# Visceral Leishmaniasis Kala-azar

> Visceral leishmaniasis or kala-azar for NEET-PG Paediatrics, covering the fever, splenomegaly and pancytopenia triad, rK39 test and liposomal amphotericin B.

- Canonical URL: https://prepelephant.com/topics/neet-pg/paediatrics/visceral-leishmaniasis-kala-azar
- Exam / course: NEET-PG · Subject: Paediatrics
- 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: Nelson Textbook of Pediatrics; Park's Textbook of Preventive and Social Medicine; National Vector Borne Disease Control Programme guidelines
- How to cite: "Visceral Leishmaniasis Kala-azar", PrepElephant, https://prepelephant.com/topics/neet-pg/paediatrics/visceral-leishmaniasis-kala-azar

## Direct answer

Visceral leishmaniasis, or kala-azar, is a protozoal infection caused by Leishmania donovani and transmitted by the bite of female Phlebotomus sandflies. It presents as prolonged fever with massive splenomegaly, hepatomegaly and pancytopenia, and untreated disease is usually fatal. A positive rK39 rapid test supports the diagnosis, and liposomal amphotericin B is the preferred treatment.

## What you must remember

- **Organism and vector:** Leishmania donovani, transmitted in India by the sandfly Phlebotomus argentipes.
- **Classic triad:** prolonged fever, massive splenomegaly and pancytopenia form the core picture.
- **Immunology:** hypergammaglobulinaemia with a reversed albumin to globulin ratio is typical.
- **Hyperpigmentation:** darkening of the skin gave the disease its name, kala-azar, meaning black fever.
- **Rapid test:** the rK39 immunochromatographic test supports diagnosis in endemic areas.
- **Confirmation:** amastigotes seen on a splenic or bone marrow aspirate, with the splenic aspirate having the higher yield.
- **Treatment:** liposomal amphotericin B is preferred, given as a single-dose regimen under the national programme.
- **Post-kala-azar dermal leishmaniasis:** skin lesions after treated disease act as a reservoir for transmission.

## A pathway from fever to treatment

A 6-year-old from a village in Bihar has had fever for three weeks, pale skin and a large spleen. The pathway below moves from clinical suspicion to confirmation and treatment, with each step building on the one before.

1. **Suspect the triad:** a child with fever beyond two weeks, progressive splenomegaly and weight loss should prompt a blood count.
2. **Check the blood count:** pancytopenia and a reversed albumin to globulin ratio strengthen the suspicion.
3. **Run the rK39 test:** a positive rapid test in an endemic setting supports the diagnosis.
4. **Confirm parasitologically:** aspirate the spleen or bone marrow and look for amastigotes, remembering that splenic aspiration carries a bleeding risk.
5. **Start liposomal amphotericin B:** the single-dose regimen is preferred, with monitoring for infusion reactions and renal function.
6. **Treat complications in parallel:** look for secondary infection, bleeding and malnutrition, and manage them alongside the antileishmanial drug.
7. **Follow up for PKDL:** watch for hypopigmented or erythematous skin lesions in the months to years after treatment.

## Where the exam tries to catch you

Questions on this topic test the triad, the diagnostic test and the drug choice.

- **Trap:** choosing pentavalent antimony as first-line treatment in Bihar — **Correct:** resistance has made liposomal amphotericin B the preferred regimen in the national programme.
- **Trap:** treating post-kala-azar dermal leishmaniasis as a relapse of visceral disease — **Correct:** PKDL is a skin manifestation after treated kala-azar, and it needs its own evaluation.
- **Trap:** relying on a single negative rK39 test to exclude kala-azar — **Correct:** a suspected case with a negative test still needs parasitological evaluation.
- **Trap:** attributing pancytopenia with splenomegaly to a marrow disorder without considering kala-azar — **Correct:** in an endemic setting, leishmaniasis is a key cause that the examiner expects you to consider.

## Frequently asked questions

### What is the classic clinical triad of visceral leishmaniasis?

The classic triad of visceral leishmaniasis is prolonged fever, massive splenomegaly and pancytopenia. Hepatomegaly, weight loss and hypergammaglobulinaemia commonly accompany it. Hyperpigmentation of the skin gave the disease its name, kala-azar, meaning black fever.

### What is the rK39 test used for in kala-azar?

The rK39 test is a rapid immunochromatographic test that detects antibodies in suspected visceral leishmaniasis. It is used for field diagnosis in endemic areas, where a positive result supports the diagnosis. Demonstration of amastigotes on a splenic or bone marrow aspirate remains the definitive step.

### Which drug is preferred for treating visceral leishmaniasis in India?

Liposomal amphotericin B is the preferred drug for visceral leishmaniasis in India, given as a single-dose regimen under the national programme. Pentavalent antimony is no longer preferred in many endemic areas because of resistance. Monitoring for infusion reactions and renal function is part of the treatment.

### What is post-kala-azar dermal leishmaniasis?

Post-kala-azar dermal leishmaniasis is a skin manifestation that can appear after treated visceral leishmaniasis. Hypopigmented or erythematous skin lesions develop, and they act as a reservoir for transmission. It needs its own evaluation and treatment rather than being labelled a relapse of visceral disease.

### Which vector transmits visceral leishmaniasis in India?

The sandfly Phlebotomus argentipes is the vector that transmits visceral leishmaniasis in India. Only the female sandfly takes blood meals and transmits the parasite. The disease is concentrated in parts of Bihar, Jharkhand and West Bengal.