Bioterrorism Agents Flashcards
What are 5 questions to think about in a bioterrorism case?
- What is it?
- How did they get it?
- How is it causing disease?
- Can it be treated?
- Can it be prevented
What is a deliberate release of viruses, bacteria, or other agents used to cause illness or death in people, animals, or plants?
Bioterrorism
Where are bioterrorism agents usually found?
In nature
Mutations to bioterrorism agents can do what 3 things?
- To increase their ability to cause disease
- Make them resistant to current medicines
- Increase their ability to be spread into the environment
What are 3 ways bioterrorism agents can be spread?
- Air
- Water
- Food
How many categories of bioterrorism agents exist?
3
Which category of agents is
- Easily disseminated or transmitted between people
- Has high mortality rates and potential for major public health impact
- Might cause public panic and social disruption
- Requires special action for public health preparedness?
Category A: High priority agents
What category of agents is
- Moderately easy to disseminate
- Has moderate morbidity and low mortality rates
- Requires enhancements of CDC’s diagnosis capacity?
Category B
What are the 2 characteristics of Category C agents?
- Availability, easily produced and disseminated
2. Potential for high morbidity and mortality rates
How are category A agents transmitted?
Respiratory or blood
What are 6 examples of Category A agents?
- Anthrax (Bacillus anthracis)
- Botulism (Clostridium botulinum toxin)
- Plague (Yersinia pestis)
- Smallpox (variola major)
- Tularemia (Francisella tularensis)
- Viral hemorrhagic fevers
- Filoviruses (e.g., Ebola, Marburg)
- Arenaviruses (e.g., Lassa, Machupo)
- Spore-forming
- Gram-Positive Rod
- Aerobic
- Non-Motile
Bacillus anthracis
How is bacillus anthracis arranged?
Long serpentine chains and clumps (medusa head) that can be single or paired
Where is bacillus anthracis found?
Soil, worldwide
What allows bacillus anthracis to survive in soil for years?
Spores (no spores in clinical specimens)
What kind of capsule does anthrax have?
Poly-D Glutamic acid, it’s antiphagocytic
When is the anthrax capsule produced?
Only during infection
True or False: Anitbodies against capsule for anthrax are not protective?
TRUE
What are the 3 proteins the anthrax toxin is composed of?
- Protective antigen (PA)
- Edema factor (EF)
- Lethal factor (LF)
What carries the edema factor and lethal factor for anthrax and what does it do?
PA
Penetrates cells
What causes edema from anthrax?
Protective antigen and edema factor
EF is a cAMP-inducing toxin
What causes death in anthrax?
Protective antigen and lethal factor
Where is anthrax serious?
In countries where herd vaccination isn’t practiced (rare in US)
What is the required exposure for anthrax?
Infected animals or animal products
What are the 3 routes of anthrax acquisition?
- Inoculation
- Inhalation
- Ingestion
What % of anthrax infections are via inoculation of spores through exposed skin?
95%
True or False: Anthrax is highly contagious
False… not highly contagious, not spread person-person
What is another name for inhalation anthrax?
Woolsorter disease
Is ingestion of anthrax common?
No, it’s rare (herbivores common)
What are the 4 steps of clinical disease and progression of pulmonary anthrax?
- Inhale spores or droplets from infected individual
- Carried from lungs by macrophages to lymphatic system (1-5 days of malaise, fever, and non-productive cough)
- Spores germinate and multiply in LN (bacteria make toxin and spread)
- In 24 hours: Pulmonary necrosis, septicemia, ect.
What 3 clinical features happen within 24 hours of pulmonary anthrax?
- Progressive respiratory distress and cyanosis
- Massive edema of neck, chest, mediastinum
- Death if untreated
What % mortality is seen with anthrax if therapy isn’t started in 48 hours?
95%
What has the greatest potential for mass casualties and civil disruption (CDC)?
Anthrax
-Death in 48 hours if untreated
What is the number 1 bioterrorism agent for clinical case scenario?
Anthrax
What are 3 situations where anthrax has been used before?
