Добірка наукової літератури з теми "Tuberculose – Cameroun"

Une étude a été menée pour identifier, entre autres contraintes, les conditions pathologiques qui affectent la productivité des porcs et leur potentiel en tant que filière de l’élevage dans la zone semi-aride du Nord Cameroun. Les données ont été collectées en trois étapes : une enquête transversale, un suivi des troupeaux sélectionnés au cours d’une année et une inspection de la viande porcine pendant une année. Les résultats ont montré que les infestations dues à Haematopinus suis étaient la condition pathologique la plus fréquente avec une prévalence supérieure à 50 p. 100 dans les troupeaux au cours de la phase de suivi et de 75,8 p. 100 dans un échantillon de 750 porcs abattus. Les gastro-entérites étaient de faible prévalence (4 p. 100), mais fortement associées à la mortalité des porcelets. Les lésions pathologiques importantes pour la santé publique enregistrées à l’inspection de la viande porcine étaient celles de la tuberculose et de la cysticercose avec des prévalences respectivement de 33,2 et 12,3 p. 100. Les résultats de la sérologie indirecte par Elisa effectuée sur 150 échantillons étaient négatifs à 98 p. 100 pour le virus de la peste porcine africaine (PPA), ce qui laisse à penser que la région était indemne de PPA. Cette région pourrait par conséquent être considérée comme une zone favorable au développement de l’industrie porcine dans le pays. L’inspection de la viande de porc et les mesures d’hygiène devraient être mis en œuvre pour assurer la protection de la population humaine contre les viandes infectées.

La thèse présentée se propose d'apporter des réponses à trois questions ? Comment naissent les politiques verticales de santé ? Comment expliquer les échecs répétitifs des politiques de santé menées en Afrique ? Qu'est-ce qui justifie "l'acharnement" à vouloir améliorer la santé des (pays) pauvres. En réponse à la première question, l'auteur note que les politiques de santé ne naissent pas toujours du constat d'une situation épidémiologique critique. Elles sont souvent l'initiative d'acteurs insérés dans des réseaux de pouvoirs, capables de mobiliser l'attention et les ressources financières. La thèse pose la question de "l'acharnement" à coopérer ou à améliorer la santé des (pays) pauvres. Réfutant l'argument humanitaire, l'auteur utilise l'analyse foucaldienne du racisme d'Etat et explique cet "acharnement" à coopérer par le désir de "faire vivre pour vivre soi-même". Quant aux échecs répétitifs des politiques de santé menées en Afrique, l'auteur propose une analyse fondée sur la notion foucaldienne du biopouvoir, expliquant ces échecs par une carence, une absence, un éclatement de celui-ci
The thesis seek to answers three questions: how can we explain the emergence of selective health programs in Africa? How can we explain the repetitive failures of health policies in Africa ? What justifies the "eagerness" to improve the health of the poor (countries). As answer to the first question, the author notes that selective health policies are not always based on the report of a critical epidemiologic situation. They are often the initiative of actors inserted in power networks, able to mobilize interest and financial resources. The thesis raises the question of "eagerness" to cooperate or improve the health of the poor (countries). Refuting the humanitarian argument, the author uses Michel Foucault analysis of the "racisme d'Etat" and explains this by the desire "de faire vivre pour soi-même". As for the repetitive failures of health policies implemented in some African countries, the author proposes an analysis based on the "biopouvoir", explaining these failures by a deficiency, an absence, a bursting of it

Pour etudier l'epidemiologie descriptive de la tuberculose bovine et de son agent, mycobacterium bovis, dans trois provinces du nord-cameroun (adamaoua, nord, et extreme-nord), deux approches ont ete mises en uvre : - une enquete tuberculinique dans 163 troupeaux (5388 bovins) constitues sur la base du volontariat des eleveurs, - la collecte d'organes dans les abattoirs de trois regions en vue du typage des isolats de m. Bovis obtenus. 75 isolats ont ete types par spoligotyping, 65 par electrophorese en champ pulse (ecp) et 18 seulement par l'etude du polymorphisme de longueur de fragments de restriction (ou restriction fragment length polymorphism = rflp) avec une sonde is6110. Les conclusions sont : a) quelle que soit la technique de typage, les isolats du cameroun apparaissent assez homogenes, avec seulement : * 10 spoligotypes sur 75 isolats (dont 1 spoligotype dominant, c1, present chez 63% des souches) * 4 profils differents en ecp sur 65 isolats (dont 94% de profils dominants, pc1 et pc2) * 3 profils differents en rflp sur 18 isolats (dont 83% de profil dominant rc1) b) certains types sont tres ubiquitaires, accreditant l'hypothese d'une circulation des souches : cette hypothese est confortee par la mise en evidence par idt de la presence de m. Bovis dans les elevages transhumants, c) l'association des trois techniques de typage des isolats de m. Bovis du nord-cameroun permet une meilleure discrimination des isolats (avec au moins 16 types differents), cependant, pour l'etude preliminaire des types, le spoligotyping est a privilegier ; pour une analyse plus fine, l'etude du polymorphisme de longueur de fragment de restriction avec une sonde pgrs ou le typage des segments repetes en nombre variable ou vntr (variable number tandem repeat) est a preconiser. Cette etude meriterait d'etre poursuivie sur un plus grand nombre d'isolats afin de disposer d'outils objectifs permettant de mieux maitriser la tuberculose bovine au niveau du pays et de la region.

La tuberculose (TB) est une maladie causée par le bacille de Koch. Elle est la neuvième cause de décès dans le monde et la première cause de décès d’origine infectieuse, devant le VIH/SIDA. Le développement de résistance due à une mauvaise utilisation des médicaments antituberculeux a donné naissance à de nouvelles formes de tuberculose, dont la tuberculose multirésistante (TB-MR). La TB-MR est une forme particulièrement dangereuse de TB qui se défini par la résistance à la fois à l’isoniazide et à la rifampicine, les deux antituberculeux de première intention les plus efficaces. Les pays en voie de développement, dont le Cameroun, sont particulièrement touchés. Un traitement efficace de la TB-MR passe par l’association de plusieurs médicaments pendant une longue période comme le recommande l’Organisation mondiale de la Santé. En effet, depuis 2016 le régime de traitement court et standardisé recommandé par l’OMS subdivisait la prise en charge de la TB-MR en deux phases distinctes pouvant aller de 9 à 11 mois. La première phase dite intensive durait 4 à 6 mois avec la prise de 7 antituberculeux (Kanamycine/amikacine, moxifloxacine, prothionamide, isoniazide haute-dose, clofazimine, ethambutol, et pyrazinamide). La deuxième phase dite phase continue avait une durée fixe de 5 mois avec 4 antituberculeux (Moxifloxacine, clofazimine, ethambutol, and pyrazinamide). L’objectif de cette thèse était d’évaluer la sécurité des médicaments antituberculeux utilisés dans la prise en charge de la TB-MR au Cameroun. Dans un premier temps, nous avons réalisé une étude dont l’objectif principal était d’évaluer le profil de sécurité des traitements utilisés pour la TB-MR dans le principal hôpital de prise en charge de cette maladie au Cameroun. Cette étude a permis d’identifier la surdité liée aux aminosides comme principale cause de changement ou d’arrêt de traitement. Deuxièmement, nous avons évalué la conformité aux recommandations de l’OMS sur le traitement de la TB-MR, ainsi que la persistance des patients au programme et au traitement. Cette étude a quant à elle révélé une très bonne conformité aux recommandations de l’OMS, mais aussi une baisse progressive de la persistance, en particulier pendant la phase continue. Enfin, étant donné qu’au cours de notre thèse, les aminoglycosides ont été remplacés par la bédaquiline dans le nouveau régime de traitement court et standardisé recommandé par l’OMS, en raison de problèmes d’ototoxicité et autres, nous avons réalisé une étude préliminaire de la sécurité et de la persistance de ce nouveau traitement. Ce travail a montré que les problèmes d’ototoxicité ont disparu et que la persistance au traitement s’est améliorée, tout en soulignant les risques de douleurs articulaires et de problèmes cardiaques associés au nouveau régime. Ces résultats montrent que malgré le changement de médicaments, les effets indésirables sont couramment associés aux schémas thérapeutiques de la TB-MR au Cameroun. Il est donc nécessaire de mettre en place un système solide de surveillance de la sécurité des médicaments qui permettra aux prestataires de soins de santé et aux décideurs politiques d’évaluer en permanence le profil de sécurité des médicaments utilisés et d’améliorer les résultats cliniques. Comme le traitement mis en œuvre est maintenant basé sur la bédaquiline, il faut être prudent dans la surveillance des événements cardiovasculaires car d’autres médicaments comme la clofazimine, et la moxifloxacine ont également le pouvoir de prolonger l’intervalle QT
Tuberculosis (TB) is a disease caused by Koch’s bacillus. It is the ninth leading cause of death worldwide, and the most common infectious cause of death, surpassing HIV/AIDS. The development of resistances due to misuse of anti-tuberculosis drugs has resulted in new forms of TB, including multidrug-resistant tuberculosis (MDR-TB). MDR-TB is a particularly dangerous form of tuberculosis, characterized by its resistance to both isoniazid and rifampicin, the two main and most effective anti-tuberculosis drugs. Developing countries, including Cameroon, are heavily affected. Effectively treating MDR-TB requires the combination of several drugs over several months. Indeed, from 2016 to 2020 the World Health Organization recommended the use of shorter treatment regimen for MDR-TB patients. This lasts for 9–11 months and is divided into two phases: An intensive phase, and a continuous ambulatory phase. The intensive phase involved 4–6 