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DECONTAMINATION FOR THE MOST LIKELY USED AGENTS IN BIOWARFARE
ANTHRAX
Isolation and Decontamination: Standard precautions for healthcare workers. After an invasive procedure or autopsy is performed, the instruments and area used should be thoroughly disinfected with a sporicidal agent (hypochlorite).
Decontamination and Isolation: Drainage and secretion precautions should be practiced. Anthrax is not known to be transmitted via the aerosol route from person to person. Following invasive procedures or autopsy, instruments and surfaces should be thoroughly disinfected with a sporicidal agent (high-level disinfectants such as iodine or 0.5% sodium hypochlorite). In fact, 0.1% bleach solution reliably kills anthrax spores, the hardiest of biological agents.
Outbreak Control: Although anthrax spores may survive in the environment for many years, secondary aerosolization of such spores (such as by pedestrian movement or vehicular traffic) generally presents no problem for humans. The carcasses of animals dying in such an environment should be burned, and animals subsequently introduced into such an environment should be vaccinated. Meat, hides, and carcasses of animals in affected areas should not be consumed or handled by untrained and/or unvaccinated personnel.
'Jeanne Guillemin is a medical anthropologist, and a Professor of Sociology and Senior Fellow at MIT's Security Studies Program. In 1992, she was part of a team that investigated a suspicious anthrax epidemic that took place in 1979 in the former USSR. She is an affiliate of the Harvard-Sussex Program, which is involved with the elimination of chemical and biological weapons' advises the following: "Sunshine destroys anthrax spores, but very little else does. Heat doesn't, radiation doesn't. It's resistant to explosives. That's precisely the reason why anthrax was developed as a weapon, because it's tough, whereas most bacteria and viruses are fragile."'6
BOTULISM - (Toxin)
Isolation and Decontamination: Standard Precautions for healthcare workers. Toxin is not dermally active and secondary aerosols are not a hazard from patients. Decon with soap and water. Botulinum toxin is inactivated by sunlight within 1-3 hours. Heat (80oC for 30 min., 100oC for several minutes) and chlorine (>99.7% inactivation by 3 mg/L FAC in 20 min.) also destroy the toxin.
Decontamination and Isolation: Decontamination of surfaces contaminated by toxin may be accomplished using soap and water, or 0.5% hypochlorite. Spores are best killed by pressure-cooking of foodstuffs to be canned. Toxin is not dermally active (although spores may enter through skin wounds) and secondary aerosols from affected patients pose no risk of botulism transmission.
Outbreak Control: Intentionally-released aerosols of botulinum toxin probably pose little risk beyond the immediate period of release. In the event that contamination of foodstuffs is suspected, pre-formed toxin may be destroyed by boiling for 10 minutes.
BRUCELLOSIS
Isolation and Decontamination: Standard precautions are appropriate for healthcare workers. Person-to-person transmission has been reported via tissue transplantation and sexual contact. Environmental decontamination can be accomplished with a 0.5% hypochlorite solution.
Decontamination and Isolation: Drainage and secretion precautions should be practiced in patients who have open skin lesions; otherwise no evidence of person-to-person transmission of brucellosis exists. Animal remains should be handled utilizing universal precautions and disposed of properly. Surfaces contaminated with brucella aerosols may be decontaminated by standard means (0.5% hypochlorite).
Outbreak Control: In the event of an intentional release of brucella organisms, it is possible that livestock will become infected. Thus, animal products in such an environment should be pasteurized, boiled, or thoroughly cooked prior to consumption. Proper treatment of water, by boiling or iodination, would also be important in an area subjected to intentional contamination with brucella aerosols.
CHOLERA
Decontamination and Isolation: Personal contact rarely causes infection; however, enteric precautions and careful hand-washing should be employed. Gloves should be used for patient contact and specimen handling. Bactericidal solutions, such as 0.5% hypochlorite, would provide adequate surface decontamination.
Outbreak Control: Strict attention must be paid to the avoidance of contaminated water in an outbreak area. Drinking water, as well as water used in bathing, washing utensils, and cooking, must be obtained from a safe source or must be boiled or chlorinated prior to use.
GLANDERS AND MELIOIDOSIS
Isolation and Decontamination: Standard Precautions for healthcare workers. Person-to-person airborne transmission is unlikely, although secondary cases may occur through improper handling of infected secretions. Contact precautions are indicated while caring for patients with skin involvement. Environmental decontamination using a 0.5% hypochlorite solution is effective.
