Peroxide Vapor Research Articles

Role of Hydrogen Peroxide Vapor (HPV) for the Disinfection of Hospital Surfaces Contaminated by Multiresistant Bacteria.

The emergence of multiresistant bacterial strains as agents of healthcare-related infection in hospitals has prompted a review of the control techniques, with an added emphasis on preventive measures, namely good clinical practices, antimicrobial stewardship, and appropriate environmental cleaning. The latter item is about the choice of an appropriate disinfectant as a critical role due to the difficulties often encountered in obtaining a complete eradication of environmental contaminations and reservoirs of pathogens. The present review is focused on the effectiveness of hydrogen peroxide vapor, among the new environmental disinfectants that have been adopted. The method is based on a critical review of the available literature on this topic

An outbreak of two strains of OXA-48 producing Klebsiella pneumoniae in a teaching hospital

SummaryOXA-48 producers can be difficult to detect in clinical specimens due to phenotypic low-level resistance to carbapenems. Additionally, low infection rates make clinical specimens poor sentinels for the presence of OXA-48 producers within a healthcare institution.We report an outbreak of OXA-48-producing Klebsiella pneumoniae (OXAKp) that was discovered following culture of OXAKp in a urine specimen from a patient with no known risk factors for acquisition. Widespread screening across medical wards in the trust revealed evidence of transmission across several wards. Samples from 60 patients were positive for OXAKp. Five patients had OXAKp clinical infection, four of whom were treated with ceftazidime/avibactam. Variable number tandem repeat analysis of the OXAKp isolates revealed two predominant strain types clustered around two groups of wards.Infection prevention measures included isolation and cohort nursing of infected and colonized patients, restriction of affected ward areas to new admissions, stringent hand hygiene and use of personal protective equipment. Environmental cleaning of patient areas was carried out using chlorine-releasing disinfectants and hydrogen peroxide vapour. Entire wards were decanted to enable effective cleaning of empty ward areas. The outbreak lasted almost five months and is estimated to have cost around £400 000.During the course of the outbreak, there were five reported prescription and administration incidents related to confusion between ceftazidime and ceftazidime/avibactam. No patient harm resulted from these incidents and the implementation of brand name prescribing for ceftazidime/avibactam prevented further incidents.

Disposable masks: Disinfection and sterilization for reuse, and non-certified manufacturing, in the face of shortages during the COVID-19 pandemic

The COVID-19 pandemic is posing a huge global health threat. To deal with this problem, in addition to research and work in the medical field, the main health measures being taken in the workplace and at home involve the establishment of safety protocols, which include distance measures, hygiene and the use of personal protective equipment, such as masks, etc. The WHO still does not recommend the use of masks for the general population. However, their successful use in China, South Korea and the Czech Republic has encouraged their widespread use, and the shortage that already existed. This has caused that companies and individuals are looking at the best way to reuse them, and to manufacture, homemade or not, of non-certified masks. This paper is based on two objectives: to consult the scientific literature to identify the main strategies for disinfecting them, and to determine the effectiveness of non-certified disposable masks. A rapid review has been conducted in which the main publications and other information available online have been analyzed. Results showed that the most promising methods are those that use hydrogen peroxide vapor, ultraviolet radiation, moist heat, dry heat and ozone gas. Soapy water, alcohol, bleach immersion, ethylene oxide, ionizing radiation, microwave, high temperature, autoclave or steam are not fully recommended. Regarding the effectiveness of surgical masks compared to PPE, the former have been seen to be slightly less effective than PPE. As for other types of masks the effectiveness of homemade or non-certified masks is very low.

COVID-19 global pandemic planning: Decontamination and reuse processes for N95 respirators.

