Neutralization of ricin toxin on building interior surfaces using liquid decontaminants.

Ricin is a highly toxic protein, capable of inhibiting protein synthesis within cells, and is produced from the beans of the Ricinus communis (castor bean) plant. Numerous recent incidents involving ricin have occurred, many in the form of mailed letters resulting in both building and mail sorting facility contamination. The goal of this study was to assess the decontamination efficacy of several commercial off-the-shelf (COTS) cleaners and decontaminants (solutions of sodium hypochlorite [bleach], quaternary ammonium, sodium percarbonate, peracetic acid, and hydrogen peroxide) against a crude preparation of ricin toxin. The ricin was inoculated onto four common building materials (pine wood, drywall joint tape, countertop laminate, and industrial carpet), and the decontaminants were applied to the test coupons using a handheld sprayer. Decontamination efficacy was quantified using an in-vitro cytotoxicity assay to measure the quantity of bioactive ricin toxin extracted from test coupons as compared to the corresponding positive controls (not sprayed with decontaminant). Results showed that decontamination efficacy varied by decontaminant and substrate material, and that efficacy generally improved as the number of spray applications or contact time increased. The solutions of 0.45% peracetic acid and the 20,000-parts per million (ppm) sodium hypochlorite provided the overall best decontamination efficacy. The 0.45% peracetic acid solution achieved 97.8 to 99.8% reduction with a 30-min contact time.

Fate and transport of viable bacillus anthracis simulant spores in ambient air during a large outdoor decontamination field exercise.

IMPLICATIONS: Following an incident involving a release of Bacillus anthracis spores or other biological threat agent into the outdoor environment, understanding the factors that may affect the bioagent's fate and transport can help predict viable contaminant spread via the ambient air. This article provides scientific data for the first time on ambient air concentrations of bacterial spores over time and location during different phases of a field test in which Bacillus atrophaeus (surrogate for B. anthracis) spores were released outdoors as part of a full-scale study on sampling and decontamination in an urban environment. This study advances the knowledge related to the fate and transport of bacterial spores (such as those causing anthrax disease) as an aerosol in the outdoor environment over the course of three weeks in a mock urban environment and has exposure and health risk implications. The highest spore air concentrations occurred at the beginning of the study (e.g. during inoculation of surfaces and characterization sampling), and in the downwind direction, but diminished over time; few B. atrophaeus spores were detected in the air after several weeks and following decontamination. Therefore, in an actual incident, potential reaerosolization of the microorganism and subsequent transport in the air during surface sampling and remediation efforts should be considered for determining exclusion zone locations and estimating potential risk to neighboring communities. The data also provide evidence suggesting that the large-scale decontamination of outdoor surfaces may reduce air concentrations of the bioagent, which is important since exposure of B. anthracis via inhalation is a primary concern.

Review of techniques for the in-situ sterilization of soil contaminated with Bacillus anthracis spores or other pathogens.

This review summarizes the literature on efficacy of techniques to sterilize soil. Soil may need to be sterilized if contaminated with pathogens such as Bacillus anthracis. Sterilizing soil in-situ minimizes spread of the bio-contaminant. Soil is difficult to sterilize, with efficacy generally diminishing with depth. Methyl bromide, formaldehyde, and glutaraldehyde are the only soil treatment options that have been demonstrated at full-scale to effectively inactivate Bacillus spores. Soil sterilization modalities with high efficacy at bench-scale include wet and dry heat, metam sodium, chlorine dioxide gas, and activated sodium persulfate. Simple oxidants such as chlorine bleach are ineffective in sterilizing soil.

Effectiveness of formaldehyde in various soil types as a wide area decontamination approach for Bacillus anthracis spores.

The purpose of this study was to evaluate and compare the decontamination efficacy of liquid formaldehyde solutions for three soil types (sand, loam, and clay) against spores of Bacillus anthracis (B.a.) and Bacillus atrophaeus. Approximately 1 x 108 colony forming units were inoculated into each sample. Through a series of six bench-scale experiments, two concentrations and two volumes of liquid formaldehyde solution were then added to the soil samples and allowed to remain in contact for either 24 or 48 hours. Decontamination efficacy was assessed at either 22° or 10°C with or without lids atop the sample jars. Complete inactivation (no spores recovered from the soil samples, typically providing > 7 log reduction) of B.a. occurred in all soil types in five of the six tests, while complete inactivation of B. atrophaeus was achieved in all soil types for three of the six tests. The results demonstrated a higher probability of complete inactivation of spores for samples that were covered, samples that received the higher volume of formaldehyde, and those contaminated with B.a. Overall, the use of liquid formaldehyde solution (2.5-5%) was highly effective in inactivating entire spore populations (typically > 107 CFU) for both B.a. and B. atrophaeus in the soil matrices studied. Covering the soil after application would allow for less formaldehyde solution to be used without impacting the overall efficacy of the process. The data from this study may aid in the selection of appropriate decontamination parameters when using liquid formaldehyde for soil remediation. The data may also aid in the decision to use B. atrophaeus as a surrogate for B.a. when performing further decontamination studies using liquid formalin solutions.

