Microbial Bioterrorism Notes

Microbial Bioterrorism

Since ancient times, microbial pathogens have been used as potential weapons of war or terrorism, whether it is by poisoning of water supplies, or spreading of plague or smallpox in an enemy country or hostile population.

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In recent times, the use of virulent microbe-laced letters in the mail as a weapon of terrorism alarmed the world how modern science and research can be misused and thus need constant vigil against such attacks.

Some of the key features of biological agents used as potential bioweapons are as under:

1. Causes high morbidity and mortality
2. Effective in low doses, generally spread by aerosol
3. Rapid spread from person-to-person
4. Lack of availability of effective vaccine
5. Feasibility of its production

The US-CDC (Centres for Disease Control) has classified potential biologic threats into three Categories:

1. Categories: A
2. Categories: B, and
3. Categories: C.

These are:

1. Category A: These agents pose the greatest risk to life and security because they can be quickly disseminated and cause maximum mortality.
   • It includes the following biologic agents:
     • Anthrax (Bacillus anthracis)
     • Botulism (Clostridium botulinum toxin)
     • Plague (Yersinia pestis)
     • Smallpox (Variola major)
     • Tularaemia (Francisca tularensis)
     • Viral haemorrhagic fevers
2. Category B: These agents are in the moderate category in terms of spread, morbidity and mortality.
   • It includes examples such as:
     • Brucellosis
     • Agents for food poisoning (for example, Clostridium perfringens, Salmonella species)
     • Cholera-contaminated water supplies (Vibrio cholera).
3. Category C: These are some of the emerging pathogens, mainly viruses, for which individuals lack immunity. The examples are:
   • Hantavirus
   • SARS
   • Other flu viruses

Thus, public health measures by surveillance and by education along with appropriate countermeasures for containing such an attack by diagnosis, therapy, and vaccines are the need of the day for the world in anticipation of such attacks by rogue groups and countries.

Microbial Bioterrorism:

• Potential biologic agents used as bioweapons have a few common features: high morbidity and mortality, rapid spread in low doses by aerosol, and lack of availability of vaccines.
• CDC has divided these biological threats into three categories:
• Category A microbes carry a high risk of mortality and include anthrax, botulism, plague, smallpox, tularaemia, and viral haemorrhagic fevers.
• Category B has organisms with moderate risk to life and includes brucellosis, agents for food poisoning and contaminating water supplies, cholera etc.
• Category C includes some emerging viral diseases such as Hantavirus, SARS, other flu viruses etc