scholarly journals Heat-treated virus inactivation rate depends strongly on treatment procedure: illustration with SARS-CoV-2

2021 ◽  
Author(s):  
Amandine Gamble ◽  
Robert J. Fischer ◽  
Dylan H. Morris ◽  
Kwe Claude Yinda ◽  
Vincent J. Munster ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Personal Protective Equipment ◽  
Biological Samples ◽  
Inactivation Rate ◽  
Medical Laboratory ◽  
Protective Equipment ◽  
Virus Inactivation ◽  
Infectious Agents ◽  
Treatment Procedure ◽  
Treatment Procedures

Decontamination helps limit environmental transmission of infectious agents. It is required for the safe re-use of contaminated medical, laboratory and personal protective equipment, and for the safe handling of biological samples. Heat treatment is a common decontamination method, notably used for viruses. We show that for liquid specimens (here, solution of SARS-CoV-2 in cell culture medium), virus inactivation rate under heat treatment at 70°C can vary by almost two orders of magnitude depending on the treatment procedure, from a half-life of 0.86 min (95% credible interval: [0.09, 1.77]) in closed vials in a heat block to 37.00 min ([12.65, 869.82]) in uncovered plates in a dry oven. These findings suggest a critical role of evaporation in virus inactivation via dry heat. Placing samples in open or uncovered containers may dramatically reduce the speed and efficacy of heat treatment for virus inactivation. Given these findings, we reviewed the literature temperature-dependent coronavirus stability and found that specimen containers, and whether they are closed, covered, or uncovered, are rarely reported in the scientific literature. Heat-treatment procedures must be fully specified when reporting experimental studies to facilitate result interpretation and reproducibility, and must be carefully considered when developing decontamination guidelines. Importance Heat is a powerful weapon against most infectious agents. It is widely used for decontamination of medical, laboratory and personal protective equipment, and for biological samples. There are many methods of heat treatment, and methodological details can affect speed and efficacy of decontamination. We applied four different heat-treatment procedures to liquid specimens containing SARS-CoV-2. Our results show that the container used to store specimens during decontamination can substantially affect inactivation rate: for a given initial level of contamination, decontamination time can vary from a few minutes in closed vials to several hours in uncovered plates. Reviewing the literature, we found that container choices and heat treatment methods are only rarely reported explicitly in methods sections. Our study shows that careful consideration of heat-treatment procedure — in particular the choice of specimen container, and whether it is covered — can make results more consistent across studies, improve decontamination practice, and provide insight into the mechanisms of virus inactivation.

scholarly journals Heat-treated virus inactivation rate depends strongly on treatment procedure

2020 ◽  
Author(s):  
Amandine Gamble ◽  
Robert J. Fischer ◽  
Dylan H. Morris ◽  
Kwe Claude Yinda ◽  
Vincent J. Munster ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Critical Role ◽  
Experimental Studies ◽  
Credible Interval ◽  
Inactivation Rate ◽  
Virus Inactivation ◽  
Infectious Agents ◽  
Treatment Procedure ◽  
Laboratory Equipment ◽  
Heat Treated

AbstractDecontamination of objects and surfaces can limit transmission of infectious agents via fomites or biological samples. It is required for the safe re-use of potentially contaminated personal protective equipment and medical and laboratory equipment. Heat treatment is widely used for the inactivation of various infectious agents, notably viruses. We show that for liquid specimens (here suspension of SARS-CoV-2 in cell culture medium), virus inactivation rate under heat treatment at 70°C can vary by almost two orders of magnitude depending on the treatment procedure, from a half-life of 0.86 min (95% credible interval: [0.09, 1.77]) in closed vials in a heat block to 37.0 min ([12.65, 869.82]) in uncovered plates in a dry oven. These findings suggest a critical role of evaporation in virus inactivation using dry heat. Placing samples in open or uncovered containers may dramatically reduce the speed and efficacy of heat treatment for virus inactivation. Heating procedures must be carefully specified when reporting experimental studies to facilitate result interpretation and reproducibility, and carefully considered when designing decontamination guidelines.

