Case study Identity Card

Long title:  Tsetse fly elimination project in the Niayes area of Senegal to promote intensive farming
Geographical coverage of the case: Niayes area (1000Km²), Senegal
Case study team: Jeremy Bouyer (CIRAD, ASTRE), Fanny Bouyer (CIRAD, ASTRE / ISRA), Momar Talla Seck (ISRA), Carole Nyonse (ISRA), Véronique Alary (CIRAD, Selmet)
Years covered: 2007-…

Case study description

The innovation under study: In Senegal, researchers and veterinary services team up for tsetse fly eradication

In Sub-Saharan Africa, tsetse flies are vectors of parasitic diseases. These diseases can be fatal in humans, but they also affect animals, killing more than three million heads of cattle every year. In Senegal, CIRAD, ISRA and the Senegalese veterinary services have adapted an existing technique aimed at eradicating the tsetse fly by releasing sterile males into infested areas. The project is still underway, but researchers have already used modelling tools to simulate the impacts of this initiative up to 2030: direct impacts on herd health, but also broader impacts on other diseases and new livestock farming practices are anticipated.

Tsetse fly bites can transmit a parasitic disease caused by trypanosomes. In humans, this results in “sleeping sickness”, which affects the central nervous system. It causes sensory dysfunctions which, without treatment, may lead to death.

In cattle, the disease, which can be fatal, causes a decline in fertility and weight loss. This results in lower meat and milk production and weakened animals, which can no longer be used for ploughing or carrying.

A disease central to research

For all of these reasons, the tsetse fly has been central to research projects for more than 40 years. In the 1970s, CIRAD and the International Atomic Energy Agency (IAEA) laid the foundations for the sterile insect technique (SIT) against tsetse, aimed at sterilising then eliminating wild populations. The pest control campaigns of the 1970s and 1980s helped to reduce vector populations, but failed to eradicate them. Neighbouring populations of flies re-invaded the cleared areas and the disease reappeared, representing one of the key obstacles to the intensification of livestock farming.

In the 2000s, the Pan-African Tsetse and Trypanosomiasis Eradication Campaign (PATTEC) was established. In 2007, the Veterinary Services Department and the IAEA launched the eradication project in the Niayes area in north-western Senegal.

Targeting a fly population

The project managers defined a badly affected target zone.

The first stage consisted in characterising the limits and isolation status of the population of tsetse flies across the zone, collecting entomological and genetic data. During this phase, the methods developed by researchers from the Institut Sénégalais de Recherches Agricoles (ISRA - Senegalese Agricultural Research Institute) and CIRAD led to substantial progress, for example reducing sampling costs by more than 90% during the identification of the target population.

The project continued with socio-economic studies and surveys of herds, which were used to establish an eradication strategy. From 2012, the teams then analysed the behaviour of the flies, their density, their distribution and the impact of insecticides, etc.

Optimising a proven technique

The programme uses an irradiation technique to sterilise male flies, subsequently reducing overall fly populations in the zone. In areas where fly control operations have already been conducted, these releases wipe out the last wild flies through the sterilisation of the last wild females.

Before its implementation in the Niayes area, two projects, one in Burkina Faso and the other in Zanzibar, demonstrated the feasibility of eradication using this technique.

The Niayes project was the opportunity for researchers from CIRAD, ISRA and the IAEA to improve and optimise the sterile insect technique against tsetse, in particular with automatic releases of flies from a gyrocopter.

Responsive coordination and financing

At the same time, the programme broke new ground in terms of its organisation, with the creation of a coordination unit involving researchers and veterinary services. This unit met on a monthly basis, enabling high reactivity to difficulties encountered over the course of the eradication project.

This programme received funding that was dependent on the success of each of its phases. The IAEA financed the feasibility study conducted between 2007 and 2010, then the pre-operational phase in 2011.

In view of the results, it defined this project as a priority in its Peaceful Use of Nuclear Energy initiative, a decision which led the US Department of State to contribute to funding the subsequent phases, from 2012 onwards. Around 30% of the budget was earmarked for operational research.

Scenarios to achieve the anticipated impacts

Although the project is still underway, the researchers have used a modelling tool to simulate its impacts up to 2030, based on a considerable amount of data already collected on the health, socio-economic and environmental impacts of the project.

Initially, the researchers developed scenarios taking into consideration experiments conducted in Zanzibar in the 1990s and using in-depth interviews with 10 livestock farmers in the Niayes region.

The researchers then hypothesised that eradicating the tsetse fly in the Niayes region would foster innovation on farms, enabling farmers to stop using trypanotolerant but low productivity livestock in favour of more productive breeds. These new breeds would then enable them to reduce herd sizes, a real opportunity in a context of pressure on land.

The participatory workshop, and in particular the focus group with farmers, was the opportunity to not only validate these hypotheses, but also to refine them by quantifying the pace of change expected from these scenarios.

This collaboration between researchers and farmers has also enabled better understanding of other factors driving changes to livestock farming in the zone: land pressure, theft, and deaths caused by ingestion of plastic.

Measuring impacts

In order to measure the impacts of this project as it evolves, the regional veterinary services adapted their practices, and researchers and development actors established regular communication with each other.

The eradication of the tsetse fly is the fundamental intermediate impact of the project, but this impact goes much further. The reduction in the density of tsetse flies was measured by an entomological surveillance system. This reduction has already resulted in a substantial decrease in the disease, which has been measured by the annual monitoring of three “sentinel herds”. It has also been confirmed by interviews conducted within the framework of the project and during the participatory workshop.

A socio-economic survey has also already revealed two significant impacts: a reduction in the proportion of trypanotolerant breeds in herds and a reduction in cultivated areas. The largest herds have also diminished in size and the smallest have grown. Other similar surveys will be organised in the future to monitor these impacts, and the sentinel systems are still in place.

This project also has an important impact in institutional terms thanks to the creation of the coordination unit involving researchers and veterinary services. This organisation has changed the way these veterinary services function, fostering real-time adaptation of their operations to the project, as well as capacity building.

Broader impacts

The sterile insect technique and its implementation against the tsetse fly according to the principles of this project have already been rolled out in other countries such as Ethiopia. They have also led to the development of a new mosquito control strategy, which will benefit the whole world.

Moreover, this project has encouraged the veterinary services and researchers to step up their collaboration in order to manage other animal diseases (Rift Valley fever, African horse sickness and Peste des Petits Ruminants).

Finally, at the international level, this project has helped to promote peaceful uses of nuclear energy.

Stakeholders

Stakeholders involved in the innovation process

Value chain stakeholders : Cattle farmers and farmers associations
Research stakeholders : ISRA, CIRAD
Civil society stakeholders : Domaine du Kalahari (aerial releases)
Institutional stakeholders : Vet Services (Ministry of Livestock) and Ministry of Agriculture
Others (International): FAO-IAEA, US-State Department

Stakeholders impacted by the innovation process

Value chain stakeholders : Cattle farmers and farmers associations
Civil society stakeholders : Domaine du Kalahari (aerial releases)
Institutional stakeholders : Vet Services