Scientists Make Breakthrough in Fight Against Tsetse Fly

Promises to yield powerful genetic tools that could one day eliminate the disease from sub-Saharan Africa

After 10 years of research, scientists have finally been able to understand the DNA code for the devastating tsetse fly. This will help in controlling trypanosomiasis disease in livestock and sleeping sickness in humans.

According to a study published in the journal Science, the precise knowledge of the insect’s biology and physiology promises to yield powerful genetic tools that could one day eliminate the disease from sub-Saharan Africa.

The study ‘Genome Sequence of the Tsetse Fly (Glossina morsitans): Vector of African Trypanosomiasis’ states that although official reports of new infections in humans recently dropped below 10,000 per year, many cases especially in rural areas with limited access to health facilities go undiagnosed.

According to the World Health Organisation, the estimated number of actual cases is 20,000 and the population at risk is approximately 70 million people in 36 African countries.

Geoffrey Attardo, a research scientist and the lead author, said while there are drugs to treat sleeping sickness, they are expensive, have many undesirable side effects, and are difficult to administer in wide swathes of rural Africa where the disease is most pronounced.

“Left untreated, sleeping sickness inevitably leads to death. This is a major milestone for the tsetse research community. Our hope is that this resource will facilitate functional research and be an ongoing contribution to the vector biology community,” said Attardo.

Found only in Africa, tsetse flies are vectors for the single-cell parasites that cause trypanosomiasis, or nagana, an often-lethal disease that affects some three million animals in the region each year at massive costs to farmers’ livelihoods and food security.

FAO says the disease leads to a debilitating chronic condition that reduces fertility, weight gain, meat and milk production, and makes livestock too weak to be used for ploughing or transport, which in turn affects crop production.

Humans bitten by carrier flies can develop African sleeping sickness, which can be fatal without treatment. No vaccine against the disease exists for livestock or humans because the parasite is able to evade mammalian immune systems, so control methods primarily involve targeting tsetse flies through trapping, pesticide treatments and sterile male release strategies.

“Decoding the tsetse fly’s DNA is a major scientific breakthrough that opens the way for more effective control of trypanosomiasis, which is good news for millions of herders and farmers in sub-Saharan Africa. Detection and treatment of trypanosomiasis is currently expensive, difficult and dangerous for the livestock as it often involves toxic drugs, but this new knowledge will accelerate research on tsetse control methods and help scientists develop new and complementary strategies to reduce the use of costly drugs and insecticides,”said Kostas Bourtzis of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture.

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