Harmful microbes, weapons, history, advantage, disadvantages

1. Harmful Microbes and Biological
Weapons
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2. Introduction:
• A biological agent — also called bio-agent, biological threat
agent, biological warfare agent, biological weapon, or
bioweapons is a bacterium, virus, protozoan, parasite, or fungus
that can be used purposefully as a weapon in bioterrorism or
biological warfare.
• Biological agents have the ability to adversely affect human
health in a variety of ways, ranging from relatively mild allergic
reactions to serious medical conditions, including death.
• Many of these organisms are ubiquitous in the natural
environment where they are found in water, soil, plants, or
animals.
• Biological weapons may be employed in various ways to gain a
tactical advantage over the enemy, either by threat by actual
deployments.
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3. Cont...
 Biological weapons are unique because they are made up of
pathogenic organisms that can reproduce and cause infection
(and death) in a large number of hosts.
 It takes hours to days for symptoms of exposure to appear
Biological weapons are relatively inexpensive to produce.
 All of the equipment used to produce biological agents is dual
use, with applications in the pharmaceutical, food, cosmetic, and
pesticide industries.
 Dissemination and dispersion are key to the effective
employment of biological weapons.
 Many toxic organisms are subject to destruction by external
forces (e.g., sunlight, explosives).
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4. History of Biological Weapons
 Crude forms of biological warfare have been employed ,when the
decaying corpses of animals and humans were placed near water
and food supplies of adversaries.
 Over the years, different diseases, including plague and
smallpox etc.
 World War I saw the development of biological warfare
strategies.
 Cholera and plague were thought to be used in Italy and Russia
while anthrax was presumably used to infect animals in Romania.
 A consequence of such events was the 1925 Protocol for the
Prohibition of the Use in War of Asphyxiating, Poisonous, or
Other Gases, and of Bacteriological Methods of Warfare—known
as the Geneva Protocol.
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5. Cont...
 This protocol banned the use of biological agents in warfare
but not research, development, production, or stockpiling of
such agents.
 The advent of World War II, rapid developments occurred in
biological warfare capability in the United States and other
nations.
 In February 1942, the U.S. National Academy of Sciences
established a Biological Warfare Committee, chaired by Edwin
B. Fred of the University of Wisconsin.
 The technologies examined at Fort Detrick included pathogen
identification, modes of transmission, infection, detection,
public health measures, containment, rapid drying of
organisms, and packing for delivery.
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6. Microbes as Biological Weapons
 The microorganisms and toxins that could act as biological
weapons are naturally occurring.
 The agents that could potentially to be used as biological weapons
are diverse and widely distributed in nature and include
− viruses, bacteria, fungi, and protozoa
−the toxins produced by many microbes
 „These microbes are found naturally in soils, waters, plants, and
animals.
 Biological terrorism, the use of biological weapons non-state
government groups and crazed individuals.
 The threat of release of biological agents in a particular
community, tranportation system, school, or shopping mall causes
a crippling effect.
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7. Conti....
 Biological weapons derived from biological materials are
considered weapons of mass destruction.
 Biological weapons is actually a four-part system
 Payload
 Munition
 Delivery system
 Dipersion
Payload:
 The payload is biological material consisting of an infectious
agents (pathogen) or a toxin produced by bacteria, plant or
animal.
Munition :
 The serves to containerize the payload to maintain it potency
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8. Conti...
Delivery System :
 The delivery system can be missile, vehicle (aircraft, boat,
automobile, truck) or an artillery shell that transport the
payload to a susceptible target.
Dispersion System :
 The dispersion system provided by an explosive force or spray
mechanism, ensures dissemination of the payload at the
intended target.
 Infectious biological payloads that could potentially be used
include those causing anthrax (Bacillus anthracis), Plague
(Yersinia pestis), tularemia (Francisella tularensis) equine
encephalitides, hemorrhagic fevers (arenaviruses, filoviruses,
and flaviviruses) and small pox (variola virus).