Coronavirus disease 2019 (COVID-19) is an illness caused by a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The disease was first identified as a cluster of respiratory illness in Wuhan City, Hubei Province, China, in December 2019, and has rapidly spread across the globe to greater than 200 countries. Healthcare providers are at an increased risk for contracting the disease due to occupational exposure and require appropriate personal protective equipment (PPE), including N95 respirators. The rapid worldwide spread of high numbers of COVID-19 cases has facilitated the need for a substantial supply of PPE that is largely unavailable in many settings, thereby creating critical shortages. Creative solutions for the decontamination and safe reuse of PPE to protect our frontline healthcare personnel are essential. Here, we describe the development of a process that began in late February 2020 for selecting and implementing the use of hydrogen peroxide vapor (HPV) as viable method to reprocess N95 respirators. Since pre-existing HPV decontamination chambers were not available, we optimized the sterilization process in an operating room after experiencing initial challenges in other environments. Details are provided about the prioritization and implementation of processes for collection and storage, pre-processing, HPV decontamination, and post-processing of filtering facepiece respirators. Important lessons learned from this experience include, developing an adequate reserve of PPE for effective reprocessing and distribution, and identifying a suitable location with optimal environmental controls (i.e. operating room). Collectively, information presented here provides a framework for other institutions considering decontamination procedures for N95 respirators.Impact statementThere is a critical shortage of personal protective equipment (PPE) around the globe. This article describes the safe collection, storage, and decontamination of N95 respirators using hydrogen peroxide vapor (HPV). This article is unique because it describes the HPV process in an operating room, and is therefore, a deployable method for many healthcare settings. Results presented here offer creative solutions to the current PPE shortage.

The importance of fit testing in decontamination of N95 respirators: A cautionary note

