Disinfectant Spray Research Articles

Toward A Novel Design for Spray Disinfection System to Combat Coronavirus (Covid-19) Using IoT Based Drone Technology

The recent pneumonia spread brought about by a novel coronavirus (COVID-19) in China is representing an incredible risk and proclaimed a worldwide emergency of public health The new type of coronavirus was identified as SARS-CoV-2 or known as novel coronavirus (nCov-2019) It has spread to the world and infected people with Covid-19 disease In addition to the absence of explicit treatment as well as vaccine, covid 19 are currently known to reveal a noteworthy environmental resistance The transmission of the virus was found to be spread through human-to-human that make it easily diffused The transmission comes from the droplets of infectee when sneezing or coughing These droplets can survive on the inanimate surface even in air (aerosol) and transmitted the virus to human Absence of remedy, high mortality, and transmission patterns of COVID-19 include the development of robust and oriented means of prevention to halt the spread of this virus worldwide In the face of a shortage of particular antiviral remedy, it is profoundly to develop efficient methods of prevention and confirm that existing means are effective based on the field case The aim of this study is to design and develop an antiseptic- disinfection spraying system utilizing technology of IoT based drone In addition, the presented system has ability to disinfect large scale area with less time consuming and minimal human interactions It additionally proposes details of the range of Antiseptics-Disinfectants and Denaturation that have been used in this operation Moreover, it underlines the tremendous potential of this technique and future trends for future researches

COVID Operation Theatre- Advisory and Position Statement of Indian Society of Anaesthesiologists (ISA National).

COVID Operation Theatre- Advisory and Position Statement of Indian Society of Anaesthesiologists (ISA National).

Evaluation of the Reduction of Escherichia coli O157:H7 Surrogates in Beef Ribeye Rolls at 54.4°C

ObjectivesE. coli infections are a primary source of gastroenteritis requiring strict cooking and handling procedures for meat producing companies as directed by the USDA. This study evaluated the reduction of Escherichia coli O157:H7 surrogates in a low temperature cook process at a local medium-large meat processor. This is one of three microbial validation projects; the other projects will investigate Clostidium perfrigens and Salmonella spp. The objective of maintaining meat quality (rare color) throughout cooking processes urges the study of low temperature cook processes to determine their efficacy in microbial control.Materials and MethodsThis study was completed in three replications each consisting of a sample size of n = 25. Four strains of Escherichia coli (American Type Culture Collection, ATCC® BAA-1427, 1428, 1429, and 1431), each approved as a surrogate for E. coli O157:H7, were used in this study. Each surrogate was grown separately. Inoculations of surrogates were prepared utilizing 800 mL of distilled water mixed with 24 g of TSB and inoculated with surrogates. The inoculations were incubated at 37°C for 24 h prior to application. The surrogates were mixed together to make a cocktail just prior to inoculation of meat. Seventy-five (25 per replication) ribeye rolls (IMPS 112-A) were removed from vacuum bags and trimmed. Initial samples were taken to determine initial microbial load prior to inoculation. The pH and temperature were taken in raw meat, after spraying with antimicrobial, and after brining. The pH and temperature of the brine was also recorded. Meat was inoculated with 90 mL of inoculum and was distributed evenly on the surface with a sponge on a stick. The inoculum was allowed to dry for 30 min prior to sampling for inoculation load. Ribeye rolls were then sampled 15 min after going through an antimicrobial spray. Samples for raw meat, initial inoculated meat, and after antimicrobial spray were taken from the surface of the ribeye roll (approximately 100 g). Following sampling, the ribeye rolls were pumped with a brine solution (sugar, salt, and proprietary ingredients) to 15%. The meat was vacuum-packaged in cook-in bags and allowed to sit in a cooler to mimic the longest period of time from packaging until it would be placed in the smokehouse. Ribeye rolls were cooked according to Appendix A at 54.4°C for 112 min, and chilled until the internal temperature was below 4.4°C. Final cooked and chilled samples were taken by cutting a 4 cm steak from the center of the roast. All samples were packaged and sent to Food Safety Net Services (FSNS) for culturing on coliform film. At FSNS 25 g of meat and 225 mL of BPW were stomached, serial dilutions were done and plated on coliform petrifilm and allowed to incubate for 24–48 h. Results were analyzed using the proc GLM procedure of SAS, determining the LSMean and StdError as well as Microsoft Excel.ResultsInitial inoculation loads after inoculation were 6.5 logs and all cooked and chilled samples had less than 1 log. Therefore, the mean log reduction was 5.1 with a standard error of 0.04 from inoculation to post-cook over the three replications.ConclusionThe results suggest that this cook method is sufficient to reduce E. coli O157:H7 in whole-muscle beef ribeye rolls. This information would be beneficial to companies looking to preserve meat quality while utilizing a low temperature cook process.