months of daily treatment with 6 antibiotics (moxifloxacin, protionamide, isoniazid high-dose, clofazimine, ethambutol, and pyrazinamide) associated with kanamycin or amikacin. The continuous ambulatory phase had a fixed treatment duration of 5 months with 4 antibiotics: Moxifloxacin, clofazimine, ethambutol, and pyrazinamide. The aim of this thesis was to assess the safety of anti-tuberculosis drugs used in the management of MDR-TB in Cameroon. Initially, we conducted a study to assess the safety profile of treatments used for MDR-TB in the main TB treatment center or hospital in Cameroon. This study identified aminoglycoside-related deafness as the main cause of treatment change or discontinuation. Secondly, we assessed compliance with WHO recommendations on MDR-TB treatment, as well as patient persistence with the program and the treatment. This study revealed very strong compliance with the WHO recommendations, although a progressive decline in persistence was recorded notably during the continuation phase. Finally, in view of the fact that during the course of our thesis, aminoglycosides were replaced by bedaquiline in the WHO-standardized MDR-TB treatment regimen, due to ototoxicity and other problems, we carried out a preliminary study on the safety and persistence of the new MDR-TB regimen. This work showed that ototoxicity problems disappeared, and that treatment persistence improved, while highlighting the risks of joint pain and cardiac problems associated with the new regimen. These results demonstrate that MDR-TB treatment regimens in Cameroon are consistently associated with adverse drug reactions despite changes in the medicines used. Thus, there is a need to implement a strong drug safety monitoring system which will allow health care providers and policy makers to continuously evaluate the safety profile of drugs in use and improve clinical outcomes. As the current treatment regimen is now bedaquiline-based, the strict monitoring of cardiovascular events is vital since other drugs like clofazimine, and moxifloxacin can also prolong the QT interval

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Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, BA, Brasil
A resistência aos fármacos utilizados no tratamento da tuberculose (TB) é um importante desafio no combate à doença. A rifampicina e a isoniazida são dois fármacos de primeira linha essenciais para a cura da doença, a qual tem como agente o M. tuberculosis. Pacientes com TB cujos isolados de M. tuberculosis apresentem resistência in vitro simultânea a estes dois fármacos desenvolvem a TB multirresistente (TBMR). A resistência do M. tuberculosis está relacionada com mutações em genes importantes para a sobrevivência do bacilo. O tratamento da TBMR é mais longo e utiliza fármacos anti-TB de segunda linha, os quais são de maior toxicidade, predispondo os pacientes à não adesão aos esquemas de tratamento. O paciente com TBMR, quando não devidamente tratado, pode selecionar cepas resistentes aos fármacos anti-TB de segunda linha, proporcionando o surgimento da TB extensivamente resistente (TBXDR). Por sua vez, estas cepas podem ser transmitidas em comunidades, constituindo um grave problema de saúde pública. Segundo a Organização Mundial de Saúde, a TBXDR tem sido documentada em alguns países, mas no Brasil estes dados são escassos. A caracterização genética de cepas de M. tuberculosis envolvidas com os casos TBMR/TBXDR pode facilitar a identificação de vias de transmissão. OBJETIVO: Pesquisar casos de TBXDR na Bahia e caracterizar perfis genéticos de isolados de M. tuberculosis de pacientes com TB multirresistente, associando o perfil genético encontrado com as características sócio-demográficas e clínicas dos pacientes envolvidos. MATERIAIS E MÉTODOS: Isolados de M. tuberculosis obtidos de pacientes com diagnóstico de TBMR entre 2008-2011 residentes no Estado da Bahia (Brasil) foram submetidos ao teste de sensibilidade utilizando fármacos anti-TB de primeira e segunda linha e genotipados pela técnica do Número Variável de Repetições em Tandem de Unidades Repetitivas Inter-espaçadas Micobacterianas (MIRU-VNTR) para obtenção de perfis genéticos que foram associados com perfis da base de dados internacional MIRU-VNTRplus. Isolados com perfis genéticos não associáveis a linhagens com o uso desta técnica foram adicionalmente genotipados por Spoligotyping e ambas as informações foram consideradas para assimilação de linhagens