Types of viral encephalitis Flashcards Preview

Microbiology Exam 5 > Types of viral encephalitis > Flashcards

Flashcards in Types of viral encephalitis Deck (161):
1

what part of the brain is affected by viral encephalitis

brain parenchyma

2

what are the most frequent etiology of viral encephalitis

Arbovirus
HSV-1

3

What is the key in signs and symptoms of viral encephalitis

to determine whether signs and symptoms is focal or diffused

4

what are etiologic agents of diffused encephalitis besides arbovirus

HSV1
non-polio enterovirus

5

what are etiologic agents of focal encephalitis besides HSV-1

arbovirus
non-polio enterovirus
rarely polio virus or rabies

6

if one of the viral encephalitis agents produces an asymptomatic infection does the infection spread to the CNS

NO

7

What are togaviridiae group of arbovirus

comprised most arthropod-borne virus, also rubella

8

what are categories of togaviridae

Alphavirus and flavivirus

9

what are examples of alphaviruses

EEEV, WEEV, VEEV

10

what are examples of flavivirus

SLEvirus
WNEvirus
POWvirus

11

what are examples of bunyavirus

Hantavirus
California Virus, Jamestown canyon virus, LaC virus

12

where is the highest incidence of California encephalitis serogroup

California, Midwest, SE U.S.

13

what are examples of reoviridae

rotovirus, CLTFvirus

14

arbovirus causes what two primary syndromes

hemorrhagic fever
encephalitis/meningitis

15

what is the seasonality of arbovirus

varies annually, peak in summer months when animals are out

16

what is the primary cause of epidemic encephalitis

arbovirus

17

what are the principle arthropod vectors

mosquitoes and ticks

18

what are CLFV and POW virus spread by and what about the rest

ticks
Rest is spread by mosquitoes

19

what are the principle reservoir of arbovirus

birds and small mammals

20

how is arbovirus transmitted to humans

tangent transmission

21

what is the age and gender relationship in arbovirus

primarily children others in elderly
N/A gender

22

what is the seasonality of arbovirus

sporadic epidemic occur in summer months when reservoir vector and humans are out doors

23

what is the RF for arbovirus in individuals

summer exposure to mosquitoes and ticks, age

24

for creation of arbovirus epidemic what is needwed

large reservoir (birds), large vector (mosquitoes), favorable climate

25

how do you monitor the arbovirus activity in the US

sample mosquitoes,
wild birds are captured and bleed
sick dying animals are observed

26

what is the pathogenesis of arboviris

primary viral replication causes none/mild symptoms
secondary replication causes viremia attacks brain and other organs

27

what is the most common clinical manifestation of arbovirus

asymptomatic infection most common result

28

what are possible disease outcomes of arbovirus

self-limiting flu
self-limiting aseptic meningitis
encephalitis and death +/- flaccid paralysis

29

how do diagnose arbovirus

CSF
Serological
EEG
CT

30

what is the treatment of arbovirus

supportive

31

what is the prevention of arbovirus

goal is limiting the vector population and education and precaution (DEET)

32

What type of immunity is there against arbovirus

specific and life long
2 vaccines for horse
US military vaccine against EEV and WEEV

33

what geographical location does EEEV predominate

East Coast , wooded areas near swamps and marshes

34

what arbovirus has the worst mortality rate and more likely to manifest with neurological sequelae

