Infectious Disease Research Institute : Our Products : Leishmania Diagnostics

Leishmaniasis is caused by unicellular, haemoflagellate protozoan parasites of the genus Leishmania. The disease is transmitted by bites of infected female sand flies. Leishmania infection can give rise to several distinct clinical manifestations, ranging from a single skin ulcer to many in cutaneous leishmaniasis (CL) to systemic disease in visceral leishmaniasis (VL). Annual incidence is estimated at 1-1.5 million cases of CL and 500,000 cases of VL.

Diagnosis of VL is complicated by the fact that its clinical features are shared by a host of other commonly occurring diseases, such as typhoid, malaria and tuberculosis. Definitive diagnosis of VL is accomplished by microscopic confirmation of the amastigote form of the parasite in tissue aspirates from spleen, bone marrow or lymph nodes. These methods are risky, inefficient, and expensive. They also require technical expertise, hospitalization and use of laboratory facilities, which are often not available in low-resource settings.

Early and accurate laboratory diagnosis is essential before initiating treatment for the following reasons:

The disease is usually always fatal if not treated in a timely manner
The effective drugs are potentially toxic and expensive, often requiring long periods of hospitalization for administration
Untreated cases of VL are active reservoirs of infection, thereby putting the community at risk of ongoing transmission

Our Solutions

New, accurate and cost-effective point-of-care tests are needed to enable timely administration of therapy to acutely diseased individuals. In addition to the need for diagnostics, an accurate test of cure would be of great benefit for evaluating new therapeutics. Related tests may also help identify asymptomatic individuals who are reservoir hosts for the parasite. We are working toward the following strategies to achieve our goals:

Develop and evaluate a cost-effective and affordable point-of-care antibody detection test for African VL that is highly specific and sensitive.
Develop and evaluate an efficient and cost-effective point-of-care parasite test that is capable of detecting parasite products (antigen and/or nucleic acids) in blood, serum or urine. A parasite detection test will allow for differentiating actively infected individuals from those who are not.
Evaluate several of the most promising technologies to develop a robust, simple and accurate test of cure for VL.

Publications

Design, development and evaluation of rK28-based point-of-care tests for improving rapid diagnosis of visceral leishmaniasis. Pattabhi S, Whittle J, Mohamath R, El-Safi S, Moulton GG, Guderian JA, Colombara D, Abdoon AO, Mukhtar MM, Mondal D, Esfandiari J, Kumar S, Chun P, Reed SG, Bhatia A. PLoS Negl Trop Dis. 2010 Sep 14;4(9). pii: e822.

Molecular characterization of a kinesin-related antigen of Leishmania chagasi that detects specific antibody in African and American visceral leishmaniasis. Burns JM Jr, Shreffler WG, Benson DR, Ghalib HW, Badaro R, Reed SG. Proc Natl Acad Sci U S A. 1993 Jan 15;90(2):775-

Distinct antigen recognition pattern during zoonotic visceral leishmaniasis in humans and dogs. Goto Y, Howard RF, Bhatia A, Trigo J, Nakatani M, Netto EM, Reed SG. Vet Parasitol. 2009 Mar 23;160(3-4):215-20. Epub 2008 Nov 5

Key Scientists

Malcolm S. Duthie
Greg Ireton