New Rapid Diagnostic Test to Tackle Fatal Sleeping Sickness

By LabMedica International staff writers
Posted on 27 Jan 2016
Using an innovative approach, scientists have developed a simple serodiagnostic method, similar to a dipstick pregnancy test, to fight human African trypanosomiasis (HAT) caused by Trypanosoma brucei gambiense. The new test requires only a pin-prick blood sample and will remove the need to take complex equipment into remote areas.

Although millions are at risk of contracting HAT, some at-risk areas remain uncovered by surveillance and control efforts. Existing tests for T. b. gambiense rely on samples extracted directly from this dangerous parasite. A research team, led by Dr Barrie Rooney and Prof. Mark Smales of the University of Kent (Kent, UK), has designed a safer, easier, faster (about half the time of traditional methods), and less costly method for preparing samples. Also, fewer people will be needed to administer the test.

Image: The bite of an infected female tsetse fly taking a bloodmeal can transmit Trypanosoma brucei gambiense, cause of Human African Trypanosomiasis (HAT), also called African sleeping sickness, usually fatal if untreated with patients falling into a coma before death (Photo David Bygott/Flickr, courtesy of Biotechnology and Biological Sciences Research Council (UK)).

This next-generation test is based on genetic engineering to express selected T.b. gambiense recombinant antigens in a safe, easy-to-grow strain of the non-human parasite Leishmania tarentolae.

The work is part of the Biotechnology and Biological Sciences Research Council (BBSRC)’s Flexible Interchange Program (FLIP) in a project with Medecins Sans Frontieres (MSF; Geneva, Switzerland). Dr Rooney said: “I have been involved with MSF mobile HAT screening teams in central African countries for over 10 years. Traditional testing involves a large team in remote areas doing time-consuming microscopic work, and painful lumbar punctures. For this you need electricity and refrigeration. By combining the latest genome databases and old fashioned fermentation techniques we have come up with a fast, simple way of making robust and reliable tests. The new tests are designed to be heat-stable and user-friendly, like a dipstick pregnancy test. It will be a major improvement for screening and treatment of this deadly disease and speed us on the way to ‘the elimination of sleeping sickness as a public health hazard’ which is a World Health Organization target.”

Prof. Melanie Welham, executive director, BBSRC, Science, said, “This is a brilliant example of exactly what the FLIP scheme is all about. FLIP funding allowed Dr Rooney to work with the University of Kent and MSF to design and develop this test in just 14 months. The promise and potential impact of this new diagnostic is obvious and I wish Dr Rooney success in the forthcoming work in the Democratic Republic of the Congo (DRC). FLIP brings scientists into different environments where they can learn new skills and exploit their existing expertise in new collaborations, enhancing the impact of bioscience research.”

In July, Dr Rooney traveled to DRC to identify areas where field trials of the new test could be carried out, alongside an MSF HAT mobile team. The method also has potential to be developed for diagnosis of other tropical diseases, such as Chagas disease (T. cruzi) and visceral leishmaniasis.

The study, by Rooney B et al., was published December, 2015, in the journal PLOS Neglected Tropical Diseases.

Related Links:

University of Kent
Biotechnology and Biological Sciences Research Council (BBSRC) 
Medecins Sans Frontieres



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