Evaluation of electrostatic sprayers and foggers for the application of disinfectants in the era of SARS-CoV-2.

Although research has shown that the COVID-19 disease is most likely caused by airborne transmission of the SARS-CoV-2 virus, disinfection of potentially contaminated surfaces is also recommended to limit the spread of the disease. Use of electrostatic sprayers (ESS) and foggers to rapidly apply disinfectants over large areas or to complex surfaces has emerged with the COVID-19 pandemic. ESSs are designed to impart an electrostatic charge to the spray droplets with the goal of increasing deposition of the droplets onto surfaces, thereby promoting more efficient use of the disinfectant. The purpose of this research was to evaluate several spray parameters for different types of sprayers and foggers, as they relate to the application of disinfectants. Some of the parameters evaluated included the spray droplet size distribution, the electrostatic charge, the ability of the spray to wrap around objects, and the loss of disinfectant chemical active ingredient due to the spray process. The results show that most of the devices evaluated for droplet size distribution had an average volume median diameter ≥ 40 microns, and that four out of the six ESS tested for charge/mass produced sprays of at least 0.1 mC/kg. A minimal wrap-around effect of the spray deposition onto a cylindrical object was observed. The loss of disinfectant active ingredient to the air due to spraying was minimal for the two disinfectants tested, and concurrently, the active ingredient concentrations of the liquid disinfectants sprayed and collected 3 feet (1 meter) away from the spray nozzle do not decrease.

The use of ozone gas for the inactivation of Bacillus anthracis and Bacillus subtilis spores on building materials.

A study was conducted to assess the efficacy of ozone gas in inactivating spores of both Bacillus anthracis and Bacillus subtilis inoculated onto six building materials (glass, wood, carpet, laminate, galvanized metal, and wallboard paper). Testing conditions consisted of ozone gas concentrations ranging from 7,000-12,000 parts per million (ppm), contact times from 4 to 12 h, and two relative humidity (RH) levels of 75 and 85%. Results showed that increasing the ozone concentration, contact time, and RH generally increased decontamination efficacy. The materials in which the highest decontamination efficacy was achieved for B. anthracis spores were wallboard paper, carpet, and wood with ≥ 6 log10 reduction (LR) occurring with 9,800 ppm ozone, 85% RH, for 6 h. The laminate and galvanized metal materials were generally more difficult to decontaminate, requiring 12,000 ppm ozone, 85% RH, and 9-12 h contact time to achieve ≥6 LR of B. anthracis. Lastly, overall, there were no significant differences in decontamination efficacy between the two species.

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.

Review of Decontamination Techniques for the Inactivation of Bacillus anthracis and Other Spore-Forming Bacteria Associated with Building or Outdoor Materials.

Since the intentional release of Bacillus anthracis spores through the U.S. Postal Service in the fall of 2001, research and development related to decontamination for this biological agent have increased substantially. This review synthesizes the advances made relative to B. anthracis spore decontamination science and technology since approximately 2002, referencing the open scientific literature and publicly available, well-documented scientific reports. In the process of conducting this review, scientific knowledge gaps have also been identified. This review focuses primarily on techniques that are commercially available and that could potentially be used in the large-scale decontamination of buildings and other structures, as well as outdoor environments. Since 2002, the body of scientific data related to decontamination and microbial sterilization has grown substantially, especially in terms of quantifying decontamination efficacy as a function of several factors. Specifically, progress has been made in understanding how decontaminant chemistry, the materials the microorganisms are associated with, environmental factors, and microbiological methods quantitatively impact spore inactivation. While advancement has been made in the past 15 years to further the state of the science in the inactivation of bacterial spores in a decontamination scenario, further research is warranted to close the scientific gaps that remain.

Influence of environmental conditions on the attenuation of ricin toxin on surfaces.

