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Exploring HIV drug resistance in sub-Saharan Africa as a complex adaptive system

Boek - Dissertatie

HIV drug resistance (HIVDR) remains a threat to the efficiency of antiretroviral therapy (ART), especially in low-and-middle income countries. To avoid HIVDR it is important that people living with HIV (PLHIV) adhere to their ART, which currently has to be taken on a daily basis. In sub-Saharan Africa, the still high levels of stigmatisation surrounding HIV, the need to take the ART with a meal to assure proper absorption and avoid side effects, and occasional drug stock outs are only a few of the reasons why adhering to therapy can be challenging. Moreover, it is essential that PLHIV are prescribed effective ART regimens and are timely switched to a different line of therapy when a high viral load persists. These and other influencing factors make HIVDR an extremely complex, or wicked, problem. Wicked problems require a systems approach, considering the whole network of interconnected factors and stepping away from a linear, reductionist way of thinking. We therefore, by our knowledge for the first time, studied HIVDR as a complex adaptive system (CAS). Such CASs consist of individual elements which are interconnected, behave in sometimes unpredictable ways and can interact as feedback loops. To construct a first general overview of the HIVDR CAS in sub-Saharan Africa, we developed a systems map with all known factors influencing HIVDR based on interviews with HIVDR experts from diverse disciplines and institutions (Chapter 3). We identified three main interconnected feedback loops or subsystems. First, the 'adherence-motivation subsystem' concerns the interplay between all individual factors which may influence PLHIV to alternate between adherence and non-adherence. Second, at the local population level, the 'healthcare burden subsystem' reveals a reinforcing loop where an increase in healthcare burden leads to an increase in HIVDR, further increasing the healthcare burden and so on. Third, the 'ART overreliance subsystem' is a balancing feedback loop showing the potential risk of developing HIVDR against (new) ART when high standards of quality of care are not maintained. We then continued to develop another systems map, this time representing the HIVDR CAS for a local study site, the Ukonga and Gongolamboto areas of Dar es Salaam, Tanzania, informed by interviews with local actors and PLHIV (Chapter 4). We identified several interconnected feedback loops, and suggested three potential leverage points for sustainable interventions with a system-wide impact. The first leverage point is a reinforcing feedback loop which can be strengthened by stimulating the motivation to adhere to therapy, for example by positive, celebratory messages from healthcare workers when a suppressed viral load is reached. The second leverage point, is to weaken the feedback loops driven by stigmatization, possibly through community education provided by religious or traditional leaders. The third and deepest leverage point is at the design level of the system and concerns the organization of microfinance groups for PLHIV, simultaneously targeting the needs for economic support, HIV(DR) education and psycho-social support. In Chapter 5, we bundled our experience with the HIVDR CAS and developed an operational methodological guide for mapping and analysing complex public health problems. The guideline particularly focuses on situations in which data is collected from semi-structured interviews, as this, in contrast to theoretical literature and group model building approaches, was only limitedly described in the public health literature. Next to providing concrete insights in how to collect data, map the system, analyse it and explore system dynamics, the guideline also stresses the importance of continuous transdisciplinary reflexivity throughout the process. In Chapter 6 we illustrated one of the applications of our systems maps by visualizing the interconnectedness of the AIDS and the COVID-19 pandemics. This showed the importance of addressing both pandemics simultaneously. Taken together, this thesis provides the groundwork for the further transdisciplinary exploration of HIVDR and other complex public health problems as CASs. This will help researchers, stakeholders and policy makers to design complexity-informed interventions with a system-wide impact, and to understand external impacts on the system such as the effects of the COVID-19 pandemic. Additionally, quantitative modelling based on our systems map will provide opportunities to establish key performant indicators that can monitor the effects of interventions or events on different parts of the system.
Jaar van publicatie:2022
Toegankelijkheid:Embargoed