Characteristics of exposure factors and inhalation exposure to selected spray consumer products in Korean population

Many consumer spray products are sold for various purposes. Use of spray products can cause adverse health effects. This study evaluated exposure factors for consumer spray products and assessed the particle inhalation exposure. Six consumer spray products were evaluated: an automobile interior cleaner, car deodorizing spray, anti-static spray, waterproofing spray, microorganism deodorizer, and disinfectant spray. The exposure factors were based on 10,000 respondents over 15 years old. Inhalation dose was calculated from the concentration released into the room air and time used. The use rates of the spray products ranged from 0.4 to 11% and differed significantly by gender (p < 0.001). Aerosol types had a higher mass per use and longer duration of usage than trigger types. The median concentration of the trigger type ranged from 17.35 to 373.38 mg/m3, while that of the aerosol type ranged from 36.66 to 1601.97 mg/m3. The median inhalation dose of the trigger and aerosol types ranged from 2.04 × 10−3 to 0.20 and 2.60 × 10−3 to 1.71 mg/kg/day, respectively. The inhalation dose of the disinfectant spray increased with the level of education (p < 0.001), while the inhalation doses of the other spray products were not significantly associated with gender, age, income, or education.

1218. Evaluation of a Novel Sporicidal Spray Disinfectant for Decontamination of Surfaces in Healthcare

BackgroundSurfaces in healthcare facilities are typically cleaned by manual application of liquid disinfectants. However, thoroughness of cleaning is often suboptimal and application can be challenging and time-consuming when surfaces are irregular.MethodsWe tested the effectiveness of a novel spray disinfectant technology that uses an electrostatic sprayer to thoroughly apply a sporicidal disinfectant to surfaces after minimal pre-cleaning to remove visible soil. In a laboratory setting, we compared the effectiveness of the spray disinfectant vs. manual application of disinfectant for removal of Clostridium difficile spores inoculated onto the seat, armrest, and seat back of a wheelchair and measured the time required for each method of disinfection. In a healthcare setting, we tested the effectiveness of a 15-second spray application for reduction of C. difficile spores on 130 items with irregular or hard to clean surfaces, including 30 wheelchairs, 40 pieces of portable equipment, and 30 waiting room chair seats.ResultsIn laboratory testing, application of disinfectant using the electrostatic sprayer was as effective as wiping in reducing C. difficile spores inoculated onto wheelchair surfaces, but required only one-fourth the time for application. C. difficile spore contamination was common on mobile equipment, wheelchairs, and waiting rooms chairs, and spray application of the sporicidal disinfectant was effective in reducing contamination (figure).ConclusionCommonly shared items such as wheelchairs, portable equipment, and waiting room chairs were frequently contaminated with C. difficile spores. Application of a sporicidal disinfectant using an electrostatic sprayer provided a rapid and effective means to reduce spore contamination on these surfaces. Disclosures All authors: No reported disclosures.

Decontamination of aerosolised bacteria from a pig farm environment using a pH neutral electrochemically activated solution (Ecas4 anolyte).

