Bio-terrorism - Introduction, Classification, Category, Prevention, Control
Introduction to Bio-terrorism
Bio-terrorism is the deliberate use of microbial agents or their toxins as weapons against non-combatants outside the settling of armed conflict (COHEN). In other words, it is the deliberate release of infectious viruses, bacteria, or other agents for purpose of causing illness or death in people, animals, and plants.
The microorganisms with the potential to be used in bio-terrorism include:
Bacillus anthracis
Yersinia pestis
Franciella tualrensis
Serratia marcescens
Salmonella enterica
Shigella dysentriae
They are typically found in nature but their virulence, drug resistance pattern, and spreading capacity can be increased for the purpose.
It can spread through the air, water, and food.
Classification of Bio-terrorism
Based on the ability to spread or cause disease, bio-terrorism, can be classified into 3 types
Category A – highest risk
Category B
Category C – emerging threats
Category A
Category A bio-terrorism includes microorganisms/toxins posing the highest risk. The characteristics include:
easily spread from person to person
may result in high mortality
require special treatment
may cause panic and social disruption
Bacterial agents used for bio-terrorism include:
anthrax (Bacillus anthracis)
Botulism (Clostridium botulinum toxin)
Plague (Yersinia pestis)
Tularemia (Francisella tularensis)
Viral agents used for bio-terrorism include:
Smallpox (variola major)
Filoviruses - Ebola, Marburg – hemorrhagic fever
Arenavirus (Eg: Lassa virus)
Bacillus anthracis as a bio-weapon (Anthrax)
Bacillus anthracis – aerobic, gram-positive, endospore-forming, non-motile, capsulated, rod-shaped. Anthrax spores are easily found in nature and can also last for a long time in the environment. Moreover, the Bacillus anthracis as a bio-weapon can be easily produced in the lab and can be released without public knowledge.
Yersinia pestis (Plague)
Yersinia pestis is a gram-negative, non-motile, rod/cocco-bacilli, facultative anaerobe that causes the plague disease. The transmission occurs via infected rats.
The Yersinia pestis as a bio-weapon used in an aerosol attack could cause a pneumonic form of plague. The incubation period is around 1-6 days and can spread from person to person, and are contagious. Since the incubation period is several days, infected people can travel and transmit diseases without their knowledge.
Francisella tularensis (Tularemia)
Francisella tularensis are strict aerobe, gram negative, non-motile, non-sporing bacilli. It can be utilized as a bio-weapon through aerosol or contaminating of food or drinking water. They are very infectious (10-50 microorganisms can cause disease).
People who inhale an infectious aerosol of Francisella tularensis as bio-terrorism would generally experience severe respiratory illness, including life-threatening pneumonia and systemic infection if left untreated.
Clostridium botulinum toxin (Botulism)
Clostridium botulinum toxin as a bio-weapon. They are gram-positive, rod, anaerobe, sporing, and motile which produces the neurotoxin botulinum.
Botulism is a muscle-paralyzing disease caused by a toxin produced by C. botulinum. The toxin would likely be dispersed as an aerosol or contaminated in the food supply. Inhalation botulism is the main concern
Category B
These pathological agents in category B bio-terrorism are of the second highest priority. They are moderately easy to spread, has a low death rate, and result in moderate illness.
Bacterial agents in category B bio-terrorism include:
Brucellosis (Brucella spp.)
Clostridium perfringes (Epsilon toxin)
Salmonella spp. (food safety threats)
E. coli (food safety threats)
Shigella spp. (food safety threats)
Psittacosis (Chlamydia psittaci)
Q fever (Coxiella burnetti)
Staphylococcal enterotoxin B
Typhus fever (Rickettsia prowazekii)
Category C
This category C bio-terrorism is the third lowest priority. It includes emerging pathogens that could be engineered for mass spread as they are easily available, easily produced and spread, and have the potential for high morbidity and mortality rate.
Viruses in category C bio-terrorism:
Nipah virus
Hantavirus
Coronavirus
Influenza virus
Prevention, Control of bio-terrorism
Prevention, Control of bio-terrorism are:
The suspected samples should be handled with double bagging.
Autopsies of suspected cases must be performed using strict measures
cremation must be done without embalming
use of air-purifying respirators
appropriate isolation of a diseased person