DFID Research: sleeping sickness - waking up to reality?
Human and animal forms of sleeping sickness are an obstacle to rural development in Africa.
Blood slides are examined for the presence of trypanosomes
Sleeping sickness threatens over 60 million people in 36 countries in sub-Saharan Africa and kills an estimated 40,000 Africans per year. Fewer than 4 million people have access to diagnosis and treatment. The acute form of the disease is caused by parasites that are transmitted to humans by tsetse flies that feed on infected cattle or wildlife.
The human and animal forms of the disease remain a major obstacle to the development of rural regions of sub-Saharan Africa: human loss, decimation of cattle and abandonment of fertile land. Although parasites that cause sleeping sickness in humans cause no gross pathologies in cattle, animals are affected by other sub-species of the parasite, causing serious disability and death. Importantly, cattle can become reservoirs for the parasite. Treatment of the disease in cattle is relatively simple and cost-effective with drugs and insecticides available, which can eliminate the disease from the animal population and therefore prevent the further spread of the acute form of the disease.
The first symptoms of sleeping sickness in humans are non-specific (fever, headaches and joint pain), so often the disease remains undiagnosed. At this early stage the disease is relatively easy to treat. Symptoms in the more advanced stages include confusion, profound behaviour change and then coma and death. People in the late stages of disease are difficult and costly to treat (US$200) and fatalities are high. Currently old and dangerous drugs are used: for example melarsoprol which is so toxic that it kills 1 in 20 patients.
DFID’s Animal Health Programme and the Livestock Production Programme have been working together in East Africa where the disease in animals, known as nagana, was until recently confined to southeast Uganda and western Kenya. But the disease is spreading as farmers find it too costly to treat their cattle. The DFID research programmes have jointly identified a more cost-effective method for treating cattle to restrict the spread of the disease. This is done by restrictive application of an insecticide to the legs of cattle, rather than treating the whole animal since flies feed mostly on the legs (for more details see the case study Fighting sleeping sickness in Uganda).
DFID is providing £6.5 million to the Drugs For Neglected Diseases Initiative (DNDi) over 3 years. This extremely important initiative is a not-for-profit drug development organisation that focuses on some of the most neglected diseases in the world - sleeping sickness, Chagas disease and leishamaniasis. DNDi aims to improve the health and quality of life of people suffering from neglected diseases through research into better drugs. DNDi is evaluating the usefulness of different drug combinations to treat sleeping sickness and is exploring the possibility of identifying new drug candidates with possible relevance to sleeping sickness.
Further information
See also the following Project records: