Dissertations / Theses on the topic 'Public health – Africa, Sub-Saharan'

The purpose of this study is to gain a greater understanding of the perceptions and barriers that influence condom use amongst male and female students at the Polytechnic of Namibia (Technical Vocational Education &
Training Department). The specific objectives of this study include the following: To obtain a better understanding of knowledge amongst students about the correct use of condoms. To identify some of the problems students have in accessing condoms. To identify the common sources of information regarding condoms, the common perceptions that exist about condoms, and the extent to which students discuss condoms with others.

Without exception, healthcare systems in the Sub-Saharan Africa, including Ghana, face many challenges. Difficulties in Ghana’s healthcare system stem from many factors, but the most notable one is professional migration, which has crippled the former British colony since 1980. Statistical data demonstrate the yearly migration of healthcare workers from Ghana and its impact on healthcare services (the doctor/nurse population ratio). This study used a quantitative multiple regression research method to examine and empirically analyze the relationship between healthcare workers, technological innovations, and changes in healthcare services in Ghana from 1990 to 2010. The main result was that technological innovations had a significant impact on healthcare services in Ghana during the observed period. Also, regional disparities in the number of medical doctors and nurses were largely explained by the degree of urbanization and economic development. Therefore, the pooled regression analysis from the panel data consistently showed that technological innovations significantly impacted the healthcare system in Ghana during the observed period. However, the numerical impact of the technological innovation coefficients was relatively lower in Ghana during the observed period.

Background: As the world becomes more urban and slums continue to grow in developing countries, research is needed to measure utilization of health services, health outcomes, and access to health care providers among urban slum residents. Estimating trends in urban health among slum residents relative to other urban inhabitants provides evidence of health disparities for priority-setting by program implementers and policy-makers. Research on the negative effects of slum environments on human health has started to emerge, yet there remains a paucity of evidence on morbidity trends over time and inequalities between slum residents and other urban residents. The goal of this study is to quantify maternal and child health care access, utilization and outcomes among urban slum dwellers in selected countries in sub-Saharan Africa and South Asia over time. These three areas are addressed in three separate dissertation manuscripts.

Methods: This dissertation offers an in-depth analysis of household and health facility data to measure trends in maternal and child health care utilization and health outcomes among slum residents over time, as well as inequalities in access, utilization and outcomes between other urban and rural populations. Manuscripts 1 and 2 apply a unique spatial inequality approach to existing population-based household data from the Demographic and Health Surveys (DHS) to identify a sample of slum residents. Manuscript 1 assesses trends in maternal and child health care (MCH) utilization and health outcomes using DHS data in Bangladesh, Ethiopia, Kenya, Malawi, Nepal, Nigeria and Tanzania between 2003 and 2011. In Manuscript 2, a trend analysis is performed in Kenya to examine diarrheal disease and acute respiratory infection (ARI) in children under-five in both slums and other urban and rural areas during the roll-out of a national slum upgrading program. Manuscript 3 further explores local-level dimensions of health care access from two slums in Kenya, generating evidence on service availability and readiness in slums. In this section, we analyze health facility data collected using a modified version of the World Health Organization’s (WHO) Service Availability and Readiness Assessment (SARA).

Results: Manuscript 1 reports significant disparities between slum dwellers and other urban residents’ utilization of key maternal health interventions—appropriate antenatal care (ANC), tetanus toxoid vaccination, and skilled delivery—in Bangladesh, Ethiopia, Kenya and Nigeria. In addition, child health outcomes examined in Manuscript 1 suggest that the prevalence of diarrheal disease in children under-five is declining among other urban and rural residents, but not significantly among slum residents. Nigeria was the only exception, with significant declines in diarrheal disease prevalence in slums over the study period. Because ARI improvements are found across populations, the data suggests this condition is not unique to slum settings. The trend analysis in Manuscript 2 supports these findings—ARI is declining steadily over time not only among slum residents, but also among other urban and rural residents as well. Diarrheal disease prevalence, on the other hand, has not changed significantly over time, with stable levels among slum dwellers between 1993 and 2014. In Manuscript 3, analysis of general service availability and readiness in two locations—the Nyalenda slum of Kisumu and the Langas slum of Eldoret—reveals that slums perform far below recommended benchmarks set by WHO. When we compare service availability and readiness indicators with regional, urban, and national averages, in general slums in Kisumu and Eldoret perform poorly. However, there were some instances—typically involving standard precautions for infection control—where Kenyan slums actually performed better than comparison sites.

