B3-027 Vector-Bourne Infections Flashcards

1
Q

__________ contributes to changes in vector distribution and local risk

A

climate change

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2
Q

arboviruses: flaviviridae

A

yellow fever, dengue, west nile

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3
Q

arboviruses: togaviridae

A

chikungunya virus

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4
Q

arboviruses are transmitted through

A

arthropod bite

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5
Q

non-neuroinvasive symptoms of arbovirus

A

GI symptoms, rash

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6
Q

neuroinvasive symptoms of arboviruses

A

meningitis or encephalitis

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7
Q

flavivirus binds to

A

non-specific heparin sulfate or to specific receptors via E protein

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8
Q

+ssRNA flaviviruses use ______________ for protein translation and processing in the ER

A

host and viral proteases

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9
Q

flaviviruses replicate in the

A

cytoplasm

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10
Q

flavivirus particles mature in the

A

trans-golgi

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11
Q

Yellow Fever Virus has _______ antigenic type[s]

A

a single

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12
Q

YFV endemic areas

A

Sub-saharan Africa
Central and South America

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13
Q

YF testing is done at

A

CDC

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14
Q

YF vaccine is

A

live attenuated

causes a robust innate immune response

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15
Q

IgM and IgG from the YF vaccine can

A

persist for years

**note patient immunization status when interpreting serology

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16
Q

WNV testing is done at

A

State PH lab or CDC

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17
Q

treatment for WNV

A

supportive therapy

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18
Q

prevention of WNV

A

anti-mosquito measures

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19
Q

dengue virus has [#] different serotypes

A

4

DENV 1-4

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20
Q

DENV viral entry is facilitated through

A

host receptor DC-SIGN or Fc receptors

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21
Q

DENV surface proteins

A

E, prM, and M

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22
Q

NS1 is a virulence factor of

A

DENV

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23
Q

NS1 causes

A

thrombocytopenia, hemorrhage, inhibition of complement

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24
Q

anti-body dependent enhancement occurs

A

upon secondary infection with DENV serotype

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25
Q

anti-body dependent enhancement causes

A

vascular damage, shock, hemorrhage (GI and skin)

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26
Q

dengue case definition

A

febrile person with travel history or residence in endemic area +

> 2: nausea, vomiting, rash, aches, pains, a positive tourniquet test, leukopenia

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27
Q

severe dengue case definition

A

plasma leakage
bleeding
organ impairment
altered consciousness
heart impairment

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28
Q

Trioplex rRT-PCR can be used to diagnose

A

dengue, chikungunya, zika

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29
Q

dengue can be diagnosed in the acute phase using

A

DENV-1-4 rRT-PCR
Trioplex
NS1 antigen test

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30
Q

dengue can be diagnosed in the acute and convalescent stage using

A

serology
IgM: 3d-3m p.i.

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31
Q

the vaccine for dengue is

A

a live attenuated tetravalent vaccine

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32
Q

the vaccine for dengue is only administered

A

to non naive people living in endemic areas

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33
Q

symptoms of chikungunya

A

acute high fever with severe and debilitating polyarthralgia

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34
Q

chickungunya virus is a _______virus spread by ________

A

togavirus; aedes mosquitos

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35
Q

rocky mountain spotted fever is caused by

A

rickettsia rickettsii

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36
Q

epidemic typhus is caused

A

rickettsia prowazekii

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37
Q

human monocytic ehrlichiosis is caused by

A

ehrlichia caffeensis

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38
Q

human granulocytic anaplasmosis

A

anaplasma phagocytophilum

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39
Q

small pleomorphic bacteria

A

rickettsia

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40
Q

obligate intracellular of mammalian cells; grow in cytoplasm

A

rickettsia

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41
Q

best stain for rickettsia

A

giemsa

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42
Q

RMSF has a _________ mortality

A

severe, 5-10%

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43
Q

rickettsia reservoir

A

rodents

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44
Q

rickettsia rickettsii vector

A

ticks (dermacentor)

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45
Q

R. prowazekii vector

A

body louse

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46
Q

R. prowazekii cause epidemics following

A

war, natural disasters, and in refugees

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47
Q

R. prowazekii is also found in

A

flying squirrels and squirrel fleas

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48
Q

RMSF classic triad

A

fever
rash
headache

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49
Q

RMSF fever starts _________ after tick bite

A

7 days

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50
Q

RMSF rash appears ________ after fever and spreads _______

A

3-5 days; centripetally

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51
Q

rash spreads centrifugally; on palms and soles

A

RMSF

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52
Q

rash spread centrifugally; spares face, palms and soles

A

R. prowazekii

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53
Q

mild recrudescence of latent typhus infection
anamnesic IgG response

A

Brill Zinsser disease caused by R. prowazekii

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54
Q

rickettsia multiplies in the vascular endothelial cells causing

A

vasculitis, most prominent in the skin

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55
Q

rickettsia treatment

A

Doxy immediately based on presumptive diagnosis

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56
Q

rickettsia diagnosis

A

serology
IFA on two paired samples
PCR
IHC

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57
Q

virulence factors rickettsia

A

phospholipase A: escape from phagosome
actin based motility
inhibition of apoptosis

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58
Q

obligate intracellular
replicate in phagosome of monocyte (morulae)

A

ehrlichia/anaplasma

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59
Q

resovoir for ehrlichia chaffeensis

A

deer/dog

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60
Q

reservoir for anaplasma phagocytophilium

A

rodent

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61
Q

HME/HGA are clinically

A

indistinguishable

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62
Q

HME/HGA symptoms

A

fever, headache, myalgia

no rash = “Spotless, Spotted Fever)

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63
Q

virulence factors ehrlichia/anaplasma

A

reduction in host cell apoptosis: promotes intracellular survival
upregulation og TfR: iron acquisition

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64
Q

diagnosis of ehrlichia/anaplasma

A

gold standard: blood culture in cell lines
IFA
morulae in Giemsa
PCR

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65
Q

ehrlichia/anaplasma treatment

A

tetracycline/doxy

even in children and pregnant women
do not delay treatment, treat for suspicion

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66
Q

borrelia burgdorferi
babesia microti
francisella tularensis

can exist as

A

co-infections with other tick-bourne pathogens transmitted from the same tick

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67
Q

Coxiella burnetti is caused by

A

dead end zoonosis

** not vector bourne

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68
Q

acute onset of atypical pneumonia

A

coxiella burnetti

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69
Q

chronic infection can lead to subacute endocarditis

A

coxiella burnetti

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70
Q

multiplication in fused phagolysosomes

A

coxiella burnetti

**need acidic pH

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71
Q

Q fever virulence factors

A

upregulation of TfR
antigenic phase variation

**highly infections in phase 1

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72
Q

Q fever treatment

A

tetracyclines, immediately-do not delay

73
Q

diagnosis Q fever

A

IFA with patient sera against cultured Phase I and Phase II C. burnetti

CF
PCR

74
Q

gram negative, aerobic, short bacilli, fastidious

A

bartonella

75
Q

causes oroyo fever and is transmitted by the sandfly

A

B. bacilliformis

76
Q

causes 5 day trench fever and is transmitted by human body louse

A

B. quintana

77
Q

5-day/trench fever

A

endocarditis, angiomatosis

78
Q

Cat scratch fever

A

bacillary angiomatosis, endocarditis

79
Q

causes Cat scratch fever and transmitted by the cat flea

A

B. henselae

80
Q

Bartonella is diagnosed via

A

serology

81
Q

treatment: bartonella

A

erythromycin, gentamycin

azithro in immunocompromised

82
Q

gram-negative, non-motile, non-spore-forming bacillus

A

yersinia pestis

83
Q

causes plaques in rodents and small mammals, transmitted to humans via infected fleas

A

yersinia pestis

84
Q

sylvatic plague reservoir of yersinia

A

prairie dogs

85
Q

humans are _______________ of yersinia

A

accidental hosts

86
Q

spread via flea bite, contact with infectious tissues, infectious aerosols

A

yersinia pestis

87
Q

there are approximately _________ cases of yersinia in the US/year

A

10

88
Q

most cases of yersinia occur in

A

four corners: NM, AZ, UT, CO

89
Q

caused the bubonic and pneumonic plagues

A

yersinia pestis

90
Q

buboes

A

local lymph node edema, black hemorrhagic lymph nodes caused by yersinia pestis

91
Q

the bubonic plague caused what diseases in infected persons

A

buboes
secondary pneumonia
internal hemorrhage –> septicemia and gangrene

92
Q

mortality rate of bubonic plague without treatment

A

70%

93
Q

pneumonic plague caused what diseases in infected persons

A

primary pneumonia (typical)

94
Q

mortality rate of untreated pneumonic plague

A

100% within 48hrs

95
Q

the “black death” of bubonic plague refers to

A

DIC

96
Q

yersinia virulence factors

A

endotoxin
T3SS
Fra1 capsule (pestis sp only)
Pla (pestic sp only)

97
Q

fra1

A

antiphagocytic protein capsule in yersinia pestis

98
Q

Pla

A

protease at body temp: degrades complement
coagulase at low temp: creates blood clot in infected flea

yersinia pestis virulence factor

99
Q

Diagnosis: yersinia

A

direct staining, DFA stain of Fra1, confirmatory test

100
Q

antibiotics must be started within _______ hours of onset of pneumonic plague

A

18

101
Q

DOC yersinia pestis

A

gentamycin, streptomycin

102
Q

PEE: yersinia pestis

A

doxy or cipro

103
Q

yersinia pestis vaccine

A

no vaccine

104
Q

small gram negative coccobacillus
fastidious
strict aerobe
facultative intracellular
non-fermentor

A

francisella tularensis

105
Q

glandular fever, rabbit fever, tick fever, deer fly fever

A

francisella tularensis

106
Q

reservoir wild rabbits

A

francisella tularensis

107
Q

francisella tularensis transmission in spring/summer

A

vector (ticks, deer flys)

108
Q

francisella tularensis transmission in winter

A

direct contact, aerosols

109
Q

francisella tularensis transmission can also be

A

food bourne

110
Q

endemic areas: francisella tularensis

A

KS, MO

pacific northwest
martha’s vineyard

111
Q

francisella tularensis transmission via tick bite can cause

A

ulceroglandular tularemia

112
Q

at a low ID tularemia can manifest as _______________ causing _______ disease

A

multiple necrotizing granulomas; respiratory

113
Q

other tularemia manifestations

A

oropharingeal, ocular

114
Q

diagnosis of francisella tularensis

A

DFA
antibody agglutination
culture
serology

115
Q

francisella tularensis should be cultured on __________ agar

A

cysteine containing (chocolate)

116
Q

DOC francisella tularensis

A

gentamycin, tobramycin

117
Q

alternative treatment francisella tularensis

A

doxy

**cephalosporin resistance

118
Q

francisella tularensis vaccine

A

live attenuated, used for lab personnel

119
Q

francisella tularensis prevention

A

avoid direct contact with infected animals (wear goggles)
tick prevention

120
Q

lyme borreliosis is caused by

A

borrelia burgdorferi

121
Q

relapsing fever is caused by

A

borrelia spp.

122
Q

syphilis is caused by

A

treponema pallidum

123
Q

leptospirosis is caused by

A

leptospira interrogans

124
Q

spirochetes have a

A

periplasmic flagella

125
Q

leptospira virulence factors

A

LPS
lipoproteins

126
Q

treponema pallidum virulence factors

A

none
no LPS- stealth mode

127
Q

borrelia virulence factors

A

lipoproteins

**NO LPS

128
Q

borrelia spp. are transmitted by several species of _______ ticks

A

ornithodoros

129
Q

B. hermsii occurs in the

A

NW

130
Q

B. turicatae occurs in the

A

SW

131
Q

why are ornithodoros bites rarely noticed?

A

they are fast feeders

132
Q

RF borrelia resides in the ________ and is quickly transmitted during feeding

A

salivary gland

133
Q

the ID of TBRF is

A

1

134
Q

LBRF comes from

A

crushing of louse

135
Q

each serotype is defined by

A

the expression of a different single immunodominant surface lipoprotein

136
Q

DOC LBRF

A

tertracycline

137
Q

DOC TBRF

A

doxy

138
Q

detection of Borrelia

A

spirochetes in blood smears

culture
serology

139
Q

abrupt onset of fever, chills, myalgias, tachycardia, flushing, exacerbated skin rash, mild hypertension

A

jarisch herxheimer reaction

not a penicillin reaction

140
Q

what causes jarisch herxheimer reaction?

