Visceral Leishmaniasis: New Health Tools Are Needed

Abstract

Visceral leishmaniasis (VL), commonly known as kalaazar, from the Hindu vernacular, is a human systemic disease caused by parasitic protozoan species of the genus Leishmania. Transmitted by the bite of the tiny and seemingly innocuous female phlebotomine sandfl y (Figure 1), the parasite enters macrophages, where it multiplies and establishes the infection (Figure 2). A multitude of clinical features of the disease ensue gradually, the most important being splenomegaly, recurring and irregular fever, anaemia, pancytopenia, weight loss, and weakness. Unlike malaria, there is no early dramatic fever to announce its arrival; the presentation is insidious, with symptoms appearing over a period of weeks or even months. Affected patients become progressively more anaemic, weak, cachectic, and susceptible to intercurrent infections. The disease is a silent killer, invariably killing almost all untreated patients [1]. VL affects not only the weakest in the community, such as children and those weakened by other diseases such as HIV and tuberculosis, but also healthy adults and economically productive social groups.