Better planning for tsetse control |
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| Tsetse muse, an interactive computer programme to assist in the design and analysis of area-wide interventions against tsetse | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
A user-friendly decision-support tool called 'Tsetse Muse' is now available to help users better plan and budget when using the many different methods of tsetse fly control available. Tsetse flies affect 10 million square kilometres in tropical Africa, where they transmit the trypanosomes that cause sleeping sickness in humans and nagana in livestock. Plus, the flies can easily travel large distances. This means that tsetse controls are very difficult to plan, as they have to be applied over very large areas at once - often in combination. The 'Tsetse Muse' computer programme can help these efforts in a number of ways, and is already being applied in Botswana, Uganda, Mozambique and Zimbabwe. Uses include assessing the impact and cost effectiveness of techniques like aerial spraying. Project Ref: AHP15:
Research Programmes: The research projects that contributed to the development of this output were supported by: DFID's Animal Health (AHP) and Livestock Production (LPP) programmes, the EU-supported Farming in Tsetse-Controlled Areas (FITCA) project and the Zimbabwe Department of Veterinary Services. Relevant Research Projects:
Project Partners (contact person):
Tsetse occupy 10 million km2 of tropical Africa where they transmit trypanosomes causing sleeping sickness in humans and nagana in livestock. Each year these diseases cost the rural poor ~1.6 million disability-adjusted life years (DALYs) and produce livestock production losses of ~US$4.5 billion. Drugs to relieve both diseases exist but drug resistance is widespread and vaccines are unlikely to become available soon, if ever. Hence, the only safe and reliable way of eliminating African trypanosomiases is by controlling tsetse. The many effective methods of tsetse control differ grossly in cost and complexity, and hence their suitability for poor countries. At one extreme is the expensive and technically demanding Sterile Insect Technique (SIT) involving the release of sterile males. At the other end is the cheaper and simpler use of insecticide-treated cattle (ITC). In between are various spraying measures which spread insecticide widely, as in aerial spraying, or apply it to artificial baits (eg, odour-baited targets). Unfortunately, all methods of tsetse control are difficult to plan. For example, tsetse are highly mobile so they must be tackled over wide areas, not by one farmer alone. Some methods, such as aerial spraying, are suitable for the first attack; others such as insecticide-treated cattle and artificial baits are also useful to clear residual infestations and prevent re-invasion. Moreover, the timing and impact of different methods varies, making integrated control difficult - but not impossible. In 2005, the decision-support tool 'Tsetse Muse' was developed to assist the understanding, planning and budgeting of all methods of tsetse control, employed singly or together, sequentially or simultaneously, in the same area or adjacent blocks, and in homogeneous or varied habitats. The programme has been used to examine matters such as a general comparison between SIT and ITC, the impact of aerial spraying in Botswana and the cost-effectiveness of various techniques in Uganda. The African Union's Pan-African Tsetse and Trypanosomiasis Eradication Programme (PATTEC) has initiated area-wide operations to eliminate tsetse in Angola, Botswana, Burkina Faso, Ethiopia, Ghana, Kenya, Mali, Uganda and Zambia. These operations will use various methods including SIT, ITC, aerial spraying and artificial baits. Smaller-scale operations to control tsetse are also being promoted by NGOs and government organisations in many countries. The widespread use of 'Tsetse Muse' will assist in the successful integration of these methods and operations, and provide a framework for assessing their cost-effectiveness.
The better understanding, planning and budgeting of tsetse control will improve the health of cattle, other livestock and humans, at lower cost and greater speed. Improvements in the health and productivity of draught animals - particularly cattle - will benefit mixed crop-livestock systems. For example, the absence of draught animals in tsetse-affected areas of Ethiopia causes delayed planting, low yields and high costs of producing maize, cotton and sorghum. Research by AHP-supported projects shows that the use of insecticide-treated cattle could also be refined to deal simultaneously with malaria in southern Africa, the Maasai steppe of East Africa, the Greater Horn, and the Sahel. The main vector of malaria in these places is Anopheles arabiensis which feeds on humans and cattle. To elucidate this means of tackling malaria, and in recognition of the benefits of the type of output produced by the present project, the South African Centre for Epidemiological Modelling and Analysis is producing a programme, called SacemaM, to help teach the dynamics of mosquito-borne diseases and to plan their control. SacemaM is copying almost all of the format and programming code of Tsetse Muse. Taken together, the two programmes could cover virtually any disease transmitted by any blood-feeding insect, and so assist the control of many diseases of livestock and humans throughout the World, so benefiting the production of numerous commodities.
The Tsetse Plan output could be included in the following clusters. Decisions tools to support the control of vector-borne diseases. An integrated package of decision support tools could be produced by clustering Tsetse Muse with its sister programme 'Tsetse Plan' (AHP Output) and tools developed by non-DFID research initiatives such as SacemaM (a tool for modelling mosquito populations; SACEMA, South Africa) and Mageta Model (a tool to assess the effect of auto-sterilisation of tsetse; EU-funded FITCA). Reducing the cost of vector control. This output is linked closely to the AHP output 'Tsetse control through restricted application of insecticide to cattle'. Recent data and field experience with the restricted application of insecticide to cattle would add value if incorporated into Tsetse Muse. Improving human and animal health and productivity. The present output also clusters with those concerned with controlling sleeping sickness (AHP outputs: 'Diagnostics that can identify human-infective trypanosomes in cattle blood' and 'Treatment of cattle to eliminate the animal reservoir of T. b. rhodesiense'). The prompt and accurate diagnosis of the diseases affecting livestock is a prerequisite for cost-effective management and hence there are synergistic links between this output and 'Simple decision tools for diagnosis of endemic diseases in Africa' which includes tools to improve the diagnosis and management of trypanosomiasis. Moreover, healthy livestock are an integral part of mixed farming systems in sub-Saharan Africa, especially through their contributions to draught power (CPP: Draught animal power; LPP: Draught animal toolbox). Capacity building. Tsetse Muse could be developed as a training resource for animal health specialists. Accordingly, this output links to the AHP outputs: 'AUVEC' and 'Creation of a common African veterinary network'. More generally this output also links with those concerned with the dissemination of knowledge using electronic media (eg, LPP output: Information kiosks in India). How the outputs were validated: How. - The simulation models underpinning Tsetse Muse were based on data for the behaviour and dynamics of tsetse and on planning principles that had already been validated by their successful use in closely monitored campaigns. For example, information on the release of sterile insects came from work on Unguja Island, Zanzibar. Matters related to various spraying techniques, traps, targets and insecticide-treated cattle originated from many countries, including Burkina Faso, Ethiopia, Ivory Coast, Kenya, South Africa, Tanzania, Malawi, Zambia and Zimbabwe. This information was then generalised and built into the programme's model, with facilities to allow variation in the full range of local conditions and technical specifications. Not surprisingly, the model "predicted" the results actually achieved by the many and varied campaigns with which it was "trained". The more critical yard-stick is the extent to which the programme can explain the failure or delayed success of other campaigns, ie, the work with which it was not trained, and how well it covers the tactics needed to put such operations right. Hence, it is encouraging that the Tsetse Muse outputs accord with the poor performance of campaigns such as sterile insect releases on mainland Africa, the use of insecticide-treated cattle over a relatively small area of Mkwaja Ranch in Tanzania, and the many seasons of aerial spraying in Botswana in the last century. The outputs also show why the increased scale of aerial spraying in Botswana, coupled with the proper use of baits, eventually solved the problem (Kgori et al., 2006). Who. - Tsetse Muse was initially developed using information derived from international refereed journals and discussions with campaign managers. An account of the structure, function and application of the programme is provided by Vale & Torr (2005). Use of Tsetse Muse to analyse control operations in Botswana was undertaken by Kgori et al. (2006), and Shaw et al. (2006) used the program to compare the costs of various strategies to control tsetse in Uganda. Proponents of SIT have challenged aspects of the program as it is applied to the use of this particular technique but none of their objections has been substantiated in peer reviewed journals. The TECA (2006) website entry for Tsetse Muse (TECA record 1926) erroneously reports that Tsetse Muse 'only allows for a constant mortality rate to be applied to the whole population' and concludes that 'Tsetse Muse is unable to predict the cost of an elimination of G. palpalis in West Africa since it predicts that it would be possible using sprayed cattle only, whereas field results have concluded that this is not possible without the use of SIT'. In fact, Tsetse Muse does allow the user to specify variable mortality rates (Vale & Torr, 2005) and there are no peer-reviewed data showing that the elimination of G. palpalis can be achieved with SIT only. Where the Outputs were Validated: The simulation models that underpin Tsetse Muse were initially validated by scientists working in Zimbabwe and the UK between 2003 and 2005. Applications of the program to (i) assess the impact of aerial spraying operations in Botswana and (ii) compare the costs of various tsetse control interventions in Uganda were undertaken in 2005-2006 by scientists working in Botswana, Uganda, Rome (FAO) and UK. Who are the Users? Tsetse Muse became available as a user-friendly programme only a year ago and hence its current use is limited to the following. 1. The FAO's Pro-Poor Livestock Policy Initiative (PPLPI) is using Tsetse Muse to assist the government of Uganda in the development of a rational strategy for controlling tsetse. In particular, the model is being used to provide information on the likely timing, impact and material requirements of various methods of control. These data are then incorporated into various economic models which allow the project to compare the cost and effectiveness of various interventions. 2. Scientists of the Government of Botswana have used Tsetse Muse to analyse the impact of aerial spraying operations in Ngamiland. The program was used to assess the probability that tsetse had been eliminated by aerial spraying operations conducted in 2001-02 and to explore why these operations were so much more successful than the ca. 19 operations conducted over the previous two decades (Kgori et al., 2006) 3. In Mozambique, Cawood Beef Ltd is using Tsetse Muse to assess the feasibility of various tsetse control measures near Tete in Mozambique. 4. The Zimbabwe Department of Veterinary Services is using Tsetse Muse as a training tool for its entomologists. 5. The University of Greenwich has continued to host the Tsetse Muse programme which, together with supporting literature, can be downloaded from the tsetse.org website (http://www.tsetse.org/). The programme has been downloaded 86 times in 2006. All the above users have been supported by the original authors of Tsetse Muse. Where the outputs have been used: 1. Tsetse Muse is being used to support tsetse control operations in Botswana, Uganda, Mozambique and Zimbabwe as described above. 2. The programme can be downloaded from http://www.tsetse.org/ and hence is available to any users who have access to the world-wide web. CD-ROMs of the programme have also been distributed at meetings in Ethiopia, Uganda, Kenya and Zimbabwe. 14. What is the scale of current use? Indicating how quickly use was established and whether usage is still spreading Current use of the programme is limited to a few (<10) users associated with tsetse control projects in Botswana, Mozambique, Uganda and Zimbabwe. In general, use of Tsetse Muse is being supported by direct help from the original authors (Vale & Torr) of the programme. Policy and Institutional Structures, and Key Components for Success: The following matters are likely to influence uptake of Tsetse Muse.
Direct and Indirect Environmental Benefits: With effective land-use planning and implementation, tsetse control can alleviate environmental-degradation associated with the concentration of people and livestock into areas naturally free of tsetse. Adverse Environmental Impacts: Modern bait methods of tsetse control do not have any significant direct impact on the environment. Widespread application of insecticide by either aerial or ground spraying may have an impact on some non-target species but evidence from Botswana, Zambia and Zimbabwe suggests that these are slight and transient. The Sterile Insect Technique is always used in conjunction with an insecticidal technique and operations using this method may have slight and transient impacts. Without effective land-use planning and implementation, tsetse control could lead to environmental-degradation arising from inappropriate land-use. Coping with the Effects of Climate Change, or Risk from Natural Disasters: Predictive models of climate change suggest that there will be shifts in both (i) areas suitable for pastoral and mixed system and (ii) the distribution of tsetse (Thornton et al., 2002, 2006). Tsetse-borne trypanosomiasis will continue to be a significant problem and area-wide approaches to tsetse control will play an important role in any future scenario. More generally, tsetse control will contribute to the health and productivity of livestock which play an important role in reducing vulnerability to natural and man-made disasters (see under "How the Poor have Benefited "). References Barrett, J.C. (1992) The economic role of cattle in communal farming systems in Zimbabwe. Network Paper 32b. Overseas Development Insitute, London, UK Barrett, J.C. (1994) Economic issues in trypanosomiasis control: case studies from southern Africa. Ph.D thesis. University of Reading, UK. Barrett, J.C. (1997) Economic Issues in Typanosomiasis Control Bulletin 85. Natural Resources Institute, Chatham Maritime. Doran, M. (2000) Socio-economics of trypanosomosis. Implications for control strategies within the Common Fly-Belt of Malawi, Mozambique, Zambia and Zimbabwe. Bovine trypanosomosis in Southern Africa, Vol. 3. Harare, Zimbabwe, Regional tsetse and trypanosomiasis control project for Southern Africa. 156 pp. Kgori, P.M. et al. (2006) The use of aerial spraying to eliminate tsetse from the Okavango Delta of Botswana. Acta Tropica, 99, 000-000 LID (Livestock in Development). 1999. Livestock in poverty focused development. Livestock in Development, Crewkerne, UK. Shaw et al. (2006) Comparable costings of tsetse control alternative approaches for dealing with tsetse flies - a suite of examples from Uganda. Proceedings of the 11th International Congress of Parasitology (ICOPA XI, Glasgow, Scotland; 6-11 August, 2006) Shaw et al. (2006) Mapping the benefits: a new decision tool for tsetse and trypanosomiasis interventions. Research Report. Department for International Development, Animal Health Programme, Centre for Tropical Veterinary Medicine, University of Edinburgh, UK and Programme Against African Trypanosomiasis, Food and Agriculture Organization of the United Nations, Rome, Italy. Shaw, A.P.M. (2004) Economics of African Trypanosomiasis. In The Trypanosomiases (ed. by I. Maudlin et al.). pp. 369-402, CABI Wallingford Swallow, B.M. (2000) Impacts of Trypanosomiasis on African Agriculture. PAAT Technical and Scientific Series 2, FAO, Tome, 52 pp. TECA (2006) Tsetse Muse: Helping planners design cost-effective tsetse control strategies. Website: http://www.fao.org/sd/teca/search/tech_dett_en.asp?tech_id=1926 Thornton et al. (2002) Mapping poverty and livestock in developing countries. International Livestock Research Institute (ILRI) Nairobi, Kenya, 132 pp. Thornton et al., (2006) Cattle trypanosomiasis in Africa to
2030. Website: Torr et al. (2005) Towards a rational policy for dealing with tsetse. Trends in Parasitology 11, 537-541. Vale, G.A. & Torr S.J. (2005) User-friendly models of the cost and efficacy of tsetse control: application to sterilising and insecticidal techniques. Medical and Veterinary Entomology, 19, 293-305. Relevant Research Projects,
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