Delivering \u2018tiny targets\u2019 in a remote region of southern Chad: a cost analysis of tsetse control in the Mandoul sleeping sickness focus

Jean-Baptiste Rayaisse,Mahamat Hisséne Mahamat,Philippe Solano,Wilfrid Yoni,Mahamat Chérif,Alexandra P M Shaw,Steve J Torr,Nadmba M O Gadjibet,Mallaye Peka,Fabrice Courtin

doi:10.1186/s13071-020-04286-w

Abstract

BackgroundSince 2012, the World Health Organisation and the countries affected by the Gambian form of human African trypanosomiasis (HAT) have been committed to eliminating the disease, primarily through active case-finding and treatment. To interrupt transmission of Trypanosoma brucei gambiense and move more rapidly towards elimination, it was decided to add vector control using ‘tiny targets’. Chad’s Mandoul HAT focus extends over 840 km2, with a human population of 39,000 as well as 14,000 cattle and 3000 pigs. Some 2700 tiny targets were deployed annually from 2014 onwards.MethodsA protocol was developed for the routine collection of tsetse control costs during all field missions. This was implemented throughout 2015 and 2016, and combined with the recorded costs of the preliminary survey and sensitisation activities. The objective was to calculate the full costs at local prices in Chad. Costs were adjusted to remove research components and to ensure that items outside the project budget lines were included, such as administrative overheads and a share of staff salaries.ResultsTargets were deployed at about 60 per linear km of riverine tsetse habitat. The average annual cost of the operation was USD 56,113, working out at USD 66.8 per km2 protected and USD 1.4 per person protected. Of this, 12.8% was an annual share of the initial tsetse survey, 40.6% for regular tsetse monitoring undertaken three times a year, 36.8% for target deployment and checking and 9.8% for sensitisation of local populations. Targets accounted for 8.3% of the cost, and the cost of delivering a target was USD 19.0 per target deployed.ConclusionsThis study has confirmed that tiny targets provide a consistently low cost option for controlling tsetse in gambiense HAT foci. Although the study area is remote with a tsetse habitat characterised by wide river marshes, the costs were similar to those of tiny target work in Uganda, with some differences, in particular a higher cost per target delivered. As was the case in Uganda, the cost was between a quarter and a third that of historical target operations using full size targets or traps.

Highlights

Since 2012, the World Health Organisation and the countries affected by the Gambian form of human African trypanosomiasis (HAT) have been committed to eliminating the disease, primarily through active case-finding and treatment
The World Health Organization (WHO) and the affected countries have made a commitment to achieving elimination as a public health problem by 2020 of the gambiense form of the disease, which occurs in West and Central Africa and is caused by Trypanosoma brucei gambiense [2, 3]
The cost of targets in Mandoul averaged United States dollars (USD) 4667 per year, or USD 5.6 per km2. This accounted for 25.8% of the cost of the deployment activity but only 8.3% of the cost of all activities. In this cost analysis for Chad, as detailed above, the total cost per target came to USD 1.56, of which 0.33 was the actual recorded costs for freight and insurance and USD 0.23 was for target assembly

Summary

Introduction

Since 2012, the World Health Organisation and the countries affected by the Gambian form of human African trypanosomiasis (HAT) have been committed to eliminating the disease, primarily through active case-finding and treatment. Since about 2005, a growing body of evidence on the costs of tsetse control based on field operations has been gathered and published This reflects the renewed focus on both human and animal African trypanosomiasis (HAT and AAT). The World Health Organization (WHO) and the affected countries have made a commitment to achieving elimination as a public health problem by 2020 of the gambiense form of the disease, which occurs in West and Central Africa and is caused by Trypanosoma brucei gambiense [2, 3]. They further aim to achieve zero incidence by 2030 [4] and substantial progress towards achieving this has been made [5]. The only previously recorded use of vector control in a Chadian HAT focus is a mention of a pilot project using 77 targets undertaken in 1987/88 in the Tapol focus, located west of Moundou about half-way to the Cameroonian border [16]

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