An electrochemically activated solution (ECAS), generated by electrolysis of a dilute sodium chloride solution in a four-chamber electrolytic cell (Ecas4), was tested as a sanitising aerosol in eliminating bacteria from the environment of a weaning room vacated 24-48h earlier, at a continuous flow pig farm. An ultrasonic humidifier was used to fill the environment with a fog (droplets with diameters of 1–5 μm) containing 0.25 ppm of hypochlorous acid. The weaning room was fogged for 3 min at 30 min intervals during five hours of aerosol disinfection. An innovative sample treatment with propidium monoazide dye in conjunction with cyclonic air sampling was optimised and adapted for discerning live/dead bacteria in subsequent molecular quantification steps. Without fogging, total bacterial load ranged from 5.06 ± 0.04 to 5.75 ± 0.04 Log10 CFU/m3. After the first hour of fogging, a 78% total bacterial reduction was observed, which further increased to > 97% after the second hour, > 99.4% after the third and 99.8% after the fourth hour, finally resulting in a 99.99% reduction from the farm environment over five hours. Unlike the current formaldehyde spray disinfection protocol, which requires a long empty period because of its hazardous properties, this economically viable and environmentally friendly disinfection protocol may significantly lower downtime. Moreover, ECAS fogging can be easily adapted to a variety of applications, including the elimination of pathogens from livestock farm air environment for disease prevention, as well as decontamination after disease outbreaks.

Glow Powder: See the Germs? An Innovative Teaching Technique in a Student Sonography Laboratory

The purpose of this study was to compare the disinfection rate of a laboratory environment before and after glow powder exposure and training of sonography students (n = 23) and establish if glow powder was an effective teaching technique for infection protection and control (IPC). Fourteen locations at four scanning stations were contaminated with glow powder, visible under ultraviolet light. Students were shown contaminated areas and debriefed on the importance of disinfection. This activity was repeated to ascertain effectiveness of the training. In total, 204 areas were examined for contamination. Observation 1 revealed 21 locations (30.8%), and observation 2 detected glow powder on 12 locations (17.6%). Overall decrease in contamination rate was 13%. The gel bottle was the most frequently contaminated. The curved 3.5-MHz transducer was consistently cleaned. Disinfectant spray, time gain compensation, bed, stool, screen, and handles of the machine remained contaminated. Students’ IPC increased significantly after glow powder training, and secondary spread was reduced by 16%.

Disinfection of dental impressions: knowledge and practice among dental technicians.

Background: Dental impressions are a common source for transmission of infection between dental clinics and dental labs. Dental impressions can be cross-contaminated by patient’s saliva and blood, which then cross-infect the dental casts poured from the impressions.Objective: To evaluate the current practices of disinfection of dental impressions and their protocols and to assess the knowledge of cross-infection control among dental technicians in Jordan.Method: Dental technicians (n=85) completed a self-administered questionnaire about their practices of disinfection for dental impressions.Results: The distribution of dental technicians was 63.8% fixed prosthodontics, 23.5% removable prosthodontics, 7.8% orthodontics, and 4.8% maxillofacial prosthodontics. The majority of the laboratories did not have instructions related to disinfection of impressions. About 50% of technicians were vaccinated against HBV. About 44.7%, and 42.9% of labs reported that they never disinfect alginate or silicon impressions, respectively. In addition, the majority of lab owners (53%) believed that the dentist should disinfect the impressions before shipping them to dental laboratories, while (45%) believed that disinfecting the impressions is the responsibility of the dental assistant. Moreover, about 38% of this study population reported not using gloves in their labs. In those labs were disinfection was used, 51% used spray disinfection whereas 32.6% used immersion disinfection. The cost of disinfectant was ranked as the most important factor (51.3% of the cases) for the dental technician to choose the disinfectant followed by its effectiveness.Conclusion: Dental technician practices in impression disinfection was not satisfactory, therefore, education programs about impression disinfection are needed.