Conclusions: This research provides a comprehensive view of health systems dimensions in urban slums in sub-Saharan Africa and South Asia. Manuscript 1 confirms evidence of an urban penalty and emphasizes a need to focus on maternal health care utilization in slums. Manuscript 2 detects little improvement in child health outcomes among slum dwellers in Kenya during the roll-out of the country’s national slum upgrading program. An integrated approach to health and urban policy development is recommended based on these results. Manuscript 3 identifies areas of service availability and readiness in two Kenyan slums that fall below global targets and are in need of improvement in order to achieve desired health outcomes. Taken together, this study makes a significant contribution to the crucial demand for research on growing marginalized urban populations in developing countries.

Among the multitude of interventions to address the worst forms of child labor (WFCL), one of the responses to the presence of WFCL has been the institution of child labor monitoring (CLM). While systems to systematically monitor children with respect to their exposure and risks have been implemented, the degree of their efficacy and ultimately their effect on the targeted populations begs academic scrutiny. This dissertation seeks to provide an empirical view of the community-level dynamics that emerge in response to a community-based CLM program and their effects, in turn, on the CLM itself.

An embedded multiple case study methodology, surveying longitudinally at two points in time using a mix of purposive and probability sampling techniques, was employed for this study. Two communities, Ahokwa in the Western Region, and Dwease in the Ashanti Region of Ghana, were selected as cases.

The study finds that between the two points of observation – before and after the introduction of CLM – a profound reduction of WFCL is observed in Dwease, whereas much less reduction was observed in Ahokwa. A point-by-point analysis within and between the two villages reveals that individual, social and institutional factors worked together to transform behavior in Dwease. The principal change catalysts in Dwease were (a) a heightened awareness of child work hazards and a deepened parental investment in child education working at the individual level, coupled with (b) new norms created by the town's opinion leaders and the emergence of peer accountability at the social level, and (c) monitoring carried out by the Community Data Collection (CDC) and enforcement carried out by the Community Child Protection Committee (CCPC) – the two new institutions constituting CLM at the community-level. The underlying social dynamic proved to be decisive: a tipping point was crossed in Dwease whereby progressive opinion leaders in the community, who, once sensitized to recognize the pejorative effects of CL/WFCL, created new social norms and spurred a critical mass of community members to rid their community of CL/WFCL.

This study shows that with sufficient local ownership, and if properly instituted, the tandem operation of child protection committees and child labor monitoring enables a community to effectively detect, police and mitigate the practice of child labor and WFCL.

Background: HIV testing saves lives. It is fundamental to combating the global HIV epidemic. Key populations at higher risk for HIV in Mozambique, including Men who have Sex with Men (MSM), Female Sex Workers (FSW) and mineworkers, are in urgent need of effective HIV prevention strategies. This is the first analysis ever conducted in Mozambique to identify levels of HIV testing and associated factors that inform these strategies.

Methods: This analysis used data from seven cross-sectional surveys conducted between 2011-2012 among MSM, FSW and Mineworkers in Mozambique. Participants completed a questionnaire and provided blood samples for HIV testing. MSM and FSW were recruited used Respondent Driven Sampling in Maputo, Beira and Nampula. Mineworkers were recruited using Time Location Sampling in Ressano-Garcia. Participants with previous HIV-positive tests or missing HIV test histories were excluded (<5% overall). Weighted logistic regression was used to measure associations with recent HIV testing (<12 months). Theory-driven multivariate logistic regression was conducted in R v2.15 using the Health Behavior Model as a conceptual framework.

Results: The prevalence of recent testing for HIV ranged from 29.8-59.5%, yet 4.4-25.0% had HIV and did not know it. Between 11.9-57.4% had never been tested, and fear was given as the primary barrier. Recent HIV testing was positively associated with knowledge of ARV drugs, knowing the HIV status of a sexual partner, knowing where to go to get tested, and having had contact with a peer educator. It was negatively associated with having had a genital sore or ulcer and unprotected sex. Between 32.1-90.0% of HIV-positive undiagnosed, key population members had used a healthcare service in the previous 12 months and 23.4-47.5% had tested negative for HIV in that time period.

