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Parasite (Paris, France) Sep 2008The accurate identification of the causative organisms of disease is fundamental to the study of epidemiology. Hence molecular tools are now widely used to detect and... (Review)
Review
The accurate identification of the causative organisms of disease is fundamental to the study of epidemiology. Hence molecular tools are now widely used to detect and distinguish pathogens, and have greatly improved our understanding of epidemiology. David Godfrey pioneered the use of molecular markers in the epidemiology of African trypanosomiasis, thus enabling the light of reliable evidence to shine on this previously problematic and controversial subject area. From the early 1970's David's group employed first isoenzyme electrophoresis and subsequently DNA-based characterization methods to aid identification of typanosomes collected from a range of endemic countries across Africa. These investigations had a major impact on our understanding of the zoonotic nature of human trypanosomiasis in Africa and of the genetic diversity of African trypanosomes.
Topics: Animals; Disease Reservoirs; Genetic Markers; Genetic Variation; Humans; Molecular Epidemiology; Trypanosoma; Trypanosoma brucei gambiense; Trypanosomiasis, African
PubMed: 18814686
DOI: 10.1051/parasite/2008153233 -
Research in Immunology Jun 1993
Review
Topics: Animals; Host-Parasite Interactions; Humans; Immune Tolerance; Interferon-gamma; Macrophages; Mice; T-Lymphocyte Subsets; Trypanocidal Agents; Trypanosoma brucei brucei; Trypanosomiasis, African; Tumor Necrosis Factor-alpha
PubMed: 8278660
DOI: 10.1016/s0923-2494(93)80082-a -
Parasite Immunology 2013Trypanosoma brucei are extracellular kinetoplastid parasites transmitted by the blood-sucking tsetse fly. They are responsible for the fatal disease human African... (Review)
Review
Trypanosoma brucei are extracellular kinetoplastid parasites transmitted by the blood-sucking tsetse fly. They are responsible for the fatal disease human African trypanosomiasis (HAT), also known as sleeping sickness. In late-stage infection, trypanosomes cross the blood-brain barrier (BBB) and invade the central nervous system (CNS) invariably leading to coma and death if untreated. There is no available vaccine and current late-stage HAT chemotherapy consists of either melarsoprol, which is highly toxic causing up to 8% of deaths, or nifurtimox-eflornithine combination therapy (NECT), which is costly and difficult to administer. There is therefore an urgent need to identify new late-stage HAT drug candidates. Here, we review how current imaging tools, ranging from fluorescent confocal microscopy of live immobilized cells in culture to whole-animal imaging, are providing insight into T. brucei biology, parasite-host interplay, trypanosome CNS invasion and disease progression. We also consider how imaging tools can be used for candidate drug screening purposes that could lead to new chemotherapies.
Topics: Animals; Cell Survival; Host-Parasite Interactions; Humans; Microscopy, Confocal; Trypanosoma brucei brucei; Trypanosomiasis, African
PubMed: 23790101
DOI: 10.1111/pim.12046 -
MMWR. Morbidity and Mortality Weekly... Mar 1983
Topics: Aged; Humans; Male; Trypanosomiasis, African; United States
PubMed: 6403828
DOI: No ID Found -
Transactions of the Royal Society of... Mar 2011We conducted a situation analysis of human African trypanosomiasis (HAT) in Zambia from January 2000 to April 2007. The aim of this survey was to identify districts in... (Review)
Review
Disappearance of some human African trypanosomiasis transmission foci in Zambia in the absence of a tsetse fly and trypanosomiasis control program over a period of forty years.
We conducted a situation analysis of human African trypanosomiasis (HAT) in Zambia from January 2000 to April 2007. The aim of this survey was to identify districts in Zambia that were still recording cases of HAT. Three districts namely, Mpika, Chama, and Chipata were found to be still reporting cases of HAT and thus lay in HAT transmission foci in North Eastern Zambia. During the period under review, 24 cases of HAT were reported from these three districts. We thereafter reviewed literature on the occurrence of HAT in Zambia from the early 1960s to mid 1990s. This revealed that HAT transmission foci were widespread in Western, North Western, Lusaka, Eastern, Luapula, and Northern Provinces of Zambia during this period. In this article we have tried to give possible reasons as to why the distribution of HAT transmission foci is so different between before and after 2000 when there has been no active national tsetse fly and trypanosomiasis control program in Zambia.