Ricin is a highly-toxic compound derived from castor plant beans. Several incidents involving contamination of residences and buildings due to ricin production or dissemination have occurred in recent years. The goal of this study was to determine whether ricin bioactivity could be attenuated in reasonable time via simple modifications of the indoor environment. Attenuation was assessed on six different materials as a function of temperature, relative humidity (RH), and contact time, using both a pure and crude preparation of the toxin. Ricin bioactivity was quantified via a cytotoxicity assay, and attenuation determined as the difference in ricin recovered from test and positive controls. The results showed that pure ricin could be attenuated successfully, while the crude ricin was generally more persistent and results more variable. We found no significant attenuation in crude ricin after two weeks at typical indoor environmental conditions, except on steel. Attenuation mostly improved with increasing temperature, but the effect of RH varied. For pure ricin, heat treatments at 40°C for 5 days or 50°C for 2-3 days achieved greater than 96% attenuation on steel. In contrast, appreciable recovery of the crude ricin preparation still occurred at 40°C after two weeks.

Anaphylaxis-related Malpractice Lawsuits.

INTRODUCTION: Anaphylaxis continues to cause significant morbidity and mortality. Healthcare providers struggle to promptly recognize and appropriately treat anaphylaxis patients. The goal of this study was to characterize anaphylaxis-related malpractice lawsuits. METHODS: We collected jury verdicts, settlements, and court opinions regarding alleged medical malpractice involving anaphylaxis from May 2011 through May 2016 from an online legal database (Thomson Reuters Westlaw). Data were abstracted onto a standardized data form. RESULTS: We identified 30 anaphylaxis-related malpractice lawsuits. In 80% of cases, the trigger was iatrogenic (40% intravenous [IV] contrast, 33% medications, 7% latex). Sixteen (53%) cases resulted in death, 7 (23%) in permanent cardiac and/or neurologic damage, and 7 (23%) in less severe outcomes. Fourteen (47%) of the lawsuits were related to exposure to a known trigger. Delayed recognition or treatment was cited in 12 (40%) cases and inappropriate IV epinephrine dosing was reported in 5 (17%) cases. Defendants were most commonly physicians (n=15, 50%) and nurses (n=5, 17%). The most common physician specialties named were radiology and primary care (n=3, 10% each), followed by emergency medicine, anesthesiology, and cardiology (n=2, 7% each). Among the 30 cases, 14 (47%) favored the defendant, 8 (37%) resulted in findings of negligence, 3 (10%) cases settled, and 5 (17%) had an unknown legal outcome. CONCLUSION: Additional anaphylaxis education, provision of epinephrine autoinjectors or other alternatives to reduce dosing errors, and stronger safeguards to prevent administration of known allergens would all likely reduce anaphylaxis-related patient morbidity and mortality and providers' legal vulnerability to anaphylaxis-related lawsuits.

Inactivation of Bacillus anthracis spores to decontaminate subway railcar and related materials via the fogging of peracetic acid and hydrogen peroxide sporicidal liquids.

The inactivation of Bacillus anthracis spores on subway and used subway railcar materials was evaluated using fogged peracetic acid/hydrogen peroxide (PAA) and hydrogen peroxide (H2O2). A total of 21 separate decontamination tests were conducted using bacterial spores of both B. anthracis Ames (B.a.) and Bacillus atrophaeus (B.g.) inoculated onto several types of materials. Tests were conducted using commercial off-the-shelf fogging equipment filled with either PAA or H2O2 to fumigate a ∼15 cubic meter chamber under uncontrolled ambient relative humidity and controlled temperature (10 or 20 °C) from 8 to 168 h. For the present study, no conditions were found that resulted in complete inactivation of either B.a. Ames or B.g. on all test materials. Approximately 41% and 38% of the decontamination efficacies for B.a. and B.g., respectively, exhibited ≥6 log10 reduction (LR); efficacy depended greatly on the material. When testing at 10 °C, the mean LR was consistently lower for both B.a. and B.g. as compared to 20 °C. Based on the statistical comparison of the LR results, B.g. exhibited equivalent or greater resistance than B.a. for approximately 92% of the time across all 21 tests. The efficacy data suggest that B.g. may be a suitable surrogate for B.a. Ames when assessing the decontamination efficacy of fogged PAA or H2O2. Moreover, the results of this testing indicate that in the event of B.a. spore release into a subway system, the fogging of PAA or H2O2 represents a decontamination option for consideration.

Evaluation of the Efficacy of Methyl Bromide in the Decontamination of Building and Interior Materials Contaminated with Bacillus anthracis Spores.