utilizando esta mesma base de dados. Informações clínico-epidemiológicas foram obtidas do banco de dados “Sistema TBMR” do Ministério da Saúde. RESULTADOS: Foram analisados 392 isolados. Destes, 35% foram excluídos por ausência de crescimento ou contaminação e 12% constituíam amostras em duplicata, resultando em 206 pacientes com TBMR no estudo. Comprovou-se a ocorrência da TBXDR em 7% (14/206) dos pacientes; destes, dois não possuíam registro anterior para qualquer tratamento anti-TB. Os pacientes estudados foram provenientes de 45 municípios do Estado. A capital, Salvador, concentrou 71% dos casos TBMR e 76% dos TBXDR. Dos casos TBXDR, 36% (5/14) apresentaram isolados resistentes a todos os fármacos testados. Observou-se associação de resistência combinada entre estreptomicina e etambutol (8/14, 57%) e o perfil TBXDR (RP 4,0; IC95% 1,2-13,8; P=0,01). Dos casos TBXDR, 71% (10/14) desenvolveram uma ou mais comorbidades (P=0,04), sendo o transtorno mental uma comorbidade significativa neste grupo (21%; 3/14; P=0,04). Encontrou-se 56 perfis genéticos, 38 únicos e 18 agrupados em clusters (contendo de 2 a 11 isolados). Quase a totalidade (92%) dos casos TBXDR esteve agrupada em clusters, diferindo dos casos não-TBXDR (P=0,049). Os perfis genéticos estiveram principalmente associados a seis famílias: LAM (70%), Cameroon (16%), Haarlem (10%) e as famílias X, S, Uganda I, que combinadas perfizeram 4%. Os casos TBXDR foram representados pelas famílias LAM (45%, ST’s 376, ST42, ST20), Cameroon (36%, ST61 único) e Haarlem (18%, ST50). CONCLUSÕES: A Bahia apresentou casos de TBXDR e as famílias de M.tuberculosis envolvidas com estes casos foram LAM, Cameroon e Haarlem. A genotipagem auxiliou na descoberta de casos epidemiologicamente relacionados.
Resistance to drugs used in tuberculosis (TB) chemotherapy is a major challenge to fighting this disease caused by M. tuberculosis. Rifampin and isoniazid are two main first-line drugs to achieve TB cure. TB patients whose M. tuberculosis isolates exhibit resistance simultaneously to these two drugs develop multidrug-resistant TB (MDR-TB). M. tuberculosis resistance is related to mutations in genes important for bacillus survival. MDR-TB treatment is longer and uses more toxic second-line anti-TB drugs, predisposing patients to non-adherence to treatment regimens. Patients with MDR-TB, when not properly treated, can select strains resistant to second-line anti-TB drugs leading to the emergence of extensively drug-resistant TB (XDR-TB). These strains can be transmitted in communities, constituting a serious public health problem. According to the World Health Organization, XDR-TB has been documented in some countries, but in Brazil these data are scarce. The genetic characterization of M. tuberculosis strains involved in MDR/XDR-TB cases could facilitate the identification of transmission chains. AIMS: To investigate cases of XDR-TB in Bahia and to characterize the genetic profiles of the isolates of M. tuberculosis from patients with multidrug-resistant TB, associating the genetic profiles observed with the socio-demographic and clinical characteristics of patients involved. MATERIALS AND METHODS: M. tuberculosis isolates obtained from patients diagnosed with MDR-TB between 2008-2011 resident in the State of Bahia (Brazil) were tested for sensitivity against first and second-line anti-TB drugs and genotyped by the Variable Number of Tandem Repeats in Repetitive Unit Inter- Mycobacterial spaced (MIRU-VNTR) technique to obtain the genetic profiles that were associated with profiles in the international database MIRU-VNTRplus. Isolates whose genetic profiles have not matched any lineage with the use of this technique were further genotyped by Spoligotyping and information from both methods were considered to test for the possible matching with lineages from the same database. Clinical and epidemiological data were obtained from the database "Sistema TBMR" of the Ministry Health. RESULTS: We analyzed 392 isolates. Of these, 35% were excluded due to absence of growth or contamination and 12% corresponded to duplicate samples, resulting in 206 patients with MDR-TB in the study. XDR-TB was found in 7% (14/206) of the patients, two of which had no previous record of any anti-TB treatment. The patients studied were from 45 cities of the State. The capital, Salvador, concentrated 71% of all MDR-TB and 76% of the XDR-TB cases. Among XDR-TB cases, 36% (5/14) had isolates resistant to all drugs tested here. Combined resistance to streptomycin and ethambutol (8/14, 57%) was associated with the XDR-TB profile (OR 4.0, 95% CI 1.2 to 13.8, P = 0.01). 