Rabies :Diagnosis and Negri bodies

Rabies :Diagnosis and Negri bodies

Q. 1

Which of the following sites in the brain is a favored locations for ischemic damage, rabies virus infestation, and toxic damage resulting from alcohol?

 A

Nucleus basalis of Meynert cell

 B

Purkinje cells of cerebellum

 C

Third, fifth, and sixth cortical layers of neurons in cerebral hemispheric grey matter

 D

Ammon’s horn of the hippocampal gyrus

Q. 1

Which of the following sites in the brain is a favored locations for ischemic damage, rabies virus infestation, and toxic damage resulting from alcohol?

 A

Nucleus basalis of Meynert cell

 B

Purkinje cells of cerebellum

 C

Third, fifth, and sixth cortical layers of neurons in cerebral hemispheric grey matter

 D

Ammon’s horn of the hippocampal gyrus

Ans. B

Explanation:

The site in the brain that is a favored location for ischemic damage, rabies virus infestation, and toxic damage resulting from alcohol is the Purkinje cells in the cerebellum.

In chronic ischemia, the Purkinje cells undergo apoptosis (individual cell necrosis) and assume a shrunken, deeply eosinophilic cytoplasm with fading out of the nucleus (red neuron). The eosinophilic Negri inclusion body of rabies is located in the cytoplasm of the Purkinje cells. Alcohol has a direct toxic effect on Purkinje cells, resulting in cerebellar atrophy. 

The nucleus basalis of Meynert is associated with neuronal loss in Alzheimer disease. 


Q. 2 Which of the following is seen in Rabies:
 A Cowdry B
 B Negri bodies
 C Guarneri bodies
 D Bollinger bodies
Q. 2 Which of the following is seen in Rabies:
 A Cowdry B
 B Negri bodies
 C Guarneri bodies
 D Bollinger bodies
Ans. B

Explanation:

Negri bodies


Q. 3 Inclusion body in neuron is seen in:
 A Rabies
 B Diphtheria
 C Yellow fever
 D Japanese encephalitis
Q. 3 Inclusion body in neuron is seen in:
 A Rabies
 B Diphtheria
 C Yellow fever
 D Japanese encephalitis
Ans. A

Explanation:

Rabies


Q. 4

A adolescent was bitten by a stray dog. To rule out rabies in the animal, brain tissue sample was taken. Which of the part of brain tissue should be taken to see the characteristic Negri bodies?

 A

Hippocampus

 B

Hypothalamus

 C

Medulla

 D

Midbrain

Q. 4

A adolescent was bitten by a stray dog. To rule out rabies in the animal, brain tissue sample was taken. Which of the part of brain tissue should be taken to see the characteristic Negri bodies?

 A

Hippocampus

 B

Hypothalamus

 C

Medulla

 D

Midbrain

Ans. A

Explanation:

Rapid diagnosis of rabies infection in the animal is usually made by examination of brain tissue by using either PCR assay, fluorescent antibody to rabies virus or histologic staining of Negri bodies in the cytoplasm of hippocampal neurons.
Negri bodies are sharply demarcated, more or less spherical, and 2–10 μm in diameter, and they have a distinctive internal structure with basophilic granules in an eosinophilic matrix. Negri bodies contain rabies virus antigens.
 
Ref: (2012). Chapter 39. RNA-Enveloped Viruses. In Levinson W (Eds), Review of Medical Microbiology & Immunology, 12e.

Q. 5

Susceptible cultured cells infected with which of the following viruses would exhibit hemadsorption with the appropriate erythocyte – 

 A

Sindbis virus

 B

Rabies virus

 C

Measles virus

 D

b and c

Q. 5

Susceptible cultured cells infected with which of the following viruses would exhibit hemadsorption with the appropriate erythocyte – 

 A

Sindbis virus

 B

Rabies virus

 C

Measles virus

 D

b and c

Ans. D

Explanation:

Ans. is ‘b’ Rabies Virus & ‘c’ Measles Virus 

Hemadsorption

.                                   When hemagglutinating viruses grow in cell cultures, their presence can be indicated by the addition of guinea pig erythrocyte to culture. If the viruses are multiplying in the culture, the erythrocytes will adsorb on to the surface of cells. This is known as Hemadsorption.

