Human African Trypanosomiasis (HAT, sleeping sickness) and Animal African Trypanosomiasis (AAT) are neglected tropical diseases generally caused by the same etiological agent, Trypanosoma brucei. Despite important advances in the reduction or disappearance of HAT cases, AAT represents a risky reserv...oir of the infections. There is a strong need to control AAT, as is claimed by the European Commission in a recent document on the reservation of antimicrobials for human use. Control of AAT is considered part of the One Health approach established by the FAO program against African Trypanosomiasis. Under the umbrella of the One Health concepts, in this work, by analyzing the pharmacological properties of the therapeutic options against Trypanosoma brucei spp., we underline the need for clearer and more defined guidelines in the employment of drugs designed for HAT and AAT. Essential requirements are addressed to meet the challenge of drug use and drug resistance development. This approach shall avoid inter-species cross-resistance phenomena and retain drugs therapeutic activity.
more
A wide spectrum of disease severity has been described for Human African Trypanosomiasis (HAT) due to
Trypanosoma brucei rhodesiense (T.b. rhodesiense), ranging from chronic disease patterns in southern countries of East Africa to an increase in virulence towards the north. However, only limited d...ata on the clinical presentation of T.b. rhodesiense HAT is available. From 2006-2009 we conducted the first clinical trial program (I MPAMEL III) in T.b. rhodesiense endemic areas of
Tanzania and Uganda in accordance with international standards (ICH-GCP). The primary and secondary outcome measures were safety and efficacy of an abridged melarsoprol schedule for treatment of second stage disease. Based on diagnostic findings and clinical examinations at baseline we describe the clinical presentation of T.b. rhodesiense HAT in second stage patients from two distinct geographical settings in East Africa.
more
Since 2000, concerted efforts by national programmes, supported by public–private partnerships, nongovernmental organizations, donors and academia under the auspices and coordination of the World Health Organization (WHO), have produced important achievements in the control of human African trypan...osomiasis (HAT). As a consequence, the disease was targeted for elimination as a public health problem by 2020. The Sixty-sixth World Health Assembly endorsed this goal in resolution WHA66.12 on neglected tropical diseases, adopted in 2013.
National sleeping sickness control programmes (NSSCPs) are core to progressing control of the disease and in adapting to the different epidemiological situations. The involvement of different partners, as well as the support and trust of long-term donors, has been crucial for the achievements.
more
The twentieth century ended with human African trypanosomiasis (HAT) epidemics raging across many parts of Africa. Resistance to existing drugs was emerging, and many programs aiming to contain the disease had ground to a halt, given previous success against HAT and the competing priorities associat...ed with other medical crises ravaging the continent. A series of dedicated interventions and the introduction of innovative routes to develop drugs, involving Product Development Partnerships, has led to a dramatic turnaround in the fight against HAT caused by Trypanosoma brucei gambiense. The World Health Organization have been able to optimize the use of existing tools to monitor and intervene in the disease. A promising new oral medication for stage 1 HAT, pafuramidine maleate, ultimately failed due to unforeseen toxicity issues. However, the clinical trials for this compound demonstrated the possibility of conducting such trials in the resource-poor settings of rural Africa.
more
A clear understanding of the knowledge, attitudes and practices (KAP) of a particular community is necessary in order to improve control of human African trypanosomiasis (HAT).New screening and diagnostic tools and strategies were introduced into South Sudan, as part of integrated delivery of primar...y healthcare. Knowledge and awareness on HAT, its new/improved screening and diagnostic tools, the places and processes of getting a confirmatory diagnosis and treatment are crucial to the success of this strategy.
more
Treatment of second-stage gambiense human African trypanosomiasis relied on toxicarsenic-based derivatives for over 50 years. The availability and subsequent use of eflornithine,initially in monotherapy and more recently in combination with nifurtimox (NECT), has drasticallyimproved the pro...gnosis of treated patients. However, NECT logistic and nursing requirementsremain obstacles to its deployment and use in peripheral health structures in rural sub-SaharanAfrica. Two oral compounds, fexinidazole and SCYX-7158, are currently in clinical development.The main scope of this article is to discuss the potential impact of new oral therapies to improvediagnosis-treatment algorithms and patients’access to treatment, and to contribute to reach theobjectives of the recently launched gambiense humanAfrican trypanosomiasis elimination program
more
Arsenical monotherapies were previously very successful for treating human African trypanosomiasis (HAT).
Melarsoprol resistance emerged as early as the 1970s and was widespread by the late 1990s.
Melarsoprol resistance represents the only example of widespread drug resistance in HAT patients wher...e the genetic mechanism has been established.
The current goal of elimination of HAT as a public health problem by 2020 may be undermined by the emergence and spread of resistance to current or new drugs.