To the Editor: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) COVID-19 pandemic resulted in a critical shortage of personal protective equipment (PPE), particularly N95 filtering facepiece respirators (FFRs). Decontamination methods and reuse of FFRs, including ultraviolet germicidal irradiation (UVGI), hydrogen peroxide vaporization, microwave-generated steaming, and dry heating, have been rushed into implementation. However, if the treatment affects filtration or fit, decontamination is achieved but loss of integrity could be catastrophic to the wearer. Our recent JAAD publication discusses research with a repurposed dermatology phototherapy desktop device to administer UVGI for N95 decontamination.1Hamzavi I. Lyons A.B. Kohli I. et al.Ultraviolet germicidal irradiation: possible method for respirator disinfection to facilitate reuse during COVID-19 pandemic.J Am Acad Dermatol. 2020; 82: 1511-1512Abstract Full Text Full Text PDF PubMed Scopus (90) Google Scholar This letter highlights critical differences in fit testing performance collected for different respirator models treated with UVGI administered with this repurposed unit. The effects on respirators of using the suggested UVGI dose of 1 to 2 J/cm2 were variable.2Heimbuch B.K. Harnish D. Research to Mitigate a Shortage of Respiratory Protection Devices During Public Health Emergencies.2020https://www.ara.com/sites/default/files/MitigateShortageofRespiratoryProtectionDevices_3.pdfDate accessed: April 10, 2020Google Scholar The respirator fit testing was conducted by the Henry Ford Health System Department of Infection Prevention and Control according to the saccharin solution aerosol protocol laid out by the United States Occupational Safety and Health Administration (OSHA).3Occupational Safety and Health AdministrationAppendix A to §1910.134—Fit Testing Procedures (Mandatory).https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.134AppADate accessed: April 10, 2020Google Scholar Irradiation of respirators with UVGI was conducted by the Henry Ford Health System Department of Dermatology Photomedicine Unit. A new, unused respirator served as the test respirator, and irradiation was performed after establishing that an unused respirator passed a baseline fit test. The outside-facing and wearer-facing surfaces of the respirators were irradiated by the Daavlin Desktop UVC Germicidal Lamp (Daavlin, Bryan, OH) with a dose of 1.5 J/cm2 to each side. If the respirator passed this test, it was considered to have successfully completed 1 cycle. This process was then repeated to establish the number of irradiation cycles that the respirator would pass the fit test. Testing was ceased if a respirator did not pass the fit test. The results are reported in Table I.Table IResults of Henry Ford Health System respirator fit testingFFR model∗3M, St Paul, Minnesota; Cardinal Health, Dublin, Ohio; Moldex-Metric, Culver City, California.Saccharin solution aerosol fit test performedUVC cycles attempted/fit test cycles passedPassing cumulative UVC dose (3 J/cm2 = 1 cycle)3M N95 Respirator—1860 NIOSH TC-84A-0006Baseline, cycles 1-6, 15, 20 & 2525/2060 J/cm23M N95 Respirator—9210 NIOSH TC-84A-2669Baseline, cycles 1-22/2†Limited resources prevented testing of additional UVC cycles.6 J/cm23M N95 Respirator—8210 NIOSH TC-84A-0007Baseline, cycles 1-22/13 J/cm2Cardinal Health USA N95 R/S Respirator—NIOSH TC-84A-5529 & 5527 (small/regular)Baseline, cycles 1-22/13 J/cm2Moldex N95 Respirator #2300N95—NIOSH TC-84A-0328This N95 respirator passed the baseline fit test on 1 individual. Owing to immediate breakage of straps upon user removal on 2 respirators, testing ceased.0N/AMoldex N95 Respirator 1511 (small)—NIOSH TC-84A-0013This N95 respirator failed the baseline fit test on 3 individuals.0N/AMoldex N95 Respirator 1512 (medium)—NIOSH TC-84A-0013Baseline, cycles 1-33/26 J/cm23M N95 Respirator—9010 NIOSH TC-84A-4243This N95 respirator failed the baseline fit test on 2 individuals.0N/ACardinal Health USA N95A-S Respirator—NIOSH TC-84A-5463This N95 respirator failed the baseline fit test on 2 individuals.0N/AGB2626-2206 KN95 Respirator—KN95-01-01This N95 respirator failed the baseline fit test on 2 individuals.0N/AFFR, Filtering facepiece respirator; N/A, not available; NIOSH, National Institute for Occupational Safety and Health; UVC, ultraviolet C.∗ 3M, St Paul, Minnesota; Cardinal Health, Dublin, Ohio; Moldex-Metric, Culver City, California.† Limited resources prevented testing of additional UVC cycles. Open table in a new tab FFR, Filtering facepiece respirator; N/A, not available; NIOSH, National Institute for Occupational Safety and Health; UVC, ultraviolet C. The UVGI treatment may degrade polymers in the respirators themselves and impact the elasticity of the bands.4Lindsley W.G. Martin Jr., S.B. Thewlis R.E. et al.Effects of ultraviolet germicidal irradiation (UVGI) on N95 respirator filtration performance and structural integrity.J Occup Environ Hyg. 2015; 12: 509-517Crossref PubMed Scopus (164) Google Scholar The myriad respirators available in this crisis react differently to a given UVGI dose and survive different numbers of decontamination cycles. This may hold true for other respirator treatment methods as well. Our data strongly indicate that to protect the safety of the N95 respirator user, fit testing after decontamination must be done each time a new model is introduced to a health care system. This has significant safety implications, because varied decontamination methods are being used by different institutions.5Torres A, Lyons AB, Narla S et al. Ultraviolet-C and other methods of decontamination of filtering facepiece N-95 respirators during the COVID-19 pandemic [e-pub ahead of print]. Photochem Photobiol Sci. https://doi.org/10.1039/D0PP00131G. Accessed April 10, 2020.Google Scholar In addition, N95 respirators should be physically examined before and after decontamination cycles to check for signs of degradation that may have occurred while removing and handling.

What are the effective methods of decontaminating N95 mask for reuse?

