Microorganisms have been used as biological weapons throughout history. This document discusses the role of microorganisms in biological warfare and bioterrorism. It defines biological warfare and lists some key characteristics that make microorganisms suitable agents. The document then reviews the history of biological warfare and provides examples of past uses of microorganisms as weapons. It also discusses bioweapons, bioterrorism principles, categories of biological agents, and provides details on specific agents like anthrax and their use in anti-agriculture warfare.

1. Role of microorganisms in
Biological Warfare
Prepared by Misbah Ajaz
M.Sc Microbiology

2. Contents
 Biological warfare
 Characteristics
 History
 Bioweapons
 Bioterrorism its principles
 Types of Agent
 Anthrax
 Anti-agriculture Warfare

3. Biological warfare
Biological warfare is the intentional use of
micro-organisms and toxins generally of
microbial, plant or animal origin to produce
disease and death in humans, livestock and
crops.
Source: Arora et al. (2002)

4. Characteristics of Biological warfare
Easy access
Low production costs
Non detection by routine security systems
Easy transportation from one place to another

5. PAST
 190 B.C., Hannibal used venomous snake to disrupt enemy ships
(Pergamon and Bithynia)
 1763, French-Indian war, small-pox infested blankets were given to
Indians, setting off an epidemic.
 Worldwar-1, Germans attacked cattle and horses of Europe by infecting
them with anthrax and glanders.
 Worldwar-2, Japan used typhus, cholera and plague against Chinese
prisoners.
 U.S. initiated its own biological weapon programme
 1969, U.S. disbanded its offensive B.warfare program and in 1972
signed Biological Weapons Convention (BWC)
 As of june 2005=171 signatories
 No. of Ratification and Accessions =155
 No. of non signatories= 23 (Source:Science,(2006)

6. in 1952, Mau Mau poisoned cattle in Kenya by using a plant toxin from the African milk
bush plant; (2) in 1985, the USDA claimed that Mexican contract workers were involved in
deliberately spreading screwworm (Cochliomyia hominivorax) among livestock; (3) in
2000, Palestinian media reported that Israeli settlers released sewer water into Palestinian
agricultural fields; and (4) in 2011, a person was sentenced to prison after threatening US
and UK livestock with the deliberate spread of foot-and-mouth disease virus.

7.  1979: accidental release of spores into the atmosphere from a Soviet Union
bioweapons facility in Sverdlosk:
 77 cases of anthrax
 Development of clinical illness =2 to 43 days(death =1 to 4 days )
 September 2001: anthrax spores delivered through the U.S. Postal System.
 CDC identified 22 confirmed or suspected cases of anthrax
 (11 patients=inhalational anthrax, of whom 5 died,
 11 patients =cutaneous anthrax - 7 confirmed - all of whom survived)
 one letter contained 2 g of material, equivalent to 100 billion to 1 trillion
spores
 The strain used in this attack was the Ames strain

8. Confirmed anthrax cases associated with bioterrorism: U.S., 2001.
A. Geographic location and clinical manifestation of the 11 cases of confirmed
inhalational and 7 cases of confirmed cutaneous anthrax.
B. Epidemic curve for the 18 confirmed cases of inhalational and cutaneous anthrax
and 4 cases of suspected cutaneous anthrax.

9. 2001 Anthrax attacks
 A letter sent to Senate Majority Leader Tom Daschle containing anthrax powder killed
two postal workers
 Date - Letters postmarked September 18, 2001, and October 9, 2001;
some were opened at a later date
 Target - ABC News, CBS News, NBC News, New York Post, National Enquirer, Senators
Tom Daschle and Patrick Leahy
 Attack type - Bioterrorism
 Weapons - Anthrax
 Deaths - 5

10. Bioweapons
 These are defined as micro organisms that infect
and grow in the target host producing a clinical
disease that kills or incapacitates the targeted
host.
 Examples:
 Bacillus anthracis (bacteria)
 Variola (virus)
 Aflatoxin (Toxin)
Source: Arora et al. (2002)

