# Leishmaniasis and Kala-Azar

> Leishmaniasis and kala-azar for NEET-PG Microbiology, covering LD bodies, the rK39 test, PKDL, liposomal amphotericin B and the national elimination programme.

- Canonical URL: https://prepelephant.com/topics/neet-pg/microbiology/leishmaniasis-and-kala-azar
- Exam / course: NEET-PG · Subject: Microbiology
- Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team
- First published: 2026-10-14
- Last updated: 2026-10-14
- Reference basis: Ananthanarayan and Paniker's Textbook of Microbiology; Markell and Voge's Medical Parasitology; Harrison's Principles of Internal Medicine
- How to cite: "Leishmaniasis and Kala-Azar", PrepElephant, https://prepelephant.com/topics/neet-pg/microbiology/leishmaniasis-and-kala-azar

## Direct answer

Leishmaniasis is a protozoan infection transmitted by sandflies, and kala-azar is its visceral form caused by Leishmania donovani, with prolonged fever, hepatosplenomegaly and pancytopenia. The parasite appears as LD bodies, which are amastigotes inside macrophages of the spleen, liver and bone marrow. In India, the rK39 rapid test supports diagnosis, and single-dose liposomal amphotericin B is the preferred treatment under the national programme.

## What you must remember

- **Vector:** Phlebotomus argentipes, the sandfly that transmits Leishmania donovani in India's kala-azar belt.
- **LD bodies:** round or oval amastigotes, about 2 to 4 micrometres, with a nucleus and a kinetoplast, seen inside macrophages.
- **Kala-azar features:** prolonged fever, weight loss, massive splenomegaly, pancytopenia, hypergammaglobulinaemia and hypoalbuminaemia.
- **rK39 test:** an immunochromatographic strip test on blood that gives a rapid result and is widely used in endemic districts.
- **Parasitological confirmation:** splenic aspirate has the highest yield, while bone marrow aspirate is safer and still useful.
- **PKDL:** post-kala-azar dermal leishmaniasis, skin macules, papules or nodules after apparent cure, with amastigotes in skin scrapings.
- **Cutaneous leishmaniasis:** a separate form, with Leishmania tropica causing disease in parts of north-west India.

## Fever and pancytopenia in an endemic district

A rural patient from eastern India has three months of fever, weight loss, a large spleen and low counts across all cell lines.

1. **Think of the setting:** prolonged fever, massive splenomegaly and weight loss in an endemic district raise kala-azar as the leading consideration.
2. **Run a rapid test:** the rK39 strip test on blood gives a quick result, and a positive result supports the diagnosis, although past infection can also test positive.
3. **Confirm parasitologically:** a splenic or bone marrow aspirate is examined for LD bodies, and splenic aspirate has the highest yield.
4. **Check for complications:** pancytopenia, secondary bacterial infection, hypoalbuminaemia and HIV coinfection are looked for and treated alongside the parasite.
5. **Treat with the national regimen:** liposomal amphotericin B is given per the national protocol, with single-dose therapy used in the Indian programme.
6. **Watch for PKDL after cure:** hypopigmented patches or nodules that appear later raise the question of PKDL, which needs follow-up and treatment.

The steps move from clinical suspicion to parasite proof, and the follow-up step matters because PKDL keeps the human reservoir active.

## Where the exam tries to catch you

Leishmaniasis questions test the form of the parasite, the test of choice and the meaning of the skin lesions.

- **Trap:** looking for LD bodies in a peripheral blood smear — **Correct:** amastigotes live inside macrophages of the spleen, bone marrow and liver, so an aspirate from these organs is needed.
- **Trap:** assuming PKDL is a relapse of kala-azar — **Correct:** PKDL is a skin manifestation after apparent cure, with amastigotes in the skin, and it serves as a reservoir for transmission.
- **Trap:** treating fever with splenomegaly as malaria without considering kala-azar — **Correct:** malaria can coexist, but kala-azar is separated by pancytopenia, hypergammaglobulinaemia and LD bodies in an aspirate.

## Frequently asked questions

### What are LD bodies in kala-azar?
LD bodies are the amastigote forms of Leishmania donovani, seen as small round or oval bodies with a nucleus and kinetoplast inside macrophages. They are found in splenic, bone marrow or liver aspirates. Identifying them confirms the parasitological diagnosis of kala-azar.

### Which test is used for rapid diagnosis of kala-azar in India?
The rK39 immunochromatographic strip test is widely used for rapid diagnosis of kala-azar in endemic districts of India. It detects antibodies in a blood sample and gives a result within minutes. A positive result supports the diagnosis, but it does not prove active disease, so clinical correlation is needed.

### What is post-kala-azar dermal leishmaniasis?
Post-kala-azar dermal leishmaniasis is a skin eruption of macules, papules or nodules that appears after apparent cure of visceral leishmaniasis. Amastigotes are found in skin scrapings. It matters because affected people can act as a reservoir for sandfly transmission.

### What is the aim of the National Kala-azar Elimination Programme?
The National Kala-azar Elimination Programme aims to reduce kala-azar to under one case per 10,000 population at block level. It combines case detection, prompt treatment and vector control. This is a public health target, and it is separate from the clinical management of an individual patient.