Lec50 Bioterrorism Flashcards
What should you think when you see widened mediastinum with fever and sepsis?
inhalational anthrax
what should you think when you see localized skin lesion with depressed black eschar?
cutaneous anthrax
what should you think when you see vesicular/pustular rash starting on face and hands with all lesions same stage of development?
smallpox
What properties make agents of bioterorrism dangerous?
- readily available
- easy to weaponize
- easy to disperse/transmit [aerosol or P2P]
- cause severe illness
What is definition category A agents of bioterrorism?
- high priority agents
- easily disseminated or transmitted person to person
- high mortality/public panic/social disruption
- need special action for public health preparedness
What are the four main category A agents of bioterrorism?
- anthrax [bacillus anthracis]
- tularemia [ francisella tularensis]
- plague [yersinia pestis]
- botulism [clostridium botulinum toxin]
- smallpox [variola major]
- filoviruses, viral hemorrhagic fever
What are characteristics of bacillus anthracis?
- large gram pos bacilli
- spore forming
- facultative anaerobe
- non-motile
- sticky –> adheres to agar surface
- catalase positive
- boxcar morphology
How do you get infection of bacillus anthracis?
- inhaled, ingested, inoculated through exposed skin
What are the virulence factors of bacillus anthracis?
- capsule
- protective antigen [PA]
- edema factor [ EF]
- lethal factor [LF]
What is anthrax edema toxin?
PA [protective antigen] + EF [edema factor]
What is anthrax lethal toxin?
PA [protective antigen] + LF [lethal factor]
What is anthrax lethal factor function?
zinc metalloprotease, stimulates inflammatory cytokine production and cell death
What is anthrax edema factor function?
adenylate cyclase, increased cAMP intracellular levels
What happens in cutaneous anthrax?
- direct contact organism and non-intact skin
- within 1/2 wks have local edema –> macule or papule –> ulcer –> vesicles –> black depressed exchar
- mortality in 20% without antibiotics
What happens in GI anthrax?
- spores ingested
- edematous response
- huge mesenteric lymph node
- lots of tissue necrosis –> can see eschar
What happens in inhalational anthrax?
- responsible for most anthrax related deaths
- inhale spore-bearing partiles
- spores phagocytosed by macrophages to mediastinal lymph node
- up to 60 days later have clinical disease
- get widened mediastinal lymph nodes and widened mediastinum
What are symptoms of pt with inhalational anthrax?
- fever, nigh sweats, fatigue, respiratory
- enlarged mediastinal lymph node, widened mediastinum
What makes anthrax a good weapon? limitations?
- aerosol is odorless/colorless
- spores highly stable
- disease has high case fatality rate
limitations: little [cutaneous] or no [inhalational] person to person spread
How do you treat anthrax?
- penicillin, ciproflaxicin
- anthrax vaccine by military
What is responsible for the plague?
yersinia pestis
What are characteristics of yersinia pestis?
- biopolar “safety pin” gram neg bacilli
- slow growing
- member of etnerobacteriaceae
What is reservoir of yersinia pestis?
- wild rodents
How is yersinia pestis transmitted?
- via fleas or direct exposure to infect tissue or resp droplets
What are diseases of yersinia pestis?
- bubonic plague [regional lymphadenitis]
- septicemia without bubo
- pharyngitis and cervical lymphadenitis
- pneumonic plague
What are characteristics of variola virus?
- large DNA virus
- genus orthopoxvirus
- brick shaped viral structure
- low infectious dose [just a few virions]
How is variola virus transmitted?
person to person
- via droplet nuclei or aerosols
- by direct contact
- by fomites
What is pathogenesis of variola? symptoms?
- implants on respiratory mucosa
- migrates and multiplies in regional lymph nodes
- day 3/4: asymptomatic viremia w/ spread to spleen, bone marrow, lymph
- day 8: secondary viremia w/ fever, toxemia, organisms in small blood vessels of dermis/oropharynx leading to pox
- fever/malaise/headache/backache/delerium
How do you differentiate chickenpox from smallpox?
chickenpox
- palms and soles rarely involved
- lesions apepar first on face or trunk
- lesions in crops of different stages
- no or mild prodrome
- dewdrop on rose petal lesions
How do you prevent smallpox?
- vaccination with vaccinia virus [cowpox]
- can use for pre and post exposure prevention
- -> pre-exposure protection wanes over time
- -> post exposure w/4 das
What is treatment for smallvox?
- vaccinia virus within 4 days of exposure
- supportive care
- can give cidofovir
What makes smallpox a good agent of bioterrorism? limitation?
- highly susceptible population
- efficient P2P spread
- high case fatality
- limited treatment options
limitations: not in nature, only 2 known repositories [WHO labs]
Who gets monkey pox?
- owners of prairie dogs due to cross contamination with gambian rats
What are characteristics of clostridium botulinum?
- spore forming obligate anaerobic bacillus
- found in soil
What is pathogenesis of clostridium botulinum? How do you get it?
AB toxin –> flaccid paralysis
- food born from canned foods
- infant from spores in honey
- rarely wound botulism
- inhalational botulism = terrorism agent
What makes botulinim a good terrorism agent? limitations?
good:
- found in nature
- multiple routes of exposure
- toxic lethal dose –> 1gm could kill 1 million
limitations
- hard to concentrate
- commercially available produts have very low conc of it
- not spread P2P
What are signs of inhalational botulsim?
- blurred vision
- drooping eyelids
- slurred speach
- descending paralysis
- respiratory paralysis
How do you treat inhalational botulism?
supportive
antitoxin
What are properties of trancicella tularensis?
- poorly staining
- tiny gram neg coccobacilli
How is tularemia transmitted?
- by ticks, handling animal carcasses
- can be aerosolized
What are the 3 viral hemorrhagic fevers?
- ebola
- marburg
- lassa fever
What is definition category B agents of bioterrorism?
- second highest priority agents
- moderately easy to disseminate and have morbidity but usally low mortality
What are some examples of category B agents of bioterrorism?
- brucella
What is definition category C agents of bioterrorism?
- third highest priority agents
- include emerging pathogens that have ease of production or potential for high morbidity/mortality
What are examples of category C agents?
- nipah virus
- hantavirus
- MDRTB
- yellow fever