Diagnosing chicken diseases using fuzzy Tsukamoto web-based expert system

Chicken is one source of protein favored by the community. One of the benefits we can take on chicken is meat and eggs. But chicken disease becomes one of the problems that are very detrimental to chicken farmers. This was assessed because of the lack of knowledge of farmers in handling conditions that occur in chicken. Accurate information about handling chicken disease among farmers is still difficult to obtain. Therefore, it is necessary to design an expert system application in detecting diseases that are experienced by chickens based on the symptoms shown and how to handle them. The method used is fuzzy Tsukamoto as an inference engine to determine the disease based on its symptoms and use the PHP programming language in making applications and MySQL as its database. Based on the results of the diagnosis in the sample taken showed the results of the fuzzy Tsukamoto diagnosis were 97.97% (very good) with the type of disease: typhoid chicken based on the symptoms seen. The solution given is isolation of chickens that show symptoms and give disinfectant water, spray disinfectant, replace all water and feed, clean the entire cage, and destroy dead chickens.

Efficacy of plant-derived antimicrobials for controlling Salmonella Schwarzengrund on dry pet food

Salmonella enterica is a major human pathogen that is responsible for 23,000 hospitalizations annually in the United States. Contact with contaminated pet food and infected companion animals can transmit salmonellosis to humans. Recent multistate human outbreaks of salmonellosis linked to commercial contaminated dry dog foods underscore the need for controlling the pathogen in pet foods for protecting pet and public health. In this study, the efficacy of five Generally Recognized as Safe (GRAS) status, plant-derived antimicrobials (PDAs), namely trans-cinnamaldehyde (TC), carvacrol (CR), thymol (TY), eugenol (EG), and caprylic acid (CA) applied as a vegetable oil or chitosan based antimicrobial spray on dry pet food for reducing Salmonella Schwarzengrund was investigated. Three hundred gram portions of a commercial dry dog food were inoculated with a two-strain mixture of nalidixic acid (NA) resistant S. Schwarzengrund (~6 log CFU/g), followed by a spray treatment with 0%, 0.5%, 1% or 2% of TC, CR, TY, EG or CA in combination with 5% vegetable oil or 1% chitosan as a carrier. The control and treated dog food samples were stored at 25 °C for 28 days. On days 0, 1, 3, 5, 7, 14, 21, and 28, Salmonella on pet food was enumerated by serial dilution and plating on xylose lysine desoxycholate (XLD) agar. All PDAs at 1% and 2% applied in vegetable oil or chitosan reduced S. Schwarzengrund by at least ~2 log CFU/g on day 3 of storage when compared to control (P < 0.05). No significant reductions in Salmonella were observed on feed sprayed with only vegetable oil or chitosan (P > 0.05). Overall, 2% TC in vegetable oil or chitosan was the most effective treatment, where at least 3 to 3.5 log CFU/g reduction in bacterial populations was observed during storage (P < 0.05). Results suggest that the aforementioned PDAs could potentially be used as an antimicrobial spray to reduce S. Schwarzengrund on dry dog food. However, further studies on the acceptance of PDA-treated dry food by dogs are needed.

Design and experiment of spray and rotary tillage combined disinfection machine for soil

A spray and rotary tillage combined disinfection machine for soil was designed to solve the serious problems of plant diseases and insect pests, and it was divided into two operations which were soil disinfection and rotary tillage. The main structure and working principle of this machine were illustrated and analyzed. The reasonable structural parameters of the key parts of this machine were optimized, such as spraying disinfection system and rotary tillage land preparation system. To optimize the working performance and obtain better operation parameters, the orthogonal experiments were carried out to analyze the influences of three factors (forward speed of driving machine, rotational speed of rotary tillage, and working pressure) on the working performance. The mixing uniformity coefficient and the variation coefficient of spraying were selected for evaluating working performance. The range analysis and variance analysis were studied based on experimental data. The results showed that, the mixing uniformity coefficient of spraying was 93.95% and the variation coefficient was 6.01% with a working speed of 3 km/h, rotational speed of 2000 r/min and working pressure of 2.0 MPa. The machine can meet the agronomic requirements of disinfection and plowing, which was designed simply, compactly and strong applicability. The results can provide a guidance and technical support for preventing the plant diseases and insect pests, developing sustainable and ecological agriculture and improving the efficiency of compound cultivation. Keywords: agricultural machine, soil disinfection, spray, rotary tillage, compound operation DOI: 10.25165/j.ijabe.20191201.3640 Citation: Wang J W, Yang W P, Sun X B, Li X, Tang H. Design and experiment of spray and rotary tillage combined disinfection machine for soil. Int J Agric & Biol Eng, 2019; 12(1): 52–58.

Impact of a hygiene intervention on virus spread in an office building.

Viral illnesses have a significant direct and indirect impact on the workplace that burdens employers with increased healthcare costs, low productivity, and absenteeism. Workers' direct contact with each other and contaminated surfaces contributes to the spread of viruses at work. This study quantifies the impact of an office wellness intervention (OWI) to reduce viral load in the workplace. The OWI includes the use of a spray disinfectant on high-touch surfaces and providing workers with alcohol-based hand sanitizer gel and hand sanitizing wipes along with user instructions. Viral transmission was monitored by applying an MS2 phage tracer to a door handle and the hand of a single volunteer participant. At the same time, a placebo inoculum was applied to the hands of four additional volunteers. The purpose was to evaluate the concentration of viruses on workers' hands and office surfaces before and after the OWI. Results showed that the OWI significantly reduced viable phage concentrations per surface area on participants' hands, shared fomites, and personal fomites (p = 0.0001) with an 85.4% average reduction. Reduction of virus concentrations on hands and fomites is expected to subsequently minimize the risk of infections from common enteric and respiratory pathogens. The surfaces identified as most contaminated were the refrigerator, drawer handles and sink faucets in the break room, along with pushbar on the main exit of the building, and the soap dispensers in the women's restroom. A comparison of contamination in different locations within the office showed that the break room and women's restrooms were the sites with the highest tracer counts. Results of this study can be used to inform quantitative microbial risk assessment (QMRA) models aimed at defining the relationship between surface contamination, pathogen exposure and the probability of disease that contributes to high healthcare costs, absenteeism, presenteeism, and loss of productivity in the workplace.

The Addition of ViriditecTM Aqueous Ozone to Peracetic Acid as an Antimicrobial Spray Increases Air Quality While Maintaining Salmonella Typhimurium, Non-pathogenic Escherichia coli, and Campylobacter jejuni Reduction on Whole Carcasses.

Currently, the most utilized antimicrobial in processing facilities is peracetic acid, PAA; however, this chemical is increasingly recognized as a hazard to human health. Preliminary evidence suggests that ozone, when introduced in a specific manner, can reduce the noxious nature of PAA. Therefore, the objective of the current study was to evaluate the efficacy of TetraClean Systems aqueous ozone, O3, in combination with PAA as an antimicrobial spray on whole chicken carcasses. This trial used 70 whole hen carcasses (7 treatments; 10 replications) that were inoculated in a 400 mL cocktail containing Salmonella, Escherichia coli, and Campylobacter (107 CFU/mL) and allowed to adhere for 60 min at 4°C for a final concentration of 105 to 106 CFU/g. The experimental 5 s (4×) spray treatments included: a no treatment negative control, TW; TW + O3 (10 ppm), TW + PAA (50 ppm), TW + PAA (500 ppm), TW + O3 + PAA (50 ppm), and TW + O3 + PAA (500 ppm). During treatment application, ambient PAA vapor was measured with a ChemDAQ Safecide PAA vapor sensor. After treatment, carcasses were immediately rinsed in 400 mL of nBPW for 2 min. Following rinsing, the dot method was utilizing for enumeration with 10 μL of rinsate being serially diluted, plated on XLD and mCCDA agar, and incubated aerobically at 37°C for 24 h or microaerophilically at 42°C for 48 h. Log-transformed counts were analyzed using ANOVA in JMP 14.0. Means were separated using Tukey’s HSD when P ≤ 0.05. There was a significant treatment effect among Salmonella, E. coli, and Campylobacter counts, and a significant treatment effect among ambient PAA (P < 0.05). TW + O3 + PAA (500 ppm), reduced Salmonella significantly compared to TW (5.71 and 6.30 log CFU/g). Furthermore, TW + PAA (500 ppm), reduced the presence of E. coli significantly compared to TW or no treated control (5.57 and 6.18 log CFU/g). Also, TW + PAA (50 ppm), TW + PAA (500 ppm), and TW + O3 + PAA (500 ppm) significantly reduced Campylobacter compared to carcasses not treated (4.80, 4.81, and 4.86 log CFU/g). Lastly, the addition of ozone significantly reduced the ambient PAA when O3 was added to 500 ppm of PAA, as TW + O3 + PAA (500 ppm) produced less ambient PAA than TW + PAA (500 ppm) (0.052 and 0.565 ppm). In conclusion, the addition of ozone to PAA may demonstrated the ability to effectively reduce ambient PAA, thus increasing employee safety.