The primary goal of this study was to determine the conditions required for the effective inactivation of Bacillus anthracis spores on materials by using methyl bromide (MeBr) gas. Another objective was to obtain comparative decontamination efficacy data with three avirulent microorganisms to assess their potential for use as surrogates for B. anthracis Ames. Decontamination tests were conducted with spores of B. anthracis Ames and Geobacillus stearothermophilus, B. anthracis NNR1Δ1, and B. anthracis Sterne inoculated onto six different materials. Experimental variables included temperature, relative humidity (RH), MeBr concentration, and contact time. MeBr was found to be an effective decontaminant under a number of conditions. This study highlights the important role that RH has when fumigation is performed with MeBr. There were no tests in which a ≥6-log10 reduction (LR) of B. anthracis Ames was achieved on all materials when fumigation was done at 45% RH. At 75% RH, an increase in the temperature, the MeBr concentration, or contact time generally improved the efficacy of fumigation with MeBr. This study provides new information for the effective use of MeBr at temperatures and RH levels lower than those that have been recommended previously. The study also provides data to assist with the selection of an avirulent surrogate for B. anthracis Ames spores when additional tests with MeBr are conducted.

Environmental Persistence of Bacillus anthracis and Bacillus subtilis Spores.

There is a lack of data for how the viability of biological agents may degrade over time in different environments. In this study, experiments were conducted to determine the persistence of Bacillus anthracis and Bacillus subtilis spores on outdoor materials with and without exposure to simulated sunlight, using ultraviolet (UV)-A/B radiation. Spores were inoculated onto glass, wood, concrete, and topsoil and recovered after periods of 2, 14, 28, and 56 days. Recovery and inactivation kinetics for the two species were assessed for each surface material and UV exposure condition. Results suggest that with exposure to UV, decay of spore viability for both Bacillus species occurs in two phases, with an initial rapid decay, followed by a slower inactivation period. The exception was with topsoil, in which there was minimal loss of spore viability in soil over 56 days, with or without UV exposure. The greatest loss in viable spore recovery occurred on glass with UV exposure, with nearly a four log10 reduction after just two days. In most cases, B. subtilis had a slower rate of decay than B. anthracis, although less B. subtilis was recovered initially.

Capture of methyl bromide emissions with activated carbon following the fumigation of a small building contaminated with a Bacillus anthracis spore simulant.

A wide-area Bacillus anthracis spore contamination incident will present immense challenges related to decontamination capacity. For this reason, fumigation with methyl bromide (MeBr) has been proposed as a potential remediation option. Although a few bench-scale laboratory studies have been conducted to evaluate activated carbon for the capture of MeBr, these studies were conducted at conditions replicating commodity fumigation using relatively low MeBr concentrations, temperatures, and/or relative humidity (RH) levels. The more rigorous MeBr fumigation requirements to fully inactivate B. anthracis spores are much more of a challenge for an activated carbon system (ACS) to capture MeBr, and warrant their own investigation. Further, while the aforementioned studies have shown activated carbon to be a possible option for the capture of MeBr in gas streams, these tests were conducted at laboratory bench scale, and thus lack operational perspective and data. Thus, we present for the first time the results of a full-scale study to evaluate an ACS employed for the capture of MeBr at conditions that would be used for decontaminating a building structure contaminated with B. anthracis spores. Airflow rate, temperature, RH, and MeBr levels were measured within the ACS during its operation. Despite the relatively high humidity, temperature, and MeBr levels, the MeBr capture efficiency of the ACS was demonstrated to be more than 99%. The concentration of MeBr exhausted from the structure was reduced from 41,000 to 136 ppmv in 3.5 hr, corresponding to an overall atmospheric emission rate of less than 2 kg. The practical adsorption rate of the ACS was determined to be 4.83 kg MeBr/100 kg carbon. The information and data presented here will facilitate future use of this technology when fumigating with MeBr.

Emergency department rapid medical assessment: overall effect and mechanistic considerations.

