Science, medicine, and the future: Leishmaniasis

Abstract

Leishmaniasis constitutes a diverse collection of human diseases ranging in severity from a spontaneously healing skin ulcer to overwhelming visceral disease. Worldwide, two million new cases occur each year, and a 10th of the world's population is at risk of infection. 1 Although the disease is highly endemic throughout northern Africa, the Middle East, parts of Europe, and Central and South America, epidemics are well recognised. For example, in southern Sudan more than 10% of the population died from visceral leishmaniasis over the past five years.Outcome of infection is determined by interactions between the host and parasite, which are governed by the genomes of the host and parasite. It is therefore exciting to see that both host and parasite genomes have been targeted for sequence analysis. 2 The leishmania genome project began as a large scale attempt to sequence part of each of the transcripts of all the genes of the organism, and the plan is now to sequence its entire genome. The genetic information from both human and parasite and the emergence of new tools such as microarray technologies will allow us to gain an understanding of the interaction between parasite virulence factors and host response factors. Molecular knowledge of the host-parasite interaction will facilitate targeting of new treatments. MethodsWe chose topics for this article to convey the impact that current research will have on the pathophysiology and treatment of leishmaniasis. We used a variety of sources for the topics, including published original articles and reviews, the internet, and personal communications.

A Controlled, Randomized-Blinded Clinical Trial to Assess the Efficacy of a Nitric Oxide Releasing Patch in the Treatment of Cutaneous Leishmaniasis by Leishmania (V.) panamensis

“…5 Cutaneous leishmaniasis is caused by intracellular protozoan parasites of the genus Leishmania , which are transmitted by the bite of the female Phlebotomus (in Africa, Asia, and Europe) and Lutzomyia (in America) sandflies. 1,6 The typical lesions of this disease are ulcers that may heal spontaneously over a period of 3 months to a year depending on the strain of the parasite, leaving a flat, atrophic, and depigmented scar. 7,8 For more than 60 years the pentavalent antimony compounds sodium stibogluconate (Pentostan) and meglumine antimoniate (Glucantime) have been the treatments of choice for this entity.…”

Neurologic Manifestations ofLeishmania spp.Infection

“…VL transmission is primarily vector borne via the sand fly, with dogs and humans as natural host species [45]. Infected dogs are the primary reservoir for zoonotic visceral leishmaniasis in endemic regions, and are the most significant risk factor predisposing humans to infection [17].…”

Immunologic Indicators of Clinical Progression during CanineLeishmania infantumInfection

“…L. infantum infection often does not equate with clinical disease (18). Typical clinical signs of VL include fever, weight loss, anemia, lymphadenopathy, and hepato-and splenomegaly (4,22,27).Clinical stages of infection can be classified by the severity of clinical signs, humoral and cell-mediated immune responses, and parasite load (33). We propose that these parameters can also be used to determine the best window for treatment and in some cases predict the appearance of clinical signs and prognosis (24).…”

“…Both dogs and humans are natural hosts (27), and in endemic regions, infected dogs are the primary domestic reservoir for zoonotic VL and the most significant risk factor predisposing humans to infection (9). L. infantum infection often does not equate with clinical disease (18).…”