EEEV

35

How is EEEV unique to other arboviruses

asymptomatic is not the norm. Norm is Eastern Equine Encephalitis

36

what geographical location does WEE predominate

west of Mississippi River highest in rural residence

37

what age does most WEEV occur

50% in children <1yo

38

what arbovirus is the most benign form of encephalitis

WEEV

39

what geographical location does SLEV predominate

Midwest

40

What age does most SLEV occur

varies due to herd immunity
Children in West
Elderly in East

41

what is the leading cause of epidemic arboviral encephalitis before WNEV in 2002

SLEV

42

What agent does WNEV relate to

SLEV

43

what is the geographic distribution of WNEV

Africa, Europe, middle east, west Asia, Australia. North america

44

what is the most common arbovirus in the US today

WNEV

45

how else can WNEV be transmitted beside mosquitoes

transfusions, in utero

46

what are s&s of West Nile Fever

flu symptoms, muscle aches, nausea, maculopapular rash, frontal HA, eye pain

47

what are S&S of West Nile Encephalitis

West nile fever with at least one of the following:
meningitis, encephalitis, parkinsonism, focal muscle weakness

48

what is treatment of WNEV

Ribavirin useful in vitro

49

where does CAL serogroup predominate

California, East of Mississippi

50

What is the age relationship in CAL serogroup

almost all occur in children and adolescents

51

what is the most important cause of arbovirus pediatric encephalitis in the USA

LAC

52

what symptom of CAL serogroup is unique and can occur as a sequelae

siezures

53

what is poliomyelitis

acute infection systemic infectious disease destroying motor neurons in the spinal cord results in flaccid, ascending, asymmetrical paralysis

54

what is the morphology of Polio virus

enterovirus, non-enveloped, + sense RNA virus

55

which serotype of Polio virus is responsible for most of the paralytic polio

type 1

56

what serotype of Polio virus is often isolated in vaccine-associated poliomyelitis

types 2 and 3

57

why is Polio virus rare in us today

vaccine

58

what was the original though of Polio virus

disease of developed countries in older populations, but child and young adults present with serious disease

59

where is paralytic polio still a significant concern

underdeveloped counyties

60

what is the transmission of Polio virus

fecal oral route through water. Virus in stool for 3-6 weeks
less so through respiration (oral-oral)

61

what is the host of Polio virus

humans

62

what are the reservoir of Polio virus

humans and water

63

how infectious is Polio virus

highly communicable

64

what population is primarily infected by Polio virus

<3yo children, but young adults, prego, and elderly can be susceptible as well

65

what is the relationship with severity of polio/paralytic polio and age

severity and chance of getting paralytic polio increases with age

66

what is the seasonality of polio

summer-fall

67

what is the pathogenesis of Polio virus

incubation is long
infected cells train to lymph nodes along GI, first pharynx then intestine, shed in resp. weeks shed in feces for months

68

is Polio virus lytic or lysogenic

lytic

69

what is a rare occurrence of Polio virus in the body

entering cns is rare

70

what happens if Polio virus enters cns

but if it does it spread through neural routes and pns like rabies and herpes destroys nerve fiber pathway
results in flaccid paralysis with no sensory lose (unlike GBS)

71

what is the most common clinical syndrome in Polio virus

asymptomatic

72

what are signs of minor poliomyelitis

fever, malaise, HA, muscle aches, pharyngitis, nausea, abd pain, constipation last 72 hours

73

what are signs of aseptic meningitis in Polio virus without paralysis

signs of minor poliomyelitis and
pain in neck, back, and leg
muscle stiffness and tenderness or spasm lasts 1-2weeks

74

what are signs of paralytic poliomyelitis

initial like aseptic meningitis
paralysis after that complete by fever break, muscle spasms, loss of superficial and deep tendon reflex, abnormal sensations

75

what are three forms of paralytic poliomyelitis

spinal
bulbar polio
bulbospinal polio

76

what is post polio syndrome

survivors of paralytic polio fatigue, new muscle weakness/pain, progressive atrophy
happens in 30-40yo not activation of latent virus but to over use

