FINDing an alternative
Dr Joseph Ndung'u
Head of HAT Diagnostics programme FIND
Foundation for Innovative New Diagnostics
Control of human African trypanosomiasis (HAT) depends primarily on a combination of active and passive case detection and curative treatment. During the first stage of the disease, when treatment is safer and more effective, infection produces few symptoms and, given the current state of diagnostics, is rarely detected. Thus, the disease usually progresses to the second stage, when the parasite invades the central nervous system (CNS), is difficult to treat, and results in considerable morbidity and mortality.
As early-stage disease is so difficult to recognize clinically, and late-stage disease is so morbid, the World Health Organization (WHO) recommended disease control strategy relies on systematic screening of at-risk populations using the card agglutination test for trypanosomiasis (CATT), and confirmation of the presence of parasites by microscopy. The CATT test is for T.b. gambiense, and though quite effective, has problems of sensitivity and specificity. No similar test is available for T.b.rhodesiense disease which causes an acute form of sleeping sickness. Microscopy is both laborious and insensitive, and many patients go undiagnosed. Further, the molecular-based tests that have been developed are impractical in the endemic rural areas due to absence of required infrastructure.
Individuals in whom infection is detected must go on to have cerebrospinal fluid (CSF) examinations to determine whether specific treatment for stage 2 disease is required. This can only be done via a lumbar puncture, which is an additional complexity that seriously limits access to diagnosis. Better diagnostic tests simple, accurate, robust, and capable of determining disease stage would revolutionize HAT control, making mass screening a realistic goal.
The Foundation for Innovative New Diagnostics (FIND), launched at the World Health Assembly in May 2003 as a public private partnership based in Geneva, Switzerland - Photo credits: DNDi, is developing rapid, accurate and affordable first point-of-care diagnostic tests for HAT and other poverty-related diseases that are endemic in the developing world. Since its launch in early 2006, the HAT diagnostics programme, executed jointly with the WHO, has established linkages with industry, academic, and research institutes in developed and endemic countries, and initiated projects that will allow the development of diagnostic tests into kits. The areas of emphasis include improvement in parasite separation from blood and CSF, serological and molecular tests, and staging of the disease.
Published by Drugs for Neglected Diseases Initiative - 1 Place St Gervais 1201 Geneva Switzerland - Photo credits: DNDi
Editor: Ann-Marie Sevcsik - Tel: +41 22 906 9230 - Fax: +41 22 906 9231 - www.dndi.org