- Iraq and Soviet Union
- US attacks in 2000 (Letter to abortion clinical from Lexington, KY)
- Letters after 9/11
What are 3 ways to diagnose anthrax?
- Culture on non-selective media
- Serology
- Mediastinal widening on CXR
What does anthrax look like on culture?
Gray ground-glass appearance
Anthrax colonies?
Non-hemolytic, grow rapidly
How is anthrax treated?
- Ciprofloxacin
- Doxycycline
- For victims of warfare
Is there a vaccination for anthrax?
Yes
- Formalin-killed B. Anthracis
- 6 doses over 18 months
- Only available to military personnel
- Gram-Positive
- Anerobic Rods
- Spore former
C. Botulinum
What is adult botulinum associated with?
Home canning (food-borne)
What is infant botulinum associated with?
Honey
What type of toxin is associated with foodborne intoxication with C. Botulinum?
Heat-labile neurotoxin
What does the heat-labile neurotoxin associated with C. Botulinum do?
- Inhibits the release of acetylcholine
- Causes flaccid paralysis- Most potent known neurotoxin (7 toxins known)
What is the classic way to get Botulism?
Foodborne: Associated with the consumption of home-canned foods (Under 30 cases per year)
(Bacteria replicates in food, the toxin is ingested = Intoxication)
What is a proposed scenario of Botulism that is a major concern for bioterrorism?
Inhalation botulism
-Toxin inhaled, potential for high mortality
(NO CASES DIAGNOSED)
Once you ingest Botulism toxin in food, how many days is the incubation?
1-2 days
What are the symptoms of Botulism?
Initial weakness and dizziness, blurred vision, dry mouth, dilated pupils, constipation*, abdominal pain, NO FEVER
What is death attributed to from Botulism?
Respiratory paralysis
What is the % mortality from Botulism?
10% -Higher mortality proposed with inhalation
Recovery can take months to years
What is the treatment for Botulism?
- ANTITOXIN GIVEN IMMEDIATELY
- Supportive care: Respirator or tracheotomy
- Stomach lavage to remove source of toxin
* Antibiotics NOT WARRANTED for intoxication
What causes the pneumonic plague?
Yersinia pestis
- Oxidase-Negative
2. Gram-Negative Rod
Yersinia pestis
What kind of pneumonia does the pneumoic plague cause?
Hemorrhagic
True or False: Yersinia Pestis is easily transmitted between people
True
What is the % mortality associated with Yersinia Pestis (pneumonic plague)?
Over 90%
-Dead in 2 days, some within 24 hours
How do you diagnose the pneumonic plague?
Gram stain of LN aspirate
What does Yersinia Pestis look like on staining?
Bipolar safety pins
True or False: It is safe to culture Yersinia Pestis?
False: It is dangerous to culture (cold-enrichment)
What is done to prevent Yersinia Pestis?
You isolate the patient and notify health officials
Inactivated vaccine is no longer available
How smallpox transmitted (Variola)?
- Respiratory droplets
- Person to person
- Fomites
How does smallpox (Variola) occur and what is the associated mortality?
-Occurs in outbreaks
~30% mortality
What results in a rash with papules that become pustules that crust and scab?
Smallpox (Variola)
True or False: The pustules caused by Smallpox will present in various stages of development
FALSE: Pustules are all in the SAME stage of development
What is the prevention of smallpox (variola)?
There is a vaccine, but immunixation stopped in 1980
What causes Tularemia?
Francisella Tularensis
- Aerobic
2. Gram-Negative Bacillus
Francisella Tularensis
What is the % mortality for untreated tularemia?
8%
How many cases per year of Tularemia are seen in the US?
Several hundred
True or False: Clinical disease associated with Francisella Tularensis is rare
TRUE
How many bacilli of Francisella Tularensis need to be inhaled for infection?
10-50
What are symptoms of Tularemia?
- Dry cough, dyspnea, chest pain
- Lobar pneumonia may develop, ARDS in some pts
- Can lead to Typhoidal (septicemic) tularemia
Is the sputum gram stain for Francisella tularensis usually positive?
No, it’s usually negative
What kind of agar does francisella tularensis grow on?
Buffered Charcoal Yeast Extract Agar
What are category B Agents?