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9. Cont...
 Toxins include botulinum toxin from clostridium botulinumricin
toxin trichothecene mycotoxins from fusarium.
 Staphylococcal enterotoxin from staphylococcal.aureus and toxins
from marine organisms such as dinoflagellates, shellfish & blue –
green algae.
Biological Exposure Routes
 Biological agents vary in how they are transmitted to
humans and how they enter the body.
 Transmission of biological agents through the air (aerosol
transmission) is likely to impact the greatest number of
individuals, but transmission by other means water, food,
insect vectors, etc. may also be routes of exposure of
individuals to biological agents.
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10. Differences in Effects and Transmissibility
„
 Among the viruses, bacteria, and fungi that may be used as
biological weapons, there are significant differences in their
effects and transmissibility.
 They also differ greatly in the rates of morbidity (disease) that
occur following exposure and mortality (death) that occur as a
consequence of disease development.
 This has a significant impact on the threat posed by each
specific biological agent and how we might defend against
them.
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11. Disease Outcomes
 Exposure to biological agents can have various outcomes,
ranging from mild disease with few symptoms to severe
disease and high rates of mortality.
 Some diseases, like many of the hemorrhagic fevers (Ebola,
Marburg, etc.), can not be prevented, except by avoiding
exposure.
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12. Biological warfare and Terrorism :
 Biological Weapons are the tools of Biological Warfare,
Bioterrorism, and Biocrime.
 Biological Warfare is the sanctioned employment of biological
weapons by nations in the conduct of war.
 Biological Terrorism is the employment of biological weapons by
non-state government groups, including religious cults, militants,
and crazed individuals.
 Biocrime is a bioterrorist act that targets a specific individual or
group rather than the masses.
 Evidence of biological terrorism worst attack in American history
occurred when a truck bomb caused a massive explosion that took
down the north face of the Alfred p. Murrah Federal Building in
Oklahoma City.
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13. Cont...
• One Hundred sixty-eight people died, including 19 Children,
and hundreds were wounded.
• The terrorist was Timothy McVeigh, Who was seeking revenge
for ‘crimes’ committed by the U.S. Government.
• The study of history reveals the influential role played by
microbes in battles and wars, perhaps even more influential than
artillery, tanks, and other weapons of conventional warfare.
• Battlefield Condition to the spread of infectious disease
because of unsanitary conditions, the unavailability of
uncontaminated drinking water, poor personal hygiene,
crowding, inadequate supplies of safe foods, overwhelmed and
inadequate medical facilities.
•Epidemic typhus fever and relapsing fever transmitted from
person to persons by the feces of body lice, prevail under
crowded conditions , and the inability to practice good personal
hygiene.
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14. Conti...
 During the war, bacterial, viral, and protozoan diseases, including
typhoid fever, staphylococcal and streptococcal infections,
battlefield gangrene, smallpox, chicken pox, measles, malaria,
amebic dysentery, killed and incapacitated more soldiers than did
rifles, cannon, and other weapons.
 The animals, plants, water supplies, and food supplies are also
likely targets for biological weapons.
 International relief agencies, including the red Cross and the
United Nations (UN), play a vital role in attempting to minimize
human misery.
 The empoyment of biological weapon is difficult because of
several factors, including confirmation of allegation of
empolyment, the lack of reliable microbiological and
epidemiological data particularly during war.
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15. Pathogens &ToxinsPathogen Toxins
Bacillus anthracis (Anthrax)
Yersinia pestis (Plaque)
Brucella Species (Brucellosis)
Vibrio cholerae (Cholera)
Viral Hemorragic fever (Yellow
Fever)
Variola species (Small pox)
Botulinum Toxin
Mycotoxins
Enterotoxins
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16. Viral Hemorragic fever : (Yellow fever)
Etiology : Yellow fever virus, a flavivirus causing viral
hemorrhagic fever
Epidemiology : Occurs mainly in tropical Africa and South
America
Has two cycles :
 Urban pattern of interhuman transmission, with the mosquitos
of Aedes aegypti as vectors
 Sylvatic cycle, involving monkeys and Haemogogus and
Sabethes mosquitos
 Considered a zoonotic infection
Incubation period: 3-6 days usua
 Clinical disease can range from non-specific to hemorrhagic
fever. Person appears acutely ill.
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17. Cont...
 Clinical course:
◦ Acute illness gives way to apparent remission for about 24
hours; and in some, disease "aborts."
◦ In 15-25%, illness reappears and is more severe (period of
intoxication).
◦ In this phase, may see:
 Fever
 Vomiting, may be black
 Epigastric pain
 Jaundice and hepatic injury
 Renal failure
 Myocardial injury
 May be major hemorrhagic manifestations
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18. Cont...
Diagnosis:
Detection of virus or viral antigen in blood, serologic diagnosis
by measurement of IgM antibodies by ELISA.
Complications:
may see:
Hypotension
Delirium
Coma
Metabolic acidosis
In those surviving, there is a long convalescent period with
weakness and fatigue.
There may be tubular necrosis requiring dialysis, as well as
pneumonia and hepatic injury.
Mortality:
20-50% of patients with hepatorenal disease die.
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19. Recent Developments Affecting Biological
Warfare Capability
• The introduction of modern biotechnology during the past 25
years has markedly changed the qualitative and quantitative
impact that biological warfare, or the threat of such warfare, can
have on military forces and urban communities.
• This new technology provides the potential capability of
(1) developing biological agents that have increased
virulence and stability after deployment;
(2) targeting the delivery of organisms to populations;
(3) protecting personnel against biological agents;
(4) producing, by genetic modification, pathogenic
organisms from non-pathogenic strains to com- plicate detection
of a biological agent.
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20. Cont...
(5) modifying the immune response system of the target
population to increase or decrease susceptibility to pathogens; and
(6) pro- ducing sensors based on the detection of unique signature
molecules on the surface of biological agents or on the interaction
of the genetic materials in such organisms with gene probes.
The specific technologies used in realizing these capabilities
include
(1) cell culture or fermentation;
(2) organism selection;
(3) encapsulation and coating with straight or crosslinked
biopolymers;
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21. Cont...
(4) genetic engineering;
(5) active or passive immunization or treatment with biological
response modifiers.
(6) monoclonal anti- body production.
(7) genome data bases, polymerase chain reaction equipment,
DNA sequencers, and the rapid production of gene probes
(8) the capability of linking gene probes and monoclonal
antibodies on addressable sites in a reproducible manner
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22. Advantages & DisadvantagesAdvantages:
 The advantages of biological weapons include deadly or
incapacitating effects on the target population, low cost,
continued microbial proliferation, difficulty of immediate
detection, and lack of physical damage to the area.
Disadvantages :
 The disadvantages include danger to the healthy of the
aggressors, the effects of physical factors such a weather
conditions on the success of an attack, public aversion to use,
and the environmental persistenence of some agents.
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23. CONCLUSION
 Biological weapons have recently attracted the attention and
the resources of the nation. The terrorist activities will
continue to involve bombs and firearms, also include weapons
of mass destruction, including biological agents.
 140 nations have participated in the Biological and Toxin
Weapons Convention (BWC) which prohibits the acquisition
of biological materials for hostile purpose and armed conflict.
 24 Emergency services must build and maintain their ability to
manage large scale biological weapon attacks and that requires
continued education, training.
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24. Reference
• Wheelis, Mark; Rózsa, Lajos; Dando, Malcolm (2006). Deadly
Cultures: Biological Weapons Since 1945. Harvard University .
• Robertson AG, Robertson LJ. From asps to allegations :
Biological warfare in history.
• Wiener SL. Strategies for the prevention of a successful
biological warfare aerosol attack. Mil Med.
• Microbial Challenge - Robert l. Krasner
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