This document discusses bioterrorism and various biological agents that could potentially be used for bioterrorism. It describes the US CDC categories of biological agents (Category A, B, C) and provides details on specific agents like smallpox, anthrax, plague, and their pathogenesis. It also outlines measures for biosurveillance, personal protection during autopsies of suspected bioterrorism cases, and protocols for specimen collection that can aid in identifying the biological agent used.

1. By Dr. Shameera Begum

2. Bioterrorism
• Terrorism involving the intentional release or dissemination
of biological agents
• Bacteria, viruses and toxins

3. US Centres for Disease Control and Prevention
• A bioterrorist attack is the deliberate release of viruses,
bacteria, toxins or other harmful agents used to cause illness
or death in people, animals or plants.
• These agents are typically found in nature, but it is possible
that they could be mutated or altered to increase their ability
to cause disease, make them resistant to current medicines,
or to increase their ability to be spread into the environment.

4. Motives for bioterrorism
• Cause mortality and morbidity
• Disrupt health services
• Induce fear in the population
• Disrupt society
• Force change of government / government policies

5. Bioterrorism events
USA 1984
Contamination of salad bars with Salmonella
typhimurium
Iraq 1990 Botulinum toxin, aflatoxin, anthrax spores
USA 1996
Contamination of food with Shigella
dysenteriae
USA 2001 Anthrax spores were sent in envelopes

6. Potential agents for bioterrorism
• Easily available from laboratories
• Easily disseminated as aerosol 1 - 5 µm size particles
• Long lasting and stable for infectivity
• Contagious
• No effective treatment
• No effective prophylaxis for infected or asymptomatic people

7. Various means of dissemination
• Aerosol dispersion
• Contamination of food and water supplies
• Contamination of milk tankers
• Direct inoculation

8. Aerosol dispersion
• 1 – 5 µm, invisible and small enough to be inhaled into
alveoli without filtering
• Means of spreading – paint sprayers, fogging machines,
perfume atomisers, asthma inhalers

9. Types of agents
US CDC
• Category A
• Category B
• Category C

10. Category A
• Can be easily disseminated or transmitted from person to
person
• Result in high mortality rates and have the potential for
major public health impact
• Might cause public panic and social disruption
• Require special action for public health preparedness

11. Category A Agents
• Small pox (Variola)
• Viral hemorrhagic fevers (Ebola, Lassa, Marburg viruses)
• Anthrax (Bacillus anthracis)
• Plague (Yersinia pestis)
• Tularaemia (Francisella tularensis)
• Botulinum toxin (Clostridium botulinum)

12. Category B
• Moderately easy to disseminate
• Cause morbidity and low mortality
• Require specific enhancement of diagnostic capacity and
enhanced disease surveillance

13. Category B Agents
• Q fever (Coxiella burnettii)
• Brucellosis (Brucella spp.)
• Glanders (Burkholderia mallei)
• Melioidosis (Burkholderia pseudomallei)
• Psittacosis (Chlamydia psittaci)
• Food safety threats (Salmonella and Shigella spp., E.coli,
Staphylococcus aureus)
• Water supply threats (Vibrio cholerae, Cryptosporidium
parvum)

14. Category C
• Includes emerging pathogens that might be engineered for
mass destruction because of their availability, ease of
production and dissemination, high mortality rate, or ability
to cause a major health impact.

15. Category C Agents
• Nipah virus
• Hantaviruses
• Tick-born haemorrhagic fevers
• Tick- borne encephalitis
• Yellow fever virus
• MDR tuberculosis
• SARS
• H1N1 strain of influenza
• HIV /AIDS

16. Small pox
• In 1979, the WHO certified that
smallpox had been eradicated
• In 1980, the World Health Assembly
recommended that all countries
cease routine vaccination
• Kept in two approved labs in the
U.S. and Russia

17. • Transmission
• Clinical features
• Incubation period – 1 week
• High fever, macular rash in oropharynx, face, forearms and
trunk
• Papular (2 days)  vesicular (2 days) centrifugal pattern 
pustular  scabs  pitting scars

20. Treatment
• No proven antiviral drugs
• Cidofovir
VACCINATION
• Vaccines are being generated because of threat of
bioterrorism
• Limited stock
• Supply is controlled by Dept of Health (England)

