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Veterinary Parasitology Jul 2016African Animal Trypanosomiasis (AAT) is endemic in at least 37 of the 54 countries in Africa. It is estimated to cause direct and indirect losses to the livestock... (Review)
Review
African Animal Trypanosomiasis (AAT) is endemic in at least 37 of the 54 countries in Africa. It is estimated to cause direct and indirect losses to the livestock production industry in excess of US$ 4.5 billion per annum. A century of intervention has yielded limited success, owing largely to the extraordinary complexity of the host-parasite interaction. Trypanotolerance, which refers to the inherent ability of some African livestock breeds, notably Djallonke sheep, N'Dama cattle and West African Dwarf goats, to withstand a trypanosomiasis challenge and still remain productive without any form of therapy, is an economically sustainable option for combatting this disease. Yet trypanotolerance has not been adequately exploited in the fight against AAT. In this review, we describe new insights into the genetic basis of trypanotolerance and discuss the potential of exploring this phenomenon as an integral part of the solution for AAT, particularly, in the context of African animal production systems.
Topics: Africa; Animal Husbandry; Animals; Breeding; Disease Resistance; Livestock; Trypanosomiasis, African
PubMed: 27369574
DOI: 10.1016/j.vetpar.2016.05.003 -
Expert Review of Anti-infective Therapy Nov 2014Treatment of second-stage gambiense human African trypanosomiasis relied on toxic arsenic-based derivatives for over 50 years. The availability and subsequent use of... (Review)
Review
Treatment of second-stage gambiense human African trypanosomiasis relied on toxic arsenic-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 drastically improved the prognosis of treated patients. However, NECT logistic and nursing requirements remain obstacles to its deployment and use in peripheral health structures in rural sub-Saharan Africa. 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 improve diagnosis-treatment algorithms and patients' access to treatment, and to contribute to reach the objectives of the recently launched gambiense human African trypanosomiasis elimination program.
Topics: Animals; Disease Progression; Drug Therapy, Combination; Humans; Trypanocidal Agents; Trypanosoma brucei gambiense; Trypanosomiasis, African
PubMed: 25204360
DOI: 10.1586/14787210.2014.959496 -
PLoS Medicine Feb 2008While the number of new detected cases of HAT is falling, say the authors, sleeping sickness could suffer the "punishment of success," receiving lower priority by public... (Review)
Review
While the number of new detected cases of HAT is falling, say the authors, sleeping sickness could suffer the "punishment of success," receiving lower priority by public and private health institutions.
Topics: Africa; Animals; Forecasting; Humans; Trypanosoma brucei gambiense; Trypanosoma brucei rhodesiense; Trypanosomiasis, African
PubMed: 18303943
DOI: 10.1371/journal.pmed.0050055 -
Journal of Medical Entomology Mar 2022Human African trypanosomiasis (HAT), despite considerable progress in the control, is still occurring in many countries in both west and central African regions. The HAT... (Review)
Review
Human African trypanosomiasis (HAT), despite considerable progress in the control, is still occurring in many countries in both west and central African regions. The HAT situation in the Republic of Congo has always been overshadowed by its neighbor the Democratic Republic of Congo where over 60% of all HAT cases occur. In the Republic of Congo, HAT cases have been significantly reduced to about 20 reported cases yearly and the disease is still prevalent in few foci across the country. Although continuous assessment of HAT situation in Congo is been led by the National Control Program for HAT, research on the vector, parasite, and vector control has received little attention. Because there have not been enough reviews summarizing key findings from studies conducted so far, there is still a poor understanding of the global situation of HAT in Congo. In order to achieve sustainable elimination of HAT in Congo a deep appraisal of HAT situation is required. The present study provides a review of studies conducted on HAT in the republic of Congo since the 1950s to date in order to identify gaps in knowledge and help consolidate the gains and progress towards the elimination of sleeping sickness.
Topics: Animals; Democratic Republic of the Congo; Humans; Trypanosomiasis, African
PubMed: 35137146
DOI: 10.1093/jme/tjab225 -
PLoS Neglected Tropical Diseases Nov 2022Sleeping sickness, or human African trypanosomiasis (HAT), is transmitted by tsetse flies in endemic foci in sub-Saharan Africa. Because of international travel and...
