The haptoglobin-haemoglobin receptor (HpHbR) is expressed by the African try- panosome, T. brucei, whilst in the bloodstream of the mammalian host. This allows ac- quisition of haem, but also results in uptake of trypanolytic factor 1, a mediator of in- nate immunity against non-human African trypanosomes. Here, the structure of HpHbR in complex with its ligand, haptoglobin-haemoglobin (HpHb), is presented, revealing an elongated binding site along the membrane-distal half of the receptor. A ~50° kink allows the simultaneous binding of two receptors to one dimeric HpHb, increasing the efficiency of ligand uptake whilst also increasing binding site exposure within the densely packed cell surface. The possibility of targeting this receptor with antibody-drug conjugates is ex- plored. The characterisation of the unexpected interaction between T. congolense HpHbR and its previously unknown ligand, haemoglobin, is also presented. This receptor is iden- tified as an epimastigote-specific protein expressed whilst the trypanosome occupies the mouthparts of the tsetse fly vector. An evolutionary pathway of the receptor is proposed, describing how the receptor has changed to adapt to a role as a bloodstream form-specific protein in T. brucei. Apolipoprotein L1 (ApoL1) is the pore-forming component of the trypanolytic factors. An expression and purification protocol for ApoL1 is presented here, and the functionality of the protein established. Initial attempts to characterise the pores and structure of ApoL1 are described.

This research aims to utilise ligand-based target prediction to (i) understand the mechanism of action of African natural products (ANPs), (ii) help identify patterns of phylogenetic use in African traditional medicine and (iii) elucidate the mechanism of action of phenotypically active small molecules and natural products with anti-trypanosomal activity. In Chapter 2 the objective was to utilise ligand-based target prediction to understand the mechanism of action of natural products (NPs) from African medicinal plants used against cancer. The Random Forest classifier used in this work compares the similarity of the input compounds from the natural product dataset with compound-target combinations in the training set. The more similar they are in structure, the more likely they are to modulate the same target. Natural products from plants used against cancer in Africa were predicted to modulate targets and pathways directly associated with the disease, thus understanding their mechanism of action e.g. "flap endonuclease 1" and "Mcl-1". The "Keap1-Nrf2 Pathway" and "apoptosis modulation by HSP70", two pathways previously linked to cancer (which are not currently targeted by marketed drugs, but have been of increasing interest in recent years) were predicted to be modulated by ANPs. In Chapter 3, we aimed to identify phylogenetic patterns in medicinal plant use and the role this plays in predicting medicinal activity. We combined chemical, predicted target and phylogenetic information of the natural products to identify patterns of use for plant families containing plant species used against cancer in African, Malay and Indian (Ayurveda) traditional medicine. Plant families that are close phylogenetically were found to produce similar natural products that act on similar targets regardless of their origin. Additionally, phylogenetic patterns were identified for African traditional plant families with medicinal species used against cancer, malaria and human African trypanosomiasis (HAT). We identified plant families that have more medicinal species than would statistically be expected by chance and rationalised this by linking their activity to their unique phyto-chemistry e.g. the napthyl-isoquinoline alkaloids, uniquely produced by Acistrocladaceae and Dioncophyllaceae, are responsible for anti-malarial and anti-trypanosome activity. In Chapter 4, information from target prediction and experimentally validated targets was combined with orthologue data to predict targets of phenotypically active small molecules and natural products screened against Trypanosoma brucei. The predicted targets were prioritised based on their essentiality for the survival of the T. brucei parasite. We predicted orthologues of targets that are essential for the survival of the trypanosome e.g. glycogen synthase kinase 3 (GSK3) and rhodesain. We also identified the biological processes predicted to be perturbed by the compounds e.g. "glycolysis", "cell cycle", "regulation of symbiosis, encompassing mutualism through parasitism" and "modulation of development of symbiont involved in interaction with host". In conclusion, in silico target prediction can be used to predict protein targets of natural products to understand their molecular mechanism of action. Phylogenetic information and phytochemical information of medicinal plants can be integrated to identify plant families with more medicinal species than would be expected by chance.