21. Diagnostic procedures and autopsies
• RT PCR
• Electron microscopy
HPA guidelines for those who die
• If diagnosis is known, no requirement for autopsy
• If smallpox is suspected, examination with minimum
invasiveness. There is no need to open the cadaver to prove
smallpox
• All staff in autopsy must be vaccinated
• Full respiratory protection , standard universal precautions
• Skin samples
• Post mortem blood through cardiac puncture
• Transport of samples to reference centre laboratory

22. Pathology of small pox

23. Pathology of smallpox
• Heart : myocarditis
• Lung : smallpox pneumonitis and secondary bacterial
infections

24. Anthrax
• Bacillus anthracis
• Aerobic Gram positive spore forming bacterium
• Wool sorter’s disease
• Disease of sheep, cattle and horses
• Infection is by spores in the soil and animals

25. Transmission
• Cutaneous anthrax
• Inhalational anthrax
• Gastrointestinal anthrax
• Incubation period
• 2 – 60 days following pulmonary exposure
• 1 -7 days following cutaneous exposure or ingestion

27. • The spores are extremely hardy and can survive for years
• Disease is caused by exposure to spores, not the bacilli in
their vegetative state`

28. • The spores germinate into bacilli inside macrophages
• Release toxins
• Cause edema and cell death

29. GI anthrax
• Ingestion of contaminated meat

30. Inhalational Anthrax
• Most lethal form of disease
• Caused by inhaling spores into the lungs
• Spores germinate and are transported to tracheobronchial
lymph nodes

31. Clinical manifestations
• Initial phase
• Non productive cough, chest discomfort
• 50 % develop haemorrhagic meningitis
• Abrupt deterioration
• Overwhelming sepsis
• Dyspnoea, stridor
• Haemorrhagic mediastinitis

32. Investigation
• Widened mediastinum and hilar adenopathy

33. Mediastinal Widening and Pleural Effusion

34. • Haemorrhagic effusion involving mediastinal lymph nodes
and pleura
• Necrosis of lymph nodes, abundant Gram positive bacilli but
little acute inflammation
• Lung parenchyma shows oedema, haemorrhage and acute
lung injury

35. • Meningitis – haemorrhagic
• CSF – features of acute bacterial meningitis with abundant
Gram positive bacilli

36. Cutaneous Anthrax
• Spores are introduced into skin through open wounds or
abrasions
• Epidermal and dermal oedema, necrosis, acute inflammation
and Gram positive bacilli

37. Eschar

39. • Autopsy – discouraged.
• If essential, full protective clothing and equipment must be
used

40. Plague
• Yersinia pestis
• Gram-negative bacterium
• Zoonotic disease - transmitted to humans by bite of infected
rodent fleas
• Incubation period – 1-6 days

41. Clinical Presentation
• Bubonic (>80%) – rapid onset of fever, painful, swollen and
tender lymph node, usually inguinal, axillary, or cervical
• Pneumonic – high fever, overwhelming pneumonia, cough,
bloody sputum, chills
• Septicemic – prostration, hemorrhagic and/or thrombotic
phenomena progressing to acral gangrene

42. Diagnosis
• Specimens
• Bubo aspirates, blood cultures, sputum culture if pneumonic
• Microscopic identification
• Culture confirmation
• Serologic tests

43. Planning and Response
Biosurveillance
• Automated bioterrorism detection system (RODS – Real Time
Outbreak Disease Surveillance)
• Designed to collect data from many data sources and use
them to perform signal detection
• Detects bioterrorism event at the earliest possible
• Data sources – clinical data, laboratory data and data from
over -the -counter drug sales
• Detects both natural and man-made epidemics
• Not only monitors infected persons but also attempts to
discern the origin of outbreak

44. Personal protection during autopsy in bioterrorism cases
• Surgical scrub suit
• Hat
• Eye protection
• Reinforced rubber boots
• Multiple glove layers – cut resistant neoprene glove
Respiratory protection
• Modified disposable masks
• Powdered air purifying respirator

45. Powered air purifying respirator

46. General protocol for autopsy and specimen
collection in suspected bioterrorism cases
• Autopsies – done within 24 hrs
• Aseptic techniques
• Histopathology and microbiology samples
• Local inflammatory lesions or abscesses, liver, spleen, lung,
heart, kidney, lymph nodes, bone marrow
• Heart blood samples
• CSF
• Urine
• Gut contents

47. Pathological Identification of Bioterrorism
Agents
• Clinicopathological syndrome
• H and E – to identify viral inclusion bodies
• Special stains
• IHC
• Molecular diagnostics – for microbiological identification in
fresh material

48. Thank You