71 %(10/14) of XDR-TB cases developed one or more comorbidities (P= 0.04), mental disorder being a significant comorbidity in this group (21%, 3/14, P=0.04). Genotyping yielded 56 profiles, 38 unique and 18 in clusters (containing 2 to 11 isolates). Almost all (92%) XDR-TB cases were clustered, differing from non-XDR-TB cases (P=0.049). The genetic profiles were mainly associated with six families: LAM (70%), Cameroon (16%), Haarlem (10%), and the families X, S, Uganda I, which altogether amounted to 4%. The XDR-TB cases were represented by LAM (45% ST's 376, ST42, ST20), Cameroon (36%, single ST61) and Haarlem (18% ST50). CONCLUSIONS AND STUDY CONTRIBUTIONS: Bahia presented cases of XDR-TB and the families involved with these cases were LAM, Haarlem and Cameroon. Genotyping helped in epidemiologically linked case finding.

Bovine tuberculosis (TB) is a contagious neglected zoonosis of cattle that is prevalent but under-investigated in Cameroon, hence this study was designed to assess the epidemiology of bovine TB in cattle, risks for M. bovis infection in cattle and humans; and public health implications of zoonotic bovine TB in the highlands of Cameroon. A retrospective study of meat inspection records (1994 – 2010) was done to estimate the prevalence of TB lesions in slaughtered cattle in the North West region. The prevalence of bovine TB and anti-bovine TB antibodies in live cattle based on tuberculin skin tests (2 surveys) and immune-chromatographic assays respectively were carried out in the Western and Adamawa highlands of Cameroon. The performance of the tuberculin tests for bovine TB diagnosis in cattle using various tuberculin skin test cut-off points against the detection of anti-bovine TB antibodies (hypothesised risks of exposure) was compared. Suspected TB lesions from slaughtered cattle and infected human sputa were cultured on Lowentein – Jesen and Middlebrook 7H9 media to isolate mycobacteria agents for molecular genotyping using genomic deletion analysis and spoligotyping. Risk factors for exposure and transmission of zoonotic bovine TB infection of cattle and cattle professionals, and its public health significance were determined using structured questionnaires. Seventeen years of meat inspection record revealed that suspect TB lesions were identified in 599 of 129,165 slaughtered cattle at the Bamenda abattoir. The lungs and associated lymph nodes (over 60%) were the most affected tissues. Other results showed that the prevalence of anti-bovine TB antibodies in cattle in the study regions was 37.17%. Chi square statistics revealed that irrespective of the tuberculin test cut-off value (P<0.05; χ2>48), strong associations existed between the detection of anti-bovine TB antibodies and disease status. A 95% confidence interval analysis of the comparative cervical tuberculin tests revealed that the prevalence rates were 4.67% – 7.15%, 12.02% – 15.67% and 20.56% – 24.98% at the ≥ 4mm, ≥ 3mm and ≥ 2mm cut-off points, respectively. Overall, the best test performance was realised at ≥ 3-mm, though the ≥ 2-mm cut-off point predicted more positive reactors. Age, sex, breed and husbandry practices served as significant (P<0.05) risks to the prevalence and exposure of bovine TB in cattle. The feedbacks from cattle professionals suggested that there was high possibility of cattle to cattle and cattle to human transmission of bovine TB such as intimate and repeated animal / animal and animal / human interactions, consuming unpasteurised milk and eating raw meat. Genomic deletion analysis of cultured isolates showed evidence of M. tuberculosis from cattle and M. bovis from human while spoligotyping identified five cattle M. bovis strains; and four spoligotype patterns that had not been previously described anywhere. The study has important epidemiological and public health implications requiring prompt and decisive actions from the Cameroonian authority towards controlling zoonotic bovine TB in both humans and animals. A multidisciplinary approach is needed for further collaborative research and effective control strategies such as enhancing the awareness of people to this deadly disease through continuous education, proper food handling and personal hygiene, healthy husbandry practices and maintenance of the environment.

