Negri bodies in the brain commonly occur in:

Appeared in: DSSSB 14 August 2024

Explanation

Negri bodies are specific, eosinophilic (pink-staining) viral inclusion bodies found within the cytoplasm of nerve cells.
Their presence is considered pathognomonic, which means it is a characteristic and definitive sign of rabies infection.
These inclusions are most frequently found in the pyramidal neurons of the hippocampus and the Purkinje cells of the cerebellum.
They represent sites of viral replication within the infected neuron.

Option A: Measles is not associated with Negri bodies. Its characteristic histological findings are Warthin-Finkeldey giant cells in lymphoid organs and Dawson inclusion bodies in the brain in cases of subacute sclerosing panencephalitis (SSPE).
Option B: Poliovirus does not cause Negri bodies. It selectively infects and destroys motor neurons in the anterior horn of the spinal cord, leading to flaccid paralysis.
Option D: Tetanus is a bacterial disease caused by a potent neurotoxin. It causes muscle rigidity and spasms by blocking inhibitory neurotransmitter release and does not involve viral replication or the formation of inclusion bodies in neurons.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pathognomonic histological findings in neurological infections as background academic context rather than a clinical decision trigger.
The identification of Negri bodies in post-mortem brain tissue is a definitive method for diagnosing rabies, which is critical for public health to trace the source of infection and manage potential exposures in others.
Nurses must recognize the classic signs of rabies, such as hydrophobia and agitation, and implement strict infection control protocols, as the virus is transmitted through saliva.
Post-exposure prophylaxis (PEP) with rabies immune globulin and a series of vaccine doses is nearly 100% effective in preventing the disease if administered promptly after exposure.

How to Approach the Question

First, identify the key term in the question: 'Negri bodies'. This is a specific pathological finding.
Recognize this as a factual recall question that tests your knowledge of the characteristic signs of different neurological diseases.
Systematically evaluate each option by recalling its associated pathology:
Measles: Think of Warthin-Finkeldey cells or Dawson bodies.
Polio: Think of motor neuron destruction in the spinal cord.
Rabies: Directly associate this with Negri bodies.

Concept Tested & Keywords

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E6 Pathology- ROBBINS & COTRAN PATHOLOGIC BASIS OF DISEASE 10TH Ed p. 1264-1266

E6 Medicine Harrison 22e Part 1 p. 1695-1697

Practise the full DSSSB 14 August 2024

Attempt every question from this paper in a timed mock, then review the full solution for each one.