BACKGROUND
Sleeping sickness, or human African trypanosomiasis (HAT), is transmitted by tsetse flies in endemic foci in sub-Saharan Africa. Because of international travel and population movements, cases are also occasionally diagnosed in non-endemic countries.
METHODOLOGY/PRINCIPAL FINDINGS
Antitrypanosomal medicines to treat the disease are available gratis through the World Health Organization (WHO) thanks to a public-private partnership, and exclusive distribution of the majority of them enables WHO to gather information on all exported cases. Data collected by WHO are complemented by case reports and scientific publications. During 2011-2020, 49 cases of HAT were diagnosed in 16 non-endemic countries across five continents: 35 cases were caused by Trypanosoma brucei rhodesiense, mainly in tourists visiting wildlife areas in eastern and southern Africa, and 14 cases were due to T. b. gambiense, mainly in African migrants originating from or visiting endemic areas in western and central Africa.
CONCLUSIONS/SIGNIFICANCE
HAT diagnosis in non-endemic countries is rare and can be challenging, but alertness and surveillance must be maintained to contribute to WHO's elimination goals. Early detection is particularly important as it considerably improves the prognosis.
Topics: Animals; Humans; Trypanosomiasis, African; Trypanosoma brucei rhodesiense; Tsetse Flies; Black People; Africa, Southern; Trypanosoma brucei gambiense
PubMed: 36342910
DOI: 10.1371/journal.pntd.0010885 -
Transactions of the Royal Society of... Feb 2016The development and application of interventions for the control of vector-borne zoonoses requires broad understanding of epidemiological linkages between vector, animal...
The development and application of interventions for the control of vector-borne zoonoses requires broad understanding of epidemiological linkages between vector, animal infection and human infection. However, there are significant gaps in our understanding of these linkages and a lack of appropriate data poses a considerable barrier to addressing this issue. A move towards strengthened surveillance of vectors and disease in both animal and human hosts, in combination with linked human-animal surveys, could form the backbone for epidemiological integration, enabling explicit assessment of the animal-human (and vector) interface, and subsequent implications for spill-over to human populations. Currently available data on the spatial distribution of human African trypanosomiasis allow an illustrative example.
Topics: Animals; Health Priorities; Humans; Insect Vectors; Sentinel Surveillance; Trypanosomiasis, African; Tsetse Flies; Zoonoses
PubMed: 26822600
DOI: 10.1093/trstmh/trv115 -
Molecules (Basel, Switzerland) Jun 2022, the causative agent for human African trypanosomiasis, is an emerging ergosterol-dependent parasite that produces chokepoint enzymes, sterol methyltransferases (SMT),...
, the causative agent for human African trypanosomiasis, is an emerging ergosterol-dependent parasite that produces chokepoint enzymes, sterol methyltransferases (SMT), not synthesized in their animal hosts that can regulate cell viability. Here, we report the lethal effects of two recently described natural product antimetabolites that disrupt sterol methylation and growth, cholesta-5,7,22,24-tetraenol (CHT) and ergosta-5,7,22,24(28)-tetraenol (ERGT) that can equally target . We found that CHT/ERGT inhibited cell growth in vitro, yielding EC values in the low nanomolar range with washout experiments showing cidal activity against the bloodstream form, consistent with their predicted mode of suicide inhibition on SMT activity and ergosterol production. Antimetabolite treatment generated altered cell morphology and death rapidly within hours. Notably, in vivo ERGT/CHT protected mice infected with , doubling their survival time following daily treatment for 8-10 days at 50 mg/kg or 100 mg/kg. The current study demonstrates a new class of lead antibiotics, in the form of common fungal sterols, for antitrypanosomal drug development.
Topics: Animals; Antimetabolites; Ergosterol; Humans; Mice; Steroids; Sterols; Trypanosoma brucei brucei; Trypanosomiasis, African
PubMed: 35807334
DOI: 10.3390/molecules27134088 -
Bulletin of the World Health... Aug 2023Rhodesiense human African trypanosomiasis is a lethal parasitic infection caused by and transmitted by tsetse flies in eastern and southern Africa. It accounts for...