KEY FINDINGS
 Based on laboratory-based studies, ultraviolet germicidal irradiation (UVGI), microwave generated steam, warm moist heat, and hydrogen peroxide vapor (HPV) were able to reduce the load of influenza viruses (A/H5N1, H1N1) or G. stearothermophilus and at the same time maintain the integrity of N95 respirators.
 • Considering the current pandemic, there is a potential for shortage of N95 facepiece filtering respirator (FFR) for healthcare workers.
 • No studies in humans were found comparing effectiveness of N95 post-decontamination.
 • Laboratory based studies done on influenza virus (A/H5N1, H1N1) have shown that ultraviolet germicidal irradiation, microwave generated steam, or warm moist heat was able to reduce the viral load by as much as 4 log and at the same time maintain respirator performance by keeping the percent penetration below 5% and the pressure drop within standards.
 • While UVGI was able to maintain integrity of FFRs up to 3 cycles, microwave generated steam may melt the metallic components of certain N95 masks.
 • Hydrogen peroxide vapor (HPV) had minimal effect on respirator performance and structural integrity up to 20 cycles and was also effective in eradicating G. stearothermophilus and aerosolized bacteriophages.
 • Bleach, ethanol and isopropanol all affected the mean penetration of the mask beyond the 5% limit.
 • The Centers for Disease Control (CDC) does not recommend decontamination then reuse of FFRs as standard care but decontamination with UVGI, HPV or moist heat may be considered as an option in FFR shortages.

Persistent Corynebacterium bovis Infectious Hyperkeratotic Dermatitis in Immunocompetent Epidermal-Mutant dep/dep Mice.

During a previously reported program-wide Corynebacterium bovis outbreak, both immunocompetent depilated (dep/dep) mutant mice and transgenic mice that express the papillomavirus E6 oncoprotein became persistently infected with C. bovis. An orthokeratotic, hyperkeratotic, acanthotic dermatitis developed in the C. bovis-infected dep/dep mice, which remained C. bovis PCR-positive for >45 days prior to euthanasia as part of the program-wide C. bovis eradication effort. Since both affected strains of mice have altered skin homeostasis, immune status or the presence of hair may not alone be sufficient to explain strain susceptibility to C. bovis-related cutaneous disease. In order to avoid invalidation of preclinical studies due to C. bovis infection, it may be necessary to isolate immunodeficient mouse strains, implement facililty-wide surveillance for C. bovis, and sterilize equipment with vaporized hydrogen peroxide.

Towards an Understanding of the Adsorption of Vaporized Hydrogen Peroxide (VHP) Residues on Glass Vials After a VHP Decontamination Process Using a Miniaturized Tool

Isolators for aseptic filling of biopharmaceuticals and vaccine products are commonly sanitized by vaporized hydrogen peroxide (VHP). However, remaining traces of H2O2 may contaminate the solution and cause oxidative degradation of the pharmaceutical products. The present report aims to establish a thorough understanding of the factors influencing H2O2 adsorption on empty glass intended for pharmaceutical product filling. A lab-scale miniaturized set-up that mimics the VHP- based isolator decontamination process was used. A fractional factorial design of experiment (DoE) was performed including relative humidity (RH), VHP concentration and exposure time as variables. The results revealed that VHP concentration and RH both impacts significantly the extent of H2O2 adsorption on the surface of glass vials and rubber stoppers. The lower extent of H2O2 adsorption at elevated RH implies the existence of competitive co-adsorption. Thus, adsorbed H2O2 may be removed more efficiently from the isolator after the decontamination phase by insufflating air with a high %RH rate during the isolator's aeration phase. The understanding gained from the present set-up can be applied to optimize the design of isolator decontamination cycles and evaluate the trade-off between process performance and the resulting product quality.

Institution of a Novel Process for N95 Respirator Disinfection with Vaporized Hydrogen Peroxide in the Setting of the COVID-19 Pandemic at a Large Academic Medical Center

Personal protective equipment (PPE) has been an invaluable yet limited resource when it comes to protecting healthcare workers against infection during the 2019 coronavirus (COVID-19) pandemic. In the US, N95 respirator supply chains are severely strained and conservation strategies are needed. A multidisciplinary team at the Washington University School of Medicine, Barnes Jewish Hospital, and BJC Healthcare was formed to implement a program to disinfect N95 respirators. The process described extends the life of N95 respirators using vaporized hydrogen peroxide (VHP) disinfection and allows healthcare workers to retain their own N95 respirator across a large metropolitan healthcare system.