Despite Africa accounting for ~20% of the global cattle population, prevalence estimates and related risk factors of bovine tuberculosis (bTB), caused by Mycobacterium bovis, are still poorly quantified in many countries across the continent. Control of bTB in Africa is difficult due to poor monitoring of cattle movements and limited abattoir surveillance. Also M. bovis is zoonotic and risk factors for transmission include living in close contact with cattle and consumption of unpasteurised milk. Cattle keeping is integral to some rural populations in Cameroon and understanding the epidemiology of bTB in cattle populations is important both to bovine and public health. Detection of bTB in cattle is difficult due to variability of immune responses to M. bovis infection. The interferon-γ (IFN-γ) assay maybe useful to estimate bTB prevalence and identify bTB risk factors in Cameroon. However its performance can vary at different stages of bTB pathogenesis and in different cattle populations. Recently Fasciola hepatica co-infections have been reported to suppress IFN-γ responses in M. bovis infected cattle but the potential effect with F. gigantica co-infections on bTB prevalence estimates in Cameroon is unknown. An abattoir study was conducted in Cameroon to assess the performance of the IFN-γ assay. In 2012-13; 2064 slaughtered cattle were sampled from Bamenda abattoir (North West Region; NWR) and Ngaoundere abattoir (Vina Division; VD). Individual animal data was collected from routine meat inspection including identification of bTB and Fasciola pathology. Cattle were also tested for bTB using the IFN-γ assay and an M. bovis antibody ELISA. In the absence of a gold-standard diagnostic, the IFN-γ assay was compared to other diagnostic tests to assess agreement and identify factors that affected performance of the assay. Agreement between IFN-γ assay, TB lesion identification and an M. bovis antibody ELISA was poor-moderate, probably partly related to differences in immune response detected. A presence of Fasciola gigantica also increased the odds of false negative IFN-γ assay results. On further investigation co-infected cattle had increased odds of TB lesions and reduced IFN-γ responses that potentially could lead to ~20% reduction in test sensitivity. In an attempt to take into account the potential impact of F. gigantica, when estimating bTB prevalence, an antibody ELISA was developed to detect the exposure in live cattle. To highlight the awareness of disease in cattle-rearing communities, estimate prevalence and identify risk factors of bTB in cattle populations; two cross-sectional studies were conducted in 2013. A stratified clustered cross-sectional study of pastoral cattle herds, in the NWR and the VD, sampled 1448 pastoral cattle reared by 100 pastoralists. A smaller cross-sectional study sampled 60 dairy cattle from 46 small-holder co-operative dairy farmers. Individual animal data and herd-level data were collected and animals were screened by both the single comparative intradermal skin test (SCITT) and IFN-γ assay. Awareness of zoonotic TB was low yet consumption of raw milk was high in cattle-keeping communities highlighting the need for accurate bTB prevalence estimates. Despite the high awareness of the clinical presentation of bTB, clinical signs identified by pastoral herdsmen were not associated with cattle being bTB positive. The SCITT was used to compare two manufacturers cut offs for the IFN-γ assay, ≥0.05 and ≥0.1, and highlighted that these two diagnostics may detect different populations of bTB positive cattle. Using the IFN-γ assay at ≥0.1, bTB prevalence was highest in dairy cattle (21.67%) and was also present in pastoral cattle in the NWR and VD (11.33% and 6.55% respectively). Importantly, as F. gigantica is endemic in Cameroon and its influence could mean the true prevalence of bTB could be higher. Female pastoral cattle were at lower odds of being IFN-γ assay positive potentially due to immunosuppressive factors had lower odds of disease. Husbandry practices also decreased the odds of being IFN-γ assay positive such as drinking from streams, antelope and contact with herds at grazing. Age increased the odds of pastoral cattle being IFN- assay positive potentially being a confounder to chronicity of bTB and other co-infections may influence IFN-γ responses. Dairy cattle herds had different risk factors for being IFN- positive likely due to differences in husbandry practices. Considering the potential risk to public health of M. bovis this thesis highlights the extent of bTB across two major cattle keeping regions in Cameroon and the public health risk in cattle-rearing communities. Furthermore the relationship between Fasciola co-infection and IFN- responses to M. bovis described has potential implications for bTB diagnosis in cattle populations where the parasite is present across the globe.