Topics: Animals; Female; Health Knowledge, Attitudes, Practice; Humans; Insect Vectors; Insecticides; Male; Pest Control; Surveys and Questionnaires; Trypanosomiasis, African; Tsetse Flies; Zambia
PubMed: 21276598
DOI: 10.1016/j.trstmh.2010.12.002 -
British Medical Bulletin Apr 1985
Review
Topics: Animals; Brain Diseases; Disease Models, Animal; Humans; Trypanosomiasis, African
PubMed: 3896375
DOI: 10.1093/oxfordjournals.bmb.a072045 -
Current Opinion in Infectious Diseases Oct 2002Sleeping sickness has re-emerged as a serious problem in sub-Saharan Africa, with an estimated 100000 deaths each year. South Sudan, the Democratic Republic of Congo and... (Review)
Review
PURPOSE OF REVIEW
Sleeping sickness has re-emerged as a serious problem in sub-Saharan Africa, with an estimated 100000 deaths each year. South Sudan, the Democratic Republic of Congo and Angola have experienced serious epidemics of the Gambian form of the disease. The control of Gambian sleeping sickness, which relies primarily on active case finding followed by chemotherapy, is being threatened by problems of drug resistance. Recently, Rhodesian sleeping sickness has also posed a health risk to travellers visiting game parks in East Africa.
RECENT FINDINGS
Because of war-related constraints, which have prevented case detection, the prevalence of Gambian sleeping sickness commonly exceeds 5% and reached 29% in one focus in south Sudan. The incidence of Gambian infections refractory to melarsoprol treatment has also risen sharply in northern Uganda, northern Angola and southern Sudan, with failure rates as high as 26.9%. Molecular techniques based on the gene for human serum resistance (SRA) have enabled the identification of human infective parasites in the domestic animal reservoir. This molecular tool has shown that the Rhodesian form of the disease is being carried in cattle northwards in Uganda towards areas endemic for the Gambian form. The coalescence of distributions of the chronic and acute forms of the disease will present problems for both control and treatment.
SUMMARY
This review surveys the molecular tools that are improving our understanding of the epidemiology of sleeping sickness, and highlights the search for new diagnostics and drugs to deal with the disease.
Topics: Africa South of the Sahara; Animals; Disease Reservoirs; Drug Design; Drug Resistance; Humans; Treatment Failure; Trypanosoma brucei brucei; Trypanosomiasis, African
PubMed: 12686879
DOI: 10.1097/00001432-200210000-00004 -
Transactions of the Royal Society of... Apr 2002This review focuses on the epidemiology of human African trypanosomiasis: why it occurs in humans, the current methods of surveillance, and the drugs available to treat... (Review)
Review
This review focuses on the epidemiology of human African trypanosomiasis: why it occurs in humans, the current methods of surveillance, and the drugs available to treat it. Emphasis is placed on the identification of human-infective trypanosomes by the blood incubation infectivity test. This test distinguishes between trypanosomes that are non-infective for humans and those that are potentially infective. Currently the test requires incubation of parasites with human serum before injection into mice; any surviving parasites are considered human-infective. The factors in serum that kill all non-human-infective parasites are known as trypanosome lytic factors. The paper details the biochemistry of these factors and recommends standardization of the test based on current knowledge. This test can be used to screen animals with trypanosomiasis, in order to evaluate their role during endemic and epidemic human African trypanosomiasis.
Topics: Animals; Humans; Immunity, Innate; Lipoproteins, HDL; Trypanosoma brucei brucei; Trypanosomiasis, African
PubMed: 12055829
DOI: 10.1016/s0035-9203(02)90067-2 -
Transactions of the Royal Society of... 1980
Review
Topics: Animals; Animals, Domestic; Cattle; Cattle Diseases; Dogs; