Agents of bioterror Flashcards
What is an SSBA?
Security sensitive biological agent
What is bioterrorism?
intentional use of security sensitive biological agents (SSBAs) to produce disease and or death in humans, animals, plants
What are the two main modes of transmission for biological weapons?
- Aerosol
2. Ingestion
What is the morphology/growth conditions of B. anthracis? catalase/oxidase?
Gram positive spore forming rod
Facultative anaerobe
Catalase and oxidase positive
What are 4 tests/features that you can use to determine that you have B. anthracis
- non-hemolytic on SBA
- Phage lysis
- India ink
- DFA against capsule
What are the two virulence factors that B. anthacis has? what are they coded on?
Encoded on plasmids
pX01 -genes encoding toxins
pX02- genes encoding poly-D-glutamic capsule
Where is B. anthacis naturally found?
spores are found naturally in the soil
Is there person to person transmission for anthrax?
nope
What are the 3 forms of human anthrax?
- Cutaneous
- Gastrointestinal
- Pulmonary
What is the most common form of human anthrax?
cutaneous
What causes cutaneous anthrax? what does it present like?
inoculation of spores under the skin
painless ulcer with a black centre
What is the specimen of choice for cutaneous anthrax diagnosis?
vesicle fluid, blood, or tissue biopsies
How do people get GI anthrax?
ingestion of contaminated meat
What is the specimen of choice for GI anthrax
blood (not stool)
How do people get pulmonary anthrax?
inhalation of spores
What is the progression of pulmonary anthrax like?
- initial non-specific symptoms of fever, cough, and malaise
- Progresses rapidly in 1-2 days to high fever, dyspnea, and cyanosis
- pretty much everyone like this will die
What are the best samples to get to diagnose pulmonary anthrax?
Sterile site fluid
- blood or pleural fluid
Biopsies of mediastinal lymph nodes
What 3 antibiotics can be used to treat antrax?
Penicillin, doxycycline, ciprofloxacin
Is there a vaccine for antrax?
yes actually
- Antrax Vaccine Adsorbed but there is limited availability
What kind of virus is smallpox?
Orthopoxvirus = large dsDNA, enveloped, complex
How is smallpox transmitted?
contact, formites, aerosols
What is the reservoir for smallpox
humans
What is the vaccine like for smallpox?
made from live vaccinia virus
Intrademal inoculation (scarification)
What are 2 other viruses (in addition to variola/smallpox) that are transmitted via aerosol?
Measles and varicella
Whats the disease progression of smallpox like?
- Start with malaise, muscle aches, fever, rigors
- Rash appears. starts as papular lesions
- like chicken pox - Rash progresses around day 5 from papules to vesicular or pustular lesions
- Day 8 - rash clearly smallpox
What is different (2 things) about the lesions for smallpox and chicken pox?
- the smallpox lesions all appear at the same time while for CP you get vesicles, papules, macules all occurring at different stages
- Smallpox tends to target face and extremities while chicken pox starts on torso and face
What is the specimen of choice for diagnosing smallpox?
Vesicular fluid
What 3 lab tests can be performed to determine if its smallpox
- Culture and DFA
- PCR
- Electron microscopy
How long is someone contagious with smallpox?
Until the last scab falls off
How can vaccination after exposure help with smallpox?
Within 4 days can prevent/lessen disease
What can be done for people exposed to smallpox but can’t get vaccinated?
IV-Ig
Yersinia pestis is what kind of bacteria?
Enterobacteriaceae
- gram negative rod
What is the vector and reservoir for Yersinia pestis?
vector is fleas
reservoir is rodents
What are the 3 potential clinical presentations of Yersinia pestis/plague?
- Bubonic
- Septicemic
- Pneumonic
What is the presentation of Bubonic plague like?
- Sudden onset of fever, malaise, and myalgia
- Regional lymphadenitis - buboes
- can potentially have lesions at the inoculation site
What is another disease that causes severe swelling of lymph nodes?
tularensis
What is the specimen of choice to collect for bubonic plague?
bubo/lymph node aspirate
What is the mortality for bubonic plague if untreated?
%60
What is the presentation of Septicemic plague like?
Systemic disease but most notably get DIC and necrosis of fingers and hands
- black death
How can you get septicemic plague?
either primary or secondary infection from other forms of plague
blood borne
What is the mortality for septicemic plague if untreated
100%
Why does pneumonic plague have the potential to be a bioterror?
Because it can be passed person to person by respiratory droplets
What is the presentation/progression of pneumonic plague like?
Sudden onset: fever, malaise, myalgia, and pneumonia
Rapidly progresses to cyanosis, hemoptysis, respiratory collapse, sepsis
What is the mortality of pneumonic plague if untreated?
100%
What is/are the specimen(s) of choice for pneumonic plague?
Sputum or BAL
What two antibiotics can be used to treat plague?
Doxycycline and TMP/SMX (Septra)
How can Yersinia pestis be diagnosed in the lab?
culture: gram negative rod that grows on MacConkey agar at 25º
DFA and PCR can be used
Also can use MALDI and Vitek
What is the causative agent of tularemia?
Francisella tularensis
What is the vector/reservoir for Francisella tularensis ?
vector: demacentor tick
reservoir: mammals like rabbits
What does Francisella tularensis cause?
plague like illness with ranging symptoms from skin ulcers to respiratory failure
What are the two clinical presentations of Francisella tularensis ?
- Pneumonic
2. Typhoidal (septicemia)
Which of the two presentations of Tularemia is of concern for bioterrorism?
both the pneumonic and the typhoidal
What specimen is taken to diagnose Francisella tularensis ?
lots possible: blood, tissue, lesion aspirate, sputum..
What are Francisella tularensis bacteria like (morphologically)
poorly staining, small, gram negative cocco-bacilli
What media does Francisella tularensis grow/not grow on?
Grows poorly on SBA, CHOC, TMA
- Tiny, gray-white, translucent colonies
- Fastidious, requires cysteine
- Cysteine Heart Agar (CHA) is ideal
- *BCYE (like Legionella pneumophila)
Is there person to person transmission for tularemia?
nope
What is the infectious dose like for Tularemia?
very low, 1-10 organisms
What antibiotic is used to treat tularemia?
doxycycline