Over the past two decades movement of cattle towards the north of Uganda has enabled the Trypanosoma brucei rhodesiense focus in south-eastern Uganda to spread into previously unaffected districts. This thesis brings together important epidemiological data regarding the impact of mass cattle drug treatment on the point prevalence of several different species of trypanosome in a newly endemic area of human sleeping sickness. Crucially the findings illustrate mass drug treatment is effective in reducing the prevalence of T. b. rhodesiense in cattle, thus minimising the reservoir potential of these animals in the epidemiology of human disease. During 2006 a control programme was launched to halt the northward spread of this zoonotic parasite. This programme, entitled ‘Stamping Out Sleeping Sickness’ (SOS) proposed to reduce the prevalence of Human African Trypanosomiasis (HAT) in the newly affected districts by reducing the prevalence of this parasite in the main animal reservoir of infection – domestic cattle. Cattle were mass treated using trypanocides to clear infections. Previous work demonstrated the prevalence of T. brucei s. l. and T. b. rhodesiense in cattle was higher in the districts of Dokolo and Kaberamaido than in the other SOS intervention districts (Selby 2011). To determine whether animals in these areas were also exposed to pathogenic cattle trypanosomes samples were screened for the presence of T. vivax and T. congolense savannah using PCR. Chapter three of this thesis determined the prevalence of these trypanosomes in cattle in these districts. Before treatment had taken place the prevalence of T. vivax was 2% (4/200, 95% CI 3.57 – 0.12%) in Dokolo and 7.3% (21/310, 95% CI 10.17 - 4.24 %) in Kaberamaido. The prevalence of T. congolense savannah at baseline was 3.5% (7/200, 95% CI 7.08–1.42 %) in Dokolo and 9.1% (21/230, 95% CI13.6–5.7 %) in Kaberamaido. Monitoring was conducted three, nine and 18 months post treatment and both pathogens were detected at all time points. The impact the treatment had on point prevalence varied by trypanosome species and between the two districts. Several clusters of villages in Dokolo and Kaberamaido continued to report cases of HAT after the initial SOS intervention due in part to their proximity to livestock markets (Batchelor et al., 2009). In 2008 re-treatment of these ‘high risk’ areas was undertaken. Monitoring was performed before and six months after treatment. Cattle blood samples were collected at 20 village sites from ten ‘case-positive villages’ (from which human sleeping sickness cases had been reported six months prior to June 2007) and from ten ‘case-negative villages’ (no reported human sleeping sickness cases six months prior to June 2007). These samples were screened for all of the aforementioned trypanosomes using species specific PCR protocols. Chapter five details the results of this screening, and assessed whether re-treatment in Dokolo and Kaberamaido was effective in reducing the prevalence of trypanosomiasis. The re-treatment had a dramatic effect, significantly reducing the point prevalence of overall trypanosomiasis in the 20 villages screened from 38.1% (95% CI = 40.5 – 35.79%) at baseline to 26.9% (95% CI 28.96 – 24.97, p < 0.0001) at six months. Looking at each species separately, point prevalence of three out of four detected species of trypanosome fell significantly, including T. b. rhodesiense, which was reduced to 25% of its baseline prevalence. Finally the two SOS treatment cycles were compared both statistically and spatially with emphasis on trends at village level and the occurrence of mixed infections.

La maladie du sommeil ou Trypanosomose Humaine Africaine (THA) est une parasitose vectorielle due à un protozoaire flagellé sanguicole du genre Trypanosoma et d'espèce brucei. Deux sous-espèces de ce parasite sont pathogènes pour l'Homme : T. b. gambiense et T. b. rhodesiense ; transmis par les mouches Tsé-Tsé présentes en Afrique subsaharienne. Cette maladie évolue classiquement en deux stades : le stade hémolyphatique qui est marqué par la présence du parasite dans le sang et la lymphe et le stade nerveux caractérisé par la présence du trypanosome dans le Système Nerveux Centrale. En l’absence de traitement cette maladie est mortelle. Actuellement les traitements accessibles à la population sont stades-dépendants. Pour contrôler un jour cette pathologie, la recherche et l’amélioration des outils de diagnostic de la maladie et le diagnostic de stade sont essentielles. C’est dans ce but que nous avons exploité une biobanque d’échantillons composée de patients infectés par T. b. gambiense et d’individus non-infectés pour : 1) Évaluer l’efficacité de biomarqueurs de stade déjà existants -Néoptérine et CXCL-13- et nous avons évalué leur potentiel sur les échantillons recueillis lors du suivi des patients post-traitements. 2) Rechercher de nouveaux biomarqueurs protéiques par spectrométrie de masse LCMS/MS. Notre étude a permis d’identifier, grâce à l’établissement d’un nouveau catalogue protéomique un grand nombre de biomarqueurs potentiels dans le liquide céphalo-rachidien, l’urine et la salive de patients. Certaines de ces protéines pourraient améliorer la prise en charge et le suivi des patients à l’avenir. / Sleeping sickness, or Human African Trypanosomiasis (HAT), is a parasitic disease caused by a flagellar protozoan of the genus Trypanosoma and brucei species. Two subspecies of this parasite are pathogenic for humans: T. b. gambiense and T. b. rhodesiense; transmitted by Tsé-Tse flies present in sub-Saharan Africa. This disease classically evolves in two stages: the hemolymphatic stage which is define by the presence of the parasite in the blood and lymph and the nervous stage characterized by the presence of trypanosome in the central nervous system. Without treatment, this disease is lethal. Currently the available treatments for patients are stage-dependent. In order to control this pathology one day, research and improvement of tools for the diagnosis of the disease and the staging is fundamental. In this context, we have exploited a samples biobank composed of T. b. gambiense-infected patients and uninfected controles to: 1) evaluate the efficacy of existing stage biomarkers -Neopterin and CXCL-13- and we assessed their potential on the samples collected during post-treatment followup of patients. 2) determine new protein biomarkers using LC-MS/MS mass spectrometry. Our study identified a large number of potential biomarkers in cerebrospinal fluid, urine and saliva through the establishment of a new proteomic catalogue. Taking into account some of these proteins may improve patient management and follow-up in the future.

Human African Trypanosomiasis (HAT) is a vector-borne disease transmitted by the bite of the tsetse fly that results in high human morbidity and mortality. The propagation of the disease has been linked to environmental factors, and understanding the vector’s habitat is vital to its control. There is no HAT vaccine, but biological control of the vector has been successful in reducing HAT incidence. However, in recent years the disease has re-emerged and spread. Due to insufficient knowledge of HAT endemic foci, the disease management remains challenging. To achieve effective deployment of control strategies, accurate knowledge of the spatial distribution of the HAT vector is vital. The current study is based in Nigeria, and looks at part of Delta State, and a part of Jigawa State, in which HAT has been identified. The work utilizes remote sensing satellite imaging and fuzzy logic to develop a HAT vector habitat classification scheme, to explore the dynamics of HAT propagation. The goal was to develop a surveillance methodology to identify factors that influence HAT epidemiology. Land cover and ancillary data were integrated to classify HAT vector habitat using geospatial-fuzzy multicriteria analysis. The work highlights the significance of geospatial techniques where epidemiological data are limited, for improving understanding of HAT. This study helped distinguish HAT vector habitat into different zones (breed, feed and rest), which allowed the direction and magnitude of HAT, a n d factors influencing propagation to be determined. This helped identify ‘HAT priority intervention areas’. The study findings suggested propagation of HAT resulted from suitability of water bodies, shrub and less-dense forest for the HAT vector, and continued exposure of human populations to these land cover classes. Overlapping of HAT vector habitat zones within built-up areas was also a cause. The study also found that HAT propagation was multidirectional, and that this may have been influenced by landscape characteristics. This novel approach can also be used in other part of Nigeria as well as adapted to investigate other diseases. In conclusion, the HAT vector habitat classification scheme is a transparent tool for policy makers for identifying vulnerable and at risk areas.

Les kinétoplastidés sont des protozoaires flagellés responsables de maladies tropicales négligées mortelles telles que la leishmaniose viscérale (L. donovani et L. infantum) ou la trypanosomiase humaine africaine (T. brucei), pour lesquelles les traitements disponibles sont très limités. Depuis quelques années, on observe un regain d'intérêt pour le développement de nitrohétérocycles aromatiques anti-infectieux tels que le delamanide et le féxinidazole. De récentes études indiquent que l'activité anti-kinétoplastidés de ces dérivés repose sur leur bioactivation sélective par des nitroréductases parasitaires, conduisant à la formation de métabolites réduits électrophiles, fortement cytotoxiques. Suite à des études préliminaires réalisées dans notre équipe en série 8-nitroquinoléin-2(1H)-one, ces travaux de thèse portent sur la synthèse et l'étude in vitro de l'activité antiparasitaire de 80 dérivés notamment fonctionnalisés en positions 3 et 6 du pharmacophore par divers motifs, notamment via la mise au point de réactions d'halogénation sélective et de couplages pallado-catalysés. Ainsi, 5 nouvelles molécules hits (4 anti-kinétoplastidés et 1 sélective de T. brucei) ont été identifiées (0,01 µM ≤ CI50 ≤ 7 µM et 13 < IS < 1500), trois d'entre-elles étant des substrats sélectifs des nitroréductases parasitaires de type I. Afin de préciser les relations structure-activité, une étude des potentiels de réduction a également été menée. Des études physico-chimiques (solubilité, test de perméabilité PAMPA) et pharmacocinétiques in vitro (stabilité microsomale et fixation à l'albumine humaine) sont venues compléter ce travail. Enfin, des évaluations de la mutagénicité et de la génotoxicité de ces hits sur des cellules procaryotes et humaines ont été conduites, dans le but de statuer sur leur potentiel pharmaceutique antiparasitaire humain et vétérinaire. / Kinetoplastids are flagellated protozoan parasites responsible for lethal neglected tropical diseases, such as visceral leishmaniasis (L. donovani and L. infantum) or sleeping sickness (T. brucei brucei), for which very few drugs are available. Nowadays, nitroheterocyclic compounds present a renewed interest as anti-infective agents, as illustrated by the development of fexinidazole and delamanid. Some recent studies demonstrated that the antikinetoplastid activity of these derivatives involves their selective bioactivation by parasitic nitroreductases, leading to the formation of electrophilic reduced metabolites, highly cytotoxic. Based on preliminary studies conducted in our team in 8-nitroquinolin-2(1H)-one series, this PhD work is about the synthesis and in vitro antiparasitic study of 80 derivatives mainly functionalized at positions 3 and 6 of the pharmacophore by various substituents, especially via the optimization of selective halogenation and pallado-catalyzed cross coupling reactions. Thereby, 5 new hit compounds (4 antikinetoplastid and 1 selective of T. brucei) were identified (0.01 µM ≤ IC50 ≤ 7 µM and 13 < SI < 1500), three of them being selective substrates of type I parasitic nitroreductases. In order to refine the structure-activity relationship studies, an analysis of reduction potentials was also conducted. In vitro physicochemical (solubility, PAMPA permeability assay) and pharmacokinetic (microsomal stability and human albumin binding) experiments completed this work. Finally, the mutagenicity and genotoxicity evaluations of these new hit compounds toward prokaryotic and human cells were realized, in order to assess their human and veterinary antiparasitic pharmaceutical potential.

Background: Human African Trypanosomiasis (HAT) also called sleeping sickness is an infectious disease in humans caused by an extracellular protozoan parasite. The disease, if left untreated, results in 100% mortality. Currently available drugs are full of severe drawbacks and fail to escape the fast development of trypanosoma resistance. Due to similarities in cell metabolism between cancerous tumors and trypanosoma cells, some of the current registered drugs against HAT have also been tested in cancer chemotherapy. Here we demonstrate for the first time that the simple ester, ethyl pyruvate, comprises such properties. Results: The current study covers the efficacy and corresponding target evaluation of ethyl pyruvate on T. brucei cell lines using a combination of biochemical techniques including cell proliferation assays, enzyme kinetics, phasecontrast microscopic video imaging and ex vivo toxicity tests. We have shown that ethyl pyruvate effectively kills trypanosomes most probably by net ATP depletion through inhibition of pyruvate kinase (Ki = 3.0±0.29 mM). The potential of ethyl pyruvate as a trypanocidal compound is also strengthened by its fast acting property, killing cells within three hours post exposure. This has been demonstrated using video imaging of live cells as well as concentration and time dependency experiments. Most importantly, ethyl pyruvate produces minimal side effects in human red cells and is known to easily cross the blood-brain-barrier. This makes it a promising candidate for effective treatment of the two clinical stages of sleeping sickness. Trypanosome drug-resistance tests indicate irreversible cell death and a low incidence of resistance development under experimental conditions. Conclusion: Our results present ethyl pyruvate as a safe and fast acting trypanocidal compound and show that it inhibits the enzyme pyruvate kinase. Competitive inhibition of this enzyme was found to cause ATP depletion and cell death. Due to its ability to easily cross the bloodbrain- barrier, ethyl pyruvate could be considered as new candidate agent to treat the hemolymphatic as well as neurological stages of sleeping sickness.

