Miscellaneous Infections I (36) Flashcards
Dr. Erol
What is tularemia? It is listed as a _____
a bacterial septicemia that infects many species
category A bioterrosim agent because of the potential for fatality, airborne dissemination, and societal disruption
What is the causative agent of tularemia?
francisella tularensis
What are the characteristics of francisella tularensis? It is an [intracellular/extracellular] pathogen
gram negative
intracellular - affects macrophages
What are the types of francisella tularensis?
f. tulararensis biovar tularensis (type A)
f. tularensis biovar holarctica (type B)
Contrast f. tulararensis biovar tularensis (type A) and f. tularensis biovar holarctica (type B)
Which biotype has reservoirs of rabbits, hared, ground squirrels, ticks?
f. tulararensis biovar tularensis (type A)
Who are the reservoirs for francisella tularensis?
mammals, ticks, and some birds
ticks and rabbits most important
rodent-mosquito cycle in Russia, Sweden
What is the infectious dose for francisella tularensis?
a select agent
small for inoculation or inhalation
large for oral
How is tularemia transmitted?
ticks - transovarial transmission
mosquito, flies
How is tularemia transmitted? Elaborate
direct: contact with tissues of rabbits or other infected mammals
- skinning, necropsy
- handling contaminated skins, paws
- bite wounds
ingestion: undercooked meat, contaminated water
aerosol
Explain tularemia aerosol transmission
T/F: Tularemia involves person to person transmission
FALSE
What is the pathogenesis of tularemia?
infection by arthropod bites, skin abrasions, inhalation or ingestion
enters macrophages
What kind of pathogen is tularemia?
a facultative intracellular pathogen
can enter macrophages by pseudopod loops and survive by inhibiting phagosome/lysosome fusion
Francisella pathogenicity island encodes _____
type IV secretion system (idk what this means)
Where is tularemia only found?
northern hemisphere only
T/F: Tularemia is notifiable
TRUE
Contrast the sources of tularemia infection
endemic areas: ticks, rabbits
western: biting flies, ticks
All forms of tularemia starts with ______
sudden fever
chills
headache
myalgia
What is the ulceroglandular form of tularemia?
most common
ulcer and regional lymphadenopathy
What is the oculo-glandular form of tularemia?
conjunctiva infected
What is the oropharyngeal form of tularemia?
Describe the typhoidal and pulmonary forms of human tularemia
How do you treat tularemia? Drug of choice _____
antibiotic treatment - streptomycin
Type ___ of tularemia has a higher case-fatality rate
type A
What is tularemia disease in wildlife?
usually found dead
behave strangely
What is tularemia in sheep?
outbreaks in enzootic areas - following severe winter
fever, weight loss, etc
What is tularemia in equine, swine, and bovine?
What is tularemia in cats and dogs?
Upon necropsy of an animal with tularemia, what does it look like?
gray necrotic foci
lymph nodes, spleen, liver
Necropsy of a horse liver in North America reveals gray necrotic foci. It experienced fever, depression, ataxia, stiffness, and lymph edema. Its spleen was also enlarged. What is the causative agent and disease?
tularemia
f. tularensis (biovar tularensis type A)
How do you treat tularemia?
remove ticks as soon as possible
streptomycin
How do you prevent and control tularemia?
laboratory precautions
live attenuated vaccine
A 60-year-old woman was admitted to the hospital with a week history of sudden onset of cutaneous lesion on the second finger in her right hand, accompanied by fever, chills, headache and axillary lymphadenopathy. Initial antibiotic therapy with amoxicillin clavulanate was ineffective. The patient history includes recent handling of rabbits. What is the causative agent and disease?
tularemia - F. tularensis biovar tularensis (Type A)
