Tag Archives: DDDAC

Combating neglected tropical diseases: more than just drugs and vaccines

Neglected tropical diseases have been in the news this week. A big meeting at the World Health Organisation in Geneva has resulted in big pledges from the UK aid progamme and the Bill and Melinda Gates Foundation to banish the scourge affecting around a billion people worldwide. This is good news, and to be commended. But the focus of many of the announcements has been on drugs and vaccines – the technical solutions to prevention and cure. These are of course vital parts of the solution, but, as we have found in work on ‘sleeping sickness’ in southern Africa, as part of the ESPA-funded Dynamic Drivers of Disease in Africa project, they are not the whole story. Without a wider look at how politics and ecology interact in local situations, opportunities for disease or vector control may be missed, and money wasted.

Over the last few years, a team from the University of Zimbabwe and the Tsetse Control Branch of the Ministry of Agriculture of Zimbabwe has been looking at trypanosomiasis (a disease affecting animals and humans, when it’s called sleeping sickness), and the vector that carries it, the tsetse fly (see picture) in the Zambezi valley. We have been trying to unravel the complex puzzle that connects changing ecologies, disease and livelihood impacts, working as a cross-disciplinary team.

Despite decades of control efforts – from clearance of vegetation to wildlife extermination to aerial spraying of chemicals to baited traps (see this paper), the tsetse fly and trypanosomiasis, affecting both animals and humans, persists. And indeed in the last few years we have seen peaks in both human and animal forms. Not high, but definitely worrying – and devastating for those who are affected.

In our work, we trapped flies along transects, took blood from animals to look for parasites, examined habitat change from satellite imagery and talked to people in the villages. The question we had – why did the disease persist? – was a difficult one to answer. The official maps showed the tsetse ‘belt’ being kept to the south, into the Highveld. Control measures continued to some extent, and official reporting of trypanosomiasis, both animal and human, was highlighting very few cases.

Our tsetse fly surveys in Hurungwe district showed a peak of fly populations along the valley escarpment, with declining numbers of flies caught in our traps as you travel south away from the valley. Cluster traps located near villages and dips also showed a variable pattern. But overall tsetse fly populations (of different species) were low and relatively few were trapped. Why, if people complain about both animal and human trypanosomiasis? The answer came through an analysis of habitat change.

Abandoning very coarse grained images in favour of LANDSAT images with a higher resolution, we found a major shift in vegetation patterns over time, and particularly a noticeable fragmentation of habitat. Maybe the flies were residing in these fragmented habitat patches, and were not being picked up by the standard belt transects? This indeed proved to be the case.

When villagers analysed the satellite image maps of their area with us, they quickly pointed to particular patches where they knew flies were. The Mushangishe gorge, the pools near the Chewore river, the villages along the edge of the hunting area, the Makuti area, and so on. Some more focused trapping, sampling not randomly but purposively according to what people had indicated, showed that flies do still persist, even in heavily populated areas, but just in small patches.

So what about the disease-causing trypanosomes themselves? Analysis of 209 tsetse flies showed that nearly half were carrying trypanosomes following molecular DNA analysis at Edinburgh University. The most prevalent species was T. vivax (in 32% of flies), followed by T. brucei. This pattern was consistent across fly species (G. m. mortisans and G. pallidipes) and sex. Blood sampling of 400 cattle and 222 goats across 19 villages again showed a very heterogeneous pattern of presence, with trypanosomes (T vivax and T. brucei) being found in only four village sites, with presence in cattle ranging from 2-10 per cent. The places where infected animals were found tallied almost exactly with the places where local people had identified tsetse infested habitat patches. Perhaps surprisingly, given the reports of human trypanosomiasis, we found no evidence of T. b. rhodesiense in either fly or livestock samples; although of course this does not mean it is not present.

