Vector-borne bacterial infections Flashcards
1
Q
bacilli
A
disease causing bacteria
2
Q
what kind of bacilli is rickettsia
A
gram-negative
3
Q
what makes rickettsia different from other gram negative rods
A
- peptidoglycan layer is minimal
2. LPS has weak endotoxin activity
4
Q
what can you not use for treatment in Rickesttsi? and why?
A
Beta-lactams because LPD has weak endotoxin activity
5
Q
obligate intracellular
A
cannot produce outside of host cell
6
Q
where does Rickettsia replicate
A
in cytoplasm of cell
7
Q
what stain is used to see Rickettsia
A
Giemsa
Gimenez
8
Q
what is the common name for Rickettsia rickettsii
A
Rocky Mountain Spotted Fever (RMSF)
9
Q
what is the pathogenic factor in Rickettsia rickettsii? how does it work
A
outer membrane protein A (Omp A)
- adherence to endothelial cells
10
Q
Rickettsia rickettsii replicates where? this results in what
A
cytoplasm and nucleus
-vasculitis
11
Q
how does Rickettsia rickettsii bypass the immune system
A
intracellular growth protects the bacteria from immune clearance
12
Q
what is the most common Rickettsia causing human disease in USA
A
Rickettsia rickettsii
13
Q
90% of infections occur during what time of year
A
April - September
14
Q
what is the vector for Rickettsia Rickettsii? what family do they belong to
A
Ticks
Ixodeae family
15
Q
name the 2 forms of ticks that cause Rickettsia Rickettsii
A
Dermacentor andersoni (wood tick) Dermacentor variablilis (dog tick)
16
Q
where is Dermacentor andersoni found
A
rocky mountain states
17
Q
where is dermacentor variablilis found
A
Southeast United states
18
Q
what states had the highest incidence rates for Rocky mountain spotted fever
A
Arkansas Delaware Missouri North Carolina Oklahoma Tennessee
19
Q
what is the reservoir for rickettsia rickettsii
A
ticks via transovarian transmission
20
Q
what is the process of a tick biting a human
A
- bit is painless and goes unnoticed
- after 6-10 hours ….????
21
Q
how long does rocky mountain spotted fever incubate
A
2-14 days
22
Q
what are clinical symptoms for rocky mountain spotted fever
A
fever chills headaches myalgias abdominal pain vomiting hepatitis respiratory failure encephalitis renal failure hypotension myocarditis
23
Q
when does the pathogenic rash appear for rocky mountain spotted fever
A
after 3-5 days
24
Q
where does the pathogenic rash appear for rocky mountain spotted fever? do all victims get this rash
A
centripetal
palms and soles
no
25
what does centripetal rash mean
spreads from periphery to center
26
what happens in 20% of untreated cases for RMSF
fatal, clinical suspicion is key
27
what will the laboratory findings be for RMSF
```
Thrombocytopenia
coagulopathy
anemia
normal WBC count
hyponatremia
Transminitis
```
28
Transaminitis what does that mean
Increased ALT/AST levels
| could indicate liver damage
29
for RMSF when is diagnosis idealistic
before the onset of rash is clinical and epidemiological
30
RMSF, the organism in acute phase is detected how in the lab
1. PCR
2. Immunohistochemical methods in skin biopsy
3. serology but confirmation needed
31
according to the CDC, when is RMSF notified to them
```
fever plus any one of the following
rash
eschar
headache
myalgia
anemia
thrombocytopenia
hepatic transaminase elevation
```
32
how do you confirm RMSF in the lab
1. fourfold change in IgG specific titer reactive with R. rickettsii by indirect immunofluoresense assay (IFA) b/w paired serum specimens ( one speciemen taken in 1st week, second 2-4 weeks later )
2. detect R. rickettsii DNA in a clinical specimen via amplification of a specific target by PCR asay
3. demonstrate rickettsial antigen in biopsy or autopsy speciment by IHC
4. Isolation of R. Rickettsii from clinical specimen in cell culture
33
for laboratory confirmation of RSMF why is IgM not used
lacks specificity and are usually false +
34
common name for Rickesstia akari
Rickettsailpox
35
what is the world distribution for Rickettsia Akari
cosmopolitan
36
how is Rickettsia akari transmitted
mites
37
what is the reservoir for Rickettsia akari
rodents ( common house mouse)
38
how does R. akari present
biphasic
39
what happens in the first phase for R. akari
1 week after bite: papule to ulcer to eschar at site of bite
40
what happens after the first phase of Rickettsialpox
incubates for 7-24 days
| systemic spread
41
what happens in 2nd phage of R. akari
```
high fever
severe headache
photophobia
papulovesicular rash,
pox-like progression ( vesicles crust over)
```
42
when does R. Akari 2nd phase heal
within 2-3 weeks
43
for clinical symptoms with R. akari and R. Rickittsii which one has a milder course
R. akari
44
Anthrax
bacterial disease of sheep and cattle, typically affecting the skin and lungs.
