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African trypanosomiasis is associated with Trypanosoma evansi, T. vivax, T. congolense, and T. brucei pathogens in African animal trypanosomiasis (AAT) while T. b gambiense and T. b rhodesiense are responsible for chronic and acute human African trypanosomiasis (HAT), respectively. Suramin sodium suppresses ATP generation during the glycolytic pathway and is ineffective against T. vivax and T. congolense infections. Resistance to suramin is associated with pathogen altered transport proteins. Melarsoprol binds irreversibly with pyruvate kinase protein sulfhydryl groups and neutralizes enzymes which interrupts the trypanosome ATP generation. Melarsoprol resistance is associated with the adenine-adenosine transporter, P2, due to point mutations within this transporter. Eflornithine is used in combination with nifurtimox. Resistance to eflornithine is caused by the deletion or mutation of TbAAT6 gene which encodes the transmembrane amino acid transporter that delivers eflornithine into the cell, thus loss of transporter protein results in eflornithine resistance. Nifurtimox alone is regarded as a poor trypanocide, however, it is effective in melarsoprol-resistant gHAT patients. Resistance is associated with loss of a single copy of the genes encoding for nitroreductase enzymes. Fexinidazole is recommended for first-stage and non-severe second-stage illnesses in gHAT and resistance is associated with trypanosome bacterial nitroreductases which reduce fexinidazole. In AAT, quinapyramine sulfate interferes with DNA synthesis and suppression of cytoplasmic ribosomal activity in the mitochondria. Quinapyramine sulfate resistance is due to variations in the potential of the parasite's mitochondrial membrane. Pentamidines create cross-links between two adenines at 4–5 pairs apart in adenine-thymine-rich portions of Trypanosoma DNA. It also suppresses type II topoisomerase in the mitochondria of Trypanosoma parasites. Pentamidine resistance is due to loss of mitochondria transport proteins P2 and HAPT1. Diamidines are most effective against Trypanosome brucei group and act via the P2/TbAT1 transporters. Diminazene aceturate resistance is due to mutations that alter the activity of P2, TeDR40 (T. b. evansi). Isometamidium chloride is primarily employed in the early stages of trypanosomiasis and resistance is associated with diminazene resistance. Phenanthridine (homidium bromide, also known as ethidium bromide) acts by a breakdown of the kinetoplast network and homidium resistance is comparable to isometamidium. In humans, the development of resistance and adverse side effects against monotherapies has led to the adoption of nifurtimox-eflornithine combination therapy. Current efforts to develop new prodrug combinations of nifurtimox and eflornithine and nitroimidazole fexinidazole as well as benzoxaborole SCYX-7158 (AN5568) for HAT are in progress while little comparable progress has been done for the development of novel therapies to address trypanocide resistance in AAT.

One Health, « Une seule santé », est une stratégie mondiale visant à développer les collaborations interdisciplinaires pour la santé humaine, animale et environnementale. Elle promeut une approche intégrée, systémique et unifiée de la santé aux échelles locale, nationale et mondiale, afin de mieux affronter les maladies émergentes à risque pandémique, mais aussi s'adapter aux impacts environnementaux présents et futurs. Bien que ce mouvement s’étende, la littérature en français reste rare. Traduit de l’anglais, coordonné par d’éminents épidémiologistes et s'appuyant sur un large panel d' approches scientifiques rarement réunies autour de la santé, cet ouvrage retrace les origines du concept et présente un contenu pratique sur les outils méthodologiques, la collecte de données, les techniques de surveillance et les plans d’étude. Il combine recherche et pratique en un seul volume et constitue un ouvrage de référence unique pour la santé mondiale.

Introduction La gestion du risque de zoonoses résultant des interactions entre les animaux, les humains et l’environnement exige une action intégrée des secteurs de la santé humaine et animale, le soutien d’autres secteurs ou industries concernés par la gouvernance sanitaire et des apports clefs de la filière environnementale (Cook et al., 2004 ; Okello et al., 2011 ; Welburn, 2011 ; Zinsstag et al., 2012). Dans ...

Introduction Dans ce chapitre, nous passons en revue l’évolution de la gouvernance de la santé mondiale (GSM), depuis les premières années de la diplomatie internationale de la santé au xixe siècle, jusqu’à une remise en question des systèmes, des acteurs et des réseaux qui ont actuellement des intérêts dans la GSM aujourd’hui. En décrivant l’évolution des relations entre la politique et la pratique en matière de santé, les aute...

BackgroundThe endemic vector-borne diseases transmitted by tsetse and ticks impose heavy burdens on Africa’s livestock. Cattle offers the possibility of mitigating these losses at a cost affordable to livestock keepers, by applying deltamethrin just to the belly, legs and ears of cattle. Although studies have quantified the impacts of individual diseases on livestock productivity, little is known about the dual economic benefits of controlling both tsetse and ticks, nor about the number of cattle who need to be treated to confer these benefits. Alongside an epidemiological study in south-east Uganda, a farm level assessment was done to investigate the benefits and costs of spraying different proportions of the village cattle population using this restricted application protocol. MethodsA study comprising 1,902 semi-structured interviews was undertaken over a period of 18 months. Financial data on household income from and expenditure on cattle was collected and cost benefit analysis done, pre and post intervention and for different spraying regimes. The total cost of the intervention was obtained from the epidemiological study’s implementation costs and from expenses incurred by participating farmers enabling examination of benefit-cost ratios and incremental benefit-cost ratios for each treatment regime. ResultsThe benefit-cost analysis of spraying 25%, 50% and 75% of the cattle population yielded average benefit-cost ratios of 1.55, 3.85, 4.51 and 4.46. The incremental benefit-cost ratios from spraying each additional 25% of the cattle population were 11.38, 3.89 and 0.79 respectively, showing a very high return on investment for spraying 50% of the population, with returns reducing thereafter. ConclusionComparing the gross margins per bovine, the study found that increasing the proportion of cattle sprayed yielded increasing benefits to farmers, but that these benefits were subject to diminishing returns. From a practical viewpoint this study recommends spraying only draft cattle to control trypanosomiasis and tick-borne diseases in this area as they make 38.62% of the cattle population, approaching the 50% threshold. In areas with a lower proportion of draft males, farmers could be advised to also include cows.