Adult cardiac surgery and the COVID-19 pandemic: Aggressive infection mitigation strategies are necessary in the operating room and surgical recovery

The COVID-19 pandemic necessitates aggressive infection mitigation strategies to reduce the risk to patients and healthcare providers. This document is intended to provide a framework for the adult cardiac surgeon to consider in this rapidly changing environment. Preoperative, intraoperative, and postoperative detailed protective measures are outlined. These are guidance recommendations during a pandemic surge to be used for all patients while local COVID-19 disease burden remains elevated.

Decontamination methods of personal protective equipment for repeated utilization in medical/surgical settings

The COVID-19 pandemic has affected citizens and healthcare workers worldwide due to a number of important factors. The transmission of the SARS CoV-2 microorganism, the pathogen that causes COVID-19 infection, occurs through droplet and aerosol spread due to coughs and sneezes from infected patients. A panicked public began hoarding medical supplies and personal protective equipment (PPE), leaving healthcare workers to care for patients without adequate protection. A literature review was conducted to better understand the options available to hospital and healthcare system administrators as they develop necessary protocols for the conservation and possible reuse of PPE. This review is based upon the peer-reviewed studies of various scientific investigators, biotechnology researchers, governmental agency health officials, including meta-analyses, preliminary/pilot studies, and policy statements. Current findings indicate that extended usage of N95 respirators is practical since there are methods available for the decontamination/repeated use of N95 respirators. In evaluating the efficacy of such methods, the safety of healthcare workers is important in deciding which method to recommend. Available evidence supports the use of the Bioquell Hydrogen Peroxide Vapor (HPV) system for decontaminating N95 respirators. Information on other PPE will also be discussed about more specific items. Informed decisions regarding the policies of hospitals and healthcare systems must be considered, and with the safety of healthcare workers in mind, both factors influenced the recommendations made in this comprehensive review.

Challenges and solutions for addressing critical shortage of supply chain for personal and protective equipment (PPE) arising from Coronavirus disease (COVID19) pandemic – Case study from the Republic of Ireland

Coronavirus (COVID-19) is highly infectious agent that causes fatal respiratory illnesses, which is of great global public health concern. Currently, there is no effective vaccine for tackling this COVID19 pandemic where disease countermeasures rely upon preventing or slowing person-to-person transmission. Specifically, there is increasing efforts to prevent or reduce transmission to front-line healthcare workers (HCW). However, there is growing international concern regarding the shortage in supply chain of critical one-time-use personal and protective equipment (PPE). PPE are heat sensitive and are not, by their manufacturer's design, intended for reprocessing. Most conventional sterilization technologies used in hospitals, or in terminal medical device sterilization providers, cannot effectively reprocess PPE due to the nature and severity of sterilization modalities. Contingency planning for PPE stock shortage is important. Solutions in the Republic of Ireland include use of smart communication channels to improve supply chain, bespoke production of PPE to meets gaps, along with least preferred option, use of sterilization or high-level disinfection for PPE reprocessing. Reprocessing PPE must consider material composition, functionality post treatment, along with appropriate disinfection. Following original manufacturer of PPE and regulatory guidance is important. Technologies deployed in the US, and for deployment in the Republic of Ireland, are eco-friendly, namely vaporised hydrogen peroxide (VH2O2), such as for filtering facepiece respirators and UV irradiation and High-level liquid disinfection (Actichlor+) is also been pursed in Ireland. Safeguarding supply chain of PPE will sustain vital healthcare provision and will help reduce mortality.

Spore inactivation on solid surfaces by vaporized hydrogen peroxide-Influence of carrier material surface properties.