Insights into potential resistance mechanisms for current and new drugs will facilitate predictions of the likelihood of resistance and will also facilitate rational approaches to minimizing, monitoring, and tackling the future emergence of resistance.
more
The development of this target product profile (TPP) was led by the WHO Department of Control of Ne-
glected Tropical Diseases (NTD) following standard WHO guidance for TPP development. In order to
identify and prioritize diagnostic needs, a WHO NTD Diagnostics Technical Advisory Group (DTAG)
was... formed, and different subgroups were created to advise on specific NTDs, including a subgroup
working on the human African trypanosomiasis (HAT) diagnostic innovation needs. This group of in-
dependent experts included leading scientists, public health officials and endemic-country end-user rep-
resentatives. Standard WHO Declaration of Interest procedures were followed. A landscape analysis of
the available products and of the development pipeline was conducted, and the salient areas with unmet
needs were identified
more
Human African trypanosomiasis (HAT) has been an alarming global public health issue. The disease affects mainly poor and marginalized people in low-resource settings and is caused by two subspecies of haemoflagellate parasite, Trypanosoma brucei and transmitted by tsetse flies. Progress made in HAT ...control during the past decade has prompted increasing global dialogue on its elimination and eradication. The disease is targeted by the World Health Organization (WHO) for elimination as a public health problem by 2020 and to terminate its transmission globally by 2030, along-side other Neglected Tropical Diseases (NTD). Several methods have been used to control tsetse flies and the disease transmitted by them. Old and new tools to control the disease are available with constraints.
Currently, there are no vaccines available. Efforts towards intervention to control the disease over the past decade have seen considerable progress and remarkable success with incidence dropping progressively, reversing the upward trend of reported cases. This gives credence in a real progress in its elimination. This study reviews various control measures, progress and a highlight of control issues, vector and parasite barriers that may have been hindering progress towards its elimination.
more
More countries eliminate human African trypanosomiasis as a public health problem: Benin and Uganda (gambiense form) and Rwanda (rhodesiense form)
Human African trypanosomiasis (HAT), or sleeping sickness, transmitted by tsetse flies in sub-Saharan Africa, is a life-threatening disease that afflict...s poor rural populations. It is caused by trypanosome parasites of 2 subspecies: Trypanosoma brucei gambiense in West and Central Africa, and T. b. rhodesiense in East Africa.
HAT transmission can be reduced and interrupted by deploying and maintaining capacities for testing people at risk in order to detect and treat cases, and by controlling tsetse populations that are in contact with humans.
more
Sleeping sickness is controlled by case detection and treatment but this often only reaches less than 75% of the population. Vector control is capable of completely interrupting HAT transmission but is not used because of expense. We conducted a full scale field trial of a refined vector control tec...hnology. From preliminary trials we determined the number of insecticidal tiny targets required to control tsetse populations by more than 90%. We then carried out a full scale, 500 km2 field trial covering two HAT foci in Northern Uganda (overall target density 5.7/km2). In 12 months tsetse populations declined by more than 90%. A mathematical model suggested that a 72% reduction in tsetse population is required to stop transmission in those settings. The Ugandan census suggests population density in the HAT foci is approximately 500 per km2. The estimated cost for a single round of active case detection (excluding treatment), covering 80% of the population, is US$433,333 (WHO figures). One year of vector control organised within country, which can completely stop HAT transmission, would cost US$42,700. The case for adding this new method of vector control to case detection and treatment is strong. We outline how such a component could be organised.
more
Gambiense human African trypanosomiasis is a deadly infectious disease affecting West and Central Africa, South Sudan and Uganda, and transmitted between humans by tsetse flies. The disease has caused several major epidemics, the latest one in the 1990s. Thanks to recent innovations such as rapid di...agnostic tests for population screening, a single-dose oral treatment and a highly efficient vector control strategy, interruption of transmission of the causative parasite is now within reach. If indeed gHAT has an exclusively human reservoir, this could even result in eradication of the disease. Even if there were an animal reservoir, on the basis of epidemiological data, it plays a limited role. Maintaining adequate postelimination surveillance in known historic foci, using the newly developed tools, should be sufficient to prevent any future resurgence.
more
The main purpose of the meeting was to review tsetse control tools, activities and their contribution to the elimination of gHAT and the monitoring thereof. Seven endemic countries provided reports on recent and ongoing vector control interventions at the national level (Angola, Cameroon, Côte d’...Ivoire, Chad, Democratic Republic of the Congo, Guinea and Uganda). Country reports focused on the in situations implementing and supporting vector control activities, the tools and the approaches in use, the coverage of the activities in space and time and their impacts on tsetse populations. Future perspectives for vector control in the respective countries were also discussed, including opportunities and challenges to sustainability.
