Visceral Leishmaniasis: New Health Tools Are Needed

0590 V isceral leishmaniasis (VL), commonly known as kala-azar, 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. An estimated 500,000 new cases of VL occur each year, and a tenth of these patients will die [2]. The actual death toll from the disease may be higher than this estimate, considering the existence of unidentifi ed VL foci. Some 90% of those affected by the disease live in fi ve countries: India (especially Bihar), Bangladesh, Nepal, (northeastern) Brazil, and Sudan [2]. VL often exists in areas that are either remote or not easily accessible, and where health facilities are barely available or inadequate. Those most likely to be infected are people who are poor, living in villages far from roads and health-care centres. Patients from such remote communities often die in the villages without seeking treatment. Some may attempt to report to distant health-care centres, but in many cases it is simply too late. Even if they can make the journey to a hospital, they would still succumb to the illness because of the absence of anti-leishmanial drugs. Thus, many decide to stay at home until they die. But in doing so, they act as a reservoir of infection, passing on the parasite to family and neighbours through the bite of sandfl ies. At present, approaches to the control of VL are varied. This variety is dictated fi rst and foremost by the diverse epidemiological patterns of the disease, which range from domestic zoonosis (see Glossary) involving the dog (the Mediterranean littoral) …