A

cytokine storm triggered by lipoproteins after initiation on antibiotics

**occurs in treatment of spirochete

141
Q

Lyme disease aka

A

lyme borreliosis

142
Q

Lyme is transmitted via the _____ ticks

A

ixodes

143
Q

most common vector borne disease in the US

A

lyme disease

144
Q

two major foci of Lyme

A

northeast, great lakes areas

145
Q

humans are _______ host for lyme borreliosis

A

accidental; dead end

146
Q

ixodes ticks feed for

A

several days

147
Q

lyme borreliosis spirochetes have to travel from midgut to salivary gland making

A

transmission within 48 hours unlikely

148
Q

early localized Lyme symptoms

A

erythema migrans >5 cm in diameter (bulls eye)
nonspecific prodrome

149
Q

early disseminated Lyme symptoms

A

Neuroborreliosis: Bell’s palsy
cardiac dysfunction
secondary EMs

150
Q

late disseminated Lyme symptoms

A

oligoarticular arthritis
encephalopathy
acrodermatitis

151
Q

B. burgdorferi virulence factors

A

surface lipoproteins

OspA
OspC
adhesins
antigenic variation

152
Q

bind factor H and render bacteria “serum resistant”

A

CRASPs

153
Q

inflammatory host response to bacterial lipoproteins constant source of inflammatory stimulus
edema with neutrophil infiltration

A

lyme arthritis

154
Q

antibiotic treatment refractory arthritis is due to an

A

autoimmune response

**HLA-DRB1

155
Q

Lyme vaccine

A

recombinant lipidated OspA
blocks transmission

156
Q

Lyme disease can only be diagnosed via

A

laboratory results in combination with clinical diagnosis

157
Q

Lyme laboratory testing

A

culture, slow but most definitive

IFA
Western blot

158
Q

CDC criteria for diagnosis of Lyme borreliosis

A

western blot

159
Q

using ELISA for Lyme diagnosis is not accurate due to

A

high rate of false positive (cross reactivity)

160
Q

two step Lyme diagnosis

A
  1. EIA
  2. western blot
161
Q

preventative Lyme treatment

A

DEET, tweezer removal
doxy within 72 hours

162
Q

early Lyme treatment

A

doxy for 10 days or beta lactam for 14 days

163
Q

late Lyme treatment for severe refractory disease

A

I.V cephalosporin

164
Q

treatment: post infective Lyme arthritis

A

DMARDs

165
Q

should longer term antibiotics be used for post-treatment Lyme disease?

A

no, no credible evidence

166
Q

some damage from Lyme is

A

irreversible

167
Q

B. burgdorferi are naturally resistant to

A

rifampin, sulfonamide, phosphomycin

168
Q

CDC case definition of Lyme disease

A

diagnostic + antibody titers

169
Q

lone star tick bite can cause

A

alpha-gal meat allergy

170
Q

bourbon virus and heartland virus

A

tick born illness [borrelia lonestari?]

171
Q

STARI caused by

A

borrelia lonestari

172
Q

the infection stage of YF is characterized by

A

Faget’s sign (fever with bradycardia)

173
Q

the remission phase of YF is characterized by

A

abortive infection in 85% of cases, leads to recovery

174
Q

the intoxication phase of YF is characterized by

A

cytokine storm causing multi organ failure
fatality of 30-60%

AST>ALT**

175
Q

YF pathogenesis:

A

DCs shuttle virus to lymph nodes –> viremia –>liver cell apoptosis and hepatic dysfunction

176
Q

plaque reduction neutralization test is used to diagnose

A

west nile

determines neutralizing antibody titers in tissue culture assay

177
Q

caveat of fransicella

A

lab acquired infections

178
Q

Y. pestis may be misidentified as

A

Y. pseudotuberculosis