For decades, tsetse flies posed a major constraint to livestock production in Senegal’s Niayes region, transmitting trypanosomosis – a debilitating disease that reduced cattle productivity and forced farmers to rely on low-yield, disease-tolerant breeds. By 2007, infection rates had reached as high as 28% in some herds, limiting both income and food production.
To address this challenge, the Government of Senegal, with support from the Food and Agriculture Organization of the United Nations (FAO) and the International Atomic Energy Agency (IAEA), through the Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, launched a long-term campaign to control the tsetse fly. Implemented over more than a decade, the programme followed a phased, adaptive approach combining conventional vector control methods, including insecticide-treated traps and cattle treatments, with the sterile insect technique (SIT), a nuclear-based method that suppresses insect populations by releasing sterilized males.
Beginning with feasibility studies in 2006 and progressing through operational phases from 2012 onwards, the campaign succeeded in reducing tsetse populations in the Niayes by more than 99%, effectively eliminating the disease from most areas. The initiative was carried out in partnership with Senegalese institutions, namely the Institut Sénégalais de Recherches Agricoles (ISRA), and national veterinary services, as well as the Centre de coopération internationale en recherche agronomique pour le développement (CIRAD), France. Additional financial support was provided the United States of America and France through IAEA Peaceful Uses Initiative.
From Intervention to Evidence
Following more than ten years of sustained field activities, two socio-economic impact assessments were conducted, one with the support from FAO and the other from CIRAD, to evaluate how livestock systems and rural livelihoods had changed in the absence of the tsetse fly. The studies were carried out by agro-economists from the Bureau d’Analyses Macro-Économiques (BAME) at ISRA, alongside social scientists and entomologists from CIRAD.
“The assessments provide clear evidence that vector suppression has transformed livestock production systems in the Niayes region, with significant improvements in productivity, income and animal health. Sustaining these achievements will be critical, but the results already show how strategic investments and partnerships can drive long-term change in Senegal’s livestock sector,” said Adji Maréme Gaye, Epidemiologist at the FAO office in Senegal.
Transforming Livestock Systems
With trypanosomosis under control, farmers rapidly adapted their practices. Whereas previously only trypanotolerant local breeds could survive, the absence of the disease enabled the introduction of higher-yield dairy and meat cattle.
Before the intervention, exotic breeds accounted for just 1.5% of herds. Today, they represent more than 27% in some farming systems. At the same time, herd sizes have decreased by up to 49%, reflecting a shift towards more efficient and market-oriented production systems that place less pressure on land and natural resources.
Modern dairy farming has expanded rapidly in parallel. Since 2017, 904 modern dairy farms have been established in the Niayes region, representing nearly three-quarters of such operations nationwide.
This transformation has been accompanied by dramatic gains in productivity, with milk sales in some systems increasing from just 157 litres to over 2,100 litres per cow annually, driven by the growing presence of higher-yield exotic breeds.
Measurable Economic and Health Gains
The socio-economic assessments reveal significant improvements in both productivity and incomes:
- 45% increase in household income from livestock production
- 61% increase in income from milk sales
- 63% reduction in the cost of treating trypanosomosis
- Marked declines in cattle mortality and morbidity
By 2024, more than 11,900 exotic cattle had been introduced, including nearly 6,000 dairy cows supported through government programmes. Milk production from these animals rose sharply, from 4.3 million litres in 2018 to 62.5 million litres in 2024, driven in part by the growth of modern, intensive farming systems.
These changes have had ripple effects across the rural economy. The expansion of dairy production has stimulated processing and distribution networks, generating new employment opportunities, particularly for young people and women, both in rural communities and in Dakar. At the same time, improved animal health has reduced reliance on veterinary drugs and associated costs.
“Conventional vector control could suppress tsetse populations, but it was the sterile insect technique that allowed Senegal to push past suppression toward eradication, breaking the cycle of reinfestation for good,” noted Chantel De Beer, Technical Officer at the Insect Pest Control Laboratory of the Joint FAO/IAEA Centre. “The Niayes campaign shows that with sustained investment and partnership, eradication isn’t just a technical possibility, but it is an achievable outcome that transforms entire livestock economies, from household income to herd health to the dairy sector itself.”
Wider Benefits Beyond Livestock
The suppression of the tsetse fly has also brought broader social and environmental benefits, as per the study supported by CIRAD Farmers report improved working conditions, no longer affected by the nuisance and discomfort of tsetse bites. The decline of the insect has also supported growth in the equine sector and contributed to local tourism.
In addition, the campaign has served as a model for other countries. Training on tsetse eradication strategies provided to approximately 30 practitioners from Sub-Saharan Africa has helped transfer knowledge and inform similar initiatives elsewhere, positioning the Niayes region as a benchmark for successful area-wide integrated pest management. These training opportunities provided participants with firsthand exposure to a successful eradication programme, allowing them to observe not only the technical interventions employed but also the conditions that enable long-term success.
Sustaining the Gains
While the campaign has achieved its primary objective, sustaining these gains will require continued vigilance. Although the risk of reinfestation from outside the Niayes is considered low due to the region’s geographic isolation, some local habitats, particularly forested and wetland areas, remain suitable for tsetse survival.
Experts emphasize the importance of maintaining and strengthening surveillance systems, including regular entomological monitoring and parasitological screening in livestock. Community engagement will also remain essential, particularly in maintaining traps and supporting early detection efforts.
“Maintaining these gains requires investment in community awareness, regular entomological and parasitological surveillance, and strong partnerships,” said Assane Gueye Fall, Director of the National Laboratory for Livestock and Veterinary Research (LNERV) at ISRA.
Looking ahead, stakeholders also highlight the need to anticipate new challenges linked to livestock intensification. As production systems evolve, increased reliance on external inputs such as fodder may heighten vulnerability to climate variability.
Ensuring the long-term success of the Niayes initiative will therefore depend not only on preserving a tsetse-free environment, but also on supporting resilient and sustainable livestock systems that can withstand future shocks.
Distributed by APO Group on behalf of Food and Agriculture Organization of the United Nations (FAO): Regional Office for Africa.