Conclusion: Routine testing with strengthened post-test counseling encouraging key populations to have annual HIV screenings need to be implemented in Mozambique.

Men in sub-Saharan Africa are less likely than women to use HIV services and, thus, are more likely to die from AIDS. While much of the literature argues that men’s views of masculinity keep them from services, I use the theory of gendered organizations to provide another perspective. In this dissertation, I use a mixed methods approach to examine the gendered organization of facility-based HIV testing services in southern Malawi and how the organization of services creates additional barriers to men’s use of care.

I combine four types of data: (1) survey data with facility clients to assess if quality of care differs by sex of client; (2) in-depth interviews with healthcare providers and policy makers to examine perceptions of men as clients; (3) participant observation in health facilities to understand how institutional protocols are enacted at the local level; and (4) international and national policy documents to situate local health institutions within broader global constructs of gender and HIV priorities.

I find that heterosexual men have become an invisible category within both international and national HIV policy. When they are included, they are described as the problem, not part of the solution to HIV epidemics. On the ground, the organization of HIV testing services has followed suit.

Health institutions, like other organizations, are not gender-neutral. Men in southern Malawi were not recruited for health services, were less likely than women to receive health education when they did attend a facility, and were less likely to have access to HIV testing because services were, at times, only offered during hours for antenatal services. Furthermore, HIV testing was often located near antenatal services, again contributing to the perception that testing was designed for women – because it was. Based on these findings, I argue that HIV testing is gendered across three levels of the health institution: (1) the organizational HIV policies; (2) the physical environment in which testing occurs; and (3) interactions within facilities that require clients to enact qualities typically viewed as feminine in order to successfully receive care (e.g., waiting long hours, being compliant, and being a caregiver).

Biomedical and behavioral interventions can virtually eliminate the risk of vertical (i.e., mother-to-child) HIV transmission. Pregnant and breastfeeding women’s adherence to prevention of mother-to-child transmission (PMTCT) interventions, however, remains a challenge across sub-Saharan Africa. Using a concurrent mixed methods approach, including a survey and semi-structured interviews, I test whether a relationship exists between women’s low power within married couples (based on domains from the Theory of Gender and Power) and adherence across the PMTCT cascade of care, including drug adherence during and after pregnancy, safe infant feeding practices, and pediatric HIV testing. The results of this study indicate that intimate partner violence is particularly detrimental to PMTCT adherence. Certain PMTCT protocols are also affected by partner controlling behaviors, participation in household decisions, and economic dependence, but not to the same extent as violence. Women with low power cite a lack of partner support and an unwillingness to disclose their HIV status to the husband due to fear of violence or abandonment as reasons for low PMTCT adherence. Conversely, women with high power cite partner support and the ability to prioritize PMTCT, sometimes even over the marriage, as enabling adherence. Based on these results, augmented efforts to address gender power dynamics both in society and within the home are recommended to promote the health of HIV-positive women and their families.

To begin, filling a knowledge gap (Russell 2004), we have performed microeconomic research on the households’ costs-and-consequences-of-tuberculosis in Burkina Faso and Benin. The two case studies have been conducted both in rural and urban resource-poor settings between 2007 and 2009. This thesis provides new empirical findings on the remaining financial, social and ‘healthcare delivery related organizational’ barriers to access diagnosis and treatment services that are delivered free-of-charge to the population. The direct costs associated with illness incurred by the tuberculosis pulmonary smear-positive patients have constituted a severe economic burden for these households living in permanent budget constraints. Most of these people have spent catastrophic health expenditure to cure tuberculosis and, at the same time, have faced income loss caused by the care-seeking. To cope with the substantial direct and indirect costs of tuberculosis, the patients have shipped their families in impoverishing strategies to mobilize funds for health such as depleting savings, being indebted and even selling livestock and property. Damaging asset portfolios of the disease-affected households on the long run, the coping strategies result in a public health threat. In resource-poor settings, the lack of financial protection for health may impose inability to meet basic needs such as the rights to education, housing, food, social capital and access to primary healthcare. Special feature of our work lies in the breakdown of the information gathered. We have been able to demonstrate significant differences in the volume and nature of the amounts spent across the successive stages of the care-seeking pathway. Notably, pre-diagnosis spending has been proved critical both in the rural and urban contexts. Moreover, disaggregated cost data across income quintiles have highlighted inequities in relation to the direct costs and to the risk of incurring catastrophic health expenditure because of tuberculosis. As part of the case studies, the tuberculosis control strategies have failed to protect the most vulnerable care users from delayed diagnosis and treatment, from important spending even during treatment – including significant medical costs, and from hidden costs that might have been exacerbated by poor health systems. To such devastating situations, the tuberculosis patients have had to endure other difficulties; we mean intangible costs such as pain and suffering including stigmatization and social exclusion as a result of being ill or attending tuberculosis care facilities. The analysis of all the social and economic consequences for tuberculosis-affected households over the entire care-seeking pathway has been identified as an essential element of future cost-of-illness evaluations, as well as the need to conduct benefit incidence assessment to measure equity.

This work has allowed identifying a series of policy weaknesses related to the three dimensions of the universal health coverage for tuberculosis (healthcare services, population and financial protection coverage). The findings have highlighted a gap between the standard costs foreseen by the national programs and the costs in real life. This has suggested that the current strategies lack of patient-centered care, context-oriented approaches and systemic vision resulting in a quality issue in healthcare delivery system (e.g. hidden healthcare related costs). Besides, various adverse effects on households have been raised as potential consequences of illness; such as illness poverty trap, social stigma, possible exclusion from services and participation, and overburdened individuals. These effects have disclosed the lack of social protection at the country level and call for the inclusion of tuberculosis patients in national social schemes. A last policy gap refers to the lack of financial protection and remaining inequities with regards to catastrophic health expenditure still occurring under use fee exemptions strategies. Thereby, one year before 2015 – the deadline set for the Millennium Development Goals – it is a matter of priority for Benin and Burkina Faso and many other countries to tackle adverse effects of the remaining social, economic and health policy and system related barriers to tuberculosis control. These factors have led us to emphasize the need for countries to develop sustainable knowledge.

National decision-makers urgently need to document the failures and bottlenecks. Drawing on the findings, we have considered different ways to strengthen local capacity and generate bottom-up decision-making. To get there, we have shaped a decision framework intended to produce local evidence on the root causes of the lack of policy responsiveness, synthesize available evidence, develop data-driven policies, and translate them into actions.

Beyond this, we have demonstrated that controlling tuberculosis was much more complex than providing free services. The socio-economic context in which people affected by this disease live cannot be dissociated from health policy. The implications of microeconomic research on the households’ costs and responses to tuberculosis may have a larger scope than informing implementation and adaptation of national disease-specific strategies. They can be of great interest to support the definition of guiding principles for further research on social protection schemes, and to produce evidence-based targets and indicators for the reduction and the monitoring of economic burden of illness. In this thesis, we have build on prevailing debates in the field and formulated different assumptions and proposals to inform the WHO Global Strategy and Targets for Tuberculosis Prevention, Care and Control After 2015. For us, to reflect poor populations’ needs and experiences, global stakeholders should endorse bottom-up and systemic policy-making approaches towards sustainable people-centered health systems.

The findings of the thesis and the various global and national challenges that have emerged from case studies are crucial as the problems we have seen for tuberculosis in West Africa are not limited to this illness, and far outweigh the geographical context of developing countries.

Keywords: Catastrophic health expenditure, Coping strategies, Cost-of-illness studies, Direct, indirect and intangible costs, Evidence-based Public health, Financial and Social protection for health, Health Economics, Health Policy and Systems, Informed Decision-making, Knowledge translation, People-centered policy-making, Systemic approach, Universal Health Coverage

Doctorat en Sciences de la santé publique
info:eu-repo/semantics/nonPublished

ISBN 978-91-85721-07-8

Depuis une quinzaine d'années en Afrique, cercles de qualité, audits cliniques, cycles de résolution de problèmes et autres 'projets qualité' ont été mis en oeuvre dans les services publics de santé pour améliorer la qualité des soins. Ces projets ont souvent mis l'accent sur des approches participatives, la résolution locale de problèmes et le changement, bousculant les pratiques managériales traditionnelles. A court terme, les évaluations montrent l'amélioration des résultats de programmes ou d'activités. Mais la pérennité de la dynamique reste largement à prouver. Le véritable aboutissement d'un programme d'assurance qualité devrait être apprécié à l'aune de sa capacité à mettre la préoccupation pour la qualité au cœur du management et du fonctionnement du système, et ce de façon continue. C'est en effet la vision moderne de l'assurance qualité déclinée dans les approches du management de la qualité totale, de l'amélioration continue de la qualité ou de l'organisation apprenante.