The puzzle had been (partially) solved. Tsetse flies and so trypanosomiasis (although no human sleeping sickness causing trypanosmes found as yet) persist because of the maintenance of particular habitat patches. Who gets sick (and whose animals) depends on who goes to these sites. Those most likely to get the disease, and those whose animals are the most susceptible, are mostly poor and marginalised people who must make a living on the edge of wildlife areas. They are hired herders or children of school age moving with animals deep into forested areas; they are groups of men going on hunting trips harvesting wild animals as a source of protein; they are women who forage in the forests, or who collect water from streams and rivers; and they are the new in-migrants into the area, offered land to settle and farm in the frontier areas, sometimes in the buffer zones of the national park and hunting areas.

As people put it to us “we are now fighting a guerrilla war against the tsetse”. They don’t exist along a ‘front’, an identifiable belt on a map as in the past, but in particular sites, which only particular people go to. Gender, age, occupation all make a big difference as to who gets potentially exposed. This has important implications for both monitoring (coarse grained satellite imagery, broad transects and random sampling are no use) and response (by the same token, generic, area-wide approaches make little sense). A more targeted approach, identifying particular patches, and particular people at risk is vital.

In addition, disease risk has to be understood through an appreciation of history, politics and social relations. Such people and their animals do not become sick by chance. Disease is often caused by what Paul Farmer calls ‘structural violence’, with disease being “the biological reflection of social fault lines”. Inequality, poverty, dispossession, alienation, lack of rights, and deep neglect by states results in disease impacts that are often not even noticed or recorded. The biological impacts of disease are thus reflected through politics, class, race and gender and changing landscape ecologies.

Tackling a neglected disease like sleeping sickness requires an understanding of ecology, social relations, politics and more. Expensive, magic bullet solutions through drugs or vaccines may not be the only answer – instead much simpler solutions may be on offer, if the social causes of disease are addressed and the ecological dynamics of disease risk understood. It is good that BGMF and DFID have pledged money; let’s hope it is used in an integrated ‘One Health’ approach, where complex solutions are developed for complex, multi-sectoral challenges.

The Dynamic Drivers of Disease in Africa work was supported by ESPA (Ecosystem Services for Poverty Alleviation) programme funded by NERC, ESRC and DFID, and the Zimbabwe study was led by Professor Vupenyu Dzingirai (CASS, UZ), working with William Shereni (Ministry of Agriculture), Learnmore Nyakupinda (Ministry of Agriculture), Lindiwe Mangwanya (UZ), Amon Murwira (UZ), Farai Matawa (UZ), Neil Anderson (Edinburgh University) and Ewan McLeod (Edinburgh University), among others.

This post was adapted from an earlier blog, and was written by Ian Scoones and appeared on Zimbabweland

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Land, politics and tsetse flies: changing disease landscapes in Zimbabwe

What do land, politics and flies have to do with each other? If you live in the Zambezi valley quite a lot, as I will explain in a short series of blogs over the next few weeks.

As part of the Dynamic Drivers of Disease in Africa project, I have been working with a team from the University of Zimbabwe and the Tsetse Control Branch of the Ministry of Agriculture in Hurungwe district looking at trypanosomiasis (a disease affecting animals and humans, when it’s called sleeping sickness), and the vector that carries it, the tsetse fly. We have been trying to unravel the complex puzzle that connects changing ecologies, disease and livelihood impacts, working as a cross-disciplinary team (see earlier blog too).

Despite decades of control efforts – from clearance of vegetation to wildlife extermination to aerial spraying of chemicals to baited traps (see this paper), the tsetse fly and trypanosomiasis, affecting both animals and humans, persists. And indeed in the last few years we have seen peaks in both human and animal forms. Not high, but definitely worrying – and devastating for those who are affected.

In our work, we trapped flies along transects, took blood from animals to look for parasites, examined habitat change from satellite imagery and talked to people in the villages. The question we had – why did the disease persist? – was a difficult one to answer. The official maps showed the tsetse ‘belt’ being kept to the south, into the Highveld. Control measures continued to some extent, and official reporting of trypanosomiasis, both animal and human, was highlighting very few cases.

