L30- Multi-system Infections II Flashcards
list the common vector-borne diseases carried by the following:
- (1) mosquito
- (2) tick
- (3) fly
1- YF, Dengue, Zika, ChikV
2- *Lyme disease, *Rocky Mountain Spotted fever; Ehrlichiosis, Anaplasmosis
3- Leishmaniasis, Trypanosomiasis (american, african)
Rocky Mountain Spotted fever is caused by (1) pathogen
Lyme disease is caused by (2) pathogen
1- rickettsia rickettsii
2- borrelia burgdorferi
rickettsia rickettsii is carried by (1) tick
borrelia burgoferi is carried by (2) tick
1- Dermacentor spp.
2- Ixoides spp.
Lyme Disease:
- (1) pathogen
- (2) associated tick, common name
- (3) incubation period
- (4) duration
- (5) rash description
- (6) main common symptoms
1- borrelia burgdorferi 2- black-legged tick, deer tick 3- 3-30 days 4- wks 5- bull's eye rash 6- fever, arthralgia, myalgia
Rocky Mountain Spotted fever:
- (1) pathogen
- (2) associated tick, common name
- (3) incubation period
- (4) duration
- (5) rash description
- (6) main common symptoms
1- rickettsia rickettsii 2- Rocky Mountain wood, American dog, brown dog 3- 2-14 days 4- wks 5- macular / petechiae rash 6- fever, arthralgia, myalgia
Rickettsia rickettsii: list the many important bacterial features
- small obligate intracellular Gram- rod
- non-motile, pleomorphic (shape)
Rickettsia rickettsii:
- (1) critical geographic areas
- (2) critical season
- (3) are the other risk factors
1- NC, SC, OK, TN
2- Apr. – Sept. (late spring thru summer)
3- dog exposure, residence near forest / tall grass, children (5-9 y/o), males
Once ricketsia rickettsii is inoculated into skin, pathogens will travel to (1) cells via (2) and then multiply via (3) process. (4) is the mechanism of the rash and petechial lesions, plus is the basis for the other systemic symptoms. (5) is the typical immune response.
1- endothelium and vascular smooth muscle cells
2- blood
3- binary fission in cytoplasm –> damage heavily parasitized cells
4- RBC’s leak thru breaks in BVs (same process in other organs)
5- T cell mediated: IFN-γ, TNF-α
Rickettsia rickettsii:
- (1) incubation period
- (2) initial presentation
- (3) subsequent Sxs- many
- (4) is the dangerous complication, indicate time period
1- 2-14 days
2- abrupt onset fever, HA
3- fever/chills, rash, HA, n/v/d, abdominal pain, myalgia, loss of appetite, photophobia, sometimes conjunctival injection
4- fatal in first 8 days if not treated correctly
describe the initial presentation and progression of rash in Rocky Mountain Spotted fever
Early: red to purple, spotted/petechial rash seen around day 5 of Sxs — starts peripherally (ankles, wrists)
Late: 35-60% of Pts, rash spreads proximally on limbs (more spotted)
(1) is the main complication / concern with rickettsia rickettsii infections. (2) is the immediate risk from (1) and (3) is the concern if (1) is severe early in the infection. If (1) does not occur, Rocky Mountain Spotted fever will take (4) for recovery.
1- vasculitis (damaged BVs) => clotting / bleeding
2- fluid loss –> loss of circulation to extremities –> digital necrosis –> amputation
3- permanent long-term health deficits (neurological or to other internal organs)
4- days to months
Rocky Mountain Spotted fever:
- (1) are the recommended technique for diagnosis
- (2) are the many other possible tests used
- (3) is used for disease confirmation
1- IFA (indirect immunofluorescent assay) and EIA (enzyme immunoassays)
2:
- serology: 4-fold change in Ab titers (paired samples)
- direct IFA
- skin biopsy
- Weil-Felix: IHC Ag detection
3: specialized PCR for serum Abs
Borrelia Burgdorferi:
- (1) describe important bacterial features
- (2) geographic predominance
- (3) season predominance
- (4) describe briefly process of tick bite that spreads disease
1- Gram- spirochete
2- NE USA, N Mid-west —- Pacific coast
3- late spring thru summer
4- must be attached for 36-48hrs (or from incorrect removal of tick –> head breaks and releases bacteria)
Borrelia Burgodorferi:
- infects hosts / vectors in (1) stage
- infects humans in (2) stage
- (3) is special characteristic of blacklegged ticks lifecycle
1- (not eggs) larva –> nymph –> adults
2- nymph –> adults
3- population can double w/in 2 yrs
In Lyme disease pathogenesis, borrelia burgodorferi produces (1) to mediate binding to (2). Then infection induces synthesis of (3), affecting local area of infection. The infection spreads via (4). (5) are the factors that help the Spirochete evade host immune response and be resistant to (6) killing.
1- adhesins
2- glycoaminoglycans (GAGs) and integrins
3- pro-and anti- inflammatory CKs
4- lymph –> regional lymphadenopathy –> distant tissues (wks/mos)
5- factor H proteins, Ag variation
6- complement mediated killing
list the common symptoms of Lyme disease, most to least prevalent
- EM: erythema migrans rash, 71%
- arthritis, 28%
- facial palsy (9%), radiculopathy (4%), meningitis/encephalitis (2%), carditis (1%)
Lyme disease:
- (1) incubation period
- (2) describe progression of rash (onset to disappearance)
- (3) describe the other symptoms and duration
1- 3-30 days (at bite site)
2- ECM = erythema chronicum migrans = slowly expanding red ring = bull’s eye rash (leading edge contains pathogen) —-> disappears w/in wks
3- fever, myalgia, arthralgia may last for months (meningeal irritation also)
Lyme disease: briefly describe initial / first stage of presentation (1/3, include timing)
(incubation, 3-30 days)
- ECM rash
- accompanied flu-like Sxs
- organism spreads via lymph / blood to MSK, skin, CNS, heart, etc
