Agents Of Bioterrorism

Question 1

Select agents

Answer 1

A substance that has the potential to pose a severe threat to the public animal or plant health

Question 2

Tier 1/category A agents

Uber bad

Answer 2

Anthrax

Burkholderia/pseudomallei

Clostridium botulism

Ebola

Marburg

Smallpox

variola major/minor virus

plague (yersinia pestis)

Question 3

Steps to take during select agents

Answer 3

PPE

Disinfection

Inform

Vaccinate

Question 4

Bacillus anthracis

Answer 4

Capsules rod, gram positive, spore forming, chained, bacteria that produces spores that can last over 40 years

• • only bacteria that possesses polypeptide capsule over polysaccharide*
• Medusa head colonies

Infects via:

• inhalation (woolsorters disease) worst one
• Cutaneous
• GI / injections

Question 5

Toxins of anthrax

Answer 5

PA: protective antigen that pore forms in host cells

LF: lethal factor that suppresses immunity and kills cells via halting MAPKinases

EF: edema factor that causes cell and tissue swelling by super upregulating cAMP

Question 6

Pathogenesis of inhaled anthrax

Answer 6

Spores inhaled

Spores are phagocytosis in lung

Phagocytes transported to mediastinal lymph nodes

Phagocytes are lysed in LNs and produce toxin

Cause hemorrhagic mediastinitis and sepsis (death)

Question 7

Presentation clinically of inhalation anthrax

Answer 7

• Does not transmit from person-person*
• only cutaneous is transmitable

Fever, headache chest discomfort and shortness of breath

Chronic symptoms are pulmonary hemorrhage and shock. Produce meningitis sometimes.

Imaging shows widening of mediastinum, blood fluid in lungs and enlarged LNs

Is deadly because it progresses to shock and death very rapidly

Question 8

Treatment of anthrax

Answer 8

Prophylaxis immediately for 60 days w/ antibodies
- can potentially stop right there

3 dose of vaccine (0,2,4 weeks respectively)
- both pre and post symptoms

Antitoxins only for post symptom

• anthrax immune globulin
• raxibacumab
• both target Protective antigens on anthrax toxins*

Question 9

Yersinia pestis (Black Death, Bubonic plague)

Answer 9

Gram negative, facultative intracellular rod that is oxidase, lactase negative
- stains bipolar which appears a “safety pin” structure

Vectored by fleas on rodents such as rats/rabbits

Question 10

Most common forms of plaque

Answer 10

Bubonic plaque/Buboes (most common in inguinal/axillary LNs)

• only one with swollen painful lymph nodes
• weakest of the three

Pneumonic plaque ( most common in lungs) 
- highest mortality rate (near 100%)

Septicemic plaque ( most common in GI)
- second highest mortality rate

Question 11

Tularemia (rabbit fever)

Answer 11

Caused by Franciscella tularensis

• fastidious, gram-negative, aerobic coccobacillus
• intracellular pathogen

Vectors include (summer) ticks, deer flies and (winter) rabbits mainly

Has an extremely low infectious dose (1 bacillus) 2nd lowest of tier 1 pathogens!!

• will not transmit person-person*

Question 12

Clinical presentation of tularemia

Answer 12

Depends on route of infection

Ulceroglandular: skin abrasions/ bites

Pneumonic: inhalation

Oropharyngeal: ingestion of meat

Typhoidal: systemic spread

Question 13

Ulceroglandular tularemia

Answer 13

most common form

Inhibits phagosome-lysosome fusion which develops a painful papule/ulcer at site (bacteria survives within cells)
- not very fatal

Presents with lymphadenopathy also as well as fever, chills, malaise and myalgia

Question 14

Pneumonic tularemia

Answer 14

Highest rate of mortality in tularemia

Produces multiple necrotizing granulomas in the alveolar

Causes bronchopneumonia, bronchitis with lobar pneumonia

Can cause bacteremia

Question 15

Oropharyngeal tularemia

Answer 15

High mortality rate just under pneumonic tularemia

Caused by ingested bacteria, which crosses the mucosa and enters blood stream
- produces endotoxemia which causes sepsis

Symptoms = fever, sore throat, ab pain, splenomegaly, vomiting, diarrhea

Question 16

Oculoglandular tularemia

Answer 16

Rarest form of tularemia with low mortality and is exclusively caused by rubbing the eyes with infected hands

Bacteria inoculates within the eye and nearby lymph nodes
- pain itching, photophobia, intense ocular congestion, mucopurulent discharge

Question 17

Typhoidal tularemia

Answer 17

Mortality rate is highest or tied with pneumonic
- a combination of pneumonic and oropharyngeal

Most often caused by bite that puts the bacteria directly into the blood

Presents with fever, chills, myalgia, malaise without ulcers and lymphadenopathy
- produces sepsis shock

Question 18

Ebola

Answer 18

Filovirus that produces hemorrhagic fevers with super high mortality rates (90%)

Suspected vector is African fruit bat

Acute symptoms:
Fever, headache, sore throat, myalgia

Chronic symptoms: vomiting, ulcers, rash, diarrhea

Kills via internal/external bleeding shock and death

• is transmitable via person-person

Question 19

Brucellosis (brucella)

Answer 19

4 main species

• abortus: cattle
• canis: dogs
• suis: swine
• melitensis: goats/sheep

Most infections occur via raw/unpasteurized milk

Fastidious, gram negative aerobic coccobacillus that is an facultative intracellular pathogen

• So many different presentations*
• common is undulating fevers with malasie, back fain, fatigue, lymphadenopathy

Question 20

Brucellosis chronic issues

Answer 20

Doesn’t really kill, just extreme malaise with undulating fever/malaise

Chronic stages produces abscesses and granulomas with respiratory symptoms

Question 21

coxiella burnetii (Q fever)

Answer 21

Lowest infectious dose of any pathogen!!!

Most common in vets, farm workers

Obligated intracellular pathogen that produces endospore forms

promotes acidified phagolysosome production and localized to genital tract/mammary glands

Question 22

Modified Ziehl-Neelsen

Answer 22

A stain that is used to diagnose Q fever

• used in conjunction with a PCR

Question 23

Which Tier1 agents do we have vaccines for?

Answer 23

Small pox

Botulism toxin

Anthrax

Ebola
(not the greatest though and still investigational)

Tularemia

Question 24

Diagnosing tularemia

Answer 24

Culture aspirate from lymph nodes and/or sinus drainage

Culture with special agar

Use antibody titers (IgG should be very high however, must rule out brucellosis as well)

Question 25

Brucella clinical symptoms and pathogenesis

Answer 25

Incubation is variable as is the symptoms

Most common are undulating malaise and fever, back pain and fatigue

Has weak LPS activity (possesses strange LPS that immune system doesn’t recognize) and inhibits phagolysosome fusion

Takes forever to cure (6+ weeks)