Trends in Parasitology
Towards a rational policy for dealing with tsetse
Section snippets
The way we were
In the mid-1980s, the days of tsetse seemed numbered. In southern Africa, a programme to eliminate tsetse from a ‘fly belt’ of 320 000 km2 covering Malawi, Mozambique, Zambia and Zimbabwe was initiated with support from the European Union [1]. In East Africa, a UK-supported project aimed to use aerial spraying to eliminate the main tsetse infestation in Somalia. In Zimbabwe, ground spraying and aerial spraying were used to control tsetse over ∼10 000 km2 annually [2], and in West Africa riverine
Small is beautiful?
During the 1990s, however, progress and prospects changed. European donors, major supporters of tsetse control, abruptly shifted spending to other areas. Under the political and economic view of the day, livestock ownership was a commercial enterprise and those who benefited directly from it should, accordingly, fund tsetse control. This view was made feasible only by the newly developed bait technologies that, in contrast to spraying operations, could be applied by local communities.
Unhappily,
Back to the future?
Success stories of the past 20 years indicate a possible way forward [18]. In Zimbabwe between 1984 and 1997, aerial and ground spraying, odour-baited targets and insecticide-treated cattle eliminated tsetse from ∼35 000 km2, and trypanosomiasis disappeared from livestock (Box 2). Similarly, tsetse were cleared from 11 500 km2 of the Western Province of Zambia using odour-baited targets and, as in Zimbabwe, the cleared area was protected using target barriers. In the Kagera region of Tanzania,
Where do we SIT?
The foregoing suggests that the tools necessary to eliminate tsetse under a variety of circumstances are available. What remain are the much more difficult and contentious issues of policy, financing, and organizational and executive capacity.
On the policy front, the prominence of the sterile insect technique (SIT) in plans formulated by the Pan-African Tsetse and Trypanosomiasis Eradication Campaign (PATTEC) has stimulated much argument [20]. Despite the use of this technique to eliminate
Who controls the controllers?
In the wake of the PATTEC aim to eradicate tsetse [17], the African Development Bank (http://www.afdb.org/) recently approved a project worth US$80 000 000 to support large-scale tsetse-control operations using insecticide-treated cattle and SIT. Thus, there seems to be an increasing eagerness in Africa to provide financing for tsetse-control operations. Realistically, however, it must be envisaged that major external funding will be required if the PATTEC aim of eliminating tsetse from large
Moving on
Previous initiatives to eliminate tsetse from large areas ultimately failed owing to political, ideological or socioeconomic instability. In southern Africa, for instance, wars in Zimbabwe and Mozambique caused a resurgence of tsetse in the 1970s, and a combination of ideological shifts and socioeconomic factors caused the Regional Tsetse and Trypanosomiasis Control Programme (RTTCP) to abandon large-scale operations in the 1990s. Present efforts will suffer a similar fate unless the wider
Concluding remarks
Improvements in aerial spraying and bait technologies during the past 21 years, coupled with fuller understanding of tsetse population dynamics and the importance of scale in tsetse-control operations, greatly facilitate the rational planning of tsetse control and elimination campaigns.
Acknowledgements
We thank colleagues at the Natural Resources Institute and the Centre for Tropical Veterinary Medicine for helpful discussions, and the UK Department for International Development (DFID) for support under its Animal Health and Livestock Production Programmes. The views expressed are not necessarily those of the DFID.
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