The aim of this study was to investigate the influence of surface hydrophobicity and roughness of carrier materials on the inactivation of bacterial spores with gaseous hydrogen peroxide whereas condensate formation is prevented. Spores of Bacillussubtilis and Bacillusatrophaeus were applied either as single spore culture or as a mixed spore population to simulate natural contamination with microorganisms of different characteristics. Inactivation with gaseous hydrogen peroxide was carried out at 5200ppm hydrogen peroxide without condensate formation. The inactivation results of B. subtilis and B. atrophaeus spores on carrier materials with varying surface hydrophobicity differed significantly. However, inactivation of the mixed spore populations resulted in similar resistance compared to the single spore batches. The results of this study indicate that surface hydrophobicity most probably has an impact on the inactivation with gaseous hydrogen peroxide whereas surface roughness only plays a minor role.

Influence of UV Rays on the Volt-Capacity Characteristic of SnO2:Co Sensor of Vapors of Hydrogen Peroxide

A ceramic target based on cobalt doped SnO2 metal oxide was synthesized by the solid-phase reaction method. The target was used in the process of high-frequency magnetron sputtering. A thin SnO2:Co film was deposited, which is sensitive to hydrogen peroxide vapor. The current-voltage characteristics of the SnO2:Co sensor were measured in the presence of hydrogen peroxide vapor in the environment while ultraviolet light was exposed to the sensor at room temperature. It was shown that the sensitivity of the SnO2:Co film increases by about 1.6 times when exposed to ultraviolet rays.

604 Comparing Disinfection of Different Dosages of Vaporized Hydrogen Peroxide in Burn Ward

Abstract Introduction The objective of this study is to compare the disinfection effects using the vaporized hydrogen peroxide disinfection method in critical burn ward. Methods A 110m3 empty ward of the burn center was selected as the experimental site. The Bacillus subtilis var. niger spores were opened and placed in 15 unprepared positions (with 0 m, 1 m, 2 m, 3 m, and 4 m from the disinfection machine, each of which was divided into upper, middle, and The lower 3 planes), as well as the 15 points of the cloth (the same position as before), are fixed with hydrogen peroxide indicating tape. The amount of hydrogen peroxide was calculated according to the size of the ward (8 g/m3, 12 g/m3, respectively), and disinfected at a rate of 10 g/min of hydrogen peroxide release flow. After 5 hours of disinfection, the chemical indicator tape and the bacteria pieces were taken out. Observe the discoloration of the chemical indicating tape. The bacteria pieces were placed in a test tube containing the broth culture medium, and the results were observed after incubation in a 37 ° C incubator for 7*24 hours. Results (1) Under the condition of no cover, the two disinfecting dose chemical indicating tapes are all discolored, and in the case of obstruction, they cannot be completely discolored; (2) When the amount of hydrogen peroxide disinfection is 8g/m3 and 12g/m3 respectively, The positive rates of unobstructed specimens were 6.67% and 2.67%, respectively, no significant difference (P= >0.05), and there was no difference in disinfection effect between the positions (P >0.05); (3) 8g/m3 disinfection dose The peak concentration is 255.9g, the peak concentration is 1h48min; the peak concentration is 337.6g at 12g/m3 disinfection, and the peak concentration is 2h26min. When the two disinfection doses were disinfected for 8 hours, the peak concentrations of the chambers were basically the same(1) Under the condition of no cover, the two disinfecting dose chemical indicating tapes are all discolored, and in the case of obstruction, they cannot be completely discolored; (2) When the amount of hydrogen peroxide disinfection is 8g/m3 and 12g/m3 respectively, The positive rates of unobstructed specimens were 6.67% and 2.67%, respectively, no significant difference (P= >0.05), and there was no difference in disinfection effect between the positions (P >0.05); (3) 8g/m3 disinfection dose The peak concentration is 255.9g, the peak concentration is 1h48min; the peak concentration is 337.6g at 12g/m3 disinfection, and the peak concentration is 2h26min. When the two disinfection doses were disinfected for 8 hours, the peak concentrations of the chambers were basically the same. Conclusions The use of vaporized hydrogen peroxide for terminal disinfection should be as full as possible to expose the items to be disinfected. Applicability of Research to Practice Disinfection.