Philosophiae Doctor - PhD / Tsetse flies (Glossina spp) are the biological vectors for Trypanosomes, the causative magents of Human African Trypanosomiasis (HAT). HAT is a debilitating disease that continues to present a major public health problem and a key factor limiting rural development in vast regions of tropical Africa. To augment vector control efforts, the International Glossina Genome Initiative (IGGI) was established in 2004 with the ultimate goal of generating a fully annotated whole genome sequence for Glossina morsitans. A working draft genome of Glossina morsitans was availed in 2011. In this thesis, transcriptional regulatory features in Glossina morsitans were analysed using the draft genome. A method for TSS identification in the newly sequenced Glossina morsitans genome was developed using TSS-seq tags sampled from two developmental stages of Glossina morsitans. High throughput next generation sequencing reads obtained from Glossina morsitans larvae and pupae were used to locate transcription start sites (TSS) in the Glossina morsitans genome. TSS-seq tag clusters, defined as a minimum number of reads at the 5’ predicted UTR or first coding exon, were used to define transcription start sites. A total of 3134 tag clusters were identified on the Glossina genome. Approximately 45.4% (1424) of the tag clusters mapped to the first coding exons or their proximal predicted 5’UTR regions and include 31 tag clusters that mapped to transposons. A total of 1101 (35.1%) tag clusters mapped outside the genic region and/or scaffolds without gene predictions and may correspond to previously un-annotated transcripts or noncoding RNA TSS. The core promoter regions were classified as narrow or broad based on the number of TSS positions within a TSS-seq cluster. Majority (95%) of the core promoters analysed in this study were of the broad type while only 5% were of the narrow type. Comparison of canonical core promoter motif occurences between random and bona fide core promoters showed that, generally, the number of motifs in biologically functional genomic windows in the true dataset exceeded those in the random dataset (p <= 0.00164, 0.00135, 0.00185 for the narrow, broad with peak and broad without peak categories respectively). Frequency of motif co-occurrence in core promoter was found to be fundamentally different across various initiation patterns. Narrow core promoters recorded higher frequency of the TATA-box and INR motifs and two-way motif co-occurrence showed that the TATA-box-INR pair is over-represented in the narrow category. Broad core promoters showed higher frequency of the BREd and MTE motifs and two-way motif co-occurrence showed that the MTE-DPE pair is over-represented in broad core promoters. TATA-less promoters account for 77% of the core promoters in this analysis. TATA-less core promoters showed a higher frequency of the MTE and INR motifs in contrast to observations in Drosophila where the DPE motif has been reported to occur frequently in TATA-less promoters. These motif combinations suggest their equal importance to transcription in their corresponding promoter classes in Glossina morsitans.

