VII- Viral Zoonotic CNS

Question 1

west nile virus transmission

Answer 1

people, horses, mammals get infected by mosquitoes but humans not develop infectious level
-bird serve as reservoir
-can be person-person in transfusions, transplants or breast feeding

Question 2

west nile virus prez

Answer 2

mild illness-west nile fever with sudden onset + anorexia + nausea/vomit + eye pain + rash + lymphadenopathy

can be severe neuro dz in elderly so encephalitis mostly, some meningitis + ataxia + seizures + visual disturbance

Question 3

west nile virus dx/treat

Answer 3

strongly consider in adults 50+ with unexplained encephalitis in early summer or fall

vaccinate horses not humans

Question 4

st. louis encephalitis transmission

Answer 4

transmit to humans by culex mosquitoes that get it from infected birds
-horses serve as reservoirs
-no human-human bc viremia not high enough

Question 5

st. louis encephalitis prez

Answer 5

sudden onset mild dz fever with headache
-can be severe with stupor, disorientation, coma, convulsions, spastic paralysis

Question 6

st louis encephalitis treat

Answer 6

no vaccine so supportive therapy and probs hospitalization

Question 7

japanese encephalitis virus

Answer 7

reservoir: bird and livestock
symps: similar to other arboviral encephalitis
can have lifelong neuro sequela

Question 8

togaviruses

alphaviruses

Answer 8

eastern equine encephalitis
western equine encephalitis
venezuelan equine encephalitis

Question 9

eastern equine encephalitis prez

Answer 9

sudden onset fever + general muscle pains + headache inc severity > seizures and coma
-permanent brain damage might require permanent institutional care

Question 10

western equine encephalitis prez

Answer 10

in june or july
-sudden onset fever + headache + nausea/vomit +anorexia + altered mental status + meningeal irritation

children more severe than adults

Question 11

venezuelan equine encephalitis

Answer 11

acute viral dz - fever, chills, headache, nausea, vomit, lumbosacral pain, myalgia > disorientation, convulsions, paralysis
-kids more likely CNS involvement

in south and central america

Question 12

lacrosse encephalitis

california

Answer 12

mostly in midwestern kids
-transmitted by mosquitoes, maintained in chipmunks, tree squirrels

nonspecific summertime illness > seizures, coma, paralysis

Question 13

rabies transmission

Answer 13

thru infected saliva via bites, mucous membranes, aerosol, corneal transplantations, infected dogs/bats

Question 14

rabies prez

Answer 14

nonspecific flu signs > hydrophobia, deilirium, hallucinations, insomnia > death
-virus enters peripheral nerves > CNS
-nearly always fatal

Question 15

rabies treatment

Answer 15

vaccinate animals and high risk indivs

1 dose immune globulin + 5 doses of vaccine over 28 day period

dx with negri bodies

Question 16

LCMV transmission

Answer 16

rodent borne/house mouse = aseptic meningitis, encephalitis, or both, or mild febrile illness

inhale infectious aerosolized particles of rodent urine, feces, saliva OR contaminated food
-no person to person

mus musculus

Question 17

LCMV prez

Answer 17

biphasic febrile illness - 1 week of symps > remission for few days > second phase
-fever, malaise, anorexia, muscle aches, nausea, vomiting

most recover completely

Question 18

prions

Answer 18

small proteinaceous infectious particle PrPsc
-infectious prions secreted or in cytoplasmic aggregates in beta pleated sheets
-slow developing neurodegen dz/ spongiform encephalopathies

Question 19

human spongiform encephalopathies

Answer 19

1. kuru
2. creutzfeldt jakob dz
3. gestermann straussler scheinker dz
4. fatal familiar insomnia

Question 20

prion transmission

Answer 20

infectious, spontaneous, inherited exposure
-PrP reps in lymphatics and peripheral tissues > CNS so astrocytes, glial cells prolif and amyloid plaques

Question 21

prion dz prez

Answer 21

long incubation but rapid death once symptomatic
-loss muscle control, shivering, jerks/tremors, behavior changes, dementia

dx postmortem histologic exam brain tissue