77

how do you diagnose Polio virus

stool sample
PCR
partial genomic sequencing of stool

78

what is the treatment of polio virus

supportive

79

what is the prevention of polio

vaccine, IPV, eIPV

80

what is needed after Polio virus vaccine especially in developing countries

booster, 4th booster in developing countries

81

how does oral polio vaccine differ from parental polio vaccine

oral is live attenuated. can put unvaccinated at risk

82

what is rabies

acute, fatal. fulminant, focal encephalitis and myelitis

83

what are characteristic of rabies

rhabdoviridae, lyssavirus, -ssRNA, bullet shaped

84

how many serotypes of rabies

1

85

what is a negri body

eosinophilic cytoplasmic inclusions of viral nucleoptoteins

86

what is the incidence rate of rabies

low because of control of cats and dogs

87

what is the transmission of rabies

animal bite or scratch

88

what is the reservoir of rabies

dogs cats, skunks, fox, racoon. bat, wolves others

89

what is the geographic distribution of rabies

in the us, rabies is epizootic

90

what is the age/gender relationship in rabies

NONE

91

what is the seasonality of rabies

NONE

92

what are RF of rabies

uncontrolled animals

93

what animal is the most common source of rabies in US

bats

94

what is pathogenesis of rabies

virus enters PNS at unmyelinated sensory terminals and nm junctions
retrograde axoplasmic flow to spinal cord then brain

95

what part of the brain does rabies predominate

gray matter , but localizes in limbic system

96

when is a rabies pt potentially infectious

from 2 weeks before onset of symptoms to death

97

what is the point of no return for rabies

moment the virus enters sensory terminals and NM junctions

98

Can the rabies virus be isolated in blood

no

99

what is the prodrome of rabies

flu like symptoms for 2 to 4 days

100

what length of rabies disease is always fatal

5 to 6 days

101

what forms of rabies disease cab be seen

paralytic/dumb form
Excititation-furious form

102

What is paralytic/dumb rabies

signs are similar to viral encephalitis
paralysis extremity to trunk
hypoventilation and hypotension to coma and death

103

what is excitation-furious rabies

photo/phonophoba
hyperactivity sexual agressive, agitation anxiety, insomnia. confusion, foaming at mouth to coma and death

104

which rabies form is more common

excitation-furious rabies

105

how is rabies diagnosed

csf, DFA of cytoplasmic inclusions, isolation of virus via mouse inoculation

106

what is treatment for rabies

none

107

wat is prevention of rabies

vaccination pre and post exposure

108

where should you never inject rabies vaccine

gluteal injections

109

what should you do after exposure

clean wound, tetanus prophylaxis, Vaccination AND antiserum two diff sites

110

what agent cause 20% of all cases of viral encephalitis in the US and most common cause of all non epidemic/ sporadic focal encephalitis

HSV

111

who does HSV have peak incidence in

nenates with infected mother
young adults/elderly via reactivation of latency

112

what is the transmission of hsv

saliva, vagina secretion (esp. post partum), semen
in utero but rare

113

what is the pathogenesis of hsv

spread to the CNS by retrograde axoplasmic flow

114

is hsv lytic or lysogenic

lytic

115

what is hsv manifestation in adults

focal encephalopathy in one lobe usually temporal.
memory defect, psychosis, slurred speech, personality changes
relapse and death is high

116

in adults primary genital herpes infections can result in?

a benign, aseptic meningitis

117

what are the 3 possible presentations of HSV in neonate

Local herpes infection, SEM
Disseminated
CNS disease

118

what is the etiologic agent in bells palsy

hsv and vsv

119

how is hsv diagnosed

symptoms presentation
CSF- viral glucose protein levels, mononuclear pleocytosis and lost of RBCs
Other Tests

120

what is treatment for hsv

antivirals and nucleoside analogs, not a cure

121

where is the most common hsv infection in children from infected mother

intrapartum

122

how is hsv diagnosed in pregnant women

clinical exam plus one of the following
Swab- PCR or viral culture
or Serology for type specific AB test

123

what is tx of hsv in prego women

suppressive on in last 4 weeks of pregnancy
acyclovir daily
discuss delivery stategy
Csection if virus was aquired 3rd trimester or lesion is present