Evaluation of the Reduction of Escherichia coli O157:H7 Surrogates in Beef Ribeye Rolls at 54.4°C

ObjectivesE. coli infections are a primary source of gastroenteritis requiring strict cooking and handling procedures for meat producing companies as directed by the USDA. This study evaluated the reduction of Escherichia coli O157:H7 surrogates in a low temperature cook process at a local medium-large meat processor. This is one of three microbial validation projects; the other projects will investigate Clostidium perfrigens and Salmonella spp. The objective of maintaining meat quality (rare color) throughout cooking processes urges the study of low temperature cook processes to determine their efficacy in microbial control.Materials and MethodsThis study was completed in three replications each consisting of a sample size of n = 25. Four strains of Escherichia coli (American Type Culture Collection, ATCC® BAA-1427, 1428, 1429, and 1431), each approved as a surrogate for E. coli O157:H7, were used in this study. Each surrogate was grown separately. Inoculations of surrogates were prepared utilizing 800 mL of distilled water mixed with 24 g of TSB and inoculated with surrogates. The inoculations were incubated at 37°C for 24 h prior to application. The surrogates were mixed together to make a cocktail just prior to inoculation of meat. Seventy-five (25 per replication) ribeye rolls (IMPS 112-A) were removed from vacuum bags and trimmed. Initial samples were taken to determine initial microbial load prior to inoculation. The pH and temperature were taken in raw meat, after spraying with antimicrobial, and after brining. The pH and temperature of the brine was also recorded. Meat was inoculated with 90 mL of inoculum and was distributed evenly on the surface with a sponge on a stick. The inoculum was allowed to dry for 30 min prior to sampling for inoculation load. Ribeye rolls were then sampled 15 min after going through an antimicrobial spray. Samples for raw meat, initial inoculated meat, and after antimicrobial spray were taken from the surface of the ribeye roll (approximately 100 g). Following sampling, the ribeye rolls were pumped with a brine solution (sugar, salt, and proprietary ingredients) to 15%. The meat was vacuum-packaged in cook-in bags and allowed to sit in a cooler to mimic the longest period of time from packaging until it would be placed in the smokehouse. Ribeye rolls were cooked according to Appendix A at 54.4°C for 112 min, and chilled until the internal temperature was below 4.4°C. Final cooked and chilled samples were taken by cutting a 4 cm steak from the center of the roast. All samples were packaged and sent to Food Safety Net Services (FSNS) for culturing on coliform film. At FSNS 25 g of meat and 225 mL of BPW were stomached, serial dilutions were done and plated on coliform petrifilm and allowed to incubate for 24–48 h. Results were analyzed using the proc GLM procedure of SAS, determining the LSMean and StdError as well as Microsoft Excel.ResultsInitial inoculation loads after inoculation were 6.5 logs and all cooked and chilled samples had less than 1 log. Therefore, the mean log reduction was 5.1 with a standard error of 0.04 from inoculation to post-cook over the three replications.ConclusionThe results suggest that this cook method is sufficient to reduce E. coli O157:H7 in whole-muscle beef ribeye rolls. This information would be beneficial to companies looking to preserve meat quality while utilizing a low temperature cook process.

