Vascular Infections - Quiz 4 Flashcards
Rickettsia is what kind of organism
where do they divide
- obligate intracellular
- gram-negative
- divide in the cytoplasm of infected cells
what organism carries rickettsia
- ticks
what does rickettsia infects
what does it cause
- infects vascular endothelial cells
- causes Rocky Mountain spotted fever
how has the incidence of RMSF changed over history
what about case fatality
- it has increased
- it has decreased
when do we see most RMSF infections? What months
- spring and summer
what states do we see a high incidence of RMSF cases
- NC- Tennessee- Arkansas- Missouri- Oklahoma
can we culture rickettsia without host cells?
- no
how does rickettsia get energy
- utilize host carbon sources and host ATP
how does Rickettsia move between cells
- utilizes host actin for motility and neighboring cell invasion
- bacteria spreads cell-to-cell without encountering extracellular environment
what happens to the endothelial cells that rickettsia infects
- alters and damages membranes of endothelial cells
- platelets bind to altered endothelial cells and leads to DIC
what does endothelial damage lead to
- blood leakage out of blood vessels
- leads to shock
prodromal symptoms of RMSF occur when
- 1-2 weeks
symptoms of RMSF
- chills- fever- headache- rash
what kind of rash do people with RMSF get
where
- erythematous
- maculopapular
- petechial
- on extremities then trunk
clinical picture of RMSF infection
- fulminant vasculitis of endothelial cells
- also vascular smooth muscle cells of kidney, heart, skin, brain, and subQ tissues
vascular endothelial cell damage in relation to the number of rickettsia parasitizing them
- proportional
case fatality of RMSF without treatment
- 25%
which age population is more susceptible to severe RMSF
- older people
what is the first line treatment for adults and children of all ages when RMSF is first suspected
when should it be administered
- doxycycline
- almost immediately
- within first 5 days of symptoms
does doxy stain teeth?
- no
what kind of virus is hantavirus
- robovirus
- rodent-borne virus
transmission of hantavirus
- transmission via inhaled aerosols contaminated with rodent feces or urine
- not person-to-person
another name for hantavirus in the US
- sin nombre
genome and covering of hantavirus
- enveloped RNA virus- segmented genome