Méthode

La définition, la mesure et le management de la qualité en santé se révèlent être beaucoup plus qu'une simple procédure technique: c'est un processus social dans un système complexe dont l'étude requiert une approche méthodologique appropriée (Chapitre 1). Notre objectif est d'explorer dans quelle mesure les projets qualité ont permis aux systèmes de santé d'adopter les principes du management de la qualité.

Nous proposons de conduire une 'évaluation réaliste' de projets qualité en Afrique (Chapitre 2). Conceptualisée par Pawson et Tilley (1997) dans le domaine des sciences sociales, l'évaluation réaliste ('realistic evaluation') est une approche méthodologique de la famille des theory based evaluations. Au-delà du constat d'un effet produit par une intervention, l'évaluation réaliste cherche à comprendre ce qui marche, pour qui, dans quelles circonstances et comment. Alors que les résultats issus de la 'grounded theory', de la recherche action et d'autres méthodes de recherche sur les systèmes de santé restent très liés à un contexte, l'évaluation réaliste génère des théories intermédiaires ('middle range theories') qui permettent d'étendre la validité des interprétations au-delà d'un contexte particulier. Construite autour d'études de cas menées dans des contextes multiples et variés, l'évaluation réaliste met en effet l'accent sur l'interaction entre le contexte et la logique d'une intervention.

Résultats

Afin de construire une théorie initiale, nous comparons les systèmes de santé Européens et Africains à l'aide des configurations organisationnelles de Mintzberg (chapitre 3). Nous mettons ainsi en évidence le rôle joué par la nature bureaucratique ou professionnelle de la configuration des organisations de santé dans les résistances à l'introduction des principes du management de la qualité.

Nous menons ensuite une série d'études de cas au Niger, en Guinée, au Maroc et au Zimbabwe pour étudier cette interaction. Dans une première série comparative de trois études de cas (Chapitre 4), nous mettons en évidence la tension qui existe entre la logique de commande et de contrôle des organisations bureaucratiques et la logique de l'assurance qualité valorisant la prise d'initiative de changement par des équipes non hiérarchisées. Nous explorons ensuite cette tension dans trois études de cas distinctes au Zimbabwe et au Maroc. Laissées à la merci des contraintes bureaucratiques, les initiatives locales pour améliorer la qualité apparaissent dépendantes de la capacité des acteurs à développer des stratégies de contournement (Chapitre 6). Faute de quoi elles doivent réduire fortement leurs ambitions à moins qu'elles ne bénéficient d'un soutien émanant d'une institution située hors de la ligne hiérarchique mais reconnue légitime (Chapitre 5). Les systèmes publics de santé de ces pays, conçus comme des organisations bureaucratiques structurées autour de relations hiérarchiques de commande et de contrôle tolèrent une démarche qualité, valorisant l'innovation, la créativité, la prise d'initiative locale et le travail en équipes non hiérarchisées, à la condition qu'elle se déroule à l'abri d'un projet. Force est de constater que ces dimensions clé de la culture qualité n'ont pas fondamentalement ni durablement imprégné des pratiques de management restées bureaucratiques. L'émergence d'une véritable 'culture qualité', un produit attendu de l'introduction de projets qualité, ne semble pas s'être produite au niveau organisationnel (Chapitre 7).

Nous procédons ensuite à la synthèse 'réaliste' de l'ensemble de nos études de cas (Chapitre 8). Nous en tirons les leçons sous la forme d'un enrichissement progressif de notre théorie initiale. Nous pouvons alors formuler une théorie améliorée, toujours intermédiaire et provisoire, dérivée de nos théories intermédiaires successives.

Discussion

Notre discussion s'organise autour de deux thèmes (chapitre 9).