- Brucellosis (Brucella species) **
- Epsilon toxin of Clostridium perfringens
- Food threats (e.g., Salmonella, EHEC, Shigella)
- Glanders (Burkholderia mallei) **
- Melioidosis (Burkholderia pseudomallei) **
- Psittacosis (Chlamydia psittaci)
- Q fever (Coxiella burnetii) **
- Staphylococcal enterotoxin B
- Typhus fever (Rickettsia prowazekii)
- Viral encephalitis (VEE, EEE, WEE)
- Water threats (e.g., Vibrio cholerae, Crypto)
What 4 things can cause Brucellosis?
- Brucella Abortus
- Brucella Suis
- Brucella Meletensis
- Brucella Canis
What is Brucellosis associated with?
Aborted fetuses (zoonotic infection)
With Brucella, how many organisms need to be inhaled to establish infection?
A low number…10-100
What are the symptoms of acute disease with Brucellosis?
Fever, weakness, fatigue, malaise, depression, anorexia, profuse sweats*, chills, arthralgia, myalgia, GI symptoms, headache
How do you treat Brucellosis?
- Doxycycline and Rifampin for 6 weeks
2. Doxycycline for 6 weeks and streptomycin daily for 2-3 weeks
What causes Q Fever?
Coxiella Burnetii
Where is Coxiella Burnetii found?
- PLACENTA and feces of infected lifestock
- Goats, sheep, cattle, cats
How do you get Coxiella Burnetii?
Inhalation
What can Coxiella Burnetii cause?
Pneumonia and hepatitis
What is the most common way to diagnose Q Fever?
Serology (Phase I and II Antigens)
How do you treat Q Fever?
Acute: Doxycycline
Chronic: Combination
True or False: There is a vaccine for Coxiella Burnetii
True, there is a vaccine available in some countries like Australia, but it’s not approved in the US
What are 2 related diseases caused by Burkholderia?
- Glanders
2. Meliodosis
- Nonmotile
- Nonsporulating
- Obligate aerobic
- Gram-Negative Rods
- Nonfermenters
Burkholderia spp.
What is caused by Burkholderia Mallei?
Glanders
What is caused by Burkholderia Pseudomallei?
Melioidosis (AKA Whitmore Disease)
True or False: Glanders and Meliodosis are both considered potential biological warfare in aerosolized form
True
How do you get Glanders (Burkholderia Mallei)?
From direct contact with secretions from infected animal (horses, mules, donkeys)
-Primarily a disease of animals
How do you get Melioidosis/Whitmore Disease (Burkholderia Pseudomallei)?
From direct contact from a contaminated source (soil and water of Middle East, India, China)
Where is Malioidosis endemic in?
SE Asia and Australia
What are the 3 forms of clinical disease with Glanders and Meliodosis?
- Localized manifestations with Ulceration (usual form)
- Pulmonary Form
- Septicemia
What symptoms are associated with the pulmonary form of Glanders and Meliodosis?
- Pneumonia, pulmonary abscesses, pleural effusions
- Cutaneous abscesses may develop
What is involved and how many days until fatal is septicemia associated with Glanders?
- Cutaneous, hepatic, splenic involvement
- 7-10 days
Who is septicemia due to Melioidosis seen in?
Chronically ill patients (HIV and Diabetes)
What symptoms and what fatality rate is seen in septicemia due to Melioidosis?
- Respiratory distress, headache, fever, diarrhea, pus-filled lesions on skin, systemic abscesses
- 90% fatality rate in 24-48 hours
What is normally seen on blood cultures for Glanders and Meliodosis?
They may be negative
What is seen on gram stain of sputum, urine, and skin lesions for Glanders and Meliodosis?
- Small, gram-negative bacilli
- May have safety-pin, bipolar appearance
What 3 drugs are seen for treatment of Glanders and Meliodosis?
- Amoxicillin and clavulanate
- Doxycycline
- TMP-SMX
What is done for prevention of Glanders and Meliodosis?
Standard precautions
What are category C agents?
Emerging Infectious Diseases: Nipah virus and Hanta virus
