In West and Central Africa, a bite from the tsetse fly could send a person in to a fatal coma. Doctors have
now developed a fast and efficient way to diagnose this condition using a method that’s similar to a dipstick pregnancy test.
African sleeping sickness, also known formally as Human African Trypanosomiasis (HAT), is a disease caused by the parasites
Trypanosoma brucei gambiense (
T.
b. gambiense) or
T.b. rhodesiense. Infected tsetse flies transmit the parasite to humans through skin bites. The parasites initially invade the blood and lymphatic system. Then they begin an attack on the host’s central nervous system, causing sleep cycle disruption and neurological damage that can amount to a fatal coma when not treated properly.
Current methods of diagnosing the sleeping sickness involve highly skilled professionals and multiple complex equipments – resources that are in short supply in the remote Sub-Saharan Africa areas.
"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.” – Dr. Barrie Rooney, lead author of the study.
Working with the international medical charity Medecins Sans Frontieres (MSF) and the Flexible Interchange Programme (FLIP), researchers from the University of Kent developed a next generation diagnostic test that requires a blood sample the size of a pinprick.
The basis of this new test is a new genetically engineered parasite that’s similar to
T. b. gambiense. This modified organism provided a safe and convenient means for researchers to produce antigens that react against HAT. Similar to antigen-based tests that can tell your blood type, the binding of HAT antigen molecules to a patient’s blood will alert doctors of the disease presence.
"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.” – Dr. Rooney
The new test is classified as a rapid immunochromatography-based serodiagnostic tests (RDTs), and is considered a type of point of care test (POTC). Additionally, it fits all the criteria outlined by the World Health Organization, being “affordable, sensitive, specific, user-friendly, rapid, equipment-free and deliverable to the people at need.” This is quite a remarkable feat considering that the doctors and researchers took only 14 months to develop this rapid diagnostic test.
The test is expected to improve the screening and treatment of this disease dramatically. And although it was developed specifically for African sleeping sickness, the basic premise of the diagnostic test could theoretically be adapted for other similar tropical diseases like Chagas and visceral leishmaniasis.
Additional source:
Eurekalert