Organization of personneindividual protection conducting diagnostic and treatment procedures using radionuclide and generating sources of ionizing radiation

2017 ◽  
Vol 62 (5) ◽  
pp. 28-30
Author(s):  
В. Рубцов ◽  
V. Rubcov ◽  
В. Клочков ◽  
V. Klochkov ◽  
А. Нефедов ◽  
...  
Keyword(s):  
Nuclear Medicine ◽  
Ionizing Radiation ◽  
Personal Protective Equipment ◽  
Medical Staff ◽  
High Performance ◽  
Protective Equipment ◽  
Study Guide ◽  
Personal Protection ◽  
Radiation Sources ◽  
Treatment Procedures

Purpose: To improve radiation safety of medical staff and patients during diagnostic and treatment procedures with using of radionuclide radiation sources. Materials and methods: Staff working conditions have been analyzed and the potential for using of various personal protective equipment has been assessed based on the developed framework of personal protection of medical staff and patients at nuclear medicine centers. In accordance with methods described in the current Russian standards, specimens of personal protective equipment manufactured at Russian industrial plants and suitable for use by medical staff and patients at nuclear medicine centers have been tested. Results: Results of laboratory tests of new advanced high-performance personal protective equipment of various purposes for protection of medical staff and patients during diagnostic and treatment procedures with using of radionuclide radiation sources are provided. Training and information documents and guidelines have been developed, including “Study guide on personal protection during diagnostic and treatment procedures with using of radionuclides and ionizing radiation sources” for various departments of the Institute of Continuing Vocational Education, State Research Center – Burnasyan Federal Medical Biophysical Center of the FMBA of Russia, and “Guidelines on personal protection of medical staff and patients during diagnostic and treatment procedures with using of radionuclides and ionizing radiation sources”. Conclusion: Study guide and Guidelines on personal protection of medical staff and patients at nuclear medicine centers during diagnostic and treatment procedures with using of radionuclide radiation sources, as well as the draft of the Standard guidelines on delivery of free personal protective equipment to medical staff have been developed based on the results of work and studies.

scholarly journals Addressing Personal Protective Equipment (PPE) Decontamination: Methylene Blue and Light Inactivates SARS-CoV-2 on N95 Respirators and Medical Masks with Maintenance of Integrity and Fit

2021 ◽  
pp. 1-83
Author(s):  
Thomas Sean Lendvay ◽  
James Chen ◽  
Brian H Harcourt ◽  
Florine EM Scholte ◽  
Ying Ling Lin ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Personal Protective Equipment ◽  
Low Cost ◽  
Red Light ◽  
Test Methods ◽  
Clinical Applications ◽  
Protective Equipment ◽  
Virus Inactivation ◽  
Specialized Equipment ◽  
N95 Respirators

Abstract Objective: The coronavirus disease 2019 (COVID-19) pandemic has resulted in shortages of personal protective equipment (PPE) underscoring the urgent need for simple, efficient, and inexpensive methods to decontaminate SARS-CoV-2-exposed masks and respirators. We hypothesized that methylene blue (MB) photochemical treatment, which has various clinical applications, could decontaminate PPE contaminated with coronavirus. Design: The two arms of the study included: 1) PPE inoculation with coronaviruses followed by MB with light (MBL) decontamination treatment, and 2) PPE treatment with MBL for 5 cycles of decontamination (5CD) to determine maintenance of PPE performance. Methods: MBL treatment was used to inactivate coronaviruses on three N95 filtering facepiece respirator (FFR) and two medical mask (MM) models. We inoculated FFR and MM materials with three coronaviruses, including SARS-CoV-2, and treated with 10 µM MB and exposed to 50,000 lux of white light or 12,500 lux of red light for 30 minutes. In parallel, integrity was assessed after 5CD using multiple US and international test methods and compared to the FDA-authorized vaporized hydrogen peroxide plus ozone (VHP+O3) decontamination method. Results: Overall, MBL robustly and consistently inactivated all three coronaviruses with 99.8 - to >99.9% virus inactivation across all FFRs and MMs tested. FFR and MM integrity was maintained after 5 cycles of MBL treatment, whereas one FFR model failed after 5 cycles of VHP+O3. Conclusions: MBL treatment decontaminated respirators and masks by inactivating three tested coronaviruses without compromising integrity through 5CD. MBL decontamination is effective, low-cost and does not require specialized equipment, making it applicable in all-resource settings.

Hygienic Assessment of Risks of Thermal Balance Disruption in Medical Laboratory Workers Using Personal Protective Equipment for Biohazards

2021 ◽  
pp. 31-36
Author(s):  
VV Shkarin ◽  
NI Latyshevskaya ◽  
DV Orlov ◽  
BN Filatov ◽  
TV Zhukova ◽  
...  
Keyword(s):  
Skin Temperature ◽  
Personal Protective Equipment ◽  
Thermal State ◽  
Thermal Balance ◽  
Medical Laboratory ◽  
Protective Equipment ◽  
Heat Sensation ◽  
Laboratory Workers ◽  
The Mean ◽  
Thermoregulatory Reactions

Introduction: Specifics of activities of medical personnel in different types of laboratories can potentially create working conditions that violate occupational safety and health regulations. Objective: The study aimed to assess health risks of thermal balance disruption in PCR laboratory staff wearing personal protective equipment for biohazards in the context of the COVID-19 pandemic. Materials and methods: The study was conducted in winter 2020–2021 in PCR laboratories of the Volgograd Region. It included measurements of laboratory microclimate parameters, such as relative humidity, air temperature and velocity, used to estimate the heat load index. An observation cohort of 31 female medical laboratory workers aged 32.48 ± 1.45 years with a three to nine months experience of work in the PCR laboratory was formed to monitor the thermal state at the start and end of the work shift by measuring skin temperature at five points, sublingual temperature, and heat sensation. The results of measurements were used to estimate the mean skin temperature and heart rate while the dynamics of work ability was assessed by the results of contact tremorometry. Results: We established a significant increase in all measured values. The mean skin temperature at the end of the shift reached 33.85 ± 0.24 °C, thus exceeding the upper limit of the permissible value. The heart rate and heat sensation parameters approached the upper values of the maximum permissible thermal state of a person. Contact tremorometry results indicated a decrease in the performance by the end of the work shift. The findings gave evidence of tension of thermoregulatory reactions and the risk of thermal balance disruption posed by the use of a specific type of personal protective equipment in the PCR laboratory. Conclusion: The research results provide strong support for the conclusion that the use of PPE for biohazards poses a risk of thermal balance disruption in medical laboratory personnel. The severity of stress of thermoregulatory reactions depends on technical and design characteristics of the PPE used. The necessity of a physiological and hygienic substantiation of acceptable duration of work of medical workers wearing various types of PPE for biohazards in PCR laboratories justifies the importance of further studies.

Proper Heat Treatment to Reduce Intergranular Corrosion Susceptibility of Austenitic 304 and Ferritic 430 Stainless Steels

2013 ◽  
Vol 545 ◽  
pp. 143-147
Author(s):  
Piyanun Punburi ◽  
Napachat Tareelap
Keyword(s):  
Heat Treatment ◽  
Stainless Steels ◽  
Intergranular Corrosion ◽  
Treatment Procedure ◽  
Aisi 304 ◽  
Chromium Carbides ◽  
Corrosion Susceptibility ◽  
Treatment Procedures ◽  
Aisi 430 ◽  
Heat Treatment Procedure

Due to different heat treatment procedures being required to reduce intergranular corrosion (IGC) of austenitic AISI 304(ASS304) and ferritic AISI 430(FSS430) stainless steels, this work is aimed at achieving proper heat treatment for these metals simultaneously. Heat treatment at a temperature of 900°C for 36 hours followed by water quenching was an applicable heat treatment procedure for this study. This treatment not only prevented the formation of chromium carbides but also promoted the diffusion of chromium back to replenish chromium-depleted zones.

scholarly journals Awareness of Personal Protective Equipment Among Laboratory Workers in Tertiary Health Centre, Ibadan

2020 ◽  
Vol 1 (2) ◽  
pp. 14-21
Author(s):  
Abimbola Amoo ◽  
Christiana Ezoke
Keyword(s):  
Personal Protective Equipment ◽  
Health Centre ◽  
Medical Laboratory ◽  
P Value ◽  
Protective Equipment ◽  
Microsoft Excel ◽  
Chi Square ◽  
Laboratory Workers ◽  
Healthcare Associated

