«Agent Classiﬁcation: Biological Type: Bacteria (Bacillus anthracis), many strains Description: B. anthracis is a naturally-occurring, rod-shaped ...»
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Bacillus anthracis (Anthrax) Team (NRT) Quick Reference Guides (QRGs) for Biological Warfare Agents.
Agent Classiﬁcation: Biological Type: Bacteria (Bacillus anthracis), many strains Description: B. anthracis is a naturally-occurring, rod-shaped Gram-positive, sporulating bacterium. Anthrax disease is endemic in animal populations in the United States and sporadically occurs in wild and domestic animals (e.g., cattle and antelope). Anthrax disease can also occur in humans when exposed to infected animals or infected animal tissue (cutaneous or gastrointestinal anthrax) or when exposed to aerosolized anthrax spores (inhalation anthrax).
Incubation Period: 1-7 days, up to 60+ days Infectivity/Lethality: Moderate/High Duration of Illness: 3-5 Days Infective Dose: LD50: 8000-50,000 spores (estimated) Person-to-Person Transmission: No Persistence/Stability: Spores Highly Persistent/Stable; 40 years in soil Air/Aerosolization: In a bioterrorism event, B. anthracis will most likely be aerosolized in the form of a white powder. Powders of B. anthracis with characteristics such as high spore concentration, uniform particle size, low electrostatic charge, etc. are considered “weapons-grade.” In an aerosol release of B. anthracis, re-aerosolization Release Scenarios is a consideration depending upon the size, purity, and chemical and physical properties of the manufactured spores. An aerosol release of B. anthracis will most likely occur indoors, though an outdoor release is possible. An aerosol release of B. anthracis would have the potential to travel many km before dissipating.
Soil/Surfaces: Spores are resistant to adverse environmental conditions and may remain viable for years in soil or in dried or processed hides of animals. Spores of B.
anthracis may remain viable in soil for 40+ years. For this reason, B. anthracis is a threat to the animal population. The spore viability of B. anthracis on certain surfaces is
Inhalation anthrax: Fever, malaise, fatigue, cough, chest discomfort, stridor (noisy breathing), respiratory distress, dyspnea (shortness of breath), Health Effects
Immunoassay Tests (smart tickets): These assays are intended for rapid detection of B. anthracis and for screening environmental samples. Each ticket employs patented immunochemical tests for speciﬁc biological agents. They feature rapid identiﬁcation, minimal operator training and sample preparation, response time is 5 -15 minutes. Note: Immunoassay tests should not be used alone, but should be conﬁrmed with samples analyzed by culturing at LRN lab.
Samples that test for re-aerosolization: 1) Wipe sampling of the air duct system (ﬁlters, areas of particulate deposition) if exposure occurred indoors. 2) Sheep blood agar plates determine the presence of bacterial growth. 3) Andersen Air Sampler & Single Stage Impactors with settle plates capture airborne particulates on a series of agar plates based on their aerodynamic properties. 4) Dry ﬁlter units (DFUs) are the most direct indicator of airborne B. anthracis spores. Check for their presence/install DFUs.
Samples that can test Decon efﬁcacy: 1) Wipe Samples: Synthetic, non-cotton (Dacron/rayon) wipes pre-moistened with a nutrient solution, buffer solution, or sterile water. Good for small sample areas of nonporous surfaces. Coordinate methods and buffer solutions with designated Laboratory Response Network (LRN) laboratory.
2) Swab Samples: Synthetic, moistened, cotton sterile or macrofoam swab moistened with buffer solution (PBST) or sterile water. Most useful for hard-to-reach, nonporous surfaces. CDC study shows that rayon & polyester swabs are not as efﬁcient as cotton/macrofoam swabs in spore recovery. Do not use dry swabs. 3) HEPA Vacuum Sampling: collect samples in a HEPA sock designed to ﬁt into an inlet nozzle of a vacuum cleaner. Good for screening and determining the extent and location of contamination in large areas. Used on both porous and nonporous surfaces. For sampling method please see: http://www.bt.cdc.gov/agent/anthrax/environmentalsampling-apr2002.asp Sample packaging and shipping: Packaging and transporting samples containing or possibly containing B. anthracis spores are subject to various regulations established by DOT, CDC, USPS, OSHA, and IATA. Consult and coordinate with the analytical laboratory receiving the samples to determine packaging or shipping requirements.
