this study, we compared the inactivation profiles of MNV-1 to FCV in an effort to establish the relevance of MNV-1 as a surrogate virus. Specifically, we evaluated (i) stability upon exposure to pH extremes; (ii) stability upon exposure to organic solvents; (iii) thermal inactivation; and (iv) surface persistence under wet and dry conditions. MNV-1 was stable across the entire pH range tested (pH 2 to 10) with less than 1 log reduction in infectivity at pH 2, whereas FCV was inactivated rapidly at pH values <3 and >9. FCV was more stable than MNV-1 at 56°C, but both viruses exhibited similar inactivation at 63 and 72°C. Long-term persistence of both viruses suspended in a fecal matrix and inoculated onto stainless steel coupons were similar at 4°C, but at room temperature in solution, MNV-1 was more stable than FCV. The genetic relatedness of MNV-1 to human NoVs combined with its ability to survive under gastric pH levels makes this virus a promising and relevant surrogate for studying environmental survival of human NoVs.

RESEARCH: Dry Heat Processing of Single-Use Respirators and Surgical Masks

2020 ◽  
Vol 54 (6) ◽  
pp. 410-416
Author(s):  
Joyce M. Hansen ◽  
Scott Weiss ◽  
Terra A. Kremer ◽  
Myrelis Aguilar ◽  
Gerald McDonnell
Keyword(s):  
Microbial Contamination ◽  
Healthcare Providers ◽  
High Volume ◽  
Airborne Particles ◽  
Heat Processing ◽  
Protective Equipment ◽  
Healthcare Facilities ◽  
Dry Heat ◽  
Surgical Masks ◽  
Single Use

The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2, has challenged healthcare providers in maintaining the supply of critical personal protective equipment, including single-use respirators and surgical masks. Single-use respirators and surgical masks can reduce risks from the inhalation of airborne particles and microbial contamination. The recent high-volume demand for single-use respirators and surgical masks has resulted in many healthcare facilities considering processing to address critical shortages. The dry heat process of 80°C (176°F) for two hours (120 min) has been confirmed to be an appropriate method for single-use respirator and surgical mask processing.

scholarly journals 1215. Ultraviolet-C (UV-C) Monitoring Made Ridiculously Simple: UV-C Dose Indicators for Convenient Measurement of UV-C Dosing

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S437-S437
Author(s):  
Jennifer Cadnum ◽  
Annette Jencson ◽  
Sarah Redmond ◽  
Thriveen Sankar Chittoor Mana ◽  
Curtis Donskey
Keyword(s):  
Methicillin Resistant Staphylococcus Aureus ◽  
Fetal Calf Serum ◽  
Color Change ◽  
Calf Serum ◽  
Organic Load ◽  
Healthcare Facilities ◽  
Log Reduction ◽  
Ultraviolet C ◽  
Effective Doses ◽  
Uv C

Abstract Background Ultraviolet-C (UV-C) light is increasingly used as an adjunct to standard cleaning in healthcare facilities. However, most facilities do not have a means to measure UV-C to determine whether effective doses are being delivered. We tested the efficacy of 2 easy-to-use colorimetric indicators for monitoring UV-C dosing in comparison to log reductions in pathogens. Methods In a laboratory setting, we exposed methicillin-resistant Staphylococcus aureus (MRSA) and Clostridium difficile spores on steel disk carriers with or without an organic load (5% fetal calf serum) to UV-C for varying times resulting in fluence exposures ranging from 10,000 to 100,000 µJ/cm2. The UV-C indicators were placed adjacent to the carriers. Log reductions were calculated in comparison to untreated controls and the change in color of the indicators was correlated with dose and log reductions. Results The UV-C doses required to achieve a 3-log reduction in MRSA and C. difficile were 10,000 and 46,000 µJ/cm2, respectively. For both indicators, there was a visible color change from baseline at 10,000 µJ/cm2 and a definite final color change by 46,000 µJ/cm2 (Figure 1). Organic load had only a modest impact on UV-C efficacy. The indicators required only a few seconds to place and were easy to read (Figure 2). Conclusion UV-C doses of 10,000 and 46,000 µJ/cm2 were required to achieve 3 log reductions of MRSA and C. difficile spores, respectively. The colorimetric indicators provide an easy means to monitor UV-C dosing. Disclosures All authors: No reported disclosures.