Effects of humidity on cellulose pellets loaded with potassium titanium oxide oxalate for detection of hydrogen peroxide vapor in powders

Hydrogen peroxide vapor in detergent and pharmaceutical powders can have detrimental effects on enzymes and active ingredients. Potassium titanium oxide oxalate (PTO) adsorbed into cellulose pellets changes color upon exposure to hydrogen peroxide vapor. TGA and DVS analyses showed that cellulose dominates the interactions of PTO-loaded pellets with humidity, while the pure PTO salt can form either a mono- or dihydrate and deliquesce above 80% RH. The mono- and dihydrate forms of PTO salt gave different changes of the surface reflectance colors after exposure to hydrogen peroxide vapor. SEM-EDX and μ-CT scans showed that titanium move towards the surface of the PTO Pellets after reaction with hydrogen peroxide further affecting the surface reflectance. It is concluded that PTO-loaded pellets are suitable for detection of hydrogen peroxide vapor at an interparticle level in powders with humidity conditions in the range of 10 to 80% RH.

Evaluating the Environmental Persistence and Inactivation of MS2 Bacteriophage and the Presumed Ebola Virus Surrogate Phi6 Using Low Concentration Hydrogen Peroxide Vapor.

Ebola virus (EBOV) disease outbreaks, as well as the ability of EBOV to persist in the environment under certain conditions, highlight the need to develop effective decontamination techniques against the virus. We evaluated the efficacy of hydrogen peroxide vapor (HPV) to inactivate MS2 and Phi6 bacteriophages, the latter a recommended surrogate for EBOV. The phages were inoculated onto six material types with and without the presence of whole human blood. The inoculated materials were then exposed to either a high or low concentration of HPV for various elapsed times. The phages were also recovered from positive controls at these same elapsed times, to assess environmental persistence and decontamination efficacy. Low concentration hydrogen peroxide vapor (LCHP; 25 ppm) was effective against both phages on all materials without the presence of blood at 2 h. LCHP was ineffective against the phages in the presence of blood, on all materials, even with a 3-day contact time. Higher concentrations of HPV (>400 ppm) with contact times of 24-32 h achieved approximately 2-6 log reduction of the phages in the presence of blood.

Grafting Ti Sites on Defective Silicalite-1 via TiCl4 Chemical Vapor Deposition for Gas-Phase Epoxidation of Propylene and H2O2 Vapor

The gas-phase epoxidation of propylene and hydrogen peroxide (H2O2) vapor to produce propylene oxide (G-HPPO) is a good way to bypass the methanol solvent problem faced by the liquid-phase HPPO pro...

Quantitative and Fast Sterility Assurance Testing of Surfaces by Enumeration of Germinable Endospores

A fast Endospore Germinability Assay (EGA) was validated with traditional plate counts to enumerate single endospore germination events for monitoring surface sterilization. The assay is based on a time-gated luminescence microscopy technique enabling visualization and enumeration of individual germinating endospores. Germinating endospores release calcium dipicolinate to form highly luminescent terbium dipicolinate complexes surrounding each germinating endospore. EGA and heterotrophic plate counting (HPC) were used to evaluate the swab/rinse recovery efficiency of endospores from stainless steel surfaces. EGA and HPC results were highly correlated for endospore recovery from stainless steel coupons inoculated with range of 1,000 endospores per coupon down to sterility. Dosage-dependent decrease of surface endospore germinability were observed in dry heat, UV irradiation, oxygen plasma and vaporized hydrogen peroxide treatments, measured with EGA and HPC. EGA is a fast and complementary method to traditional HPC for quantitative sterility assurance testing of surfaces. This work introduces and validates a 15-minute or faster assay for germinable endospores to complement the conventional lengthy, culture-based surface sterility validation, which is critical in hospitals, food and pharmaceutical industries to help minimize nosocomial infection, food spoilage, and pharmaceutical contamination.

Surgeries in asymptomatic carriers during SARS-COV-2 pandemic: Challenges and future.

