Molecular Test Designed Specifically for Sleeping Sickness

A next generation field-based molecular diagnostic test has been developed for human African Trypanosomiasis (HAT) and is ready to enter accelerated trials.

The design and development phases of the Loop-mediated Isothermal Amplification (LAMP) test have been completed and it will be available for clinical use in 2012 in sites across the Democratic Republic of Congo and Uganda.

The test has been designed to be suitable for use in rural African settings where the disease is most common. The LAMP test promises to improve dramatically the ability to confirm a diagnosis of sleeping sickness, even when parasites are present in low numbers, through detection of the parasite's DNA in patient samples. The nonprofit Foundation for Innovative New Diagnostics (FIND; Geneva, Switzerland) is also exploring LAMP's utility as a tool to confirm cure after treatment of HAT, which would significantly reduce the follow-up period, and could eliminate the need for repeated lumbar punctures.

LAMP is a molecular diagnostic platform that detects pathogen DNA from patient samples with very high specificity and sensitivity. Unlike most other such tests, LAMP amplifies target DNA at a constant temperature, which means that it can be carried out with much less laboratory equipment than other molecular tests. The reagents for LAMP can be stored at room temperature, since they are dried down in the cup of the reaction tube. In addition, results can be detected by the naked eye, rather than with the complicated detection equipment required for more conventional methods. If not diagnosed and treated early, sleeping sickness inexorably progresses to a stage where the parasites enter the brain, making treatment more difficult and the likelihood of irreversible neurological damage more likely. About 60 million people in 36 countries in sub-Saharan Africa are thought to be at risk

The FIND organization have been working in partnership with the Eiken Chemical Company (Tokyo, Japan) over the past six years to develop LAMP for a range of diseases, including tuberculosis, HAT and malaria. This is in line with FIND's focus on developing multipurpose platform technologies that can be used by health workers to detect many diseases with a single instrument. The diagnosis of sleeping sickness currently relies heavily on trained health workers using a screening test to identify suspects, and then using microscopes to detect parasites in the blood and other body fluids.

Jean Jannin, MD, MPH., a coordinator in the World Health Organization's Control of Neglected Tropical Diseases Department (Geneva, Switzerland), said, "The need for sensitive and specific tools - more user-friendly, stable and cheaper - is growing as we move closer towards the elimination of diseases such as sleeping sickness, in order to sustain an efficient surveillance system at the most peripheral level."

Related Links:
Foundation for Innovative New Diagnostics
Eiken Chemical Company
World Health Organization