African trypanosomes are transmitted by the bite of the tsetse fly and cause the debilitating, and often fatal, neglected tropical disease, sleeping sickness or Human African Trypanosomiasis (HAT).  The parasites responsible for 98% of human cases first reside in the patient blood and skin for months to years before invading the central nervous system, where they cause the neurological symptoms of the disease. 

HAT is approaching elimination, with the number of cases reported in 2017 dropping to approximately 1,442 from only a dozen African Countries.  However, the reduction in cases also brings about challenges and HAT was included in the WHO roadmap on neglected tropical diseases.  As the burden drops, so does the sensitivity of any diagnostic test.  In this context, new highly sensitive and specific diagnostic tools will be required to accurately monitor the occurrence of new cases and the possible emergence of drug- resistant trypanosomes during the elimination phase.  Most diagnostic tests currently under development are based on optimization of existing methods that may not combine all the requirements to stand up to the harsh constraints imposed by the elimination phase requirements, especially in terms of sensitivity and specificity.

Scientists at the Institut Pasteur and the London School of Hygiene and Tropical Medicine are working to adapt the recently developed Specific High-sensitivity Enzymatic Reporter unlocking technology that combines a CRISPR-Cas system and lateral flow test to trypanosomes to provide the sensitivity and specificity required for a diagnostic test in the elimination and post elimination phases of HAT.