Our tsetse fly surveys showed a peak of fly populations along the valley escarpment, with declining numbers of flies caught in our traps as you travel south away from the valley. Cluster traps located near villages and dips also showed a variable pattern. But overall tsetse fly populations (of different species) were low and relatively few were trapped. Why, if people complain about both animal and human trypanosomiasis? The answer came through an analysis of habitat change.

Abandoning very coarse grained images in favour of LANDSAT images with a higher resolution, we found a major shift in vegetation patterns over time, and particularly a noticeable fragmentation of habitat. Maybe the flies were residing in these fragmented habitat patches, and were not being picked up by the standard belt transects? This indeed proved to be the case.

When villagers analysed the satellite image maps of their area with us, they quickly pointed to particular patches where they knew flies were. The Mushangishe gorge, the pools near the Chewore river, the villages along the edge of the hunting area, the Makuti area, and so on. Some more focused trapping, sampling not randomly but purposively according to what people had indicated, showed that flies do still persist, even in heavily populated areas, but just in small patches.

So what about the disease-causing trypanosomes themselves? Analysis of 209 tsetse flies showed that nearly half were carrying trypanosomes following molecular DNA analysis at Edinburgh University. The most prevalent species was T. vivax (in 32% of flies), followed by T. brucei. This pattern was consistent across fly species (G. m. mortisans and G. pallidipes) and sex. Blood sampling of 400 cattle and 222 goats across 19 villages again showed a very heterogeneous pattern of presence, with trypanosomes (T vivax and T. brucei) being found in only four village sites, with presence in cattle ranging from 2-10 per cent. The places where infected animals were found tallied almost exactly with the places where local people had identified tsetse infested habitat patches. Perhaps surprisingly, given the reports of human trypanosomiasis, we found no evidence of T. b. rhodesiense in either fly or livestock samples; although of course this does not mean it is not present.

The puzzle had been (partially) solved. Tsetse flies and so trypanosomiasis (although no human sleeping sickness causing trypanosmes found as yet) persist because of the maintenance of particular habitat patches. Who gets sick (and whose animals) depends on who goes to these sites. Those most likely to get the disease, and those whose animals are the most susceptible, are mostly poor and marginalised people who must make a living on the edge of wildlife areas. They are hired herders or children of school age moving with animals deep into forested areas; they are groups of men going on hunting trips harvesting wild animals as a source of protein; they are women who forage in the forests, or who collect water from streams and rivers; and they are the new in-migrants into the area, offered land to settle and farm in the frontier areas, sometimes in the buffer zones of the national park and hunting areas.

As people put it to us “we are now fighting a guerrilla war against the tsetse”. They don’t exist along a ‘front’, an identifiable belt on a map as in the past, but in particular sites, which only particular people go to. Gender, age, occupation all make a big difference as to who gets potentially exposed. This has important implications for both monitoring (coarse grained satellite imagery, broad transects and random sampling are no use) and response (by the same token, generic, area-wide approaches make little sense). A more targeted approach, identifying particular patches, and particular people at risk is vital.

In addition, disease risk has to be understood through an appreciation of history, politics and social relations. Such people and their animals do not become sick by chance. Disease is often caused by what Paul Farmer calls ‘structural violence’, with disease being “the biological reflection of social fault lines”. Inequality, poverty, dispossession, alienation, lack of rights, and deep neglect by states results in disease impacts that are often not even noticed or recorded.

The biological impacts of disease is reflected through politics, class, race and gender and, in the case of trypanosomiasis in the Zambezi valley, by the differential effects of changing landscapes. As discussed next week, migration into the valley is an important part of this wider story.

The Dynamic Drivers of Disease in Africa work was supported by ESPA (Ecosystem Services for Poverty Alleviation) programme funded by NERC, ESRC and DFID, and the Zimbabwe study was led by Professor Vupenyu Dzingirai (CASS, UZ), working with William Shereni (Ministry of Agriculture), Learnmore Nyakupinda (Ministry of Agriculture), Lindiwe Mangwanya (UZ), Amon Murwira (UZ), Farai Matawa (UZ), Neil Anderson (Edinburgh University) and Ewan McLeod (Edinburgh University), among others.

This post was written by Ian Scoones and appeared on Zimbabweland.

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Research collaboration for global challenges: why it’s really hard

I spent much of last week at London zoo. It was the final conference of a project I have been involved in over the past four years on zoonoses, ecosystems and wellbeing in Africa. The conference highlighted the idea of ‘One Health’, a movement aimed at linking human, livestock and ecosystem health. The focus was on how to make this happen in the ‘real world’, so that both emerging and endemic zoonotic diseases can be tackled effectively.

Over the last few years, influenza, Ebola and now Zika have struck in different parts of the world, often with devastating consequences. The argument of those at the conference – and indeed of our project, the Dynamic Drivers or Disease in Africa Consortium (DDDAC) – was that better integration, and more interdisciplinary collaboration will make a big difference to the effectiveness of responses to disease, and a focus on ecosystems, poverty and wellbeing needs to be central.

There was certainly a great buzz at the conference, and beyond (#OneHealth2016 was one of the top trending topics on Twitter in the UK on the opening day!). We had some very high level speakers, from the head of the Wellcome Trust, Jeremy Farrar, to the Chief Scientist at the UK’s Department for International Development, Charlotte Watts, as well as excellent participation from a range of stellar researchers and students working on One Health issues.

One of the recurrent themes was that making a ‘One Health’ approach, rooted in interdisciplinary science, is really tough. And perhaps even more so, when we move to a transdisciplinary approach, working with practitioners and policy makers to ‘co-construct’ knowledge and action.

There is a lot of talk of inter- and transdisciplinary research these days. Everyone wants cutting edge research that makes a difference. So whether it’s the Gates Foundation, the Wellcome Trust, the European Commission’s Horizon 2020 programme, or the new UK research council strategy, or umbrella programmes such as Future Earth, all want such problem focused research to tackle the big global issues of our time. And the themes of our conference, and our project, linking environmental change with disease with policy impacts certainly fit into this category.

Our project was supported by the UK Ecosystem Services and Poverty Alleviation Programme, funded by DFID, the UK Natural Environmental Research Council and the Economic and Social Research Council, and was hosted by the ESRC STEPS Centre based at Sussex University. It involved five countries in Africa (Zimbabwe, Zambia, Kenya, Sierra Leone and Ghana), four diseases (trypanosomiasis, Rift Valley Fever, Lassa Fever and Henipah). Each country study was focused on a puzzle, focusing on how diseases emerge, get transmitted, and who they affect different groups of people. The overall Consortium involved 19 institutions, ranging from diverse research groups in multiple universities in Africa, Europe and the US to veterinary, public health and wildlife departments in Africa. At last count there were more than 50 researchers involved in various ways. It was massively ambitious, and premised on a commitment to transdisciplinary working,

 Unpacking the process of transdisciplinary research

 Here I want to focus on the challenges and opportunities of the research process, rather than the results (more on those soon on this blog). The work has aimed to seek answers to on-the-ground problems, aiming at producing top-level research and generating an impact. But this is easier said (or written glibly into a proposal) than done. Building the ways of working in a transdisciplinary team is not easy. Much of it is about building trust, creating relationships, and finding new languages for interacting. These do not come easily. We had four all-team workshops during the project. Their tenor followed almost exactly the phases of group formation proposed by the psychologist, Bruce Tuckman.

The first was about ‘forming’ – finding out what the Consortium was about – which we held at ILRI in Nairobi. We didn’t know each other then. There was a nervousness, and not a little scepticism. The next workshop at Sussex focused on setting up the research and methodology. This was the ‘storming’ phase. Here we had to negotiate our roles, and define our stance – in a potentially threatening and confusing setting. There were a few arguments, and some misunderstandings – and some storming. We got through this, and got on with the work, but it took us a while to reach the ‘norming’ phase. This was already three years into the project at a workshop in Naivasha, Kenya. We had found a way of working, but we were only just beginning to build the relationships that really deliver transdisciplinary work. This really only happened in the final period, and at our last workshop – last week at London zoo – we could really say that we were ‘performing’. This final stage, where groups genuinely work together, came too late. We already had a nine-month no-cost extension ending next month, and the money had run out.

