Biological Weapon Toxicity

Excerpt

Biological weapons are agents, including bacteria, viruses, fungi, and toxins, used for malicious purposes: in war (biowarfare), to cause terror (bioterrorism), or for criminal acts (biocrime). [Suspected Intentional Use Of Biologic And Toxic Agents. 2018] Some agents are lethal, and others cause illness or incapacitation. Entities direct biological agents at the human population, crops, and livestock. More than 180 pathogens and biotoxins have been researched or employed as biological weapons, including those that cause anthrax, tularemia, brucellosis, plague, Legionnaire disease, Q fever, glanders, melioidosis, smallpox, viral hemorrhagic fevers, influenza, coccidiosis, rice blast, and wheat rust. Biotoxins include ricin, botulinum toxin, and staphylococcal enterotoxin B. Designers create biological weapons to disperse as aerosols, facilitating rapid spread across large populations. However, agents may also spread from person to person or by vectors, ingestion, direct contact, or other methods.

Agents used for biological weapons have distinct advantages over conventional agents (eg, chemical weapons):

1. Microbial agents are often more easily mass-produced

2. Large quantities are easy to conceal and transport

3. Agents are more easily able to become airborne or waterborne, increasing the area of dissemination

4. Some agents pass from person to person

Classification

Biological agents are classified into different categories depending on their ability to cause illness and their impact on public health. The United States Centers for Disease Control and Prevention (CDC) categorizes agents into 3 groups:

1. Category A

2. 1. Highest priority

   2. Easily disseminated or transmitted

   3. High mortality rates and potential for major public health impact

   4. Can cause public panic and social disruption

   5. Require specific actions for public health preparedness

3. Category B

4. 1. Second highest priority

   2. Moderately easy to disseminate

   3. Moderate morbidity and low mortality

   4. Require specific enhancements to the CDC's diagnostic and disease surveillance capacities

5. Category C

6. 1. Third highest priority

   2. Potentially engineered for mass dissemination

   3. Potential for high morbidity and mortality and significant health impact

Category A agents include Bacillus anthracis (anthrax), Clostridium botulinum toxin (botulism), Yersinia pestis (plague), Variola major (smallpox), Francisella tularensis (tularemia), and viruses that cause hemorrhagic fevers (eg, Ebola virus, Marburg virus, Lassa virus). Category B agents include Brucella species (Brucellosis), Chlamydia psittaci (Psittacosis), Coxiella burnetii (Q fever), ricin toxin (from Ricinus communis), enteric pathogens (Salmonella, Escherichia coli O157:H7, Shigella), Staphylococcal enterotoxin B, and viruses that cause encephalitis. Category C agents are emerging pathogens such as Nipah virus and hantavirus.