124

What does HAND stand for

HIV associated neurocognative disorders

125

what does HAD stand for

HIV associated dementia

126

what is HAND

it is a slowly progressobe demylenation of disease with neuronal loss of the CNS

127

what is the incidence of cns disease of HIV pts pre-HAART

60% will show evidence of neuropathy

128

what is RF of HAND

IVDA even despite HAART

129

what is a good prognostic indicator of pts who have HAND

plasma and viral load supression

130

what is the pathogenesis of HAD

direct infection of cns and pns occurs early in HIV infection

131

what cells does HIV replicate and infect in HAD pathology

monocyte, macrophage, microglia of CNS

132

what cells does HIV not infect

neurons and oligodendrocytes

133

hiv in the CNS is M-trophic which utilizes which receptor as a cofactor

CCR5

134

what is hiv related neuronal damage due to

gp120 or Tat proteins

135

HAD is NOT due to

autoimmune, lymphoma, infection (other than HIV of course)

136

HAD is characterized by

, astrocytosis, micrglial nodules, diffuse or focal myelin pallor or neuronal loss

137

what are manifestation of of HIV associated CNS

peripheral neuropathy, aseptic meningitis, acute encephalitis, HIV motor complex, vacuolar neuropathy, sensory pain of feet

138

what is asymptomatic neurocognative impairment (ANI)

impairments seen through testing but are symptomatic in their daily life

139

what is HIV associated mild neurocognative disorder (MND)

impairments causing mild disturbances in daily life

140

what Hiv associated cns disease is more common in the new area of HAART

ANI -> NMD

141

what type of changes are seen in HAD pts

Early: Cognitive, Motor, Behavioral
Late: Progression, mute, spasticity, death

142

how is hiv associated cns disease diagnosed specifically HAD

if pts have one or more (pleocytosis, abnormal CSF ig recoverable HIV in CNS)
Use HAD Scale

143

what should imaging studies show in HAD

cortical atrophy, enlarged ventricles , demylenation of white matter, abscence of focal abnormalities

144

what is the treatment of CNS HIV disease

HAART, could cause increase in sensory neuropathy and should be able to cross BBB

145

what does PML stand for

progressive multifocal leukoencephalopathy

146

what kind of disease is PML

uncommon, subacute, progressive demyelination of CNS

147

what is the etiologic agent in PML

papovavirus

148

what is the morphology of papovavirus

naked dsDNA with icosahedral symmetry

149

what are examples of papovavirus

Polymavirus (JC virus, BK virus, SV40)
HPV

150

what is the result of PML in immunocompetant

common asymptomatic infection

151

what percentage of people world wide are positive for BK virus

60-90%

152

how can JC and BK virus become fatal

underlyining disorder which causes reactivation of virus through immunosuppression

153

what does BKV cause

a fatal opportunistic kidney disease in renal transplant pts
or severe UTI in HIV

154

what does JCV cause

a rare opportunisitic CNS reactivation of disease in advanced HIV/AIDS and pts on Natalizumab

155

what is the pathogenesis of JCV

invades oligodendrocytes cause cell death and causes infection along the myelin tract and infects astrocytes

156

what virus is present in most pediatric brain tumors

JVC

157

what part of the brain is most affected by JVC

subcortical white matter

158

what would cells would be affected by JVC

abscence of oligodendrocytes, abnormal astrocytes, sparing of neuron and axons, enlarged oligodendritic cells with inclusions
INFLAMMATORY CELLS ARE ABSENT

159

What are the clinical manifestation of JVC disease

Rapid, Muscle weakness, ataxia, cognitive/speech impairments, visual loss

160

how do you diagnose pml

clinical signs, PCR of CSF, Neuroimaging of demyelnation, pathology seen in brain biopsy

161

what is the tx for pml

cidofovir
HAART in aids pts.
Prognosis good if HAART is started when CD4>100