.                                   Viruses causing Hemagglutination are :

– Influenza Virus          – Measles               – Rubella                – Coxsackie Virus         – Rhino Virus        – Rabies

– Parainfluenza Virus   – TogaVirus             – EnteroVirus          – EchoVirus                    ReoVirus


Q. 6

A 15 year old girl was admitted to the infectious disease hospital with a provisional diagnosis of rabies. The most suitable clinical sample that can confirm the antemortem diagnosis is-

 A

Serum for anti-rabies IgG antibody

 B

Corneal impression smear for immunofluorescence stain

 C

CSF sample for viral culture

 D

Giemsa stain on smear prepared from salivary secretions

Q. 6

A 15 year old girl was admitted to the infectious disease hospital with a provisional diagnosis of rabies. The most suitable clinical sample that can confirm the antemortem diagnosis is-

 A

Serum for anti-rabies IgG antibody

 B

Corneal impression smear for immunofluorescence stain

 C

CSF sample for viral culture

 D

Giemsa stain on smear prepared from salivary secretions

Ans. B

Explanation:

Diagnosis of rabies

The diagnosis of rabies is usually made by the detection of rabies virus antigens by immunofluorescence. The specimens collected are :

Antemortem                                                                > Corneal smear

Skin biopsy from neck or saliva

Postmortem                                                                  Brain biopsy


Q. 7

True about Rabies virus is –

 A

Rabies is diagnosed by immunofluorescence

 B

Rabies causes life long immunity

 C

Rabies has various strains of viruses

 D

Rabies vaccine is always live attenuated

Q. 7

True about Rabies virus is –

 A

Rabies is diagnosed by immunofluorescence

 B

Rabies causes life long immunity

 C

Rabies has various strains of viruses

 D

Rabies vaccine is always live attenuated

Ans. A

Explanation:

Ans. is ‘a’ i.e., Rabies is diagnosed by immunofluorescence

.  Diagnosis of rabies is usually made by the detection of rabies virus antigens by immunofluorescence.

.  Rabies does not cause life long immunity, in fact rabies infection cause death of all patients.

.  Rabies virus is of single serotype only.

.  Rabies Vaccines are killed inactivated vaccines


Q. 8

The following statments are true for negri bodies except –

 A

They are pathognomic of rabies

 B

They are found in the brain

 C

They are cytoplasmic inclusion bodies

 D

They do not contain rabies virus antigen

Q. 8

The following statments are true for negri bodies except –

 A

They are pathognomic of rabies

 B

They are found in the brain

 C

They are cytoplasmic inclusion bodies

 D

They do not contain rabies virus antigen

Ans. D

Explanation:

Ans. is ‘d’ i.e., They do not contain rabies virus antigen


Q. 9

The staining useful for antemorten diagnosis of rabies is –

 A

Seller

 B

Macchiavillo

 C

Giemsa

 D

Fluorescent

Q. 9

The staining useful for antemorten diagnosis of rabies is –

 A

Seller

 B

Macchiavillo

 C

Giemsa

 D

Fluorescent

Ans. D

Explanation:

Ans. is. ‘d’ i.e., Fluorescent

The method most commonly used for diagnosis of rabies is the demonstration of rabies virus antigen by immunofluorescence.


Q. 10

Rabies can be confirmed in patients early in illness by:

March 2013 (b, e)

 A

Antigen detection by corneal smears immunofluorescence

 B

Antigen detection by immunofluorescence of skin biopsy

 C

Demonstration of neutralizing antibodies

 D

Demonstration of Negri bodies in hippocampus

Q. 10

Rabies can be confirmed in patients early in illness by:

March 2013 (b, e)

 A

Antigen detection by corneal smears immunofluorescence

 B

Antigen detection by immunofluorescence of skin biopsy

 C

Demonstration of neutralizing antibodies

 D

Demonstration of Negri bodies in hippocampus

Ans. B

Explanation:

Ans. B i.e. Antigen detection by immunofluorescence of skin biopsy

Rabies can be confirmed in patients early in illness by antigen detection using immunofluorescence of skin biopsy, and by virus isolation from saliva and other secretions. Immunofluorescence of corneal impression smears has proved unreliable. Neutralizing antibodies are not usually detectable in serum of CSF before the eighth day.

Negri bodies

  • They are eosinophilic, sharply outlined, pathognomonic inclusion bodies (2-10 µm in diameter) found in the cytoplasm of certain nerve cells containing the virus of rabies, especially in Ammon’s horn of the hippocampus.
  • Often also found in the cerebellar cortex of postmortem brain samples of rabies victims.
  • They consist of ribonuclear proteins produced by the virus.

Q. 11

In rabies, Negri bodies can be detected in:

March 2013

 A

Cornea

 B

Saliva

 C

Skin

 D

Neuron

Q. 11

In rabies, Negri bodies can be detected in:

March 2013

 A

Cornea

 B

Saliva

 C

Skin

 D

Neuron

Ans. D

Explanation:

Ans. D i.e. Neuron

The most characteristic pathologic finding of rabies in the CNS is the formation of cytoplasmic inclusions called ‘negri bodies’ within neurons.

Negri bodies are distributed throughout the brain, particularly in Ammon’s horn, the cerebral cortex, the brainstem, the hypothalamus, the Purkinje cells of the cerebellum, and the dorsal spinal ganglia.


Q. 12

Confirmatory diagnosis of rabies on postmortem:

FMGE 09

 A

Negri bodies in saliva

 B

Negri bodies in corneal scrapings

 C

Anti-rabies antibodies in blood

 D

Negri bodies in brain

Q. 12

Confirmatory diagnosis of rabies on postmortem:

FMGE 09

 A

Negri bodies in saliva

 B

Negri bodies in corneal scrapings

 C

Anti-rabies antibodies in blood

 D

Negri bodies in brain

Ans. D

Explanation:

Ans. Negri bodies in brain


Q. 13

Rabies is diagnosed by ‑

 A

Hair follicle smear

 B

Corneal smear

 C

Isolation from blood

 D

Nerve biopsy

Q. 13

Rabies is diagnosed by ‑

 A

Hair follicle smear

 B

Corneal smear

 C

Isolation from blood

 D

Nerve biopsy

Ans. B

Explanation:

Ans. is ‘b’ i.e., Corneal smear

Diagnosis of rabies

The diagnosis of rabies is usually made by the detection of rabies virus antigens by immunofluorescence. 

The specimens collected are :

  • Antemortem
  • Corneal smear
  • Skin biopsy from neck or saliva
  • Postmortem
  • Brain biopsy
  • A definitive pathologic diagnosis of rabies can be based on the finding of Negri bodies in the brain or spinal cord.
  • Other methods for Rabies diagnosis

i)  Rabies virus specific antibodies detection in serum and CSF.

  • But rabies virus-specific antibodies develop relatively late in the clinical course when the patient survives beyond the acute phase.
  • Two methods are used to detect antibodies:
  • Indirect fluorescent antibody test.
  • Rapid fluorescent focus inhibition (RFFIT)

ii)  Reverse-transcription polymerase chain detection of rabies virus nucleic acid in the saliva.

  • It is done during early CNS infection.

Q. 14

These cells are  characteristic of

 A

Tetanus

 B

Rabies

 C

Polio

 D

AIDS

Q. 14

These cells are  characteristic of

 A

Tetanus

 B

Rabies

 C

Polio

 D

AIDS

Ans. B

Explanation:

Negri bodies

Ans. B: Rabies

Since first described by Negri in 1903, the presence of the Negri bodies are practically pathognomic for rabies and are an important diagnostic finding.

Negri bodies are discrete, intracytoplasmic, deeply eosinophilic inclusions that measure several microns in diameter. In about 75% of cases of rabies these can be seen on hematoxylin and eosin stained sections.

They occur in neurons of the brain stem, particularly those in the hippocampus, and in the Purkinje cells of the cerebellum. Ultrastructural studies have shown that Negri body consists of a mass of nucleocapsids surrounded by viral particles budding from intracytoplasmic membranes.



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