Sir, The outbreak of severe acute respiratory syndrome coronavirus (SARS-CoV-2) pandemic lead to around 5,400,000 confirmed cases in more than 210 countries all over the world (26thMay 2020).[1] To avoid burden on the health care system and to avoid disease transmission, most of the hospitals suspended all the elective procedures and are undertaking only emergency procedures. A suspected/confirmed COVID-19 patient for an emergency procedure may be treated with strict adherence to standard operating procedure (SOP) with enhanced personal protective equipment (PPE) put forth by various agencies.[23] If they are symptomatic or with contact history, we will proceed after testing for COVID-19. But what if the patient is an asymptomatic carrier?[4] Does every patient need to undergo “COVID-19” screening for an elective procedure? Even after the COVID-19 screen, are we sure the test result is not false-negative?[3] Are the health care workers always at risk after this pandemic? So, the answer would be to do the best of the best cost-effectively. Firstly, there is around 10–20% chance of false-negative results.[3] Secondly, it is not cost-effective to carry out every elective procedure with SOP in all asymptomatic patients with negative contact history. A better way would be to emphasise on areas where the chances of transmission are more, use equipment which can be reused and sterilised. The most common mode of transmission in the operating area is by aerosol-generating procedures (AGP), that is, intubation, extubation, suction and manual ventilation. Few precautions may be followed while executing these procedures: The term “elective and emergency” needs to be well understood and balanced with the health of the patient in this time of crisis. Indication of surgery needs to be evaluated against the resources. Emergency surgeries in asymptomatic carriers also stand as a risk during the pandemic Symptomatic suspected/confirmed COVID-19 cases posted for elective procedures should be done only after considering the need for surgery. Cosmetic surgeries may be avoided Pre-anaesthetic check-up also needs to be done with N95 masks, goggles, and hand hygiene. Proper history taking and informed consent (regarding asymptomatic carriers and hospital staff is not responsible if they are detected later) should be done[5] The person handling the airway may use a set of seven to eight N-95 masks/month (reused after “mask quarantine” for 3 days or sterilised with ultraviolet radiation or hydrogen peroxide vapor),[6] goggles (reusable), face shield (reusable), and standard PPE in place of enhanced PPE Use a plastic box with preferably suction/vacuum port or two holes in plastic cover, making a room for two hands, over the patient to be intubated or extubated. The mask may also be covered with plastic cover to limit the spread of aerosol. Avoid manual ventilation as and when possible. If required, small tidal volumes with heat moisture exchanger filter (HMEF) may be used[7] Preoxygenation before induction gives some time during desaturation. It reduces mistakes during induction and hence decreases aerosol generation. The routine use of rapid sequence induction using intubating dose of rocuronium or succinylcholine should be encouraged, unless contraindicated. Routine use of videolaryngoscope is preferable Limit the number of people during AGP to two-three (including a trained assistant) to minimise the exposure to AGPs. Safe extubation practices should be adopted (use of intubation box or plastic drapes) Conduct the elective surgeries under regional anaesthesia (sub-arachnoid block, regional blocks) as and when possible. Use second generation supraglottic airway devices whenever feasible Minimise the number of ventilator disconnections to avoid the operating theatre pollution and aerosol spread. A negative pressure operation theatre (OT) is preferable or if not possible increase the number of air exchanges per hour[3] Use of HMEF may be encouraged at the patient end and at the expiratory limb. Routine use of videolaryngoscopes may be encouraged Hand-hygiene before and after the procedure and social distancing need to be followed in OTs. The surgeons performing open abdominal surgeries, ophthalmological surgeries, oropharyngeal surgeries, etc. may also use the N-95 mask with goggles and face shield. Hence, considering precautionary measures would be a better choice for all asymptomatic cases, as the risk of false-negative tests cannot be negated. This adds to the safety along with COVID screening. Although the spread of the virus to people not performing AGP is not guaranteed, this is the best that can be done cost-effectively. However, for any suspicion of COVID-19 status or a confirmed case, PPE is a must. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.