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 reservoir 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
Background: East African trypanosomiasis is an uncommon, potentially lethal disease if not diagnosed and treated in a timely manner. South Africa, as a centre for emergency medical evacuations from
...
much of sub-Saharan Africa, receives a high proportion of these patients, mostly tourists and expatriate residents.
Methods: The cases of East African trypanosomiasis patients evacuated to South Africa, for whom diagnostic and clinical management advice was provided over the years 2004–2018, were reviewed, using the authors’ own records and those of collaborating clinicians.
Results: Twenty-one cases were identified. These originated in Zambia, Malawi, Zimbabwe, Tanzania, and Uganda. Nineteen cases (90%) had stage 1 (haemolymphatic) disease; one of these patients had fatal myocarditis. Of the two patients with stage 2 (meningoencephalitic) disease, one died of melarsoprol encephalopathy. Common problems were delayed diagnosis, erroneous assessment of severity, and limited access to treatment.
Conclusions: The key to early diagnosis is recognition of the triad of geographic exposure, tsetse fly bites, and trypanosomal chancre, plus good microscopy. Elements for successful management are rapid access to specific drug treatment, skilled intensive care, and good laboratory facilities. Clinical experience and the local stock of antitrypanosomal drugs from the World Health Organization have improved the chance of a successful outcome in the management of East African trypanosomiasis in South Africa; the survival rate over the period was 90.5%.
more
FIND and Standard Diagnostics (SD) have developed a lateral flow rapid diagnostic test (RDT) to screen for
T.b. gambiense HAT that is cheap and easy to use. The tests are packed individually and are stable at 40°C for
up to 25 months; they are performed on fresh blood obtained from a finger prick
...
, and no instrument or electricity is required. The RDT detects host antibodies to infection in populations that are at risk, or in suspect individuals. Positive cases are subjected to further confirmatory methods to identify HAT patients.
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
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 afflicts 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
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 discove
...
ry for HAT with special emphasis on the discovery, pre-clinical development, and operational challenges 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
This document focuses on the management of patients affected by gambiense HAT and
constitutes an update to the WHO therapeutic guidance issued in 2013. The main changes in recommendations concern the criteria and methods for deciding the treatment among the new set of therapeutic options and the pa
...
rticular conditions that apply to treatment with fexinidazole, as outlined below. Because HAT is a serious, life-threatening disease and because the efficacy of fexinidazole depends on swallowing the medicine after an appropriate intake of food as well as on completing the full 10-day
treatment schedule, the recommendations regarding fexinidazole administration are considered key elements that must be carefully followed. When the conditions listed in these guidelines are not met for any individual patient, the alternative available treatments should be prescribed.
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 i
...
n monotherapy and more recently in combination with nifurtimox (NECT), has drasticallyimproved the prognosis 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
Reports of antimicrobial-resistant (AMR) microorganisms are increasing globally, threatening to render existing treatments ineffective against many infectious diseases. In Africa, AMR has already been documented to be a problem for human immunodeficiency virus (HIV) and the pathogens that cause mala
...
ria, tuberculosis (TB), typhoid, cholera, meningitis, gonorrhoea and dysentery. Recognizing the urgent need for action, the 2016 United Nations (UN) General Assembly approved a resolution to ensure sustained and effective global action to address AMR.
more
Human African trypanosomiasis (HAT), also called sleeping sickness, is a parasitic infection that almost invariably progresses to death, unless treatment is provided. HAT caused devastating epidemic
...
s during the 20th century. Thanks to sustained and coordinated efforts during the past 15 years the number of reported cases has fallen to a historic low. Fewer than 3,000 cases were reported in 2015, and the disease is targeted for elimination by the World Health Organization. Despite recent success, HAT still poses a heavy burden on the rural communities where this highly focal disease occurs, most notably in Central Africa. Since patients are also reported from non-endemic countries outside Africa, HAT should be considered in differential diagnosis for all travellers, tourists, migrants and expatriates who have visited or lived in endemic areas. In the absence of a vaccine, disease control relies on case detection and treatment, and vector control. Available drugs are sub-optimal, but ongoing clinical trials give hope for safer and simpler treatments.
more
Human African Trypanosomiasis, also known as sleeping sickness is a devastating parasitic disease. It is a neglected tropical disease affecting communities in Africa. In this video we take a look at
...
the disease, how it presents and and ways to control it.
more
Human African trypanosomiasis (HAT) is a lethal neglected tropical disease (NTD) transmitted by the bite of infected tsetse flies. The disease is also known as “sleeping sickness”. During the 20
...
th century it caused enormous suffering in the endemic areas in sub-Saharan Africa. HAT transmission last soared in the late 1990s, triggering a renewed, coordinated and very successful control effort. In this paper, we present achievements towards HAT elimination, with a focus on the WHO road map targets for 2020. In particular, reported cases continue to decline, from over 30,000 cases per year at the turn of the century to 663 cases in 2020. Despite the impact of the COVID-19 pandemic, HAT surveillance was largely sustained, and the network of health facilities able to diagnose and treat the disease further expanded. Looking to the future, the World Health Organization (WHO) set bold new targets for HAT in its 2021–2030 road map for NTDs, namely: the elimination of transmission of gambiense HAT, which occurs in western and central Africa, and the elimination as a public health problem of rhodesiense HAT, which is found in eastern and southern Africa. The strong commitment of national health authorities and the international community will be essential if these goals are to be achieved.
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 associated 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
Sleeping sickness is a neglected tropical disease affecting rural communities in sub-Saharan Africa. The reduction in the number of reported cases in recent years indicates that disease transmission is under control. However, many aspects of patient management still need to be improved. Undiagnosed
...
patients or inappropriate treatment due to an incorrect determination of the disease stage could in fact lead to its re-emergence. There is thus a strong need for new diagnostic and staging tools to keep the disease under control and to improve the clinical care of patients. This review describes the most promising biomarkers proposed so far for the diagnosis and stage determination of patients suffering from sleeping sickness, with a particular emphasis on their translation into diagnostic tools for field applications.
more
The previous report of the WHO Expert Committee on this disease
followed a meeting in 1995. Intensive, coordinated efforts against HAT during
the intervening 18 years have resulted in a decrease in incidence to a point at
which elimination is considered feasible. This report provides informati
...
on about
new diagnostic approaches, new therapeutic regimens and better understanding
of the distribution of the disease with high-quality mapping. The roles of human
and animal reservoirs and the tsetse fly vectors that transmit the parasites are
emphasized. The new information has formed the basis for an integrated strategy
with which it is hoped that elimination of HAT will be achieved. The report also
contains recommendations on the approaches that will lead to elimination of the
disease.
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, implemented at the primary health care level, and effective against both stages of the disease.
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 so
...
uthern countries of East Africa to an increase in virulence towards the north. However, only limited data 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
Plos Neglected Tropical Diaseses, vol. 5 (2011) Issue 7 e1233. Open Access. Please download from the website
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 Afr
...
ica. 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