Tsetse flies, belonging to the genus Glossina, are present in 34 African countries, according to a newly published atlas by the Food and Agriculture Organization of the United Nations (FAO). These flies are notorious for transmitting trypanosomes, unicellular parasites that cause sleeping sickness in humans and nagana in African livestock.
Impact of Tsetse Flies on Humans and Livestock
- Sleeping Sickness in Humans: Sleeping sickness, once a significant public health threat, has seen a drastic reduction in human cases, now numbering fewer than 2,000 annually. While this disease is no longer a major public health concern, it remains important to monitor and control the presence of tsetse flies.
- Nagana in Livestock: Tsetse flies continue to cause major losses in African livestock through the transmission of nagana, leading to agricultural losses that are estimated in the billions of dollars annually. The economic impact on livestock farmers is considerable, making control efforts a priority.
The Need for Accurate Data and Mapping
Efforts to manage and eradicate trypanosomiasis in livestock must be grounded in accurate and reliable data. Unfortunately, until recently, the most comprehensive map of tsetse fly distribution was created over 50 years ago. This new FAO atlas, therefore, fills a crucial gap by providing updated information on the geographical spread of these flies.
Methodology of the New FAO Atlas
The FAO atlas combines data from multiple sources, including:
- Scientific Literature: Data was drawn from 669 scientific papers published over 31 years (from 1990 to 2020).
- Google Earth Data: The atlas incorporates geolocation data from Google Earth.
- Fieldwork: Entomological research involving fixed and mobile trapping was also included in the study.
In total, 7,386 sites across Africa were analyzed, confirming the presence of Glossina species in 34 countries. These countries range from Northern Senegal (15 degrees north) to South Africa (28.5 degrees south).
Country-Specific Insights
- Countries With Established Tsetse Fly Presence: Ethiopia’s National Institute for Control and Eradication of Tsetse and Trypanosomosis aims to use this atlas as a reference for understanding the distribution of tsetse flies in Ethiopia and other regions of western Africa.
- Countries With Limited Data: Angola, Congo, the Democratic Republic of Congo, and South Sudan have limited data on tsetse fly presence. However, these countries are still considered affected by tsetse flies.
- Countries Without Recent Data: No published data was found for Burundi, Guinea-Bissau, Liberia, Sierra Leone, and Somalia. Despite the lack of information, these countries are still assumed to be affected by tsetse flies according to the FAO.
Mapping of Tsetse Fly Species
The FAO has developed both continental and national maps for 26 of the 31 recognized species and subspecies of tsetse flies. The most widely distributed species are:
- Glossina palpalis and Glossina tachinoides in West Africa
- Glossina fuscipes in Central Africa
- Glossina morsitans and Glossina pallidipes in East and Southern Africa
Benefits of the FAO Atlas
The updated atlas is expected to be a valuable tool for:
- Veterinary practitioners and policymakers in affected countries
- International organizations, including the World Health Organization (WHO), in the fight against sleeping sickness and animal trypanosomiasis.
Conclusion
The newly published FAO atlas marks a significant advancement in understanding the distribution of tsetse flies across Africa. With its detailed maps and data collection, this tool will help guide efforts to control and eradicate diseases like trypanosomiasis, ultimately benefiting both public health and agriculture.
Multiple-Choice Questions (MCQs):
- What is the genus name of tsetse flies?
- A) Anopheles
- B) Glossina
- C) Culex
- D) Aedes
Answer: B) Glossina
- Which disease in livestock is transmitted by tsetse flies?
- A) Malaria
- B) Nagana
- C) Rabies
- D) Anthrax
Answer: B) Nagana
- How many countries in Africa are confirmed to have tsetse flies according to the new FAO atlas?
- A) 24
- B) 34
- C) 44
- D) 54
Answer: B) 34
- Which of the following is not a country mentioned with limited or no recent data on tsetse fly presence?
- A) Burundi
- B) Angola
- C) Somalia
- D) Nigeria
Answer: D) Nigeria
- Which of the following species of tsetse flies has the widest distribution in East and Southern Africa?
- A) Glossina palpalis
- B) Glossina tachinoides
- C) Glossina morsitans
- D) Glossina fuscipes
Answer: C) Glossina morsitans