What lessons have we learned from this journey?

Central is the importance of time. It takes a while for any group to go through these stages. With a large, complex, international group, it takes longer. There are no real short-cuts.

Time is also important when studying dynamic complex systems, as there will be events that cannot be planned for that reframe the way we think, and the way we work. Ebola was the big one in our project, coming in 2014, right in the middle of the Sierra Leone fieldwork, which was in the epicentre of the outbreak. This made us rethink and restructure the work. But, despite the horrors, the experience helped us focus on new issues, and appreciate the value of cross-disciplinary working; something that of course proved to be vital to the Ebola response more generally.

Time is also important as the last pieces of the puzzle may be difficult to find. The whole story of the Zimbabwe work looking at trypanosomiasis only fell into place last week, when we were able to sit together and discuss the results of the livestock blood sampling. Mapped onto our GIS information from the geographers, and combined with the participatory analysis done in the field in Hurungwe the story became much clearer (more on this on this blog soon).

Linking different disciplinary approaches is not easy. There are different languages (from complex mathematics to complex words), and different styles of collecting, analysing and writing up data. Fieldwork means different things to different disciplines; as does paper writing, policy engagement, and so on. All these have to be negotiated. To work together we have to learn both new languages and cultures, and be patient and respectful.

But we also need frameworks that help make the connections that create the new insights. The DDDAC project had a simple framework that helped our earlier ‘forming’ and ‘norming’ stages, but we really got to ‘performing’ when we were able to link analytical approaches. This particularly focused on connecting different types of ‘modelling’. Everyone models the world – it’s just a framework for understanding expressed in different ways – but what the assumptions, frames and data requirements are will depend on who is modelling, and posing the questions.

We had various modelling efforts looking at diseases, emergence, spread and impact, from mechanistic Process based models, to statistical, macro ecological Pattern models to a diversity of Participatory modelling approaches, rooted in field analysis. Our 3P approach allowed conversations to happen and new results to begin to emerge, in this final period.

In other cross-disciplinary experiences – whether around the sustainable livelihoods framework or the STEPS pathways approach – my experience has been that, for all their limitations (there are many, for sure), these frameworks (‘models’) allow new conversations to happen, and new insights to emerge. So it has been in our integrative modelling, although only just touching the surface, due to our curtailed ‘performing’ phase. Four years in, new insights on disease emergence, transmission and effect were just beginning to emerge.

But it’s not just the frameworks that are important, it’s the people who are able to make the links – creating the basis for joint work. There are many different people with different roles in a successful team, as group psychologists, such as Meredith Belbin, have long known. We had very high-powered people in our team, many top researchers in their disciplines. But getting researchers and other project participants to work together required some unusual and new skills.

Research brokers, facilitators and leaders are rarely recognised, but are essential for cross-disciplinary work. We had a number of such people luckily, but I don’t think we knew enough about their importance at the beginning to give them well thought through roles, or even identify such skills in advance. Leadership in transdisciplinary working is a very special skill and a vital, usually unrecognised, and poorly rewarded, role.

Challenges faced

Our four team workshops moved the approach to working together forward incrementally. But between our four workshops, the team dispersed, fragmented, and often went back to silo working. Sustaining a continuous process of interaction is difficult, and expensive in an international project. Students can be key, as they are not subject to the same institutional strictures, and set professional behaviours and practices. Yet in our project, studentships were not encouraged, and we had only selective engagements, often from outside the project. This undermined coherence and continuity, and constrained genuine opportunities for transdisciplinary working.