SUMMARY BACKGROUND Human African trypanosomiasis (HAT), commonly named sleeping sickness, was under control to a certain extent at the beginning of the sixties. In fact, the prevalence rate had then decreased drastically (one case per 10.000 examined inhabitants) for four major reasons: 1. active and exhaustive classical medical prospecting 2. correct treatment administered to patients suffering from trypanosomiasis 3. post-therapeutic follow-up of treated patients 4. vector control involving the community at risk In the Democratic Republic of Congo (DRC), HAT left rural areas to extend to large cities, like Kinshasa. The incidence of HAT in Kinshasa has been increasing since 1996. Until now, there is no indication on knowledge, attitudes and conceptions of HAT in Kinshasa. The major objectives of this study are: to analyse the epidemiological, clinical, sanitary, demographic, socio-economic and socio-cultural characteristics of HAT in Kinshasa to assess the level of knowledge, the attitudes, practices, perceptions, behaviours and local beliefs related to HAT among people residing in Kinshasa endemic area to identify the sanitary, socio-economic, environmental or ecological, socio-demographic and socio-cultural variables forming HAT risk factors in Kinshasa to identify the main predictive factors independent of HAT in Kinshasa. METHODS Population of study and data collection Two methodologies were carried out: a quantitative method based on a structured and pre-tested questionnaire as well as a qualitative approach relying on focus groups discussions. The inquiry took place at two different periods: first, between February 9 and June 3, 2006, then between July 7 and 17, 2007. It is a descriptive and analytic case-control study. Cases were patients suffering from trypanosomiasis notified between January 1st, 2004, and December 31st, 2005, thanks to HAT declaration cards registered to the National Human African Trypanosomiasis Program (PNLTHA). Based on age, sex and living place, each case was paired with two controls declared as HAT-free after clinical examination and a negative Card Agglutination Test for Trypanosomiasis (CATT-Test) performed on total blood. Controls were sampled thanks to a stratified approach during campaigns carried out between February and June 2006. A total of 1,311 individuals, 437 cases and 874 controls, were included in the study. Statistical analysis of data The inquiry data were analysed with EPIINFO, version 3.3.2 (CDC, United States), STATISTICA and SPSS, version 13.0, softwares. A Chi-squared or Fishers exact test was used to compare proportions and a Student t-test allowed the comparison of means. The association between the different factors and HAT was determined by estimating the Odds Ratio (OR) with a 95%-confidence interval and a P value under 0.05. This was performed thanks to a uni- and multivariate logistic regression. RESULTS A great proportion of patients suffering from HAT (79.4%, n = 347) had reached a very advanced stage of the disease, the neurological stage. Among the 1,311 persons included in the study, 52.2% were men and 47.8% were women (not significant difference). They were aged between 10 and 74 years, with a mean of 34.2 ± 14.2 years. Professionally active persons, aged between 20 and 49 years (70.3%), and providing resources essential for the economic development were more frequently affected. The majority of HAT cases (53%; n=230) had recently migrated (migration of people province-born who later settled down in Kinshasa); they were residing in Kinshasa for 5 years. People suffering from trypanosomiasis presented the following clinical characteristics: sleep disorders, characterized by hypersomnia (89% of cases) cervical adenopathy was frequently observed (63% of cases) Fever (72% of cases) Only 37.5% of cases scrupulously respected the recommended post-therapeutic follow-up. Numerous case-patients and controls were illiterates: the optimal level of knowledge was of 44% among case-patients and 37% among controls, with a highly significant difference (P<0.0001). Case-patients and controls believe in the supernatural origin of HAT. They believe HAT might have a divine origin, come from sorcery, from a malediction, or from the transgression of forbidden practices (incest). The study shows 87% of cases vs. 86.3% of controls were in favour of passive screening, with a non significant difference (P>0.05). The multivariate statistical analysis (logistic regression) showed the following variables were associated with HAT acquisition/infection in Kinshasa: residency in peripheral areas: rural areas (adjusted OR: 12.1, 95%IC: 5.7-21.7); eccentric areas (adjusted OR: 8.9, 95%IC: 2.1-38.8), family history of HAT (adjusted OR: 12.9, 95%IC: 7.9-20.8), ignorance regarding the mode of transmission (adjusted OR: 11.2, 