Introduction Health care personnel are exposed to a variety of material occupational health hazards while handling biological material and contaminated equipment. The use of appropriate and good qualitypersonal protective equipment in work places cannot be over emphasized. Several years ago, this need was highlighted to several physicians like Sir Thomas Morrison Legye. He identified the role of the employer of labour and those of the employee in reducing workplace hazards and consequently achieving a healthy workplace environment. Objectives This study was to determine level of awareness and utilization of Personal Protective Equipment among Medical Laboratory workers. Methods A questionnaire was structured with two sections and a total of 92 were administered. A pilot study was also carried out before the administration of the questionnaire. The data collected was analyzed on Microsoft excel spreadsheet in duplicate. It was then exported into EPI info version 3.4.1. Data was presented using frequency tables and chi square. Results About 77.3%, 72.9%, and 72.7% were aware of the use of goggle, gloves, and importance of hand washing in preventing exposure to Healthcare associated infections while working on patients’ samples. However, under the socio- demographic characteristics of the respondents and awareness level at P-value < 0.5 the results were 0.02. 0.5, 0.85, 0.92 for education, gender, years in service and age respectively. Hence, there is no significant relationship between respondents’ gender, age and year in service, and level of awareness. Conclusion The hospital management should ensure regular provision and supply of Personal Protective Equipment (PPE) to ensure continual usage. Also, regular training and re-training should be conducted to keep the laboratory workers at briefs with latest innovative and benefits of PPE developments to this end.

Impact of COVID-19 on Nuclear Medicine in Germany, Austria and Switzerland: An International Survey in April 2020

2020 ◽  
Vol 59 (04) ◽  
pp. 294-299 ◽  
Author(s):  
Lutz S. Freudenberg ◽  
Ulf Dittmer ◽  
Ken Herrmann
Keyword(s):  
Nuclear Medicine ◽  
Health Systems ◽  
Personal Protective Equipment ◽  
Large Scale ◽  
Diagnostic Procedures ◽  
Protective Equipment ◽  
Current Crisis ◽  
Web Based ◽  
Public Versus Private ◽  
The Impact

Abstract Introduction Preparations of health systems to accommodate large number of severely ill COVID-19 patients in March/April 2020 has a significant impact on nuclear medicine departments. Materials and Methods A web-based questionnaire was designed to differentiate the impact of the pandemic on inpatient and outpatient nuclear medicine operations and on public versus private health systems, respectively. Questions were addressing the following issues: impact on nuclear medicine diagnostics and therapy, use of recommendations, personal protective equipment, and organizational adaptations. The survey was available for 6 days and closed on April 20, 2020. Results 113 complete responses were recorded. Nearly all participants (97 %) report a decline of nuclear medicine diagnostic procedures. The mean reduction in the last three weeks for PET/CT, scintigraphies of bone, myocardium, lung thyroid, sentinel lymph-node are –14.4 %, –47.2 %, –47.5 %, –40.7 %, –58.4 %, and –25.2 % respectively. Furthermore, 76 % of the participants report a reduction in therapies especially for benign thyroid disease (-41.8 %) and radiosynoviorthesis (–53.8 %) while tumor therapies remained mainly stable. 48 % of the participants report a shortage of personal protective equipment. Conclusions Nuclear medicine services are notably reduced 3 weeks after the SARS-CoV-2 pandemic reached Germany, Austria and Switzerland on a large scale. We must be aware that the current crisis will also have a significant economic impact on the healthcare system. As the survey cannot adapt to daily dynamic changes in priorities, it serves as a first snapshot requiring follow-up studies and comparisons with other countries and regions.

“In vitro” and in Animal Model Studies on a Double Virus- Inactivated Factor VIII Concentrate

1995 ◽  
Vol 74 (03) ◽  
pp. 868-873 ◽  
Author(s):  
Silvana Arrighi ◽  
Roberta Rossi ◽  
Maria Giuseppina Borri ◽  
Vladimir Lesnikov ◽  
Marina Lesnikov ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Animal Model ◽  
Factor Viii ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Virus Inactivation ◽  
Enveloped Viruses ◽  
Model Studies ◽  
Heat Treated

SummaryTo improve the safety of plasma derived factor VIII (FVIII) concentrate, we introduced a final super heat treatment (100° C for 30 min) as additional virus inactivation step applied to a lyophilized, highly purified FVIII concentrate (100 IU/mg of proteins) already virus inactivated using the solvent/detergent (SID) method during the manufacturing process.The efficiency of the super heat treatment was demonstrated in inactivating two non-lipid enveloped viruses (Hepatitis A virus and Poliovirus 1). The loss of FVIII procoagulant activity during the super heat treatment was of about 15%, estimated both by clotting and chromogenic assays. No substantial changes were observed in physical, biochemical and immunological characteristics of the heat treated FVIII concentrate in comparison with those of the FVIII before heat treatment.

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