PLAGUE
Isolation and Decontamination: Use Standard Precautions for bubonic plague, and Respiratory Droplet Precautions for suspected pneumonic plague. Y. pestis can survive in the environment for varying periods, but is susceptible to heat, disinfectants, and exposure to sunlight. Soap and water is effective if decon is needed. Take measures to prevent local disease cycles if vectors (fleas) and reservoirs (rodents) are present.
Decontamination and Isolation: Drainage and secretion precautions should be employed in managing patients with bubonic plague; such precautions should be maintained until the patient has received antibiotic therapy for 48 hours and has demonstrated a favorable response to such therapy. Care must be taken when handling or aspirating buboes to avoid aerosolizing infectious material. Strict isolation is necessary for patients with pneumonic plague.
Outbreak Control: In the event of the intentional release of plague into an area, it is possible that local fleas and rodents could become infected, thereby initiating a cycle of enzootic and endemic disease. Such a possibility would appear more likely in the face of a breakdown in public health measures (such as vector and rodent control) which might accompany armed conflict. Care should be taken to rid patients and contacts of fleas utilizing a suitable insecticide; flea and rodent control measures should be instituted in areas where plague cases have been reported.
Q FEVER
Isolation and Decontamination: Standard Precautions are recommended for healthcare workers. Person-to-person transmission is rare. Patients exposed to Q fever by aerosol do not present a risk for secondary contamination or re-aerosolization of the organism. Decontamination is accomplished with soap and water or a 0.5% chlorine solution on personnel. The M291 skin decontamination kit will not neutralize the organism.
Decontamination and Isolation: Patients exposed to Q fever by the aerosol route do not present a risk for secondary contamination or re-aerosolization of the organism. Decontamination is accomplished with soap and water or by the use of weak (0.5 percent) hypochlorite solutions.
Outbreak Control: Spore-like forms of Coxiella burnetii may withstand quite harsh conditions and thus persist in the environment for prolonged periods. Presumably, animals, especially sheep, in such areas would be at risk for acquiring infection, and contact with the products of pregnancy of such animals would represent a continuing hazard to humans. Little information exists to permit assessment of direct long-term hazards to humans entering an area contaminated by intentional release of aerosolized Q fever.
RICIN - (Toxin)
Isolation and Decontamination: Standard Precautions for healthcare workers. Ricin is non-volatile, and secondary aerosols are not expected to be a danger to health care providers. Decontaminate with soap and water. Hypochlorite solutions (0.1% sodium hypochlorite) can inactivate ricin.
Decontamination and Isolation: Ricin may be inactivated with 0.5% hypochlorite. Since it is not dermally active and is involatile, decontamination may not be as critical as with certain other biological and chemical agents.
Outbreak Control: Ricin does not, in general, pose a risk of secondary aerosolization.
SMALLPOX
Isolation and Decontamination: Droplet and Airborne Precautions for a minimum of 17 days following exposure for all contacts. Patients should be considered infectious until all scabs separate and quarantined during this period. In the civilian setting strict quarantine of asymptomatic contacts may prove to be impractical and impossible to enforce. A reasonable alternative would be to require contacts to check their temperatures daily. Any fever above 38oC (101oF) during the 17-day period following exposure to a confirmed case would suggest the development of smallpox. The contact should then be isolated immediately, preferably at home, until smallpox is either confirmed or ruled out and remain in isolation until all scabs separate.
Decontamination: Given the extreme public health implications of smallpox reintroduction, patients should be placed in strict isolation pending review by national health authorities. All material used in patient care or in contact with smallpox patients should be autoclaved, boiled, or burned.
Outbreak Control: Smallpox has considerable potential for person-to-person spread. Thus, all contacts of infectious cases should be quarantined for 16-17 days following exposure, and given prophylaxis as indicated. Animals are not susceptible to smallpox.
STAPHYLOCOCCAL ENTEROTOXIN B - (Toxin)
Isolation and Decontamination: Standard Precautions for healthcare workers. SEB is not dermally active and secondary aerosols are not a hazard from patients. Decon with soap and water. Destroy any food that may have been contaminated.
Decontamination and Isolation: Decontamination of most surfaces may be accomplished with soap and water or with exposure to 0.5% hypochlorite solution. Food which may have been contaminated should be destroyed.
Outbreak Control: Prolonged environmental contamination would not be expected following release of aerosolized SEB.
