203 Rabies

Question 1

True or false. Rabies has encephalitic and paralytic forms that progress to death

Answer 1

True.

Question 2

Two genera of rabies that cause human disease

Answer 2

Lyssavirus and Vesciulovirus

Question 3

True or false. Rabies is usually transmitted to humans by the bit of an infected animal

Answer 3

True.

Question 4

True or false. Rabies may be acquired from skunks, foxes and raccoons.

Answer 4

True.

Question 5

True or false. In North America, human disease is usually associated with transmission from bats

Answer 5

True

Question 6

True or false. Transmission from nonbite like exposures is relatively uncommon.

Answer 6

True

Question 7

incubation period of rabies

Answer 7

20-90 days, rare less than 1 day and more than 1 year

Question 8

True or false. During the incubation period, the rabies virus is thought to be present at or close to the site of inoculation

Answer 8

True.

Question 9

the rabies virus is known to bind where in the nerves

Answer 9

bind to nicotinic acetylcholine receptors on postsynpatic membranes at neuromuscular junctions

Question 10

how does rabies virus spread inside the body

Answer 10

centripetally along the peripheral nerves towards the spinal cord or brainsteam via retrograde fast axonal transport

Question 11

what is the axonal transport speed of rabies virus

Answer 11

250 mm per day with delays of 12 hrs at each synapse

Question 12

prominently affected in rabies

Answer 12

neurons

Question 13

where does rabies virus replicate

Answer 13

in acinar cells of the salivary glands and is secreted in the saliva of rabid animals that serve as vectors

Question 14

True or false. There is no well documented evidence for hematogenous spread of rabies virus

Answer 14

True.

Question 15

microglial nodules seen in rabies

Answer 15

Babes nodules

Question 16

most characteristic pathologic finding in rabies

Answer 16

Negri bodies

Question 17

Negri bodies vs babes nodules

Answer 17

negri bodies are cytocplasmic inclusions in brain neurons composed of rabies virus proteins and viral RNA while Babes nodules are mononuclear inflammation of microglial nodules

Question 18

Where are Negri bodies in rabies observed

Answer 18

Prukinje cells of the cerebellum and in pyramidal neurons of the hippocampus and cortical and brainstem neurons

Question 19

responsible for clinical disease in rabies

Answer 19

neuronal dysfunction

Question 20

True or false. Negri bodies are no observed in all cases of rabies

Answer 20

True.

Question 21

relates tot he aggressive behavrious of rabid animals

Answer 21

infection of serotonergic neurons of the brainstem

Question 22

How does rabies present

Answer 22

atypical encephalitis with relative preservation of consciousness

Question 23

phases in rabies infection

Answer 23

prodrome, acute neurologic, comatose and death

Question 24

motor weakness in rabies

Answer 24

acute flaccid paralysis

Question 25

the clinical feature of this phase is nonspecific manifestation like fever, malaise, headache, nausea, and vomiting

Answer 25

Prodrome

Question 26

earliest specific neurologic symptoms of rabies which occur in 50-80% of patients

Answer 26

paresthesia, pain or pruritus near the site of exposure

Question 27

two acute neurologic forms in humans

Answer 27

encephalitic (furious) form 80% and paralytic form 20%

Question 28

signs of rabies encephalitis involving the brain stem

Answer 28

hydrophobia and aerophobia

Question 29

what is hydrphobia

Answer 29

involuntary painful contraction of the diaphragm and accessory respiratory, laryngeal and pharyngeal muscles in response to swallowing liquids

Question 30

mechanism of hydrophobia or aerophobia

Answer 30

exaggerated defense reflexes by the nucleus ambiguus that inhibit inspiratory neurons to protect the respiratory tract

Question 31

autonomic dysfunction in rabies

Answer 31

hypersalivation, gooseflesh, cardiac arrythmia, and priapism

Question 32

True or false. Paralytic rabies is seen in 20% of patient in which weakness predominates and cardinal features of hyperexcitability, hydrophobia and aerophobia are lacking

Answer 32

True.

Question 33

Cause of coma or death in patient with rabies

Answer 33

brainstem dysfunction

Question 34

from where are skin biopsy for rabies taken

Answer 34

cutaneous nerves at the base of hair follicles, samples are usually taken from hairy skin at the nape of the neck

Question 35

True or false. Corneal impression smears are of low diagnostic yield and are not generally performed

Answer 35

True.

Question 36

True or false. Presence of rabies virus specific neurtralizing antibodies in the CSF suggest rabies encephalitis, regardless of immunization

Answer 36

True.

Question 37

diagnostically useful specimen in the diagnosis of rabies

Answer 37

serum, CSF, saliva, skin biopsy and brain tissue

Question 38

a highly and specific test for detection of rabies virus RNA

Answer 38

RT PCR

Question 39

True or false. There is no established treatment for rabies

Answer 39

True.

Question 40

what is the prognosis of rabies

Answer 40

almost uniformly fatal

Question 41

how long should healthy dogs, cats or ferrets be confined and observed

Answer 41

10 days

Question 42

True or false. PEP for rabies is not necessary if the animal remains healthy

Answer 42

True.

Question 43

True or false. If the the animal develops signs of rabies during the observation, it should be euthanized immediately

Answer 43

True.

Question 44

Part of the animal sent for testing and viral isolation

Answer 44

head

Question 45

True or false. In high risk exposure and in areas where canine rabies is endemic, rabies prophylaxis should be initiated without waiting for laboratory results

Answer 45

True.

Question 46

Not later than how many days can RIG be administered after the first dose if not immediately available

Answer 46

no later than 7 days

Question 47

can you give RIG 7 days after the first dose

Answer 47

theoretically endogenous antibodies are being produced and passive immunization is counterproductive

Question 48

what is the dose of RIG

Answer 48

20 U/Kg, entire dose to site if anatomically feasible, if not then administered IM at a distant site

Question 49

when can RIG administered all IM

Answer 49

if exposure involves mucous membrane

Question 50

true or false. Pregnancy is a contraindication to rabies vaccine

Answer 50

False. Not contraindicated for immunization

Question 51

Can glucocorticoids be given along with rabies vaccine?

Answer 51

No. it may interfere with the development of active immunity

Question 52

when should purified inactivated rabies be given

Answer 52

immediately

Question 53

timing of the purified inactivated rabies vaccine

Answer 53

Day 0, 3, 7, 14

Question 54

alternative to RIG if not available and the dose

Answer 54

purified equine RIG can be used at dose of 40 U/ Kg

Question 55

How to give pre exposure rabies vaccination

Answer 55

Day 0,7, 21 or 28

Question 56

differentiate pre exposure versus post exposure vaccination

Answer 56

Post exposure: given 4x; Day 0,3,7,14 Pre exposure given 3x: Day 0, 7, 21

Question 57

who are given pre exposure vaccination

Answer 57

travelers to endemic areas, occupational or recreational risk

Question 58

who can be given booster rabies vaccination and how administered

Answer 58

previously immunized individual with booster dose given day 0 and day 3

Question 59

True or false. RIG should be given to previously vaccinated persons

Answer 59

False. No need. Endogenous antibodies might already have developed

Question 60

True or false. vesiculovirus can infect humans. It can cause flu like illness, conjunctivitis and small vesicular lesions

Answer 60

True.

Question 61

True or false.Vesicular stomatitis virus lasts 3-6 days with complete recovery and rarely leads to encephalitis

Answer 61

True.