Abstract

Visceral Leishmaniasis or kala azar is prevalent through out the tropical or subtropical regions of Africa, Asia, the Mediterranean, Southern Europe and South and Central America. 90% of the cases are said to be occurring in Bangladesh, India, Nepal and Sudan. Preliminary diagnosis is based on the symptoms and clinical signs of hepatosplenomegaly and high undulating fever. Confirmed diagnosis requires demonstration of the parasite in liver, splenic or bone marrow aspirates. It was believed that bone marrow aspirates are a safer but less sensitive method in the diagnosis of visceral leishmaniasis as compared to splenic aspirates. However, it has been shown that bone marrow smears if examined thoroughly are as sensitive as splenic aspirates and when combined with in-vitro culture of the marrow sensitivity is even higher.

Introduction

Kala-azar has reemerged from near eradication. The annual estimate for the incidence and prevalence of Kala-azar world wide is 0.5 million and 2.5 million respectively. Of these 90% of the confirmed cases occur in India, Nepal, Bangladesh and Sudan. In India, it is a serious problem in Bihar, West Bengal and eastern Uttar Pradesh.1 A confirmed diagnosis is achieved by demonstrating the Leishmania parasite in splenic, liver, or bone marrow aspirate and in vivo culturing of the same aspirate to demonstrate the parasite. Since splenic aspirates are less painful it is preferred over bone marrow aspirates. We present the case of our patient who was diagnosed on the basis of bone marrow aspirates and in vitro culture of the same.

Case Report

Our patient was a fourteen year old girl a resident of Bihar who presented with history of moderate grade fever on and off since eight months. Patient had a moderate non tender splenomegaly. Her peripheral blood smear showed features of a dimorphic anaemia, the total WBC count and platelet count were within normal limits. No parasites were detected. A bone marrow aspirate was done to determine the cause of the fever which was not responding to any treatment. The aspirate showed no abnormality in the myeloid series. There was erythroid hyperplasia. The striking feature was the presence of amastigote forms of Leishmania donovanii within the histiocytes (Fig. 1). Similar findings were also seen in the trephine biopsy (Fig. 2). The aspirate was sent for culture. Culture in the NNN medium was positive for the parasite.

Fig 1 : Bone marrow aspirate showing the amastigote forms of Leishmania donovani within a macrophage, highlighted in the inset.		Fig 2 : Bone marrow trephine biopsy showing the ingested parasite within the macrophage.

Discussion

As per epidemiology reports visceral Leishmaniasis or Kala-azar is prevalent throughout the tropical and subtropical regions of Africa, Asia, the Mediterranean, Southern Europe and South and Central America. 90% of the cases are said to be occurring in Bangladesh, India, Nepal and Sudan. Although the preliminary diagnosis is based on the symptoms and the clinical sign of hepatosplenomegaly with high undulating ever, a confirmed diagnosis is based on demonstration of the parasite in the liver, splenic, or bone marrow aspirates. Splenic aspiration is more acceptable by some physicians over a bone marrow aspirate since the procedure is less painful and easy.² However, there are case studies done which show that a bone marrow aspirate smear along with culture of the aspirate is an equally sensitive but more safer technique than a splenic aspirate.³In vitro culture of bonemarrow is necessary to diagnose Kala-azar and is strongly recommended to be performed along with bonemarrow smear examination as the technique of choice for the parasitologic diagnosis of visceral leishmaniasis.⁴

References

1. Epidemiology of visceral leishmaniasis in India. Bora D Natl Med J India 1997 Mar-Apr; 12 (2) : 62-8.
2. Sarker CB, Alam KS, Jamal MF, et al. Sensitivity of splenic and bonemarrow aspirate study for diagnosis of kala-azar. Mymensingh Med J 2004 Jul; 13 (2) : 130-3.
3. daSilva MR, Stewart JM, Costa CH. Sensitivity of bonemarrow aspirates in the diagnosis of visceral leishmaniasis. Am J Trop Med Hyg 2005 Jun; 72 (6) : 811-4.
4. Sinha R, Datta U, Sehgal S. Importance of bonemarrow culture for the diagnosis of Kala-azar. Scand J Infect Dis 1993; 25 (6) : 787-9.

*Associate Professor, **Resident, Department of Ophthalmology, T.N.M.C and B.Y.L. Nair Hospital, Mumbai - 400 008.