Micro Winter 4 Rabies

Front 1

what does rabies do
who does it affect
is it common

Back 1

1. neurotrophic- from periphery to CNS to cause encephalitis

2. aminals usually, human causes are rare

3. uncommon bc we have good prophylactic treatment

Front 2

what kind of virus is rabies, genome?

Back 2

rhabdovirus
enveloped- very immunogenic
ssRNA

Front 3

whats the outcome of rabies

what is the incubation period of rabies

what are the 2 types of disease caused by rabies

what does the resevoire say about the disease

Back 3

1. fatal once you get sx

2. variable incubation: dependent on where you get bit, faster when more proximal

3. Excitatory disease and paralytic disease

4. resevoire determines the course of disease, bats are the worst!

Front 4

tell me something about the excitatory and paralytic phase of rabies

Back 4

1. excitatory (furious)- this is the "mad dog" when its furicious. anxiety and apprehension, humans are afraid of water

2. paralytic (dumb)- when its it a coma, foaming at the mouth. this is still dangerous bc the saliva is loaded with virus. coma, HTN, death

Front 5

what is the prodrum for rabies

Back 5

fever, pharyngitis

**abnormal sensation at bite site. remember the more proximal the bite the shorter the innoculation time

Front 6

what weird thing is seen in pts in the excitatory phase of rabies

Back 6

hydrophobia

Front 7

whats the pathogeneiss of rabies

replication, diagnostics, prophylaxis

Back 7

1. replicaiton occurs at bite site (can be cryptic infection also, contact dependent)

2. negri bodies

3. give therapy BEFORE it reaches CNS

**Virus enters CNS via peripheral nerves and localizes via retrograde transport to limbic region of brain, secreted NO and cytokines to cause CNS damage

Front 8

what is negri body

Back 8

diagnostic of rabies infection

Front 9

where can we find rabies

Back 9

all over in LOTS of different mammal hosts

**human rabies is a reflection of the disease in aminals and the degree of human contact with thse animals

**Human cases have now been associated with all the major US reservoir animals.
Wild animals are presently the most important source of infection for humans and domestic animals in the U.S.

Front 10

ok so we know rabies is found IN LOTS of animals, what is the most common source

Back 10

wild animals infect domestic animals and humans

Front 11

whats cryptic rabies

Back 11

its when you get rabies w/o a bite

**bats can breech in tact skin. exposure of mucous membrane to animal saliva. aresol transmission

Front 12

other than bites what are 2 other ways rabies is transmitted

Back 12

1. cryptic- bats. our mucous membranes contact bat spit

2 corneal transplants

Front 13

what is standard therapy for rabies infection

Back 13

none, if its in the CNS you die

**that is why prophylaxis is SO important

The Milwaukee protocol (coma induction and administration of amantadine) is an experimental treatment first used in 2004 (successfully). Unfortunately, this approach has failed in additional North American cases.

Front 14

how is rabies dx

Back 14

determine the probability that the animal was rabid (bats common, rodents not so much) was the bite provoked or not?

**ALL ANIMALS ARE RABID UNTIL PROVEN OTHERWISE

**negri bodies
**DIRECT AB flourscnet test is gold standard for dx

Front 15

what do you do if you get bit by an animal that you dont know if its rabid

Back 15

take the prophylaxis!!!!

**if its an owned dog you can quarantine it for 10 days

Front 16

what is the gold standard for rabies detection

Back 16

direct flourscent AB test

**a bite from a fox, skunk, raccoon, bat is good enough to initiate treatment (rodents are often NOT affected)

**can also culture, animal inoculation test, PCR, negro body etc for dx

Front 17

why is PCR good for rabies detection

Back 17

rapid,
sensitive

**can help give clue as to what the resevoir is

Front 18

ok so we keep talking about hte prophylactic treatment if you are bit by a fox, raccoon, dog etc. what exactly is this

Back 18

1. HRIG (human rabies Ig). inject half into wound site, half in butt
2. Vaccine in deltoid (Human Diploid cell vaccine0 HDCV is the best!)
3. clean wound

Front 19

what is the best rabies vaccine? is it an emergency to get this after you are bit

Back 19

human diploid cell vaccine

**urgency, not an emergency

Front 20

what is teh Most common cause of sporadic fatal encephalitis in the US

Back 20

HSV encephlaitis

**caused by HSV 1 and 2

Front 21

HSV 1 encephalitis is due to what

Back 21

reactivation

**severe sequelae are common if you survive (vasculature of frontal lobe is destroyed)

Front 22

neonatal HSV encephalitis is caused by what strain

Back 22

HSV 2

**can cross the placenta, great risk for infant to have HSV encephalitis when mom has it

**infant may manifest skin leisions, and conjunctivitis

Front 23

is HSV common
is HSV encephalitis common? whats the cause
who gets it

Back 23

yes
nope, reactivation of latent infection

high in infants, and pld ppl >50

Front 24

what is the pathogenesis of HSV encephalitis

Back 24

Focal encephalitis limited to the frontal and temporal regions with associated signs and symptoms

Spread to CNS can be result of primary infection or reactivation of latent virus

Mortality rates are high and neurologic deficits in survivors are significant.

Early treatment can reduce risks

Front 25

how is HSV encephalitis dx

Back 25

EEG suggests it then we take a biopsy- start treatment ASAP. culture specimine adn stain for Tzanck smear

MRI- popular, non invasive

PCR- detection

Front 26

ok so you had an EEG that suggested HSV encephalitis so you did a biopsy cultures it with tzank smear. when do you do treatment and what is it

Back 26

ASAP! as soon as you get the EEG suggesting it (early detection is good)

**treat with acyclovir for the rest of pts life

Front 27

what is the tx for HSV encephalitis

Back 27

Acyclovir is highly effective
Specifically activated by virus thymidine kinase

start treatment ASAP- Early treatment can reduce risks