Dans une première partie, nous discutons le potentiel et les limites de nos résultats et de l'approche réaliste de l'évaluation. Nous montrons que nos résultats sont des théories provisoires et incomplètes, deux caractéristiques d'une middle range theory. En dépit de ces limites, l'approche réaliste est potentiellement très riche pour interpréter les effets d'interventions dans des systèmes complexes. Elle se situe dans une perspective d'aide à la décision pour orienter l'action sur le terrain plutôt que dans une perspective de genèse de lois universelles. Elle représente une avancée méthodologique particulièrement pertinente pour la recherche sur les systèmes de santé dans un monde turbulent où de multiples initiatives se télescopent.

Dans une deuxième partie, nous discutons les conséquences de nos résultats pour le futur de l'assurance qualité dans les systèmes de santé. Les projets qualité étudiés ne parviennent pas à changer une culture organisationnelle bureaucratique qui compromet pourtant leur pérennisation. Nous envisageons alors les stratégies susceptibles de permettre à la culture qualité de s'épanouir et au contexte organisationnel d'évoluer en conséquence. Décentralisation et nouveau management public, en vogue hier et aujourd'hui, montrent leurs limites. Il faut probablement trouver un équilibre entre trois idéaux-types décrits par Freidson: l'idéal-type bureaucratique, malmené par les stratégies de débrouille locale, l'idéal-type du marché, valorisant l'initiative, et l'idéal-type professionnel, émergent mais encore embryonnaire en Afrique. Finalement, à côté des mécanismes du contrôle et de la compétition, un troisième mécanisme régulateur devrait prendre toute sa place: la confiance.

Introduction

For nearly two decades in Africa, quality circles, clinical audits, problem solving cycles and other quality projects have been implemented in public health services to improve quality of care. Challenging traditional managerial practices, these projects usually emphasized participatory approaches, local problem solving and change. At short term, evaluation shows improvement in programs and activities output. However the capacity to put quality at the heart of system's management should be considered as the genuine achievement of a quality assurance program. Did quality projects contribute to the adoption of quality management principles by health systems ?This is the question addressed in the present thesis.

Method

Our methodology belongs to the realistic evaluation paradigm conceptualized by Pawson and Tilley and focuses on the interaction between an intervention mechanism and its context in order to understand what works, for whom, in what circumstances and how ?Based on case studies in various contexts in Niger, Guinea, Morocco and Zimbabwe, we build a middle range theory, that explains organizational behavior towards quality management.

Results

Based on Mintzberg's models, we show the role of health care organizational configuration in resisting to quality management principles. We then explore the tension between the bureaucratic organization's command and control approach and the quality assurance approach promoting initiative and change through team work. Local initiative had to develop coping strategies to overcome bureaucratic constraints. Failing to do so, ambitions had to be reduced unless there was support from an external, yet legitimate institution. Public health systems of these countries, structured as command and control hierarchical organizations, allowed innovation, creativity, local initiative and non hierarchical relationships as long as they developed within the boundaries of a project. However, these key characteristics of a quality culture did not permeate routine management. The quality culture shift expected from quality projects does not seem to have happened at organizational level.

Discussion

We first discuss the potential and limitation of realistic evaluation which appear particularly relevant for complex health systems research. We then discuss consequences of our results on the future of quality assurance in health systems. Since quality projects fail to transform a bureaucratic organizational culture, which in turn undermines their sustainability, alternative strategies must be sought to promote quality culture and relevant organizational change. Decentralization and new public management show their limitations. We suggest a balance between three ideal-types described by Freidson: The bureaucratic ideal-type, challenged by local coping strategies, the market ideal-type, which is fashionable today and promote initiative, and the professional ideal-type, emerging and promising, yet still embryonic in Africa.
Doctorat en Sciences de la santé publique
info:eu-repo/semantics/nonPublished

