Diagnostics for Visceral Leishmaniasis in low resource settings within East Africa
29 Apr 2019
Master thesis by Astrid ten Bosch
Have a look at the project video to learn more!
This report is the result of a graduation project in the domain of the Neglected Tropical Disease (NTD): Visceral Leishmaniasis (VL) in low resource settings in East Africa. The project aims to find promising ways to fit a technical principle, which is being developed at the TUDelft, in the context of VL. VL endemic regions in Eastern Uganda and North-Western were visited during a two-week field trip to understand the context of VL. VL is a parasitic disease which is endemic in several parts in the world including East Africa. The disease is strongly related to poverty and mainly persists in remote and poor areas where health care services are limited. VL affects the internal organs and is fatal if untreated. There are many barriers complicate access VL diagnostics and treatment, such as the limited number of facilities, large distances, lack of trained staff and low index of suspicion by health care workers. VL is often misdiagnosed as the symptoms of VL are similar to many other diseases. In addition, current diagnostic practices have limitations in their performance (unreliable), especially in East Africa. More reliable diagnostic practices require more advanced tools and skills which are not available in most VL endemic areas. Thus, there is a need for a more reliable diagnostic test for the African VL context. The technical principle can be integrated on a diagnostic test strip to test a patient for VL. Based on a sample, it can separate and amplify the pathogens and detect their DNA with a CRISPR/Cas9 system. The result is a colourimetric read-out which indicates whether or not the patient has VL. This technical principle is based on DNA detection, which enables reliable test results independent of someone’s immune system. Additional advantages of this technical principle are that it is quick and broadly applicable. To understand where the technical principle could be implemented, a session was held with the team of IDE and Applied Sciences (TUDelft). This session resulted in the creation of seven scenarios which represent unique ways to combine the features of the technical principle into a diagnostic test which fits a diagnostic setting in the context of VL and matches a local need.
After evaluation with Médecins Sans Frontières, the two most ‘promising’ scenarios are selected based on the feasibility of the technical principle, the contextual fit and the local need. The two selected scenarios are: ‘Screening & Confirming” scenario and the “Test-of-cure” scenario. By detailing the selected scenarios, five variables where identified which clarify that the diagnostic setting influences the features of a diagnostic test. These are:
- (geographic) location,
- resource availability,
- (medical) background of the user,
- diagnostic moment,
- patient status
Requirements are composed to see how the diagnostic setting affects the diagnostic test. The categorisation of the requirements and diagnostic setting variables have resulted in four different diagnostic tests – each with a unique set of requirements.
You can read the full thesis report here.