Term
| What is the morphology of rickettsia? |
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Definition
| small, rod shaped, obligate IC |
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Term
| Where do Rickettsiae multiply? |
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Definition
| endothelial cells of BVs: endothelial proliferation and perivascualr inflitration |
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Term
| What is the pathogenesis of Rickettsiae? |
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Definition
| attaches to surface>induces phagocytosis>leaves lysosome and enters cytoplasm>accumulates>cell lysis |
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Term
|
Definition
| lower animals>wood tick/dog tick>humans in Eastern & SE US |
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Term
| How is Rickettsiae diagnosed? |
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Definition
PCR-based assays
serological testing: complement, indirect immuno, latex agglut
Weil-Felix rnx |
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Term
| How is Rickettsiae treated? |
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Definition
Doxycycline, tetracycline, erythromycin
(penicillins are ineffective; sulfonamides increase the severity of infection) |
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Term
| What is the clinical presentation of RMSF? |
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Definition
| headache, fever, malaise, chills then macular>petechial rash (2-4 days later) on trunk, soles/palsms |
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Term
| What are complications of RMSF? |
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Definition
| DIC, thrombocytopenia, encephalitis, vasc collapse, renal & cardiac failure |
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Term
| How is R. akari (Rickettsial Pox) transmitted? |
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Definition
| house mouse>house mouse mite> people of large urban areas of US, Russia, Korea |
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Term
| What is the clinical presentation of R. akari? |
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Definition
Rickettsial Pox: vesicular rash, loacl eschar, regional lymphadenopathy, erythematous papules>vesicles>eschar
chills, fever, malaise, headache, myalgia |
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Term
| How is epidemic typhus (R. Porawzekii) spread? |
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Definition
| human/flying squirrel>human body louse or head louse> people in central & south america, africa, crowded/poor hygiene conditions |
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Term
| What is Brill-Zinsser Disease? |
|
Definition
| a mild relapse of epidemic typhus, 10-40 years later |
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Term
| What is the clinical presentation of epidemic typhus? |
|
Definition
headache, malaise and fever 1-2 weeks after infection
rash after 4-7 days: patchy, cutaneous erythema >maculopap, petechial or hemorrhage
spreads from trunk to extremeities |
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Term
| What are the complications of epidemic typhus? |
|
Definition
myocarditis
CNS dysfnx
Brill-Zinsser Disease |
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Term
| How is endemic typhus (R. typhi) spread? |
|
Definition
| rat>rat flea> SE & Gulf Coast (of US) |
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Term
| What is the clinical presentation of endemic typhus? |
|
Definition
abrupt onset of fever, headache, malaise, myalgia, skin rash: trunk > extremities
fatalities in the elderly/sick |
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Term
| How is Scrub Typhus (orientia tsutsugamushi) spread? |
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Definition
| rodents>mites>vertebrates in Japan, Australia, India, Vietnam, Korea |
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Term
| What is the clinical presentation of scrub typhus (orientia tsutsugamushi)? |
|
Definition
chills, fever, headache 3 weeks after bite
local cutaenous rash>vesicular>eschar
30% mortality if untreated |
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Term
| How is erlichiosis spread? |
|
Definition
| cattle/domestic animals/dogs>deer tick/dog tick>people in SE, mid-atlantic, south and central US |
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Term
| What is the clinical presentation of Erlichiosis? |
|
Definition
fever, headache, malaise and myalgia 10-12 days after bite
leukopenia
thrombocytopenia
mortality most common in the elderly |
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Term
| What is the morphology of Yersinia Pestis? |
|
Definition
short, gram (-) rods
Wright-Giemsa Stain: bipolar/safety pin staining |
|
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Term
| What is the pathogenesis of y pestis? |
|
Definition
facultative IC
capsular & cell wall Ags provide resistance to phagocytosis
type III secretion system: antiphagocytic, anti-inflamm, and toxic proteins |
|
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Term
| How is Y. Pestis transmitted? |
|
Definition
rodents/small mammals>fleas>humans
humans get it from contact w/rodents, biet of flea, resp transmission from man-man |
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Term
| What are the 2 cycles of Y. Pestis? |
|
Definition
1. sylvatic: bubonic
2. urban: pneumonic |
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Term
| What are the complications of Y. Pestis? |
|
Definition
septicemia: lungs, liver, spleen, meninges
DIC>death
pneumonic: hemorrhagic consolidation, sepsis, death |
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Term
| How is Y. Pestis treated? |
|
Definition
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|
Term
| What is the morphology of Francisella Tularemia? |
|
Definition
small, facultative, gram (-) coccobacillus
fastidious |
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Term
| What is the pathogenesis of Francisella Tularenis? |
|
Definition
| encapsulated (resists intraphagocytic killing), macrophages>necrosis>granulomas |
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Term
| How are humans infected w/francisella tularensis (rabbit fever)? |
|
Definition
| direct contact w/animal, bite of vector, aerosol inhalation, ingestion of contaminated food/h20 |
|
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Term
| What animals are a resevoir for francisella tularensis? |
|
Definition
| rabbits, squirrels, muskrats, beavers, deer |
|
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Term
| What are the types of Tularemia? |
|
Definition
oculoglandur: painful, purulent conjuctivitis; cervical/preauricular lymphadenopathy
typhoidal: most severe; bacteremia to lung, liver, kidney, spleen; fever, weight loss, PNA
ulceroglandular: most common; ulcerating, necrotic papule w/in 2-6 days
glandular: regional LN elnargment, fever, headache, malaise w/absecense of skin lesion |
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Term
| How is tularemia diagnosed and treated? |
|
Definition
Dx: serology: agglutination in 2-4 weeks
Tx: streptomycin or gentamicin for 7-10 days
attenuated vaccine for people at risk |
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|
Term
|
Definition
short, gram (-) rods
catalase (+)
oxidase (+)
aerobic
complex media: trypticase-soy agar, CO2 |
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Term
| What are the routes of infection for brucella? |
|
Definition
intestinal tract, mucous membranes, skin
(enter and multiply in phagocyte; spread through lymph>LNs>bloodstream>organs/tissues) |
|
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Term
| What is the clinical presentation of Brucella? |
|
Definition
insidious onset of malaise, fever, weakness, aches, sweats
undulant fever w/diurnal variation
enlarged LNs & palpable spleen |
|
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Term
| What is seen microscopically with Brucella? |
|
Definition
granulomatous nodules & abscesses in lymph, spleen, kidney, BM
epitheloid & giant cells
central necrosis
periph fibrosis |
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Term
| What are the chronic symptoms of Brucella? |
|
Definition
| low grade fever, weight loss, myalgia, nervousness |
|
|
Term
|
Definition
| combination of tetracycline w/streptomycin or gentamycin for 4-6 weeks |
|
|
Term
|
Definition
small, gram (-) coccobacilli
non-hemolytic mucoid colonies
normal flora of resp & GI tract of various animals |
|
|
Term
| What is a common cause of infection following bite/scratch of cat or dog? |
|
Definition
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Term
| What is the clinical presentation of pasteurella multocida? |
|
Definition
diffuse cellulitis w/well-defined erythematous border
chronic abscess may develop |
|
|
Term
| diffuse cellulitis w/well-defined erythematous border |
|
Definition
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