Details can be found at www.cdc.gov/od/ohs/biosfty/shipregs.htm or http://www.cdc.gov/od/sap/ OR http://www.asm.org/ASM/ﬁles/LEFTMARGINHEADERLIST/ downloadﬁlename/0000001202/ProtocolPackShip.pdf Laboratory Information: For Biological and Chemical Agent Analyses Contract Vehicles for EPA emergency lab support, contact Battelle Security 24-hour control center Laboratory Analysis: BSL-3
Decon Planning: Site speciﬁc decon/cleanup plan should be developed and approved by all necessary organizations/SMEs via ICS channels. Responders should develop a plan that takes into account: 1) The nature of contamination including purity, spore size, chemical/physical properties, how it entered the facility, etc.; 2) The extent of contamination, including the amount and possible pathways that have or could have spread B. anthracis spores. It is advisable to isolate the contaminated area; and 3) The objectives of decon, including decon of critical items for re-use and the treatment, removal, or packaging of other items for disposal. Note: Crisis exemptions from EPA Ofﬁce of Pesticides might be necessary depending on decontaminating agents used.
Decon Methods: OSCs should check with the EPA National Decon Team Subject Matter Experts regarding speciﬁc decontamination parameters, as well as speciﬁcs on the use of readily available commercial items such as standard bleach, at 513-487-2420 (after hours call 24-hour pager at 800-329-1841).
Methods used on surfaces: 1) Source reduction steps, including HEPA vacuuming; 2) Liquid Antimicrobial products such as pH amended bleach (A mixture of 1 part bleach (5.25% to 6.0%) to 1 part white vinegar to 8 parts water, is recommended). This product affects surfaces differently in terms of corrosiveness, staining, and residue.
The product will be most efﬁcient a) At higher temperatures (70F) b)when plain bleach (e.g., no added fragrance) is used to make the pH-amended bleach solution,
c) when pH is equal to 7,d) when presence of other surface contaminants is minimal, and e) when surfaces remain wet with amended bleach solution for 60 minutes.
pH-amended bleach can be deployed as a spray or liquid. Note: Store-bought bleach does degrade with time – check the expiration date. Alternate antimicrobial products include: chlorine dioxide, hydrogen peroxide, and peroxyacetic acid. Fumigation: Uses gas or vapor to decontaminate facilities in which there is evidence of high levels of Decontamination contamination, re-aerosolization of spores or if decontamination of limited access areas is required (e.g. HVAC systems). The history of usage of the agents as fumigants, materials compatibility, penetration capacity, method of removal at the end of fumigation, as well as their physical, chemical, & toxicological properties should be taken into account. Fumigants: chlorine dioxide, vaporized hydrogen peroxide, and paraformaldehyde. Each chemical has a speciﬁed range for process variables (e.g., temperature, relative humidity, conc. & contact time) that must be followed.
Other Decon: 1) Ethylene oxide sterilization is used to decontaminate items in an off-site sterilization chamber. 2) Irradiation uses cobalt-60 and electron beam technologies to destroy B. anthracis in mail, and other paper goods at off-site locations. This procedure may destroy magnetic media. Irradiation and chemical sterilization may be useful in decontaminating items that are intended to be returned to owners. The Brentwood, Trenton, and Capitol Hill remediation teams used Chloride Dioxide liquid and fumigation to decontaminate the site (ClO2 at 750ppmv for 12 hours at a minimum of 75°F and 75% relative humidity).
Decon Effectiveness: Multi-agency, multi-disciplinary experts should be consulted for advice in developing a post-decon veriﬁcation sampling strategy and establishing criteria for verifying decon effectiveness. Expert input is especially important if contamination is extensive. Rigorous environmental sampling should be performed after decontamination. The samples obtained should be veriﬁed via culture. Targeted or judgemental sampling should be performed in areas which were known to be contaminated prior to decontamination. In addition, statistically relevant sampling in the decontaminated area(s) should also be performed. Air sampling after decon may also be appropriate if spores are likely to re-aerosolize. If fumigation is to be performed, use biological indicators in hard-to-reach areas to provide assurance that the fumigant adequately penetrated all of the contaminated areas.
Clean-up Adequacy Veriﬁcation: There is currently no scientiﬁcally sound basis for determining a “safe” number of residual viable spores in a decontaminated area. In response to bioterrorist events involving B. anthracis, EPA follows the recommendation of the National Academy of Sciences that decontamination be continued until there is “no growth” of B. anthracis on post-decon samples. Viable spores may remain, but the risk of contracting anthrax in that area would be considered extremely low. In workplace situations, OSHA offers alternative criteria to the “no growth” decon goal, especially where PPE, special work practices, and engineering controls can be used to minimize the risk. OSHA provides guidance RE: alternative controls at: http://www.osha.gov/SLTC/etools/anthrax/transition_program.html B. anthracis is not regulated under Subtitle C of RCRA, but should be handled with caution. In some states and localities, waste management will vary; for instance, B.