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13 Cards in this Set
- Front
- Back
Rickettsiae -
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- Gram negative, basic lesion is widespread peripheral vasculitis
- 3 serotypes |
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1) Typhus - Epidemic Louse Borne Typhus
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a) R Prowazekii (Epidemic Louse Borne Typhus:
- War, famine, displacement, reservoir is humans, lice are vectors - Headache, fever, chills, prostration - fatality varies with age (10-40%) |
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1) Typhus - Endemic Flea Borne Typhus
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b) R. Typhi:
- spread from rats/mice, milder course |
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2) Spotted Fever - Rocky Mountain Spotted Fever
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a) R. Rickettsii :
- Most prevalent + severe example in N. America, predominantly american southeast - Fever + headache 2-12 days after wood or dog tick bite, characteristic rash 3-5 days later - 10% don't develop rash delaying diagnosis, may have fatal consequences (untreated = 20-25% mortality) - 3 Things that cause spots on soles: Syphillis, rocky mountain spotted fever, coxsackie virus |
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2) Spotted Fever - Rickettsialpox
(There's more than these 2, these are the most imp.) |
- R. Akari : Mild disease, vesicular rash transmitted by mouse mites
-MIMICS CHICKENPOX |
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3) Scrub (Mite-borne) Typhus: Fatality can reach 60%, can't be cultivated by can be grown through inoculation of blood in mice
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Orientia Tsutsugamushi:
- "scourge of military", sporadic distribution but mainly confined to Orient - Spread via bites of infected chiggers (mite larae) from rodents, reservoir can be maintained by transovarial passage in mites - Initial "punched out" skin lesion, fever headache, conjunctivitis, lymphadenopathy follow - Dull red maculpapular eruption appears on trunk + spreads to extremities late in first week |
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Coxiella
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C. Burnetii
- Causes Q fever, manifested as community acquired pneumonia - Unlike ohter rickettsiae, NO RASH assoiated with Q fever. Grows in cytoplasmic vacuoles - Extremely resistant to heat + drying, which is unusual for intracellular - Transmitted by inhalation of aerosols, often from placentas of infected sheep or cattle (slaughterhouse workers at risk) |
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Ehrlichia: 5 serotypes
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- parasitize leukocytes, grow in cytoplasmic vacuoles, creating inclusions called morulae
- All caused by ticks except Neorickettsia Sennetsu, all cause fever, myalgia, leucopenia, thrombocytopenia which can be fatal |
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a) Ehrlichia Chaffeensis
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= causes human monocytic erhlichiosis (HME), no rash, main distributor = lone star tick, found in SE + South central US
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b) Ehrlichia Ewingii
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- infects neutrophils of immunocompromised
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c) Ehrlichia Muris
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- Causes HME in russian federation
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d) Anaplasma Phagocytophylum
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- Infects neutrophils, causes human granulocytic anaplasmosis (HGA), transmitted by deer + dog ticks
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e) Neorickettsia Sennetsu
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- Causal agent of sennetsu fever, similar to infectious mononucleosis
- NO KNOWN TRANSMISSION, NOT BY TICKS |