Introduction The human immunodeficiency virus (HIV) epidemic has led to the upsurge of tuberculosis (TB) infection globally, but most especially in areas with high HIV prevalence. In the past, there was lack of a coordinated global and national response between TB and HIV programmes to curb the devastating impacts of both infections. However, the ProTEST Initiative piloted in sub-Saharan Africa in 1997 demonstrated that TB and HIV programmes could collaborate successfully in delivering joint services. This prompted the development of the WHO interim policy on collaborative TB/HIV activities in 2004, aimed at reducing the burden of TB and HIV in populations affected by both infections. This thesis explores how collaborative activities between TB and HIV programmes have been established in Cameroon and implemented in the Northwest Region. It also highlights the achievements and constraints in delivering joint services to TB patients co-infected with HIV. Methods The study was conducted in the Northwest Region, one of the 10 regions of Cameroon with the highest HIV prevalence. The study uses health system research combining qualitative and quantitative methods to explore the research objectives. Qualitative methods were used to capture the perspectives of: i) the service providers; key informants from the central, regional and district levels concerned with the collaboration process and in delivering HIV services to TB patients, and ii) TB patients regarding HIV testing as an entry point to HIV services. Quantitative methods were used to ascertain TB patients’ access to HIV services provided for by the collaboration. Results The study demonstrated that although there were varying levels of collaboration between TB and HIV programmes from the central to operational level in the health system, delivering joint services was feasible. Furthermore, despite the challenges TB patients faced in testing for HIV, overall implementing TB/HIV collaborative activities increased TB patients’ acceptability and accessibility to HIV services. These were facilitated by the improved collaboration at the operational level, and enhanced service provider-patient alliance which was instrumental in building patients’ trust in the health system. Collaboration also led to cross-training and teamwork between staffs from both programmes, and improved networking between service providers and other actors involved in TB and HIV care. Nevertheless, there were health system constraints including inadequate leadership and management, shortage of human and infrastructural resources, frequent interruptions in the supply of essential drugs and laboratory materials Conclusion TB/HIV collaborative activities have improved service delivery and TB patients’ access to HIV services. Nonetheless, appropriate stewardship which guarantees joint planning, monitoring and evaluation of essential activities, and accountability at all levels in the health system is invaluable. Besides, the identified health system constraints which could adversely influence effective joint service delivery and a sustainable collaboration deserve due appraisal.
Introduction L’épidémie du virus de l’immunodéficience humaine (VIH) a conduit à une augmentation globale  de la tuberculose(TB), particulièrement dans les régions à forte prévalence du VIH. Il y’avait par le passé un manque de coordination tant sur le plan mondial que national, des programmes de lutte contre la TB et le VIH pour freiner les effets dévastateurs liés à la co-infection des deux pathogènes. Cependant, l’initiative pilote “ProTEST”  conduite en 1997 en Afrique sub-saharienne  a démontré que les programmes de lutte contre le VIH et la TB pouvaient collaborer avec succès en combinant leurs services. Cette étude pilote a inévitablement incité a un changement de politique du bureau intérimaire a l’Organisation Mondiale de la Santé (OMS), de lutte contre le VIH/TB  à mettre sur pieds en 2004 des objectifs pour la réduction de l’impact du VIH/TB parmi les populations atteintes des deux infections. Cette thèse explore comment la collaboration entre les activités des programmes  de lutte VIH/TB a été établie au Cameroun, et comment son application se fait  dans la région du nord ouest. Il est également mis en exergue et les réalisations les difficultés que rencontrent les services combinés lors de la dispensation des soins aux malades de TB avec une coïnfection au VIH. Méthodes L’étude a été faite dans la région du nord ouest, une des 10 régions du Cameroun, avec le taux de prévalence au VIH le plus élevé. L’étude utilise le système de recherche en santé combinant des méthodes qualitatives et quantitatives pour explorer les objectifs de la recherche. Les méthodes qualitatives ont été utilisées pour enregistrer les données suivantes: i) centre offrant les services combinés; les personnes en charge au niveau central, régional, et des districts, qui sont responsables de l’intégration au processus et qui d’autre part veillent a ce que les malades de TB bénéficient des services du VIH ; et ii) les malades de TB qui considèrent le dépistage du VIH  comme porte d’entrée dans les services VIH. Des méthodes quantitatives ont été utilisées  pour confirmer  l’accès des malades de TB aux soins de services VIH offerts par la