Which of the following is NOT a causative agent of diarrhoea?

Appeared in: CIP Ranchi 2023

Explanation

Aspergillus niger is a common mold (fungus) found in the environment.
It is primarily known to cause respiratory infections called aspergillosis, particularly in immunocompromised individuals.
It can also cause ear infections (otomycosis) but is not a recognized causative agent of gastrointestinal infections or diarrhea in the general population.

Option A: Shigella is a bacterium that causes shigellosis, a form of severe, often bloody diarrhea known as bacillary dysentery.
Option B: The parasite Entamoeba histolytica causes amebiasis, which commonly manifests as amebic dysentery with bloody stools and abdominal pain.
Option D: Salmonella bacteria are a very common cause of foodborne gastroenteritis (salmonellosis), which typically presents with watery or inflammatory diarrhea.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Etiology of infectious diarrhea as background academic context rather than a clinical decision trigger.
Identifying the specific causative agent of diarrhea is crucial for appropriate management. Bacterial infections may require antibiotics, parasitic infections need antiprotozoal drugs, while viral diarrhea is managed symptomatically with fluid and electrolyte replacement.
A stool culture and microscopy (ova and parasite exam) can help differentiate between bacterial and parasitic causes of diarrhea, guiding treatment decisions.
Nurses play a key role in collecting stool specimens correctly, managing hydration with Oral Rehydration Solution (ORS), and educating patients on hygiene to prevent transmission.

How to Approach the Question

First, identify the negative keyword 'NOT' in the question. This means you are looking for the option that is an exception or does not fit with the others.
Review each option and recall the primary disease associated with it.
Recall that Shigella is a classic cause of bacterial dysentery (diarrhea).
Recall that Entamoeba histolytica is a well-known cause of amebic dysentery (diarrhea).
Recall that Salmonella is a very common cause of food poisoning that results in diarrhea.
Recognize that Aspergillus is primarily associated with respiratory diseases (aspergillosis), not gastrointestinal infections.

Concept Tested & Keywords

Concept Tested: Etiology of infectious diarrhea
Stem keywords: causative agent, diarrhoea
Lead-in keywords: NOT
Negative lead-in flag: The question asks to identify the organism that is NOT a cause of diarrhea, requiring elimination of known pathogens.

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E6 Parks TextBook of Preventive & Social Medicine part 1 — Subpart B (pp 202-403 of 604) p. 78-80

Practise the full CIP Ranchi 2023

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