A decision tool to assist the control of Human African Trypanosomiasis
HAT-trick is designed to help planners develop cost-effective strategies for controlling sleeping sickness using various methods of tsetse control. Modelling is conducted at three successive levels.
First, the Basic Level covers fundamental aspects of tsetse and trypanosome biology that apply in any situation. The users can either define their own values for each of the parameters or select a species of tsetse (e.g., G. morsitans, G. pallidipes, G. palpalis, G. fuscipes) and trypanosome (i.e., T. b. rhodesiense or T. b. gambiense) with a pre-defined set of parameters based on published data.
Second, the Map Level combines outputs from the Basic level with inputs specific to a particular operational area. The user specifies the landcover and the distribution of humans and wild hosts across a two-dimensional landscape of 625 to 40,000 square kilometres. The programme then combines these data with the Basic level outputs to generate a prediction of:
- the abundance, distribution, age structure and infection status of tsetse;
- the incidence and prevalence of HAT.
The programme produces maps and tables summarising the predicted distribution of tsetse and sleeping sickness across the landscape.
Third, the Control Level simulates the impact of tsetse control. The user has a range of tsetse control methods available:
- aerial spraying with non-residual insecticides
- insecticide-treated cattle
- insecticide-treated targets and traps
These techniques can be either used alone or in any spatial and temporal combination specified by the user. HAT-trick provides a dynamic view of tsetse and trypanosomiasis as the control operation progresses and at the conclusion of the operation, the programme produces a series of maps, graphs and tables summarising changes in:
- the distribution, abundance and age structure of the tsetse population
- the prevalence and incidence of sleeping sickness
Just like the programme Tsetse Muse, HAT-trick has a large array of input slots to allow the user to vary all key assumptions to assist 'what-if' analyses. If the user isn't sure about certain values, then the programme can make suggestions based on published knowledge of tsetse and trypanosome biology.
For a simple overview of the programme and its outputs, have a look at the poster on the right.
The HAT-trick Development Team
HAT-trick was developed by an international team of researchers with financial support from the Special Programme for Research and Training in Tropical Diseases (TDR).
The program's authors include:-
Mike Lehane, Ian Hastings, Inaki Tirados and Steve Torr from from the Liverpool School of Tropical Medicine, UK
Glyn Vale and John Hargrove from the South African Centre for Epidemiological Modelling and Analysis (SACEMA), University of Stellenbosch, South Africa;
Philippe Solano and Fabrice Courtin from the institut de recherche pour le développement (IRD), France;
Dramane Kaba from the Institut Pierre Richet, Côte d'Ivoire;
Jean-Baptiste Rayaisse from the centre international de recherche-développement sur l'elevage en zone subhumide (CIRDES), Bukina Faso;
Clement Mangwiro from the Bindura University of Science Education, Zimbabwe;
Themba Mzilahowa from the University of Malawi College of Medicine;
Andrew Chamisa from the Tsetse and Trypanosomiasis Control Department, Zimbabwe;
Atway Msangi and Mechtilda Byamungu from the Tsetse and Trypanosomiasis Research Institute, Tanzania;
Harriet Auty from the Scottish Agricultural College (Inverness) and the University of Glasgow, UK;
Nicola Wardrop from the University of Southampton and the University of Edinburgh, UK.
Ian Maudlin from the University of Edinbugh, UK;