TRICOTHECENE MYCOTOXICOSIS [T-2 MYCOTOXINS] - (Toxin)
Isolation and Decontamination: Outer clothing should be removed and exposed skin decontaminated with soap and water. Eye exposure should be treated with copious saline irrigation. Secondary aerosols are not a hazard; however, contact with contaminated skin and clothing can produce secondary dermal exposures. Contact Precautions are warranted until decontamination is accomplished. Then, Standard Precautions are recommended for healthcare workers. Environmental decontamination requires the use of a hypochlorite solution under alkaline conditions such as 1% sodium hypochlorite and 0.1M NaOH with 1 hour contact time.
Decontamination and Isolation:Clothing of T-2 victims should be removed and treated (exposed to 5% hypochlorite for 6-10 hours) or destroyed. Skin may be decontaminated with soap and water. Eye exposure should be managed with copious saline irrigation. Isolation is not required. Instruments and surfaces should be decontaminated by heating to 500(F for 30 minutes or by brief exposure to 1N NaOH. Standard disinfectants effective against most other BW agents are often inadequate to inactivate the very stable mycotoxins.
Outbreak Control: Mycotoxin-induced disease is not contagious, but the stability of the toxins in the presence of heat and ultraviolet light make for the possibility of persistence in the environment following release.
TULAREMIA
Isolation and Decontamination: Standard Precautions for healthcare workers. Organisms are relatively easy to render harmless by mild heat (55oC for 10 minutes) and standard disinfectants.
Decontamination and Isolation: Tularemia is not transmitted person-to-person via the aerosol route, and infected persons should be managed with secretion and drainage precautions. Heat and common disinfectants (such as 0.5% hypochlorite) will readily kill F. tularensis organisms.
Outbreak Control: Following intentional release of F. tularensis in a given area, it is possible that local fauna, especially rabbits and squirrels, will acquire disease, setting up an enzootic mammal-arthropod cycle. Persons entering such an area should avoid skinning and eating meat from such animals. Water supplies and grain in such areas might likewise become contaminated, and should be boiled or cooked before consumption. Organisms contaminating soils are unlikely to survive for significant periods of time and present little hazard.
VENEZUELAN EQUINE ENCEPHALITIS
Isolation and Decontamination: Patient isolation and quarantine is not required. Standard Precautions augmented with vector control while the patient is febrile. There is no evidence of direct human-to-human or horse-to-human transmission. The virus can be destroyed by heat (80oC for 30 min) and standard disinfectants.
Decontamination and Isolation: Universal precautions should be practiced when dealing with VEE patients. Virus may be destroyed by heat (80oC [176oF] for 30 minutes) and by ordinary disinfectants (such as 0.5% hypochlorite).
Outbreak Control: Humans are infectious for mosquitoes for at least 72 hours after the onset of symptoms. Efforts at mosquito control thus become paramount to the prevention of secondary VEE cases following intentional or natural VEE outbreaks. In the event of intentional release of VEE virus by belligerents, the potential would be high for the development of an equine epizootic if the proper mosquito vector were present; veterinary vaccination would be useful in such circumstances.
VIRAL HEMORRHAGIC FEVERS
Isolation and Decontamination: Contact isolation, with the addition of a surgical mask and eye protection for those coming within three feet of the patient, is indicated for suspected or proven Lassa fever, CCHF, or filovirus infections. Respiratory protection should be upgraded to airborne isolation, including the use of a fit-tested HEPA filtered respirator, a battery powered air purifying respirator, or a positive pressure supplied air respirator, if patients with the above conditions have prominent cough, vomiting, diarrhea, or hemorrhage. Decontamination is accomplished with hypochlorite or phenolic disinfectants.
Sources for the immediate above:
USAMRIID's Medical Management of Biological Casualties Handbood Fourth Edition February 2001; http://usamriid.detrick.army.mil/education/bluebook/bluebook.pdf
Medical NBC Online - http://www.nbc-med.org/
Sources for Decontaminaton:
1USAMRIID's Medical Management of Biological Casualties Handbood; Fourth Edition February 2001; pages 9-10; http://usamriid.detrick.army.mil/education/bluebook/bluebook.pdf
2Methods of Water Purification; from "Pure Water Handbook"; March 1, 1992; Osminics, Inc; http://www.osmonics.com/products/Page716.htm
3Ibid
4Water Conditioning and Purifying Magazine; 1993; http://www.cetsolar.com/uvdisinfection.htm
5How Ozone Affects Bacteria, Fungus, Molds and Viruses; http://www.trio3.com/moldsFungus.htm
Breathe No Evil; Stephen Quayle and Duncan Long; 1996; Safe-Trek Publishing
6Anthrax Risk and Prevention; Jeanne Guillemin; October 15, 2001; http://www.cnn.com/2001/COMMUNITY/10/15/guillemin/
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