Determination of the Thermal Inactivation Kinetics of Listeria monocytogenes, Salmonella enterica, and Escherichia coli O157:H7 and non-O157 in Buffer and a Spinach Homogenate

2015 ◽  
Vol 78 (8) ◽  
pp. 1467-1471 ◽  
Author(s):  
EMEFA ANGELICA MONU ◽  
MALCOND VALLADARES ◽  
DORIS H. D'SOUZA ◽  
P. MICHAEL DAVIDSON
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Salmonella Enterica ◽  
Thermal Inactivation ◽  
Inactivation Kinetics ◽  
Mild Heat ◽  
Log Reduction ◽  
D Values ◽  
Heat Processes ◽  
Kinetics Of

Produce has been associated with a rising number of foodborne illness outbreaks. While much produce is consumed raw, some is treated with mild heat, such as blanching or cooking. The objectives of this research were to compare the thermal inactivation kinetics of Listeria monocytogenes, Salmonella enterica, Shiga toxin–producing Escherichia coli (STEC) O157:H7, and non-O157 STEC in phosphate-buffered saline (PBS; pH 7.2) and a spinach homogenate and to provide an estimate of the safety of mild heat processes for spinach. Five individual strains of S. enterica, L. monocytogenes, STEC O157:H7, and non-O157 STEC were tested in PBS in 2-ml glass vials, and cocktails of the organisms were tested in blended spinach in vacuum-sealed bags. For Listeria and Salmonella at 56 to 60°C, D-values in PBS ranged from 4.42 ± 0.94 to 0.35 ± 0.03 min and 2.11 ± 0.14 to 0.16 ± 0.03 min, respectively. D-values at 54 to 58°C were 5.18 ± 0.21 to 0.53 ± 0.04 min for STEC O157:H7 and 5.01 ± 0.60 to 0.60 ± 0.13 min for non-O157 STEC. In spinach at 56 to 60°C, Listeria D-values were 11.77 ± 2.18 to 1.22 ± 0.12 min and Salmonella D-values were 3.51 ± 0.06 to 0.47 ± 0.06 min. D-values for STEC O157:H7 and non-O157 STEC were 7.21 ± 0.17 to 1.07 ± 0.11 min and 5.57 ± 0.38 to 0.99 ± 0.07 min, respectively, at 56 to 60°C. In spinach, z-values were 4.07 ± 0.16, 4.59 ± 0.26, 4.80 ± 0.92, and 5.22 ± 0.20°C for Listeria, Salmonella, STEC O157:H7, and non-O157 STEC, respectively. Results indicated that a mild thermal treatment of blended spinach at 70°C for less than 1 min would result in a 6-log reduction of all pathogens tested. These findings may assist the food industry in the design of suitable mild thermal processes to ensure food safety.

Thermal Inactivation of H5N2 High-Pathogenicity Avian Influenza Virus in Dried Egg White with 7.5% Moisture

2009 ◽  
Vol 72 (9) ◽  
pp. 1997-2000 ◽  
Author(s):  
COLLEEN THOMAS ◽  
DAVID E. SWAYNE
Keyword(s):  
Linear Regression ◽  
Avian Influenza ◽  
Thermal Inactivation ◽  
Systemic Disease ◽  
Egg White ◽  
Influenza Viruses ◽  
Log Reduction ◽  
Poultry Products ◽  
High Pathogenicity ◽  
D Values

High-pathogenicity avian influenza viruses (HPAIV) cause severe systemic disease with high mortality in chickens. Isolation of HPAIV from the internal contents of chicken eggs has been reported, and this is cause for concern because HPAIV can be spread by movement of poultry products during marketing and trade activity. This study presents thermal inactivation data for the HPAIV strain A/chicken/PA/1370/83 (H5N2) (PA/83) in dried egg white with a moisture content (7.5%) similar to that found in commercially available spray-dried egg white products. The 95% upper confidence limits for D-values calculated from linear regression of the survival curves at 54.4, 60.0, 65.5, and 71.1°C were 475.4, 192.2, 141.0, and 50.1 min, respectively. The line equation y = [0.05494 × °C] + 5.5693 (root mean square error = 0.0711) was obtained by linear regression of experimental D-values versus temperature. Conservative predictions based on the thermal inactivation data suggest that standard industry pasteurization protocols would be very effective for HPAIV inactivation in dried egg white. For example, these calculations predict that a 7-log reduction would take only 2.6 days at 54.4°C.

Synergistic Effects of Butyl Para-Hydroxybenzoate and Mild Heating on Foodborne Pathogenic Bacteria

2020 ◽  
Author(s):  
Zhujun Gao ◽  
Qiao Ding ◽  
Chongtao Ge ◽  
Robert C. Baker ◽  
Rohan V. Tikekar ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Pathogenic Bacteria ◽  
Thermal Inactivation ◽  
Heating Temperature ◽  
Synergistic Effects ◽  
Brain Heart Infusion ◽  
Similar Treatment ◽  
Log Reduction ◽  
Synergistic Enhancement ◽  
Foodborne Pathogenic Bacteria