Evaluation of efficacy of Aloe Vera as a Disinfectant by Immersion and Spray methods on Irreversible Hydrocolloid Impression Material and its Effect on the Dimensional Stability of Resultant Gypsum Cast - An in Vitro Study.

The need to use a natural alternative for disinfecting dental impression materials, which should be biocompatible and effective, led us to evaluate the efficacy of Aloe vera as a disinfectant by immersion and spray method on alginate impression material and its effect on the dimensional stability of the resultant gypsum cast.The efficacy of the disinfection procedures against Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans was evaluated by determining the number of colony-forming units (CFU) recovered after disinfection of alginate discs inoculated with 1x106 CFU for defined intervals with aloe vera solution (99.96%). Dimensional stability was determined from the mean percentage deviation of three measurements that were taken between the fixed points on the casts using a traveling microscope and compared with corresponding measurements from the master model and controls. Statistical analysis of data was determined by analysis of variance.We found out that there is a mean percentage reduction in colony count of S. aureus, P. aeruginosa, and C. albicans after 3 minutes of immersion in aloe vera and after 3 minutes spray disinfection. Complete elimination of all the microorganism cells after 7 min immersion and spray disinfection. There was a statistically significant difference in the increase of the mean anteroposterior (AP) and cross arch (CA) dimension after 3 and 7 minutes immersion in aloe vera. Spraying with aloe vera for 7 minutes was proved to be the most effective disinfection procedure without altering dimensional stability.

Design and experiment of spray and rotary tillage combined disinfection machine for soil

Design and experiment of spray and rotary tillage combined disinfection machine for soil

Effect of 0.5% glutaraldehyde disinfection on surface wettability of elastomeric impression materials

PurposeThe purpose of this in-vitro study was to evaluate the effect of 0.5% glutaraldehyde spray disinfection on surface wettability of vinyl polysiloxane and polyether impression materials. Methods and materialsThirty-six specimens were prepared of vinyl polysiloxane-light (VPL), vinyl polysiloxane-regular (VPR) viscosity and polyether-monophase (PE) impression materials according to manufacturer’s recommendations. Specimens of each material were equally divided into control and experimental groups. All specimens were washed with water, dried and stored in closed containers. Specimens of experimental groups were sprayed with 0.5% glutaraldehyde disinfectant. The disinfectant was allowed to be in contact with the impression surface for 10 min. Contact angle was measured using a Contact Angle Goniometer at 0.5, 1 and 2 min after water drop contact with surfaces of impression materials. Five measurements at five different areas at each impression surface were recorded. A statistical analysis was done using Two-way repeated measures ANOVA and multiple comparison Tukey’s Post-hoc tests. ResultsAll 0.5% glutaraldehyde-disinfected impression materials showed lower contact angle measurements than non-disinfected ones. Contact angle measurements of PE were much lower than those of VPL and VPR impression materials. However, there was a statistically significant difference of contact angle measurements between the three impression materials (p = 0.000). Contact angle measurements of all groups significantly decreased as the time was increased (p = 0.000). ConclusionDisinfection of the tested impression materials with 0.5% glutaraldehyde improved their wettability. Glutaraldehyde acted like a surface reducing agent (surfactant) that improved wetting potential of the impression materials.

Microbial transmission in an outpatient clinic and impact of an intervention with an ethanol-based disinfectant

