Leishmaniasis: current challenges and prospects for elimination with special focus on the South Asian region

Abstract

Leishmania donovani, the most virulent species of Leishmania, is found in the South Asian region that harbours the majority of visceral leishmaniasis (VL) cases in the world. The traditionally accepted relationships between the causative species of Leishmania and the resultant disease phenotype have been challenged during recent years and have underscored the importance of revisiting the previously established taxonomy with revisions to its classification. The weak voice of the afflicted with decades of neglect by scientists and policy makers have led to the miserably inadequate and slow advancements in product development in the fields of diagnostics, chemotherapeutics and vector control that continue to hinder the effective management and control of this infection. Limitations notwithstanding, the regional drive for the elimination of VL initiated over a decade ago that focused on India, Nepal and Bangladesh, the three main afflicted countries in the Indian subcontinent is therefore, commendable, with the subsequent status reviews and restructuring of strategies possibly even more so. However, the renewed efforts would need to be combined with plans to combat new challenges in the South-Asian region that includes the emergence of atypical parasite variants, in order to realistically achieve the set goal of regional elimination of VL.

Keywords: Indian subcontinent; Leishmania; Neglected tropical disease; kala azar; skin lesions.

Fig. 1

Skin lesions observed in cutaneous leishmaniasis patients. a, papule; b, Scaling nodule; c, Ulcer.

Fig 2

Microscopic appearance of a Giemsa-stained smear made from tissue aspirates from a skin lesion of a cutaneous leishmaniasis patient (under oil immersion (×1000 magnification).