BACKGROUND: Although the use of a physician and nurse team at triage has been shown to improve emergency department (ED) throughput, the mechanism(s) by which these improvements occur is less clear. OBJECTIVES: 1) To describe the effect of a Rapid Medical Assessment (RMA) team on ED length of stay (LOS) and rate of left without being seen (LWBS); 2) To estimate the effect of RMA on different groups of patients. METHODS: For Objective 1, we compared LOS and LWBS on dates when we utilized RMA to comparable dates when we did not. For Objective 2, we utilized patient logs to divide patients into groups and estimated the effects of the RMA on each. RESULTS: Objective 1. LOS fell from 297.8 min pre-RMA to 261.7 min during RMA, an improvement of 36.1 (95% confidence interval 21.8-50.4) min; LWBS did not change significantly. Objective 2. Patients seen and dispositioned by the RMA had an estimated decrease in LOS of 117.8 min (estimated decrease in LOS of 45%), but patients seen by the RMA whose care was transitioned to the main ED had an estimated increase in LOS of 25.0 min (estimated increase in LOS of 8%). CONCLUSIONS: On a system level, the addition of an RMA shift at a single facility was associated with an improvement in LOS, but not LWBS. On a mechanistic level, it seems that improvements occurred as a result of the rapid disposition component of the RMA rather than placing advanced orders at triage.

Effect of inoculation method on the determination of decontamination efficacy against Bacillus spores.

Decontamination studies investigating the effectiveness of products and processes for the inactivation of Bacillus species spores have traditionally utilized metering viable spores in a liquid suspension onto test materials (coupons). The current study addresses the representativeness of studies using this type of inoculation method compared to when coupons are dosed with a metered amount of aerosolized spores. The understanding of this comparability is important in order to assess the representativeness of such laboratory-based testing when deciding upon decontamination options for use against Bacillus anthracis spores. Temporal inactivation of B. anthracis surrogate (B. subtilis) spores on representative materials using fumigation with chlorine dioxide, spraying of a pH-adjusted bleach solution, or immersion in the solution was investigated as a function of inoculation method (liquid suspension or aerosol dosing). Results indicated that effectiveness, measured as log reduction, was statistically significantly lower when liquid inoculation was used for some material and decontaminant combinations. Differences were mostly noted for the materials observed to be more difficult to decontaminate (i.e., wood and carpet). Significant differences in measured effectiveness were also noted to be a function of the pH-adjusted bleach application method used in the testing (spray or immersion). Based upon this work and the cited literature, it is clear that inoculation method, decontaminant application method, and handling of non-detects (i.e., or detection limits) can have an impact on the sporicidal efficacy measurements.

Evaluation of peracetic acid fog for the inactivation of Bacillus anthracis spore surrogates in a large decontamination chamber.

The purpose of this study was to evaluate the sporicidal (inactivation of bacterial spores) effectiveness and operation of a fogging device utilizing peracetic acid/hydrogen peroxide (PAA). Experiments were conducted in a pilot-scale 24 m(3) stainless steel chamber using either biological indicators (BIs) or bacterial spores deposited onto surfaces via aerosolization. Wipe sampling was used to recover aerosol-deposited spores from chamber surfaces and coupon materials before and after fogging to assess decontamination efficacy. Temperature, relative humidity, and hydrogen peroxide vapor levels were measured during testing to characterize the fog environment. The fog completely inactivated all BIs in a test using a 60 mL solution of PAA (22% hydrogen peroxide/4.5% peracetic acid). In tests using aerosol-deposited bacterial spores, the majority of the post-fogging spore levels per sample were less than 1 log colony forming units, with a number of samples having no detectable spores. In terms of decontamination efficacy, a 4.78 log reduction of viable spores was achieved on wood and stainless steel. Fogging of PAA solutions shows potential as a relatively easy to use decontamination technology in the event of contamination with Bacillus anthracis or other spore-forming infectious disease agents, although additional research is needed to enhance sporicidal efficacy.

Safety of epinephrine for anaphylaxis in the emergency setting.

BACKGROUND: While epinephrine is the recommended first-line therapy for the reversal of anaphylaxis symptoms, inappropriate use persists because of misunderstandings about proper dosing and administration or misconceptions about its safety. The objective of this review was to evaluate the safety of epinephrine for patients with anaphylaxis, including other emergent conditions, treated in emergency care settings. METHODS: A MEDLINE search using PubMed was conducted to identify articles that discuss the dosing, administration, and safety of epinephrine in the emergency setting for anaphylaxis and other conditions. RESULTS: Epinephrine is safe for anaphylaxis when given at the correct dose by intramuscular injection. The majority of dosing errors and cardiovascular adverse reactions occur when epinephrine is given intravenously or incorrectly dosed. CONCLUSION: Epinephrine by intramuscular injection is a safe therapy for anaphylaxis but training may still be necessary in emergency care settings to minimize drug dosing and administration errors and to allay concerns about its safety.