07 Biological Agents_OBJECTIVE INTRODECTION
- 1. Disaster Site Worker Safety Module 7 Biological Agents
- 2. Objectives Define bioterrorism and differentiate it from chemical terrorism and biological warfare. Differentiate an act of bioterrorism from an unfortunate naturally occurring event. Describe the microbial agents most likely to be associated with an act of bioterrorism. Describe the effect a bioterrorism event would have on a given community.
- 3. Introduction Biological warfare is initiated in order to gain a military advantage by either killing or incapacitating the enemy. Bioterrorism differs from biological warfare in that the target is often the civilian population.
- 4. Natural vs. Intentional Events Epidemiologic clues that can potentially indicate an intentional attack: The presence of a large epidemic with a similar disease or syndrome, especially in a discrete population Many cases of unexplained diseases or deaths More severe disease than is usually expected for a specific pathogen or failure to respond to standard therapy Unusual routes of exposure for a pathogen, such as the inhalational route for diseases that normally occur through other exposures
- 5. Natural vs. Intentional Events Epidemiologic clues that can potentially indicate an intentional attack: A disease that is unusual for a given geographic area or transmission season Disease normally transmitted by a vector that is not present in the local area Multiple simultaneous or serial epidemics of different diseases in the same population A single case of disease by an uncommon agent (smallpox, some viral hemorrhagic fevers)
- 6. Outbreak by Bioterrorist Agents A rapid increase (hours to days) in the number of previously healthy people with similar symptoms seeking medical attention. A cluster of previously healthy persons with similar symptoms who live, work, or recreate in a common geographical area An unusual clinical presentation An increase in the reports of dead animals
- 7. Risk vs. Threat The more capable the terrorist is in identifying a target and producing and dispersing the biological, the greater the threat. The threat of a biological incident varies with the scenario.
- 8. Potential Bio-Agents Bacillus anthracis (Anthrax) Smallpox and other orthopox viruses Yersenia pestis (Plague) Francisella tularensis (Tularemia) Clostridium botulinum toxin (Botulism) Ebola and other hemorrhagic fever viruses Staphylococcus enterotoxin B (SEB) Salmonella spp. (and other foodborne illness organisms)
- 9. Incubation Periods of Selected Biological Agents Anthrax 1-5 Days++ Plague 2-3 Days Q Fever 10-40 Days Tularemia 2-10 Days Smallpox 7-17 Days Viral encephalitides 7-14 Days VHFs 4-21 Days Botulinum toxin 1-5 Days Staph. enterotoxin B 1-6 Hours
- 10. Anthrax Anthrax infections are rarely seen in the United States today but are endemic throughout much of the world.
- 11. Smallpox Variola major is the causative agent of smallpox and is considered to be one of the most dangerous biological agents because: It has a fatality rate over 30 percent. It is communicable (transmissible from person-to-person and from person to fomite to person). It can form a stable droplet that is transmissible through an aerosol. The infectious dose is very small. It is physically disfiguring and there is no treatment other than supportive care through the progression of the disease.
- 12. Plague Yersinia pestis is the causative agent for plague. Bubonic • Most common Pneumonic • Occurs when the lungs are infected
- 13. Tularemia Tularemia is harbored in wild animals, particularly the wild rabbit population, and spread to humans through the rabbit skins and meat. The most common naturally occurring form of tularemia is characterized by skin ulcers.
- 14. Tularemia Naturally occurring tularemia is found throughout the United States
- 15. Response Worker Precautions Anthrax Use APR with of high-efficiency P100 filters Hemorrhagic Fever Viruses Proper protective barrier PPE and P100 APR Smallpox Surgical masks and gloves Plague and tularemia Respiratory protection and gloves
- 16. Decon and Cleanup The need for decontamination once a biological event expresses itself will most likely not be necessary. The purpose of decontamination is to reduce the extent of external contamination and contain it to prevent further spread. It is recommended that decontamination only be considered in cases of gross contamination. Is needed when there is a suspected exposure.
- 17. Decon Biological agents can be decontaminated by : Mechanical decontamination • Involves measures to remove, but not necessarily neutralize, an agent. Chemical decontamination • Renders biological agents harmless by the use of disinfectants that are usually in the form of a liquid, gas, or aerosol. Physical decontamination • Physical means (heat, radiation) are other methods that can be employed for decontamination of objects.
- 18. Decon Dermal (skin) exposure from a suspected biological agent should be immediately treated by soap and water decontamination. Only on grossly contaminated intact skin, wash contaminated areas with a 0.5% sodium hypochlorite solution and allow a contact time of 10-15 minutes, if necessary. Make a 0.5% sodium hypochlorite solution by mixing one part Clorox or other household beach containing 5.25% sodium hypochlorite with nine parts water.
- 19. Disposal Anthrax Proper burial or preferably cremation of human and animal remains infected with anthrax is important in infection control. Smallpox Proper burial or preferably cremation of human remains and clothing infected with smallpox.
- 20. Disposal Plague Proper burial or preferably cremation of human and animal remains Tularemia Prompt removal of human or animal remains
- 21. Summary Public panic must be controlled with education before the release of a biological agent occurs. With the appropriate knowledge, the public is capable of appropriate response.