more
DNDi is now striving to make fexinidazole available to the majority of people who have T.b. gambiense sleeping sickness. We are supporting a three-year access and pharmacovigilance study that began in 2020 and have so far carried out in-country training of relevant staff in 250 hospitals and... health centres in T.b. gambiense-endemic countries; and updated national treatment and pharmacovigilance guidelines in Angola, Central African Republic, the Democratic Republic of Congo, Equatorial Guinea, Guinea, and Chad.
more
This was a Phase 3, multi-center, randomized, open-label, parallel-group, active control study where 273 male and female patients with first stage Trypanosoma brucei gambiense HAT were treated at six sites: one trypanosomiasis reference center in Angola, one hospital in South Sudan, and four hospita...ls in the Democratic Republic of the Congo between August 2005 and September 2009 to support the registration of pafuramidine for treatment of first stage HAT in collaboration with the United States Food and Drug Administration. Patients were treated with either 100 mg of pafuramidine orally twice a day for 10 days or 4 mg/kg pentamidine intramuscularly once daily for 7 days to assess the efficacy and safety of pafuramidine versus pentamidine. Pregnant and lactating women as well as adolescents were included.
more
At the forefront of DNDi’s efforts to develop new treatments is the need to understand the realities and treatment needs of patients and health care staff in the field. The ultimate goal for human African trypanosomiasis (HAT) is a truly simplified
treatment which can be orally administered, impl...emented at the primary health care level, and effective against both stages of the disease.
more
After 100 years of chemotherapy with impractical and toxic drugs, an oral cure for human African trypanosomiasis (HAT) is available: Fexinidazole. In this case, we review the history of drug discovery for HAT with special emphasis on the discovery, pre-clinical development, and operational challenge...s of the clinical trials of fexinidazole. The screening of the Drugs for Neglected Diseases initiative (DNDi) HAT-library by the Swiss TPH had singled out fexinidazole, originally developed by Hoechst (now Sanofi), as the most promising of a series of over 800 nitroimidazoles and related molecules. In cell culture, fexinidazole has an IC50 of around 1 µM against Trypanosoma brucei and is more than 100-fold less toxic to mammalian cells. In the mouse model, fexinidazole cures both the first, haemolymphatic, and the second, meningoencephalitic stage of the infection, the latter at 100 mg/kg twice daily for 5 days. In patients, the clinical trials managed by DNDi and supported by Swiss TPH mainly conducted in the Democratic Republic of the Congo demonstrated that oral fexinidazole is safe and effective for use against first- and early second-stage sleeping sickness. Based on the positive opinion issued by the European Medicines Agency in 2018, the WHO has released new interim guidelines for the treatment of HAT including fexinidazole as the new therapy for first-stage and non-severe second-stage sleeping sickness caused by Trypanosoma brucei gambiense (gHAT). This greatly facilitates the diagnosis and treatment algorithm for gHAT, increasing the attainable coverage and paving the way towards the envisaged goal of zero transmission by 2030.
more
Human African trypanosomiasis (HAT), or sleeping sickness, is a painful and protracted disease transmitted through the bite of infected tsetse flies and it is found in rural parts of sub-Saharan Africa. Sleeping sickness has two clinical phases but this review focuses only on treatment of the second...-stage, which is characterized by neurological changes and almost invariably fatal without treatment. There are only a few drugs currently available for second-stage sleeping sickness, all with considerable adverse events and variable efficacy.
The review includes nine trials with 2577 participants. Each trial reported different comparisons of the drugs currently available to treat second stage HAT (melarsoprol, eflornithine, nifurtimox) so no meta-analysis was possible.
more
Human African trypanosomiasis is caused by Trypanosoma brucei gambiense in West and Central Africa and by T. brucei rhodesiense in East Africa; both species are endemic in Uganda. Trypanosoma brucei gambiense accounts for 98% of all cases of African trypanosomiasis, and T. brucei rhodesiense account...s for 2%. African trypanosomiasis has been targeted for eradication by the World Health Organization (WHO) and, as a result of control efforts, there has been a dramatic decrease (> 95%) in the number of reported cases worldwide.
Professional version as well as patient education
more
DNDi’s long-term goal for sleeping sickness, also known as human African trypanosomiasis (HAT), is to develop and register two new drugs that are effective against both Stage 1 and Stage 2 of the disease and both subspecies of the parasite, T.b. gambiense and T.b. rhodesiense. T.b. rhodesiense is ...an acute form of the disease, occurring primarily in Eastern and Southern Africa. Better treatments for T.b. rhodesiense sleeping sickness are urgently needed.
more