Fighting the scourge of tsetse flies and trypanosomosis in Africa

Tsetse flies and the diseases they transmit, collectively known as trypanosomoses, pose a significant threat to both human and animal health in sub-Saharan Africa. Here we explore the severe impact of trypanosomosis, the ongoing efforts to combat it, and innovative tools being developed through the COMBAT project.  

The burden of trypanosomosis

Tsetse flies are blood-sucking insects that act as vectors for trypanosomes, single-celled parasites that cause debilitating and often fatal diseases. In livestock, trypanosomosis results in substantial economic losses, estimated in the billions of dollars annually. It weakens animals, reduces milk and meat production, and diminishes their ability to work the land. This translates to decreased food security and income for millions of African farmers who rely on livestock for their livelihoods.  

In humans, the disease takes a form normally called  “sleeping sickness”. While geographically confined to specific areas of endemicity, sleeping sickness is an invariably fatal illness if not detected and treated. It disrupts the nervous system, causing fatigue, debilitating headaches, coma, and ultimately death.

FAO's longstanding commitment

Recognizing the devastating impact of trypanosomosis, FAO has been actively engaged in the fight against the disease for decades. In 1997, FAO spearheaded the creation of the Programme Against African Trypanosomosis (PAAT) – an interagency collaboration with the World Health Organization (WHO), the International Atomic Energy Agency (IAEA), and the African Union (AU).

Field surveillance of animal trypanosomosis in Zimbabwe using traditional parasitological techniques (Photo Giuliano Cecchi)

Next steps: The COMBAT project

Building on the foundation of PAAT, FAO partnered with the French Agricultural Research Centre for International Development (CIRAD), who are leading the project, and 19 other partners in Africa and Europe to launch the COMBAT project in 2021.

A key strength of COMBAT lies in its collaborative nature. The project actively involves three FAO Reference Centres in Africa, each with specific expertise in vector-borne diseases like trypanosomosis. These centers, located in Burkina Faso, Kenya and South Africa are focusing on the ecology and genetics of the disease. They contribute by:

• Conducting research on the disease and its vectors hosts (tsetse flies and other biting-fly vectors, and livestock)
• Developing new diagnostic tools for faster and more accurate detection
• Creating novel vector control methods to curb disease transmission
• Supporting endemic countries in establishing robust disease control strategies and information systems

The COMBAT project boasts a broad geographical reach, involving 13 countries distributed across sub-Saharan Africa. This ensures representation from diverse ecological zones where trypanosomosis is prevalent. The project also fosters collaboration between research institutions and national veterinary authorities responsible for disease control. This synergy between scientific expertise and practical implementation holds potential for effective disease management.

The COMBAT project is developing a range of innovative tools to combat animal trypanosomosis in Africa. These tools aim to improve disease control, surveillance, and prevention. Some of the key areas include:  

Enhanced surveillance and data management

• Developing advanced systems to collect, analyze, and disseminate data on vector and disease distribution.
• Disease mapping and modeling: Creating tools to identify disease hotspots and inform control strategies.
• Risk assessment: Developing models to predict the risk of trypanosomosis spread based on various environmental factors.
  

Improved diagnostics and vector control methods

• Rapid diagnostic tests: Developing user-friendly and affordable tools for detecting trypanosomosis in animals.  
• Serological surveillance:  Refining advanced, sensitive techniques to identify trypanosomes and track their circulation in the field.
• Advanced traps and baits: Developing more effective and environmentally-friendly tsetse fly traps and baits to improve control efforts.

Understanding disease ecology and transmission

• Host-parasite interactions: Studying the complex relationships between trypanosomes, livestock, tsetse flies and other vectors to inform control strategies.
• Vector ecology: Researching fly behavior, habitat preferences, and population dynamics to optimize control interventions.
• Drug resistance: Investigating the genetic drivers of drug resistance in trypanosomes to improve its surveillance and management.
• Trypanotolerant breeds: Better characterizing livestock breeds with natural resistance to trypanosomosis and their epidemiological role.

Strengthening strategic control and livestock resilience

• Capacity building: Training a broad range of actors, from livestock farmers to veterinary professionals, on disease prevention and control measures.
• Progressive control pathway: Promoting holistic, rational approaches to control and reduce the impact of trypanosomosis on livestock.

By combining these innovative tools and approaches, the COMBAT project aims to help reduce the burden of animal trypanosomosis in Africa, improve livestock productivity, and contribute to the overall well-being of rural communities.