11. Potential Bacterial, Viral And Toxin BW’s
Bacteria Virus Toxins
Bacillus anthrasis Variola virus Aflatoxins (A.flavus and
A.parasiticum)
Clostridium
perfringens
Ebola virus Ricin
C .tetani Marburg virus Shiga Toxin
Vibro cholera Dengue fever virus Cholera Toxin(choleragen)
Clostridium botulinum Botulinum toxin
Source: Arora et al.(2002)

12. Advantages of a perfect Bioweapon:
o Efficiently dispersible
o Stable on storage.
o Highly infectious and highly effective
o Readily grown and produced in large quantities.
o Resistance enough to environmental conditions
o Resistance to treatments.

13. Disadvantages of Bioweapons
o Difficulty of protecting the workers at all stages of production,
transportation, loading of delivery systems and final delivery.
o Difficulty in maintaining quality.
o Effective delivery problem.
o Difficult to control once released

14. Bioterrorism
Bioterrorism is assumed to involve the threat or use of biological
agents by individuals or groups motivated by political, religious,
ecological, or other ideological objectives.
(Source:Carus,1998)
A bioterrorism attack is the deliberate release of Viruses, Bacteria and
Toxins used to cause illness or death in people, animals or plants
( source: U.S. Centers for Disease Control and prevention )

15. Principles
 Nature of Organisms of Concern
 Source of Organisms
 Dissemination of Organisms Leading to
Exposure and/or Disease
Source:(http://www.hopkins-biodefense.org/)

16. 1) Nature of organisms concern:
 Easily transmitted Person to person
High mortality
Public Panic and social disruption etc
Persistence for long time

17. Biological Weapon agents: Nature
Source:(http://www.bt.cdc.gov/)

18. 2) Source of organisms
 All organisms found in Nature except Small
Pox
 C.botulinum – ubiquitous in Nature.
 Viruses like Ebola, Marburg found in Sub-
Saharan Africa
 Anthrax- Animals(Animal handlers, Wool
workers)

19. AIR Explosives
FOOD AND WATER
3) Dissemination of organisms Leading to Exposure
and/or Disease
Self Exposure while handling

20. contd…
 Dissemination efficiency by aerosol sprays. –
40-60 %.

21. Contd…
Incorporation of agents with explosive devices
 Dissemination efficiency - <5% .

22. Dissemination Through
food or water supply
 Requires large amount of agent.
 Water passes through regional treatment
facilities.

23. Types of Agents
Category a
Source:Levy and Sidel 2003

24. Category b
Source: Levy and Sidel 2003

25. Category c
Source: Levy and Sidel 2003

26. Bacillus anthracis
Review
o Gram Positive
o Rod shaped
o Spore Forming
o Non-motile
o Infective Dose = 8,000 -
15,000 spores
o Incubation period = 1-6 days
o Duration of illness = 3-5 days

27. Why Would Anthrax Be Used as a Weapon?
 Anthrax spores are easily found in nature, can be
produced in a lab, and can last for a long time in the
environment.
 Anthrax can be released quietly and without anyone
knowing. The microscopic spores could be put into
powders, sprays, food, and water as they are so small,
we may not be able to see, smell, or taste them.
 Anthrax has been used as a weapon before.

28. Mechanism

29. ID50 (infective dosage that will infect 50% of exposed) is
8,000-50,000 spores.
LD50 (Lethal dosage that will kill 50% of exposed) is 2,500-
55,000 spores
Bacteria Blood stream Symptoms
Like…
Malaise
Fever
Prominent
cough
Nausea
Vomiting
Chest pain
Headache
Contd…

30. cont…
Cutaneous Anthrax:
Endospores Body through the skin
(Pre-existing lesions, abrasions)
Eschar formation at entrance site due to Toxins
• Day 1 pruritic red papule appears at the initial site of infection
• Day 2 papule becomes round ulcer
• Day 3 central papule necrotizes, ulcerates, and forms a normally
painless black eschar
Edema around anthrax lesionAnthrax eschar, neck

31. Mechanism contd…
• Endospores are often Phagocytosed by
Macrophages
• Lymph Nodes (Lymphangitis)
• Onset Symptoms like :Headache and Fever.
• Untreated -> 20% mortality

32. Anthrax
Complicated cutaneous Anthrax

33. Intestinal Anthrax
• Ingestion of contaminated
meat
• Incubation: <1 - 7 days
• Fever, acute abdomen pain,
vomiting, bloody diarrhoea
• Intestinal eschar (similar to
cutaneous lesion)
• Progression to sepsis
syndrome.
• Mortality 50 - 100% despite
treatment

34. PROTECTIVE MEASURES
 Masks
 Protective clothing
 Vaccine;
Anthrax vaccine
Adsorbed (Protects against
cutaneous and inhalation)
 Antibiotics like ;
Ciprofloxacin and
doxycycline

36. Anti-crop warfare
Involves agents resulting in debilitating
famines, severe mal-nutrition, decimation of
agriculture-based economics and food security.
Personal health and safety of harvester is
endangered.
Developing countries have a better chance of
weathering anti-crop warfare.

38. Disease Causal
organism
Primary Modes of
Transmission
Primary
Animals
Affected
Vaccine
available
?
Location Affect
humans?
Foot and
mouth
disease
Picorna virus Airborne aerosols;
direct or indirect
contact (via human
clothing,
equipment,
vehicles, or
through milk or
partially cooked
meat)
Cloven hoofed
animals, esp.
cattle and
swine
Y Asia,
Africa,
Middle
East,
South
America
Occasionally
after
prolonged
exposure,
humans can
develop
mild
symptoms.
Mad
cow
disease
Ingestion of
foods containing
infected meat
and bone meal
Cattle N Primarily
Great
Britain,
some cases
in Western
Europe
Suspected
precursor to
new variant
Jakob
disease
(fatal)
African
Swine
Fever
ASFV Insect vectors
(ticks);ingestion of
infected meat;
direct contact;
airborne
aerosols within
buildings
Swine N Africa,
Iberian
Peninsula,
Sardinia
N
LIST OF DISEASES AFFECTING PRIMARILY CATTLES AND SWINE

39. Disease Causal
organism
Primary
Modes of
Transmission
Primary
Animals
Affected
Vaccine
available?
Location Affect
humans?
Swine
Vesicular
Disease
SVDV
(enterovirus
)
Ingestion of
infected
meat
Swine N Hong Kong,
Japan,
Europe
Occasionally
causes flu
like
illness
Vesicular
stomatitis
VSV Direct
contact (i.e.
shared
feed and
water
troughs,
milking
machines);
insect
vectors
cattle,
swine,
horses
Y U.S., Mexico,
Canada,
the
Caribbean,
Central
and South
America
During
epidemics
humans can
get a
version
resembling
flu
Source:Louis and Mosby (1996)
LIST OF DISEASES AFFECTING PRIMARILY CATTLES AND SWINE

40. Levels:
1. at the national level, through policies
designed to minimize the social and
economic costs of a catastrophic
disease outbreak.
2. at the agricultural sector level,
through USDA disease detection and
response procedures; and
3. at the farm level, through facility
management techniques designed to
prevent disease introduction or
transmission
1. at the organism level, through
animal or plant disease resistance;

41. Why Agro-terrorism?
 Soft targets or ones that maintain such a low level of security
that a terrorist could carry out an attack unobserved.
 Biological agents are small, inexpensive, and nearly
impossible to detect.
 A terrorist may choose to use BW against agriculture simply
because it is the easiest and cheapest way to cause large-scale
damage.

42. Conclusion
1. Biological weapons are unique in their invisibility and their delayed effects. These
factors allow those who use them to inculcate fear and cause confusion among
their victims and to escape undetected.
2. Its goal is disruption of social and economic activity, the breakdown of
government authority, and the impairment of military responses.
3. Among the three categories of BW, Category A is highly dangerous and
destructive Biological weapon.
4. Adherence to the Biological and Toxin Weapons Convention, reinforced by
confidence-building measures (United Nations, 1997) is indeed, an important and
necessary step in reducing and eliminating the threats of biological warfare and
bioterrorism

45. t