- transmitted to humans, causing severe skin ulceration or a form of pneumonia
45
what is the difference in skin rashes with Anthrax and Rickettsialpox
anthrax patients only have eschar
| Rickettsialpox: papule --> ulcer --> eschar
46
If Rickettsialpox is on the differential diagnosis list what other thing should be on the list
Anthrax
47
R. Prowazekii has what reservoir
humans
48
how is R. prowazekii transmitted
during blood meal
- louse defecates highly infective feces
- introduced into by body by scratching/hand contamination/ injured skin or mucous membrane
49
how long can lice feces remain infectious in R. prowazekii
100 days
50
how are louse transfered from human to human in R. prowazekii
sharing clothes
51
what are 2 syndromes for R. prowazekii
acute, potentially severe vasculitis
| - Brill-Zinsser disease
52
when does acute, potentially severe vasculitis occur in R. prowazekii? what other symptoms present
7-14 days after contact with infected lice
| fever, centrifugal maculopapular rash, CNS symptoms
53
what is Brill-Zinsser disease
recrudescent from 10-50 years after primary infection
| - milder form, rash, flu-like symptoms, seen in elderly patients WWII refugees
54
how is R. prowazekii tested in the laboratory
serology (MIF) test
55
when is R. Prowazekii prevelent in the world
during disaster, war, famine
| rare in US
56
R. prowazekii is transmitted how in the US
usually rare in US
- "flying squirrels"
- squirrels have fleas, fleas bite humans
57
R. Parkeri common names
American Boutonneuse fever
| -Tidewater spotted fever
58
where does R. Parkeri usually occur
souther United States
59
what is the vector for R. Parkeri
Amblyomma maculatum ( Gulf Coast Tick)
60
clinical symptoms for R. Parkeri
fever, headache, myalgias
| eschars and rash on PE
61
what is the mortalilty rate for R. parkeri
low
62
what lab tests would be used R. Parkeri
serology
PCR
culture from skin biopsy
63
what is the treatment for R. Parkeri
Doxycycline
64
R. Typhi have what reservoir
rodants
65
what is the main vector for R. Typhi
Xenopsylla cheopis ( rat flea) also cat flea ( esp in USA)
66
where is R. Typhi usually found
worldwide, more in warm, humid areas
67
how are humans infected with R. Typhi
inoculation of infective flea feces in bite wounds
68
what is the endemic (murine ) typhus
R. typhi
69
what is the epidemic (louse-borne) typhus
R. prowazekii
70
what are some clinical manifestations of R. Typhi
fever, headache, chills, myalgias
rash ( variable)
mild symtpoms
71
what labs should be runned for R. typhi
serology by IFA
72
what is the common name for Orientia tsutsugamushi
scrub typhus
73
what is the reservoir for Orientia tsutsugamushi
larval mites ( chiggers), via transovarian
74
what is the vector for Orientia tsusugamushi
mites, feed only once in a lifetime
75
where is Orientia tsutsugmamushi found in the world
Asia Pacific rim
76
clinical symptoms of Orentia Tsutsugamushi
severe headache, fever, myalgias
maculopapular rash, spreads CENTRIFUGALLY
CNS complications
heart failure
77
what lab tests check for Orentia Tsutsugamushi
Serology (IFA)
78
what is the drug of choice to treat Rickettsial and Orientia infections
Doxycylcine
79
what are alternative drugs to treat Rickettsial and Orientia infections
Chloramphenical or Fluoroquinolone
80
when should treatment be administered if you think you have Rickettsial or Orientia infections
Immediately , don't wait for confirmatory serology
81
for RMSF what are the rules for giving Doxycline
Normally: don't > 8yrs b/c dental staining/enamal hypoplasia
RMSF: drug of choice regardless of age of patient
82
how should a tick be removed from the skin
don't twist or jerk the tick when pulling with twizzers
83
what are the 5 don'ts for Rickettsial disease
- don't wait for petechial rash to develop
- don't exclude diagnosis because no history of tick bite
- don't exclude diagnosis solely for geographic or seasonal reasons
- don't withhold therapy if there is any suspicion
- don't be afraid to use Doxycyline at any age
84
what type of bacteria are Ehrlichia and Anaplasma
obligate intracellulular
85
Ehrlichia and anaplasma don't have what in the cell memebrane? Therefore what treatment will not work for them
no peptidoglycan or LPS
| beta-lactams dont work
86
Ehrlichia and Anaplasma grow on what type of cell
Hematopoietic cells
87
where do Ehrlichia and Anaplasma replicate
phagosomes of host cells
88
what is morula
microcolony of Ehrlichiae within a vacuole
89
Another name for Ehrlichia chaffeensis
human monocytic ehrlichiosis HME
90
what is another name for anaplasma phagocyophilum
human granulocytic anaplasmosis HGA
91
what is the reservoir for Ehrlichia chaffeensis
deer and dogs
92
what is the vector for Ehrlichia chaffeensis
ticks
| Amblyomma americanum
93
where is Ehrlichia chaffeensis usually found
southeast
| south central and midwest states
94
what and when do clinical symptoms occur for Ehrlichia chaffeenis
```
1-3 weeks after bite: flue-like symptoms
late onset ( 1 week after) rash (spares hands and feet)
```
95
what lab work is done for Ehrlichia chaffeensis
serology by IFA
PCR in blood
- peripheral blood (Giemsa) to see morulae in monocytes is insensitive
96
what is the reservoir for Anaplasma phagocyphilum
Deer, sheep, rodents
97
what vector does Anaplasma phagocyphilum use
hard-shelled ticks
| Lxodes scapularis pacificus
98
where does Anaplasma phagocyphilum predominantly occur
Northeast/north-central states and Norther California
99
what are the clinical symptoms for Anaplasma Phagocyphilum
```
1-3 weeks after bite: flue-like symptoms
late onset ( 1 week after) rash (spares hands and feet)
```
100
what labs are done for Anaplasma Phagocyphilum
- serology by IFA (paired specimens to see increase IgG_
- blood PCR
- peripheral blood ( Giesma) to see morulae in granulocytes is insenstive
101
what are laboratory findings for Anaplasma and Ehrlichia
leukopenia
lymphopenia
thrombocytopenia
elevated liver enzymes
102
what is the drug choice for Ehrlichia and Anaplasma
DOXYCLYCINE REGARDLESS OF AGE
103
what happens if the patient fails to respond to Doxycycline within 3 days
there is an infection with other organism
104
Borrelia recurrentis
epidemic relapsing fever
105
Borrelia spp
endemic relapsing fever
106
Borrelia burgdorferi
lyme disease
107
what type of bacteria is Borrelia
weakly staining, gram neg. spirochetes
108
what makes Borrelia a different bacteria from the rest of them
motile (flagella)
| difficult to cultivate
109
what is the leading vector for Borrelia burgdorferi
borne disease in USA
110
what 3 main areas are Borrelia burgdorferi found
Northeast, Minnesotta, and Wisconsin
111
what are other vectors for borrelia burgdorferi
lxodes scapularis
| pacificus
112
what is the reservoir for borrelia burgdorferi
white-footed mouse (peromyscus leucopus) and white-tailed deer
113
how is borrelia transmitted
in tick's saliva during prolonged period
114
what time of the year does Lyme disease occur
June and July
115
what is the incubation period for Lyme disease
up to 1 month from tick bite
116
what are the 3 stages of Lyme disease
early localized
early disseminated
late disease
117
what happens in early localized
distinctive rash: erythema migrans (bull's eye)
118
what happens in early disseminated
multiple EM, facial nerve palsy, meningitis
119
what happens in late disease
arthritis (knees) carditis
120
what are symptoms of Lyme disease
fatigue, joint pain, cognitive problems
121
for early stage Lyme disease how is diganosis made and why
clinically b/c Ig are not detectable within the 1st 4weeks of infection
122
what laboratory items would you use for Lyme disease
EIA or FIA
| confirmatory Western Blot
123
what is used to treat Lyme disease
Amoxicillin or cefuroxime for children equal to 8 years
124
what is used to treat the CNS, carditis or recurrent arthritis in lyme disease
Ceftriaxone
125
what does STARI stand for
Southern Tick-associated rash illness
126
what are clinical symptoms for STARI
rash typical of erythema migrans and mild flu-like symptoms in NON-LYME ENDEMIC AREAS
127
STARI is associated with a bite by what
Lone Start tick ( A. americanum)
128
Preliminary studies show the cause of STARI is postulated to be a
spirochete: B. lonestari
129
where does STARI occur
```
Missouri
Maryland
Georgia
South Carolina
North Carolina
```
130
what may serve as a reservoir for STARI
white-tailed deer
131
name 4 reasons why STARI is different from lyme
onset of lesion was shorter
- less likely to have multiple skin lesions, smaller sized lesions
- rapid recovery
- not linked to arthritis, neurologic disease, or chronic symptoms
132
what medicine is used to treat STARI
Doxycycline
| Amoxicillin
133
under what circumstance does B. recurrentis occur
natural disasters
| unsanitary conditions
134
what is reservoir for Borrelia spp.
rodents, small mammals
135
how do ticks transmit Borrelia spp.
feed nocturnally and contaminate the wound with saliva and feces that are infectious
136
what are clinical syndromes for relapsing fever
fever, chills, headaches, hepatosplenomegaly
137
what is the timeline for relapsing fever clinical symtpoms
incubation 1 week
afebrile period of 1 week
return symptoms
relapse
138
what is the mortality rate for relapsing fever
high 40%
139
how does one lab diagnose relapsing fever
Giemsa on peripheral blood during febrile episode
140
what is the treatment of relapsing fever
Doxycycline
| Penicillin and Erythromycin for pregnant and children under 8 years of age
141
what is Babesia
protozoa
142
Babesia shares the same vector and reservior as what other disease
B. burgdorferi
143
what is the vector and reservoir for Babesia
v: lxodes ticks
r: white footed mouse
144
what is the most common species for Babesia
babesia microti
145
Babesia is what kind of parasite and what does it mimic
INTRA-ERYTHROCYTIC PARASITE
| MALARIA
146
what is the life cycle of Babesia
blood meal, introduces sporozoites into human host
- sporozoites enter erythrocytes, asexual replication
- replication causes the disease
147
what are clinical manifestation for Bebsia
```
hemolytic anemia
influenza like symptoms ( fever, chills, body aches)
Splenomegaly
hepatomegaly
jaundice
```
148
what are risk factors for Babesia
advanced age, immunocompromised person
149
how is Babesia lab diagnosed
- detected by microscope examination of blood smear (maltese cross)
- double check, b/c hard to distinguish from plasmodium
- PCR detects low levels of parasites
150
why is serology not helpful for Babesia
cannot distinguish between acute versus old infection
151
what is the treatment for babesiosis
combination therapy
mild disease: Atovaquone PLUS azithromycin
severe disease: Clindamycin PLUS quinine