Rhodesiense human African trypanosomiasis is a lethal parasitic infection caused by and transmitted by tsetse flies in eastern and southern Africa. It accounts for around 5% of all cases of human African trypanosomiasis. Currently, there is no simple serological test for rhodesiense human African trypanosomiasis and diagnosis relies on microscopic confirmation of trypanosomes in samples of blood or other tissues. The availability of a simple and accurate diagnostic test would aid the control, surveillance and treatment of the disease. A subcommittee of the World Health Organization's Neglected Tropical Diseases Diagnostics Technical Advisory Group has developed a target product profile for a diagnostic tool to identify infection. The optimum tool would have a sensitivity and specificity above 99% for detecting but be simple enough for use by minimally trained health-care workers in unsophisticated peripheral health facilities or mobile teams in villages. The test should yield a qualitative result that can be easily observed and can be used to determine treatment. An antigen test would be preferable, with blood collected by finger-prick. Ideally, there should be no need for a cold chain, instrumentation or precision liquid handling. The test should be usable between 10 °C and 40 °C and between 10% and 88% relative humidity. Basic training should take under 2 hours and the test should involve fewer than five steps. The unit cost should be less than 1 United States dollar.
Topics: Animals; Humans; Trypanosoma brucei rhodesiense; Trypanosomiasis, African; Africa, Southern; Sensitivity and Specificity; Diagnostic Tests, Routine
PubMed: 37529024
DOI: 10.2471/BLT.23.290173 -
The Pan African Medical Journal 2016Human African Trypanosomiasis (HAT) is a vector borne parasitic disease transmitted to humans by infected tse-tse flies cause morbidity including delayed child mental...
INTRODUCTION
Human African Trypanosomiasis (HAT) is a vector borne parasitic disease transmitted to humans by infected tse-tse flies cause morbidity including delayed child mental development. Reports of nuisance and bites from tse-tse flies by residents of Kachia grazing led to the study to determine the knowledge, practices and prevalence of HAT among residents of the grazing reserve.
METHODS
We conducted active case search in a cross-sectional study using multi-stage sampling with probability proportionate to size. We administered structured questionnaire on Knowledge, practices relating to HAT prevention and screened for HAT using card agglutination test for Trypanosomiasis (CATT). Knowledge of HAT was scored 0-5 and categorized good (3-5) and poor (0-2) based on score, predisposition to risk of HAT as exposure to ≥two risk factors and, a case of HAT as any respondent that tested positive on CATT. We analysed data using Epi-info and MS-excel.
RESULTS
Of the 300 respondents, mean age 39(±17years) interviewed, 56.3% were males, 12.0% had good knowledge of HAT and 76.3% were exposed to HAT risk factors. Prevention practices included clearing of overgrown bushes around houses (99%), use of insecticidal treated nets (75.7%) and protective clothing (41.0%). Males {Odds Ratio [OR] 5.0; 95% Confidence Interval (CI) 1.8 - 13.6}, age above 40 years {OR 5.0; 95% CI 1.1 - 24.4} and family history of HAT {OR 8.7; 95% CI 2.4 - 32.1} were significantly associated with HAT knowledge. None tested positive on CATT.
CONCLUSION
Despite poor knowledge of HAT, residents practiced HAT preventive measures and zero HAT prevalence was recorded.
Topics: Adult; Agglutination Tests; Cross-Sectional Studies; Female; Health Knowledge, Attitudes, Practice; Humans; Male; Mass Screening; Middle Aged; Nigeria; Prevalence; Risk Factors; Surveys and Questionnaires; Trypanosomiasis, African; Young Adult
PubMed: 27222686
DOI: 10.11604/pamj.2016.23.89.7999 -
PLoS Neglected Tropical Diseases May 2024
Topics: Humans; Trypanosomiasis, African; Disease Eradication; Animals; Africa; Neglected Diseases
PubMed: 38691551
DOI: 10.1371/journal.pntd.0012091