Human African Trypanosomiasis (HAT): Epidemiology, Biological Diagnosis and Treatment: A Review

The objective of the World Health Organization is to achieve the interruption of human African trypanosomiasis (HAT) transmission by 2030.

This review aims to update knowledge on HAT, through a synthesis on the epidemiology, diagnostic tools and drugs of HAT.

From 1960 to 2024 approximately 132,063 cases of HAT have been reported across Africa. The majority of HAT patients live in the Democratic Republic of Congo (DRC). The Card Agglutination Test for Trypanosomiasis (CATT) remained for a long time the reference serology test for field screening. The immune trypanolysis test (ITL) test is an accurate serodiagnostic tool increasingly used for medical surveillance of sleeping sickness, but it is reserved for reference laboratories. Prototypes of TDRs such as SD BIOLINE HAT and, HAT Sero-K-SeT have been developed to respond to constraints posed with CATT and ITL, but lack specificity. Parasitological diagnosis techniques such as the mini-Anion Exchange by Centrifugation technique (mAECT) are used for mandatory confirmation of the disease before the initiation of treatment, but their sensitivity is low. To date, the active molecules against HAT are: pentamidine, suramin, melarsoprol, eflornithine and nifurtimox. The use of these molecules does not guarantee healing and generates many side effects. A new molecule has appeared in the therapeutic arsenal. This is fexinidazole, which was approved by the WHO in 2019 for the treatment of HAT due to T.b. gambiense. The WHO recommends the oral administration of this molecule in the first stage of the disease and in the second stage for non-severe cases. Since 2024, this molecule has also been approved by the WHO for the treatment of HAT due to T. b. rhodesiense.

All these difficulties raised raise questions about the need to develop new diagnostic tools that are more specific, more sensitive and better suited to field screening. They also call out the urgency of finding new drugs that are less toxic, easy to administer and more effective.