**Question:** All of the following helps in the diagnosis of leishmaniasis except: September 2008

A. Demonstration of Leishman Donovan bodies in biopsy specimen
B. Skin test with Leishman antigen
C. Positive indirect fluorescent antibody test (IFAT)
D. Polymerase Chain Reaction (PCR)

**Correct Answer:** .

**Core Concept:** Leishmaniasis is a group of diseases caused by protozoan parasites of the genus Leishmania. Diagnosis of leishmaniasis involves various diagnostic methods including direct examination, serologic tests, and molecular techniques. Leishman Donovan bodies are characteristic parasitic structures found in histopathological examination of infected tissue samples.

**Why the Correct Answer is Right:** Leishmania is a parasite, and the presence of Leishman Donovan bodies is a direct evidence of infection. Demonstrating these bodies in a biopsy specimen provides crucial information for diagnosing leishmaniasis.

**Why Each Wrong Option is Incorrect:**

**Option A:** Demonstration of Leishman Donovan bodies in biopsy specimen is correct and essential for diagnosis. This method provides direct evidence of the parasite, which is crucial when diagnosing leishmaniasis.

**Option B:** Skin test with Leishman antigen is a test that measures the immune response to Leishmania antigens. Although it is a useful diagnostic tool, it is not specific to leishmaniasis, making it an incorrect choice in this question.

**Option C:** Positive indirect fluorescent antibody test (IFAT) is a serological test that detects immunoglobulins against Leishmania antigens. While IFAT can provide evidence of infection, it is not specific to leishmaniasis and therefore incorrect in this context.

**Option D:** Polymerase Chain Reaction (PCR) is a molecular technique used for detecting DNA sequences specific to Leishmania parasites. Although PCR has a high sensitivity and specificity, the question specifically states that September 2008 options are incorrect, making this option also incorrect.

**Clinical Pearl:** Direct examination methods like demonstration of Leishman Donovan bodies in biopsy specimen provide more definitive evidence of the parasite in the tissue sample, making them essential in diagnosing leishmaniasis. While serological tests and molecular techniques can also be useful, these options are indirect evidence of infection and may not always confirm the diagnosis.