Agents of Bioterrorism

1. Biosafety Levels
BSL-1
• Do not usually cause disease minimal
safety equipment
• Usually those found in high
school/college student labs
• Example: Bacillus subtilis
BSL-2
• Known to cause human disease
• Encompasses most clinical hospital
laboratories
• Ex. HBV and salmonellae
BSL-3
• Known to produce serious disease
• Transmitted by respiratory route
• Not identifying directly from
specimens(BSL-2) but culturing M.
tuberculosis
BSL-4
• Require containment suits
• High risk of serious disease
• No available treatment
• Ebola

2. Public Health Preparedness

Three categories

Category A
• Greatest impact


Category B


Salmonella, ricin, E.coli O157:H7
Category C
• Less impact


Anthrax, hemorrhagic fevers
MDR-TB, hantavirus
See Table 30-1 for full list of examples

3. Key Indicators of a Potential Bioterror
or Biocrime Event

4. General Characteristics of Bioterror
Agents

Easily made


Mobile


Low skill required
Easy to transport
Transmission



Aerosol
Person-to-person spread
Resistant to decay

5. History of Criminal Use of Microbial
Agents

Salmonella


Anthrax spores


Sprayed onto salad bars in restaurants
Contaminated letters in NY, DC, and Florida
Ricin toxin

6. Laboratory Response Network (LRN)


Established in 1999
Community hospitals with microbiology
capabilities

Sentinel laboratories
• Must have BSL-2 capabilities

Five agents with protocols
–
–
–
–
–
B. anthracis
Y. pestis
F. tularensis
Brucella spp.
Etc.

7. Laboratory Response Network (LRN)

Reference laboratories


Perform confirmatory tests on several biothreat
agents
• State public health laboratories
• Department of defense medical center laboratories
National laboratories


Can perform complex forensic studies
Definitive characterization of biothreat agents
• CDC
• USAMRIID
• National Research Medical Center

8. Structure of the Laboratory
Response Network

9. Agents of Bioterror

Bacillus anthracis

Cutaneous anthrax
• Very few cases


Black eschar on skin
Gastrointestinal anthrax
• Ingestion of spores in contaminated
food

Inhalation anthrax
• Generally none unless bioterror or
lab accident

10. Agents of Bioterror

Specimen collection


Swabs from black eschar
Blood sample from inhalation and gastrointestinal
anthrax
• Colonies have medusa-head morphology

Nonhemolytic

11. Morphology of Anthrax on Blood
Agar, Gram Stain, and Spore Stain

12. Agents of Bioterror

Yersinia pestis


“Black death”
Linked to bubonic plague in 1894
• Major vector is flea
Elsevier items and derived items © 2011, 2007 by Saunders, an imprint of Elsevier Inc.
13

13. Agents of Bioterror

Transmission




Bite of infected fleas
Handling contaminated materials
Inhaling aerosolized bacteria
Weaponized Y. pestis

Primarily pneumonic plague
• Person-to-person transmission

14. Agents of Bioterror

Symptoms


Fever, chills, headache, malaise
Buboes
• Inflammation of the lymph node causing swelling

Bacteria disseminate and cause DIC
– Results in gangrene in fingers and nose

15. Agents of Bioterror

Direct examination and culture


Plump gram-negative rods
Bipolar staining
• Safety pin appearance

16. Agents of Bioterror

Francisella tularensis




BSL-3 pathogen
Zoonotic disease
Infectious dose
• As low as 10 organisms
Ulceroglandular tularemia

Skin infection
• Bite of infected insect
• Handling infectious materials

17. Cutaneous Lesions

18. Agents of Bioterror

Clinical manifestations


Symptoms
• Fever with chills
• Headaches
• Cough
• Chest pain
• Lesions at site of entry
Occasionally respiratory disease

19. Agents of Bioterror

Brucella spp.



Small gram-negative pleomorphic aerobic
coccobacilli
• Brucella melitensis
• Brucella suis
• Brucella abortus
Mostly eliminated in the United States
• BSL-3 containment required
Transmission
• Breaks in skin
• Ingestion of food products
• Aerosols in laboratory conditions

20. Agents of Bioterror (Cont’d)

Symptoms


Can persist for months


Malaise, night sweats, relapsing fever, chills,
myalgia
• Requires 5-35 days of incubation before symptoms
Most recover without treatment
Previous use as a biologic weapon

21. Agents of Bioterror (Cont’d)

Burkholderia species



B. mallei
• Glanders
B. pseudomallei
• Melioidosis
Symptoms
• Fever, myalgia, headache, and chest pain

Caused by cutaneous lesions, bloodstream infections,
pneumonia

22. Agents of Bioterror (Cont’d)

Coxiella burnetii



Causative agent of Q fever (Query fever)
Reservoirs
• Cattle, sheep, goats, dogs, cats, deer, fowl, and humans
• Exposure in vet or animal handlers
Transmission
• Urine, milk, feces, tissues, and fluids expelled during
birth
• Incubation period 2-3 weeks

23. Agents of Bioterror

Smallpox

Two major forms
• Variola major


30% mortality in unvaccinated
3% in vaccinated
• Variola minor

Similar but much less severe disease

24. Smallpox Pustules

25. Agents of Bioterror

Viral hemorrhagic fevers


Ebola, Marburg, Lassa fever, Crimean-Congo, Rift
Valley fever, Hantavirus
Transmission


Direct contact
Urine, semen

26. Agents of Bioterror (Cont’d)

Clinical manifestations



Incubation period 2 to 3 weeks
Fever, rash, myalgia, arthralgia, nausea,
conjunctivitis, diarrhea, and CNS symptoms
Bleeding, DIC, hemorrhage of mucous
membranes
• Some have high mortality rates

27. Agents of Bioterror

Toxins



Clostridium botulinum toxin
Staphylococcal enterotoxins
Ricin
• Contamination of food or water sources