ABSTRACT While high temperature heat treatments can efficiently reduce pathogen levels, they also affect the quality and nutritional profile of foods, as well as increase the cost of processing. The food additive butyl para-hydroxybenzoate (BPB) was investigated for its potential to synergistically enhance the thermal inactivation at mild heating temperatures (54 – 58 ºC). Four foodborne pathogenic bacteria, Cronobacter sakazakii , Salmonella enterica serotype Typhimurium, attenuated Escherichia coli O157:H7 and Listeria monocytogenes, were cultured to early stationary phase and then subjected to mild heating in a model food matrix (Brain Heart Infusion) containing low levels BPB (≤ 125 ppm). The heating temperature used with each bacterium was selected based on the temperature that would yield an approximate 1 – 2 log reduction over 15 min heating in BHI without BPB using a submerged coil apparatus. The inclusion of BPB at concentrations ≤ 125 ppm resulted in significant enhancement of thermal inactivation, achieving 5 – > 6 log reductions of the Gram-negative strains and D-values of < 100 sec. Listeria monocytogenes achieved at 3 – 4 log reduction with a similar treatment. No significant inactivation was noted in the absence of the mild heating for the same time period. This study provides an additional proof of concept that low temperature inactivation of foodborne pathogens can be realized by synergistic enhancement of thermal inactivation by food components that affect microbial cell membranes.

scholarly journals Covalent Functionalization of Melt-Blown Polypropylene Filters with Diazirine–Photosensitizer Conjugates Producing Visible Light Driven Virus Inactivating Materials.

2021 ◽  
Author(s):  
Tyler Cuthbert ◽  
Siobhan Ennis ◽  
Stefania F. Musolino ◽  
Heather L. Buckley ◽  
Masahiro Niikura ◽  
...  
Keyword(s):  
Visible Light ◽  
Influenza A Virus ◽  
Influenza A ◽  
Bond Activation ◽  
Rna Virus ◽  
Filter Material ◽  
Pathogen Inactivation ◽  
Insertion Method ◽  
Visible Light Driven ◽  
Single Use

<p>The SARS-CoV-2 pandemic has highlighted the weaknesses of relying on single-use mask and respirator personal protective equipment (PPE) and the global supply chain that supports this market. There have been no major innovations in filter technology for PPE in the past two decades. Non-woven textiles used for filtering PPE are single-use products in the healthcare environment; use and protection is focused on preventing infection from airborne or aerosolized pathogens such as Influenza A virus SARS-CoV-2. Recently, C–H bond activation under mild and controllable conditions was reported for crosslinking commodity aliphatic polymers such as polyethylene and polypropylene. Significantly, these are the same types of polymers used in PPE filtration systems. In this report, we take advantage of this C–H insertion method to covalently attach a photosensitizing zinc-porphyrin to the surface of a melt-blow non-woven textile filter material. With the photosensitizer covalently attached to the surface of the textile, illumination with visible light was expected to produce oxidizing <sup>1</sup>O<sub>2</sub>/ROS at the surface of the material that would result in pathogen inactivation. The filter was tested for its ability to inactivate Influenza A virus, an enveloped RNA virus similar to SARS-CoV-2, over a period of four hours with illumination of high intensity visible light. The photosensitizer-functionalized polypropylene filter inactivated our model virus by 99.99% in comparison to a control.</p>

scholarly journals A Review on Wearable and Contactless Sensing for COVID-19 With Policy Challenges

2021 ◽  
Vol 2 ◽  
Author(s):  
Sagar Suresh Kumar ◽  
Kia Dashtipour ◽  
Qammer H. Abbasi ◽  
Muhammad A. Imran ◽  
Wasim Ahmad
Keyword(s):  
Patient Monitoring ◽  
Vital Signs ◽  
Risk Groups ◽  
Developed Countries ◽  
Cross Infection ◽  
Remote Patient Monitoring ◽  
Healthcare Facilities ◽  
Emergency Situations ◽  
The Us ◽  
Remote Patient

The COVID-19 pandemic has affected more than 100 million people worldwide, with around 500,000 cases reported daily. This has led to the overwhelming of healthcare systems even in developed countries such as the US, UK, etc. Remote monitoring of COVID-19 patients with non-serious symptoms can help reduce the burden on healthcare facilities and make them available for high risk groups and the seriously affected. The pandemic has accelerated the demand for the remote patient monitoring (RPM) technologies, and the market is expected to reach 2.14 billion in 2027 from the value of 786.4 million in 2019. In RPM programs, there are two types of sensors that can be used: wearable and contactless. The former, which is currently more widely used, is not only more obtrusive and uncomfortable, but can also lead to cross-infection through patient contact. These two types of technologies are discussed and compared for each vital sign. In the respiratory system, the vital signs are the respiratory rate (RR) and oxygen saturation (SpO2), while for the latter, they are the heart rate/rhythm and the blood pressure (BP). Then, the discussion is broadened to policy level changes needed to expedite the use of such technologies for remote patient monitoring (RPM) in the world. Around 80% of countries' RPM programs are either informal or in a pilot phase, and thus lack policies and an established regulatory framework to implement their programs. The various policies needed to initiate, deliver, and reimburse RPM programs during emergency situations and outbreaks are discussed. Finally, technologies such as contactless systems, robotics, and Internet-of-things (IoT) that will revolutionize healthcare in the future by reducing the interaction between physicians and patients and cross-infection are discussed.

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