In which of the following infection, examination of stool shows Charcot Leyden crystal?
**Core Concept**
Charcot-Leyden crystals are formed from the breakdown of eosinophils, a type of white blood cell involved in the body's response to parasitic infections and allergic reactions. These crystals are a characteristic finding in parasitic infections, particularly those caused by Ascaris lumbricoides, a type of roundworm.
**Why the Correct Answer is Right**
The presence of Charcot-Leyden crystals in stool is indicative of a parasitic infection, specifically Ascaris lumbricoides. When the adult worm dies and is expelled from the body, the eosinophils that were recruited to fight the infection break down and form these characteristic crystals. This process is a result of the eosinophilic response to the parasitic infection.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because Charcot-Leyden crystals are not typically associated with bacterial infections such as Salmonella or Shigella. While these infections can cause gastrointestinal symptoms, they do not typically lead to the formation of eosinophil-derived crystals.
* **Option B:** This option is incorrect because Giardiasis, a protozoal infection, may cause gastrointestinal symptoms, but it does not typically result in the formation of Charcot-Leyden crystals. Giardia infections are usually diagnosed through other means, such as stool antigen tests or microscopy.
* **Option C:** This option is incorrect because Amoebiasis, a protozoal infection, may cause gastrointestinal symptoms, but it is not typically associated with the formation of Charcot-Leyden crystals. Amoebiasis is usually diagnosed through other means, such as stool antigen tests or microscopy.
**Clinical Pearl / High-Yield Fact**
Charcot-Leyden crystals are a classic finding in parasitic infections, particularly those caused by Ascaris lumbricoides. When examining stool for parasitic infections, it is essential to consider the presence of these crystals as a diagnostic clue.
**Correct Answer:** C. Amoebiasis is not the correct answer, however, the provided options do not contain the correct answer.