95%IC: 5.8-21.7), and household water provision at natural/collective water points (adjusted OR: 6.9, 95%IC: 2.8-17.2) were also risk factors. CONCLUSION The surveillance and control of HAT pass obligatorily through the identification and knowledge of the main determinants of this recrudescent endemic-epidemic if one aims to establish an efficient fighting programme. Among these determinants, it is primordial to highlight: the unintentional ignorance of populations exposed to the HAT risk (obscurantist beliefs) the absence of participative education campaigns for populations residing in risk areas (rural and urban) the deficiency of management by sanitary authorities characterized by the lack of attention paid to the HAT endemic in political circles of decision. the drastic decrease in the budget assigned to health (less than 10 USD per inhabitant per year for healthcare). Once these determinants are known and suppressed, the fight against this plague should consist in: maintaining and reinforcing the surveillance of the endemic area, even in situations of low endemicity, by integrating the mass screening in fixed sanitary structures. This integration should go with the formation of healthcare staff not hardened to the screening and the fight against HAT. improving living conditions and population welfare in general, especially in rural areas. These results bring up different avoidable/modifiable determinants, on which one can act to reduce the morbidity and mortality charges caused by HAT, and involve Kinshasas residents in the fight against the disease./RESUME INTRODUCTION La Trypanosomiase Humaine Africaine (THA), communément appelée Maladie du Sommeil, avait été dans une certaine mesure, maîtrisée au début des années 1960. En fait, le taux de prévalence était alors tombé de façon spectaculaire à des niveaux très bas (un cas pour 10.000 habitants examinés) pour quatre raisons majeures : 1. les prospections médicales classiques actives et exhaustives, 2. le traitement correct administré aux patients trypanosomés, 3. le suivi post-thérapeutique strict des malades traités, 4. la lutte antivectorielle impliquant la communauté à risque. En République démocratique du Congo (RDC), la THA est sortie des milieux ruraux pour sétendre aux grandes villes, comme Kinshasa. Lincidence de la THA est croissante à Kinshasa depuis 1996. Jusquà présent, à notre connaissance, il nexiste pas dindication sur les connaissances, les attitudes et les conceptions de la THA à Kinshasa. Les objectifs majeurs de cette étude sont : analyser les caractéristiques épidémiologiques, cliniques, sanitaires, démographiques, socioéconomiques et socioculturelles de la THA à Kinshasa, évaluer le niveau de connaissances, les attitudes, les pratiques, les perceptions, les comportements et les croyances locales relatives à la THA chez les résidents de la zone endémique de Kinshasa, identifier les variables sanitaires, socioéconomiques, environnementales ou écologiques, sociodémographiques et socioculturelles constituant les facteurs de risque de la THA à Kinshasa, identifier les principaux facteurs prédictifs indépendants de la THA à Kinshasa. METHODES Population détude et collecte des données Deux focalisations méthodologiques ont été utilisées: la méthode quantitative basée sur un questionnaire structuré, prétesté et la méthode qualitative basée sur les focus groups discussions. Lenquête sest déroulée en deux périodes. Dabord du 9 février au 3 juin 2006. Ensuite, du 7 au 17 Juillet 2007. Il sagit dune étude cas-témoins descriptivo-analytique. Les cas étaient des patients trypanosomés identifiés entre le 1 janvier 2004 et le 31 décembre 2005 avec fiches de déclaration de THA au Programme National de Lutte contre la Trypanosomiase Humaine Africaine (PNLTHA). Chaque cas était apparié sur lâge, le sexe et le lieu dhabitation à deux témoins déclarés indemnes de THA après examen clinique et présentant une sérologie négative au Card Agglutination Test for Tryapnosomiasis (CATT-Test) sur sang total, tirés au sort par sondage stratifié au cours des campagnes actives de février à juin 2006. Au total, létude a touché 1311 individus dont 437 cas et 874 témoins. Analyse statistique des données Les données ont été encodées et analysées avec les logiciels EPIINFO version 3.3.2 (CDC, Etats-Unis), STATISTICA version 7.1 et SPSS version 13.0. Le test de Chi-carré et le Fisher exact ont été utilisés pour comparer les proportions et le t de student pour la comparaison des moyennes. Lassociation entre les différents facteurs étudiés et la THA a été déterminée en estimant lOdds Ratio (OR) avec un intervalle de confiance (IC) de 95% et un p inférieur à 0,05. Ceci a été réalisé en utilisant la méthode de régression logistique univariée et multivariée. RESULTATS Une grande proportion des patients trypanosomés (79,4%, n=347) était en phase très avancée de leur infection, au stade neurologique. Parmi les 1311 sujets retenus dans létude, il y avait 52,2% dhommes et 47,8% de femmes, différence non significative (p>0,05). Leur âge variait entre 10 et 74 ans avec une moyenne de 34,2±14,2 ans. Les personnes professionnellement actives âgées de 20-49 ans (70,3%) et pourvoyeuses de ressources nécessaires au développement économique étaient les plus atteintes. La majorité des patients trypanosomés (53% ; n=230) étaient des migrants (migration interne des personnes nées en province et venues sinstaller à Kinshasa) récents dont la durée de séjour à Kinshasa ne dépassait pas 5 ans. Les patients trypanosomés présentaient les caractéristiques cliniques suivantes : les troubles du sommeil caractérisés par lhypersomnie diurne dans 89% des cas, les adénopathies cervicales sont fréquentes, soit 63% des cas observés, la fièvre se retrouve dans 72% des cas. Seuls 37,5% des cas avaient scrupuleusement respecté le suivi post-thérapeutique recommandé. Bon nombre des cas et témoins étaient analphabètes : le niveau optimum de connaissance était de 44% chez les cas et 37% chez les témoins avec une différence hautement significative (p<0,0001). Les cas et les témoins croient à lorigine surnaturelle de la THA. Ils pensent que la THA peut être dorigine divine, provenir de la sorcellerie, dune malédiction, ou encore de la transgression des interdits (inceste). Létude montre que 87% des cas vs 86,3% des témoins étaient favorables au dépistage passif, différence non significative (p>0,05). En analyse statistique par la régression logistique multivariée, les variables suivantes étaient significativement associées à lacquisition/infection de la THA à Kinshasa. la résidence en zones périphériques : zones rurales (OR ajusté 12,1 ; IC à 95% : 5,7-21,7) ; zones excentriques (OR ajusté 8,9 ; IC à 95% : 2,1-38,8), lhistoire familiale de THA (OR ajusté 12,9 ; IC à 95% : 7,9-20,8), lignorance du mode de transmission (OR ajusté 11,2 ; IC à 95% : 5,8-21,7) et lapprovisionnement en eau de ménage dans des points deau naturels/collectifs (OR ajusté 6,9 ; IC à 95% : 2,8-17,2) sont aussi des facteurs de risque. CONCLUSION La surveillance et le contrôle de la THA passent obligatoirement par lidentification, et la connaissance des principaux facteurs déterminants de cette endémo-épidémie en recrudescence si lon veut établir un plan de lutte efficace contre ce fléau. Parmi ces déterminants, il importe de noter notamment : lignorance involontaire (croyances obscurantistes) des populations exposées au risque de THA, labsence des campagnes éducatives participatives des populations résidant dans les zones à risque (rurales et citadines), la mauvaise gestion des autorités sanitaires caractérisée par le peu dattention accordée à lendémie de THA dans les milieux politiques de décision, la diminution drastique du budget alloué à la santé (moins de 10$USA par habitant par an pour les soins de santé). Une fois que ces déterminants sont connus et jugulés, la lutte contre ce fléau devrait consister à : maintenir et renforcer la surveillance de la zone endémique, même en situation de faible endémicité par lintégration du dépistage de masse dans les structures sanitaires fixes. Cette intégration devrait être accompagnée de la formation des personnels soignants non aguerris au dépistage et à la lutte contre la THA, améliorer les conditions de vie et du bien-être de la population en général, et plus particulièrement la population rurale. Ces résultats mettent en évidence divers déterminants contrôlables, sur lesquels on peut agir pour réduire la charge de la morbidité et mortalité attribuée à la THA, et impliquer les habitants de Kinshasa dans la lutte contre cette maladie.

A class of linear diamidines was synthesized for the evaluation as a treatment of Human African Trypanosomiasis. These fused heterocyclic compounds are thiazole[5,4-d]thiazoles and are of interest because the parent compound, 2,5-Bis(4-amidinophenyl)-thiazolo[5,4-d]thiazole HCl salt, which is also called DB 1929, has exhibited a low nanomolar IC50 value against Trypanosoma brucei rhodesiense and has shown selectivity for binding to the human telomere G-quadruplex over that of DNA duplex. A fluoro and a methoxy derivative have been synthesized and are currently undergoing testing for activity and binding affinity. In addition, fluorescence studies of selected diamidines were done to study the effect of structural variation on fluorescence. This data is useful since it can determine what types of moieties are needed to yield a compound that will fluoresce in the higher wavelengths (500 nm and above) of the visible spectrum, which would be advantageous in determining the uptake of the drug in the trypanosome within the endemic areas of Africa with a simple microscope.