As so many large projects, the temptation is to break things down into ‘work packages’; manageable units, associated with certain deliverables, with devolved leadership roles. This makes sense from an ease of management point of view, and indeed was encouraged in our project by the funding going to four separate Principal Investigators in four institutions. But integration then becomes incredibly difficult, as making links between activities, and making use of budgets to make this happen is impossible, as they are held multiply in protected silos.

Breaking out of existing institutional cultures, structured around disciplines and sectors, is incredibly difficult. And any project must know its limits. People have to be rewarded in their own systems, as well as gaining benefits from new collaborations. It’s not an easy balancing act. Ultimately people get promoted in their own institutions/disciplines, not in a project. And different people in such a project have very different reward systems, styles of publishing, forms of authorship and so on. Developing ways of working that take these into account, but move people to work in new ways is important, but not easy.

As so many projects formulated in a highly competitive funding environment, the earth was promised. But inevitably it could not be delivered in three  years. It would be absurd to expect it to have been despite the generous budget. The pressure was on from the beginning – high end, international science delivering impact. Anyone involved in research projects these days will know the routine. Impact, engagement, communications are central. This is all good, but forcing it may not make sense. Impacts emerge over time through relationships, and based on results that may not emerge easily. These are complex, difficult, challenging puzzles.

So the formulaic model of impact may not be appropriate, and we perhaps should be more sanguine about what is possible. Of course in our ‘pathways to impact’ assessments we over-promise (sometimes even lie), so the audit culture of project management kicks in to assess why we haven’t met the targets. And changing course, being flexible and reinventing projects to fit the moment is regarded with horror by research managers.

There is a dangerous culture of control in much research funding. Yes, linked to accountability, and assuring ‘value for money’, but pushing an inflexible audit approach can too often undermine creative, innovative research. There were moments in this project where overbearing centralised funder management constrained operations, and undermined partnerships.

Ways forward?

At the end of our project last week, we felt we’d only just started. We had done some good work, we had struck up excellent new transdisciplinary relationships, but we had only just started ‘performing’ when the money had run out.

All large group based projects (a common feature of funding modalities these days) go through the four group formation phases. So why not fund and manage in relation to this? Fund the forming, norming and storming, and performing separately in a phased approach.

There can be an expectation that some projects never get past forming, some never generate norms, and some fall apart during the storming (I have been in projects of all these types over the last 30 years!). But if you get to performing, often after quite a while, then you need proper funding for really generating the value from the funding. In our case much of the investment is sunk in a set of relationships that sadly will not be fully utilised as the funds have finished.

One route to this is through such a phased ‘challenge’ approach (Gates follows something similar, in the language of proof of concept to final project, although the argument is a bit different here). Another is to establish long-term, well-funded Centres around successful groups that have begun ‘performing’. This is the approach of UK research councils, Wellcome Trust and others. Centres with 10-20 years of funding can really make a difference. They can provide the home (real and virtual) for the type of interactions that are required to create real transdisciplinary work.

Only as part of Centres can the ‘constructive conflict’ between disciplines be generated and the type of frameworks that allow integrative, joint working encouraged. And only in such settings can the new norms and cultures that transdisciplinary work requires be fostered – and across generations of researchers and practitioners, this is a long-haul job.

Such efforts are of course not cheap, but the investment can be very worthwhile (and great value for money), as the sunk costs can genuinely be capitalised upon for really change-making work. Too often the money is pulled just as things get going, and exciting. The costs need to be focused on the relation-building that generate impact, rather than formulaic approaches, and invested in leadership, brokerage and facilitation that allow creative partnerships to be nurtured and allowed to work. This is difficult to programme and plan, and even more difficult to fit into the audit systems that dominate funding agencies’ obsessions.

Interdisciplinary and transdisciplinary collaboration is really hard, and involves a long slog that can be conflictual and challenging. But in the big issues that confront us today – whether climate change, sustainable development, zoonotic disease emergence, or indeed any area where multiple perspectives on a complex, dynamic problem are required – such approaches are imperative, and in my view a good investment. In our DDDAC project we made a creditable start, but are only at the beginning.

