African sleeping sickness eliminated as a public health problem in Chad
The World Health Organization (WHO) announced last week that the land-locked African country, Chad, has eliminated the gambiense form of human African trypanosomiasis, also known as sleeping sickness, as a public health problem.
This is the first neglected tropical disease (NTD) to be eliminated in the country.
"The elimination of the gambiense form of human African trypanosomiasis in Chad reflects our commitment to improving the health of our people. This achievement results from years of dedicated efforts by our health workers, communities, and partners. We will continue this momentum to tackle other neglected tropical diseases and ensure a healthier future for all Chadians" said Hon. Dr Abdel Modjid Abderahim Mahamat, Minister of Health, Chad.
One of the true tropical diseases, African sleeping sickness is endemic only in sub-Sahara Africa bounded by 15° North and South latitudes.
Two varieties of African sleeping sickness exist: one primarily in East Africa caused by the parasite Trypanosoma brucei rhodesiense (found in 13 countries in East and Southern Africa). T.B. rhodesiense produces an acute infection that will usually cause severe illness and death in weeks to months.
The other species is Trypanosoma brucei gambiense. This parasite is found in West and Central Africa. (Trypanosoma brucei gambiense, found in 24 countries in West and Central Africa, accounting for more than 92% of cases).
However, the 2 species show some geographic overlap.
This infection progresses more slowly and may require months to years for disease to occur.
Both types of sleeping sickness are caused by the bite of a tse tse fly. These vicious little bugs depend on blood meals for its nutrients. It gets the blood from mammals including humans.
When taking a blood meal, the fly injects the parasite into the skin. From here the parasite is carried to the lymphatic system and eventually the bloodstream.
They go through stages in the body and eventually end up in the spinal fluid.
Symptoms are as follows:
• East African sleeping sickness: the development of a chancre at the bite site followed by fever, fatigue, aching muscles and joints and swollen lymph nodes are characteristic. After central nervous system (CNS) invasion neurological manifestations may occur followed by death if untreated.
• West African sleeping sickness: symptoms are similar to the above however taking longer to appear. Progressive confusion, personality changes, daytime sleepiness with nighttime sleep disturbances are late stage symptoms. Death will happen after several years if left untreated.
So far, seven countries have been validated by WHO for eliminating the gambiense form of human African trypanosomiasis: Togo (2020), Benin (2021), Côte d’Ivoire (2021), Uganda (2022), Equatorial Guinea (2022), Ghana (2023), and Chad (2024). The rhodesiense form of the disease has been eliminated as a public health problem in one country, Rwanda, as validated by WHO in 2022.