BackgroundHalting the spread of harmful microbes requires an understanding of their transmission via hands and fomites. Previous studies explored acute and long-term care environments but not outpatient clinics. Objectives of this study were to track microbial movement throughout an outpatient clinic and evaluate the impact of a disinfectant spray intervention targeting high-touch point surfaces.MethodsAt the start of the clinic day, a harmless viral tracer was placed onto 2 fomites: a patient room door handle and front desk pen. Patient care, cleaning, and hand hygiene practices continued as usual. Facility fomites (n = 19), staff hands (n = 4), and patient hands (n = 3-4) were sampled after 2, 3.5, and 6 hours. Tracer concentrations at baseline (before intervention) were evaluated 6 hours after seeding. For the intervention trials, high-touch surfaces were cleaned 4 hours after seeding with an ethanol-based disinfectant and sampled 2 hours after cleaning.ResultsAt 2, 3.5, and 6 hours after seeding, virus was detected on all surfaces and hands sampled, with examination room door handles and nurses’ station chair arms yielding the highest concentrations. Virus concentrations decreased by 94.1% after the disinfectant spray intervention (P = .001).ConclusionsMicrobes spread quickly in an outpatient clinic, reaching maximum contamination levels 2 hours after inoculation, with the highest contamination on examination room door handles and nurses’ station chairs. This study emphasizes the importance of targeted disinfection of high-touch surfaces.

Modeling Surface Disinfection Needs To Meet Microbial Risk Reduction Targets.

Nosocomial viral infections are an important cause of health care-acquired infections where fomites have a role in transmission. Using stochastic modeling to quantify the effects of surface disinfection practices on nosocomial pathogen exposures and infection risk can inform cleaning practices. The purpose of this study was to predict the effect of surface disinfection on viral infection risks and to determine needed viral reductions to achieve risk targets. Rotavirus, rhinovirus, and influenza A virus infection risks for two cases were modeled. Case 1 utilized a single fomite contact approach, while case 2 assumed 6 h of contact activities. A 94.1% viral reduction on surfaces and hands was measured following a single cleaning round using an Environmental Protection Agency (EPA)-registered disinfectant in an urgent care facility. This value was used to model the effect of a surface disinfection intervention on infection risk. Risk reductions for other surface-cleaning efficacies were also simulated. Surface reductions required to achieve risk probability targets were estimated. Under case 1 conditions, a 94.1% reduction in virus surface concentration reduced infection risks by 94.1%. Under case 2 conditions, a 94.1% reduction on surfaces resulted in median viral infection risks being reduced by 92.96 to 94.1% and an influenza A virus infection risk below one in a million. Surface concentration in the equations was highly correlated with dose and infection risk outputs. For rotavirus and rhinovirus, a >99.99% viral surface reduction would be needed to achieve a one-in-a-million risk target. This study quantifies reductions of infection risk relative to surface disinfectant use and demonstrates that risk targets for low-infectious-dose organisms may be more challenging to achieve.IMPORTANCE It is known that the use of EPA-registered surface disinfectant sprays can reduce infection risk if used according to the manufacturer's instructions. However, there are currently no standards for health care environments related to contamination levels on surfaces. The significance of this research is in quantifying needed reductions to meet various risk targets using realistic viral concentrations on surfaces for health care environments. This research informs the design of cleaning protocols by demonstrating that multiple applications may be needed to reduce risk and by highlighting a need for more models exploring the relationship among microbial contamination of surfaces, patient and health care worker behaviors, and infection risks.

Immune Based Evolutionary Algorithm for Determining the Optimal Sequence of Multiple Disinfection Operations

This paper presents a new multiple disinfection operation problem (MDOP) in which several buildings have to be sprayed with various disinfectants. The MDOP seeks to minimize the total cost of disinfection operations for all buildings. The problem is different from the typical vehicle routing problem since: (a) each building has to receive multiple spray applications of disinfectants; (b) the final spray application of disinfectant in each building is fixed; and (c) for safety, the time interval between two consecutive spray applications of disinfectants for each building must meet or exceed a specified minimum. The MDOP problem is NP-hard and difficult to solve directly. In this paper, we firstly develop an efficient encoding of spray operations to simultaneously determine the optimal sequence of buildings and their respective treatments with spray disinfectants. Secondly, we adopt immune algorithm to solve the presented MDOP. Finally, as a demonstration of our method, we solve the problem for a campus case to determine the optimal disinfection strategy and routes assuming both single and multiple vehicle scenarios. Numerical results of immune algorithm are discussed and compared with those of genetic algorithm and PSO to show the effectiveness of the adopted algorithm.