Development of a new diagnostic method for Human African Trypanosomiasis using Raman spectroscopy

  • Alexandre Girard

Student thesis: Doctoral Thesis

Abstract

Human African Trypanosomiasis (HAT) is a tsetse fly-transmitted parasitic disease found in Sub-Saharan Africa. Although responsible for deadly epidemics throughout the 20th century, a renewed commitment to disease control by the World Health Organisation and partners since 2000 has significantly reduced the number of new cases and motivated a target for the elimination of gambiense-HAT by 2030. However, the recent identification of latent human infections, and the detection of trypanosomes in extravascular tissues hidden from current diagnostic tools, such as the skin, has added new complexity to identifying infected individuals. New and improved diagnostic tests, capable of detecting such cases are therefore needed.This thesis investigates the potential of Raman spectroscopy as a diagnostic tool for HAT. Raman spectroscopy provides vibrational information about the composition of a matrix and could determine the biochemical changes that occurs during the infection, leading to the detection of diseased tissue. Lately, this technique has been extensively used for medical diagnostics and the recent technological advancements have improved the cost, sensitivity and portability of Raman technology, making Raman an attractive tool for the detection of HAT.The aim of this thesis was to assess and develop a new diagnostic method for gambiense-HAT using Raman spectroscopy of the skin. Two sub-species of Trypanosoma brucei were analysed and biologically characterised, with the purpose of understanding the surface biological composition of the parasite and to obtain their Raman fingerprint. The skin of T. brucei-infected and uninfected mice was then investigated to measure spectral differences using statistical analysis, thus providing information on biochemical changes in infected skin.This technique was then translated in situ by analysing infected mice over a time course of infection. Finally, this diagnostic method was tested in vivo on human patients in the field in collaboration with the HAT national control active screening program in Guinea. This study investigated for the first time, the application of Raman spectroscopy for the detection of gambiense-HAT by targeting the skin of the host. It has demonstrated significant potential to discriminate between infected and non-infected tissue and could represent a unique non-invasive diagnostic tool in the goal for elimination of T.b. gambiense disease.
Date of Award1 Oct 2017
LanguageEnglish
Awarding Institution
  • University Of Strathclyde
SponsorsUniversity of Strathclyde
SupervisorDuncan Graham (Supervisor) & Karen Faulds (Supervisor)

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