La Trypanosomiase Humain Africaine (THA) demeure un problème de santé publique pour plusieurs pays en Afrique subsaharienne. Le contrôle de la THA est basé essentiellement sur la stratégie de dépistage actif suivi du traitement des personnes infectées. Le dépistage actif est réalisé par des unités mobiles spécialisées, bien que les services de santé fixes jouent un rôle important en détectant « passivement » des cas. Le dépistage reposait jadis sur la palpation ganglionnaire mais, depuis le développement du test d’agglutination sur carte (CATT), trois possibilités se sont offertes aux programmes de contrôle à savoir: i) continuer avec la palpation ganglionnaire ii) combiner la palpation ganglionnaire avec le CATT iii) recourir au CATT seul. Certains programmes comme celui de la République Démocratique du Congo (RDC) ont opté pour la combinaison en parallèle de la palpation ganglionnaire avec le CATT. Toute personne ayant une hypertrophie ganglionnaire cervicale et/ou un CATT positif est considéré comme suspecte de la THA. Elle sera soumise aux tests parasitologiques de confirmation à cause de la toxicité des médicaments anti-THA. Les tests parasitologiques classiques sont l’examen du suc ganglionnaire (PG), l’examen du sang à l’état frais (SF), la goutte épaisse colorée (GE). La sensibilité de cette séquence a été estimée insuffisante par plusieurs auteurs et serait à la base d’une grande perte de l’efficacité de la stratégie dépistage-traitement. D’autres techniques de concentration ont été développées comme la mini-Anion Exchange Concentration Technique (mAECT), la Centrifugation en Tube Capillaire (CTC) et le Quantitative Buffy Coat (QBC), mais ces techniques de concentration ne sont pas utilisées en routine.

En RDC, une interruption des activités de contrôle en 1990 a eu comme conséquence une réémergence importante de la maladie du sommeil. Depuis 1998 les activités de contrôle ont été refinancées de manière structurée.

Ce travail vise deux buts à savoir le plaidoyer pour la continuité des activités de contrôle et la rationalisation des stratégies de contrôle. Nous avons évalué l’évolution de la maladie du sommeil en rapport avec le financement, son impact sur les ménages ainsi que la communauté. L’exercice de rationalisation a porté sur les outils de dépistage et de confirmation. Nous avons d’abord évalué la validité des tests, leur faisabilité ainsi que les coûts et ensuite nous avons effectué une analyse décisionnelle formelle pour comparer les algorithmes de dépistage et pour les tests de confirmation.

Pendant la période de refinancement structurel de la lutte contre la THA en RDC (1998-2003), le budget alloué aux activités a été doublé lorsqu’on le compare à la période précédente (1993-1997). Le nombre des personnes examinées a aussi doublé mais par contre le nombre des nouveaux cas de THA est passé d’un pic de 26 000 cas en 1998 à 11 000 en 2003. Le coût par personne examinée a été de 1,5 US$ et celui d’un cas détecté et sauvé à 300 US$. Pendant cette période, les activités ont été financées par l’aide extérieure à plus de 95%. Cette subvention pourrait laisser supposer que l’impact de la THA au niveau des ménages et des communautés est réduit mais lorsque nous avons abordé cet aspect, il s’est avéré que le coût de la THA au niveau des ménages équivaut à un mois de leur revenu et que la THA fait perdre 2145 DALYs dans la communauté. L’intervention par la stratégie de dépistage-traitement a permis de sauver 1408 DALYs à un coût de 17 US$ par DALYs sauvé. Ce coût classe l’intervention comme « good value for money ».

Le recours au CATT seul s’est avéré comme la stratégie la plus efficiente pour le dépistage actif. Le gain marginal lorsque l’on ajoute la palpation ganglionnaire en parallèle est minime et n’est pas compensé par le coût élevé lié à un nombre important des suspects soumis aux tests parasitologiques. Les techniques de concentration ont une bonne sensibilité et leur faisabilité est acceptable. Leur ajout à l’arbre classique améliore la sensibilité de 29 % pour la CTC et de 42% pour la mAECT. Le coût de la CTC a été de 0,76 € et celui de la mAECT de 2,82 €. Le SF a été estimé très peu sensible. L’algorithme PG- GE-CTC-mAECT a été le plus efficient avec 277 € par vie sauvée et un ratio de coût-efficacité marginal de 125 € par unité de vie supplémentaire sauvée. L’algorithme PG-GE-CATT titration avec traitement des personnes avec une parasitologie négative mais un CATT positif à un seuil de 1/8 devient compétitif lorsque la prévalence de la THA est élevée.

Il est donc possible dans le contexte actuel de réduire la prévalence de la THA mais à condition que les activités ne soient pas interrompues. Le recours à un algorithme recourant au CATT dans le dépistage actif et à la séquence PG-GE-CTC-mAECT est le plus efficient et une efficacité de 80%. La faisabilité et l’efficacité peut être différent d’un endroit à l’autre à cause de la focalisation de la THA. Il est donc nécessaire de réévaluer cet algorithme dans un autre foyer de THA en étude pilote avant de décider d’un changement de politique. Le recours à cet algorithme implique un financement supplémentaire et une volonté politique.

SUMMARY

Human African Trypanosomiasis (HAT) remains a major public health problem affecting several countries in sub-Saharan Africa. HAT control is essentially based on active case finding conducted by specialized mobile teams. In the past the population screening was based on neck gland palpation, but since the development of the Card Agglutination Test for Trypanosomiasis (CATT) three control options are available to the control program: i) neck gland palpation ii) CATT iii) neck gland palpation and CATT done in parallel .Certain programs such as the one in DRC opted for the latter, combining CATT and neck gland palpation. All persons having hypertrophy of the neck gland and/or a positive CATT test are considered to be a HAT suspect. Confirmation tests are necessary because the screening algorithms are not 100 % specific and HAT drugs are very toxic. The classic parasitological confirmation tests are lymph node puncture (LNP), fresh blood examination (FBE) and thick blood film (TBF). The sensitivity of this combination is considered insufficient by several authors and causes important losses of efficacy of the screening-treatment strategy. More sensitive concentration methods were developed such as the mini Anion Exchange Concentration Techniques (mAECT), Capillary Tube Centrifugation (CTC) and the Quantitative Buffy Coat (QBC), but they are not used on a routine basis. Main reasons put forward are low feasibility, high cost and long time of execution.

In the Democratic Republic of Congo, HAT control activities were suddenly interrupted in 1990 and this led to an important re-emergence or the epidemic. Since 1998 onwards, control activities were financed again in a structured way.

This works aims to be both a plea for the continuation of HAT control as well as a contribution to the rationalization of the control strategies. We analyzed the evolution of sleeping sickness in the light of its financing, and we studied its impact on the household and the community. We aimed at a rationalization of the use of the screening and confirmation tools. We first evaluated the validity of the tests, their feasibility and the cost and we did a formal decision analysis to compare screening and confirmation algorithms.

The budget allocated to control activities was doubled during the period when structural aid funding was again granted (1998-2003) compared with the period before (1993-1997). The number of persons examined per year doubled as well but the number of cases found peaked at 26 000 in 1998 and dropped to 11 000 in the period afterwards. The cost per person examined was 1.5 US$ and per case detected and saved was 300 US$. The activities were financed for 95 % by external donors during this period. This subvention could give the impression that the impact of HAT on the household and the household was limited but when we took a closer look at this aspect we found that the cost at household level amounted to one month of income and that HAT caused the loss of 2145 DALYs in the community. The intervention consisting of active case finding and treatment allowed to save 1408 DALY’s at a cost of 17 US$ per DALY, putting the intervention in the class of “good value for money”.

The use of CATT alone as screening test emerged as the most efficient strategy for active case finding. The marginal gain when neck gland palpation is added is minor and is not compensated by the high cost of doing the parasitological confirmation test on a high number of suspected cases. The concentration methods have a good sensitivity and acceptable feasibility. Adding them to the classical tree improves its sensitivity with 29 % for CTC and with 42 % for mAECT. The cost of CTC was 0.76 US$ and of mAECT was 2.82 US$. Sensitivity of fresh blood examination was poor. The algorithm LNP-TBF-CTC-mAECT was the most efficient costing 277 Euro per life saved and a marginal cost effectiveness ratio of 125 Euro per supplementary life saved. The algorithm LNP-TBF-CATT titration with treatment of persons with a negative parasitology but a CATT positive at a dilution of 1/8 and more becomes competitive when HAT prevalence is high.

We conclude that it is possible in the current RDC context to reduce HAT prevalence on condition that control activities are not interrupted. Using an algorithm that includes CATT in active case finding and the combination LNP-TBF-CTC-mAECT is the most efficient with an efficacy of 80 %. Feasibility and efficacy may differ from one place to another because HAT is very focalized, so it is necessary to test this novel algorithm in another HAT focus on a pilot basis, before deciding on a policy change. Implementation of this algorithm will require additional financial resources and political commitment.

Doctorat en Sciences de la santé publique
info:eu-repo/semantics/nonPublished