This post was written by Ian Scoones and appeared on Zimbabweland.  The blog will be back on 28 March, after a short Easter break

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Fighting the fly: drivers of disease in the Zambezi valley

The battle against the tsetse fly in the Zambezi valley is a long and continuing one. The fly is the source of both animal and human trypanosomiasis – nagana in cattle, sleeping sickness in humans – and is one of the reasons why the valley has been only sparsely inhabited until recently.  But the relationship between the fly, livestock, wildlife and people appears to be changing, with new transmission dynamics unfolding, potentially with dangerous consequences.

A new project, led by the University of Zimbabwe, with the Tsetse Control Branch in Veterinary Services in the Ministry of Agriculture, and working with the STEPS Centre at Sussex and the Universities of Edinburgh and Southampton, is trying to get to grips with the ‘dynamic drivers of disease’ that affect who and what gets infected and where.

Conquering the fly and pushing back the fly belt was seen from the colonial era as one of the great civilising efforts of colonial development. Tsetse control was seen as a prime reason for intervention: clearing vegetation, exterminating wildlife, moving people, often in draconian ways. Yet others see the fly as the saviour of wilderness, and key to conservation of remote, biodiverse landscapes, protecting such areas from encroachment by people and their animals. The fly in other words is at the centre of the classic tussle between visions of civilisation and modernity and conservation and preservation, reflecting conflicting values, perceptions, politics and interests.

The social, ecological, political and economic consequences of the tsetse fly are therefore profound, raising fundamental debates about how people and disease interact in complex ecosystems. In his classic book, The Role of Trypanosomiases in African Ecology: A Study of the Tsetse Fly Problem“, published in 1971, John Ford – a scientists centrally involved in colonial control efforts – explored some of these debates, and challenged what he described as the ‘colonial doctrine’ of tsetse control, based on an ecological understanding of disease dynamics. Forty years on, the dilemmas of fly control persist today, with some important new contexts.

In our study area in Hurungwe district in Zimbabwe, a number of cases of human sleeping sickness have been confirmed in recent months. These are unusual in Zimbabwe, although reporting is often poor, so official data is misleading. When people become sick and die, the usual diagnosis is malaria. Scientists are wondering has something occurred in the ecology of the area to increase human infections? There are other puzzles too. Dissections of tsetse flies at the government’s Rukomichi research station, in the heart of the tsetse belt in the Mana Pools National Park, show very few T. brucei rhodesiense trypanosomes, the ones that cause the disease in humans. Yet blood samples taken from cattle outside the park, show much higher incidence. And now humans are dying too. What is going on?

The new research is trying to investigate. Is it changes in rainfall and climate patterns affect fly distributions and behaviour? Is it changes in vegetation and land use, influencing livestock-fly interactions? Is it changing settlement patterns, with people moving into wildlife areas, and coming into contact with wildlife disease hosts and fly vectors? Is it changes in wildlife movements, as they seek water and grazing outside the park? Is it changes in human behaviour and susceptibility as new people come to the valley in search of farm land for elsewhere in the country?

Unfortunately, we simply don’t know the answers to any of these questions, and so cannot suggest what disease control strategies might work. There has of course been masses of work on tsetse and trypanosomiasis in Zimbabwe, part of long-term research and development programmes. But much of this has been very targeted – on fly behaviour, chemical control, and trap design, for example. While this has been enormously important in developing effective, low-cost control approaches, it has often not looked at the underlying ecological, social and economic drivers. This holistic, integrated, cross-disciplinary perspective is of course not new. John Ford was a great advocate of this from the 1960s, but it is only recently that a ‘One Health’ approach to emerging (and in this case re-emerging) infectious diseases has become central to policy debates.

Our new research, working closely with colleagues in Zambia on the other side of the Zambezi, aims to come up with new perspectives on what is going on. It is an important, but difficult challenge, and one that requires dedicated cross-disciplinary science to tackle. Watch this space for some results over the coming few years.

This post was written by Ian Scoones and originally appeared on Zimbabweland

 

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