RABIES

Question 1

TRUE OR FALSE: Transmission has resulted from corneal transplantation and also from solid-organ transplantation and a vascular conduit (for a liver transplant)

Answer 1

TRUE

Question 2

Incubation period of rabies

Answer 2

20–90 days

Question 3

The most characteristic pathologic finding in rabies

Answer 3

Negri bodies

• Negri bodies are eosinophilic cytoplasmic inclusions in brain neurons that are composed of rabies virus proteins and viral RNA.
• commonly observed in Purkinje cells of the cerebellum and in pyramidal neurons of the hippocampus

Question 4

Diagnostically useful specimens include _____?

Answer 4

Serum
CSF
Fresh saliva
Skin biopsy samples from the neck, and brain tissue

• Corneal impression smears are of low diagnostic yield

Question 5

Healthy dogs, cats, or ferrets may be confined and observed for ____ days. PEP is not necessary if the animal remains healthy during this period.

Answer 5

10 days

Question 6

TRUE OR FALSE: The use of PEP may be warranted when a person (e.g., a small child or a sleeping adult) has been present in the same space as a bat and an unrecognized bite cannot be reliably excluded.

Answer 6

TRUE

Question 7

Ideally, the first dose of post-exposure prophylaxis should be given as soon as possible after exposure. Three additional doses should be given on days __, __, and __

Answer 7

Days 3, 7, and 14

• a fifth dose on day 28 is no longer recommended

Question 8

Primary schedule of pre-exposure prophylaxis consists of three doses of rabies vaccine given on days

Answer 8

Days 0, 7, and 21 or 28.

Question 9

Which of the following is characteristic of the pathogenesis of rabies?
A) Rapid spread through the bloodstream
B) Infection of neurons with retrograde axonal transport
C) Early replication in the lungs
D) Widespread neuronal death at the site of infection

Answer 9

Answer: B
Rationale: Rabies virus spreads centripetally along peripheral nerves, using retrograde fast axonal transport to reach the spinal cord and brainstem. It primarily infects neurons.

Question 10

What is the most characteristic pathological finding in rabies?
A) Eosinophilic cytoplasmic inclusions in brain neurons
B) Absence of inflammatory changes in the CNS
C) Widespread neuronal death in the hippocampus
D) Mononuclear cell infiltration in the lungs

Answer 10

Answer: A
Rationale: The most characteristic pathological finding in rabies is the presence of Negri bodies, which are eosinophilic cytoplasmic inclusions in neurons, commonly observed in Purkinje cells of the cerebellum and pyramidal neurons of the hippocampus.

Question 11

In rabies, which form is more common in humans?
A) Paralytic rabies
B) Encephalitic (furious) rabies
C) Subclinical rabies
D) Both forms are equally common

Answer 11

Answer: B
Rationale: Encephalitic (furious) rabies occurs in 80% of human cases, while the paralytic form is seen in 20% of cases.

Question 12

What is the prognosis for a patient diagnosed with rabies?
A) Rabies is almost always fatal despite treatment
B) Rabies can be cured with early supportive care
C) Most patients survive with appropriate antiviral therapy
D) Rabies is nearly always treatable if diagnosed early

Answer 12

Answer: A
Rationale: Rabies is an almost uniformly fatal disease once clinical symptoms appear, although it is preventable after exposure with appropriate post-exposure prophylaxis

Question 13

What is the typical incubation period for rabies in humans?
A) 1–7 days
B) 20–90 days
C) 6–12 months
D) 1–2 years

Answer 13

Answer: B
Rationale: The incubation period for rabies is usually 20–90 days, although it can be as short as a few days or longer than a year in rare cases.

Question 14

How long should a healthy dog, cat, or ferret that has bitten a person be observed for signs of rabies?
A) 24 hours
B) 5 days
C) 7 days
D) 10 days

Answer 14

Answer: D
Rationale: A 10-day observation period is recommended for healthy dogs, cats, and ferrets. If the animal remains healthy, PEP is not necessary.

Question 15

In areas with endemic canine rabies, when should rabies prophylaxis be initiated after an animal bite?
A) Only after laboratory confirmation of rabies in the animal
B) After the 10-day observation period
C) Immediately, without waiting for lab results
D) Only if symptoms of rabies appear in the exposed person

Answer 15

Answer: C
Rationale: In high-risk areas, PEP should be started immediately without waiting for laboratory results to prevent the disease.

Question 16

What should be done if a person was in the same room as a bat but does not recall a bite?
A) No action is needed since no bite was felt
B) PEP should be considered
C) Wait for the person to develop symptoms before starting PEP
D) Only test the bat if it is captured

Answer 16

Answer: B
Rationale: PEP may be warranted if a small child or a sleeping adult was present in the same room as a bat, as an unrecognized bite cannot be reliably excluded.

Question 17

How should rabies immune globulin (RIG) be administered in a previously unvaccinated person?
A) Entire dose injected into the deltoid muscle
B) Infiltrated at the bite site as much as possible, with the remainder given IM at a distant site
C) Injected into the thigh muscle only
D) Given as an oral medication

Answer 17

Answer: B
Rationale: If anatomically feasible, the full dose of RIG (20 IU/kg) should be infiltrated at the site of the bite. Any remaining RIG should be administered intramuscularly at a distant site.

Question 18

When should RIG (rabies immune globulin) be administered if it is not immediately available?
A) It is not necessary if delayed
B) Within 24 hours of the bite
C) No later than 7 days after the first vaccine dose
D) After symptoms appear

Answer 18

Answer: C
Rationale: If RIG is not immediately available, it should be given no later than 7 days after the first vaccine dose.

Question 19

What is the recommended rabies vaccination schedule for PEP?
A) Days 0, 1, 2, and 3
B) Days 0, 3, 7, and 14
C) Days 0, 5, 10, and 20
D) A single dose is sufficient

Answer 19

Answer: B
Rationale: The recommended schedule is four doses on days 0, 3, 7, and 14. A fifth dose on day 28 is no longer recommended.

Question 20

Is pregnancy a contraindication for rabies post-exposure prophylaxis (PEP)?
A) Yes, PEP should be avoided during pregnancy
B) No, PEP can be given during pregnancy
C) Only if the exposure was minor
D) PEP should be delayed until after childbirth

Answer 20

Answer: B
Rationale: Pregnancy is not a contraindication for rabies immunization. PEP should be given if indicated.

Question 21

What is the recommended schedule for primary rabies PrEP vaccination?
A) A single dose at any time
B) Two doses given one week apart
C) Three doses given on days 0, 7, and 21 or 28
D) Monthly booster doses for one year

Answer 21

Answer: C
Rationale: The primary PrEP schedule consists of three doses given on days 0, 7, and 21 or 28.

Question 22

What should be done if a previously vaccinated individual is exposed to rabies?
A) No additional doses are needed
B) Two booster doses of rabies vaccine should be administered on days 0 and 3
C) Full post-exposure prophylaxis (PEP) with RIG and four vaccine doses should be given
D) A single booster dose is sufficient

Answer: B
Rationale: Previously vaccinated individuals should receive two booster doses on days 0 and 3. RIG is not needed in these individuals.

Answer 22

Answer: B
Rationale: Previously vaccinated individuals should receive two booster doses on days 0 and 3. RIG is not needed in these individuals.