collaboration. Résultats L’étude a démontré que bien qu’il y ait  plusieurs niveaux de collaborations entre les programmes de VIH et TB depuis le sommet jusqu’ à la base du  système de santé, la provision de services combinés  est faisable. Malgré les difficultés rencontrées par les malades de TB pour avoir accès au dépistage du VIH, l’application en somme de la collaboration des activités entre les programmes de VIH et de TB a augmenté l’acceptation et l’accessibilité des malades de TB aux services de VIH. Ceci fut facilité par l’amélioration de la coopération au niveau des opérations des deux programmes permettant ainsi  la facilitation de l’établissement d’une alliance entre le personnel de soin et le patient, alliance qui fut primordiale dans l’élaboration du rapport de confiance que le malade doit avoir à l’endroit du system de santé. La collaboration a également conduit  à un travail d’équipe et une formation croisée entre les équipes des deux programmes, il a été également établi une amélioration du réseau d’échange entre les personnels de soins et toutes personnes actives dans le secteur du VIH et TB.    Néanmoins, il a été relevé des défis dans le système de santé telle une insuffisance dans le leadership et la gestion de fréquente interruption dans la chaine de distribution des médicaments essentiels et du matériel de laboratoire. Conclusion La collaboration des activités des programmes VIH/TB a amélioré la qualité des soins et services  avec pour résultante une meilleure accessibilité des malades de TB aux services de VIH. Néanmoins, une conduite appropriée qui garantie une planification mixte, une évaluation et un suivi des activités essentielles, ainsi qu’une gestion fiable a tous les niveaux du système de santé est indispensable. Outre, les difficultés liées au système de santé identifiées par cette étude et qui méritent une évaluation, du fait  qu’elles pourraient affecter négativement l’application effective du but recherché et la collaboration durable entre les deux services.

Mycobacterium ulcerans is the causative agent of the subcutaneous necrotic condition known as Buruli ulcer (BU).BU is Neglected Tropical Disease. The bacillus is the third most common mycobacteria disease-causing agent after Mycobacterium tuberculosis and Mycobacterium leprae. M. ulcerans produces the toxin-Mycolactone, which plays a key role in the pathophysiological features of the disease. Buruli ulcer has been reported in 34 countries, mainly in the tropics and subtropics. Tropical countries include Benin, Cameroon, Ghana, Democratic Republic of Congo and Nigeria. BU is also prevalent in Queensland, a subtropical region, and in Victoria, a temperate area, all within Australia. The exact mode of the transmission remains unclear. However, M. ulcerans is believed to have an aquatic niche. Initial diagnosis of BU is based on the experience of the clinician, but PCR targeting the M. ulcerans DNA, IS2404, isolation and culture of the bacillus and histopathology are used for confirmation. The current, commonly used methods for confirmatory diagnosis have logistic and resource challenges. Novel cell mediated immunity (CMI) and serology-based tests would be beneficial to provide a more accurate assessment of population exposure.

Background: While multiple studies have documented the impacts of mobile phone use on TB health outcomes for varied settings, it is not immediately clear what the spatial patterns of TB treatment completion rates among African countries are. This paper used Exploratory Spatial Data Analysis (ESDA) techniques to explore the clustering spatial patterns of TB treatment completion rates in 53 African countries as well as their relationships with mobile phone use. Using an ESDA approach to identify countries with low TB treatment completion rates and reduced mobile phone use is the first step towards addressing issues related to poor TB outcomes. Methods: TB notifications and treatment data from 2000 through 2015 obtained from the World Bank database were used to illustrate a descriptive epidemiology of TB treatment completion rates among African health systems. Spatial clustering patterns of TB treatment completion rates were assessed using differential local Moran’s I techniques; and local spatial analytics was performed using local Moran’s I tests. Relationships between TB treatment completion rates and mobile phone use were evaluated using ESDA approach. Results: Spatial autocorrelation patterns generated were consistent with Low-Low and High-Low cluster patterns and were significant at different p-values. Algeria and Senegal had significant clusters across the study periods, while Democratic Republic of Congo, Niger, South Africa, and Cameroon had significant clusters in at least two time-periods. ESDA identified statistically significant associations between TB treatment completion rates and mobile phone use. Countries with higher rates of mobile phone use, showed higher TB treatment completion rates overall, indicating enhanced program uptake (P < 0.05). Conclusions: Study findings provide systematic evidence to inform policy regarding investments in the use of mHealth to optimize TB health outcomes. African governments should identify turnaround strategies to strengthen mHealth technologies and improve outcomes.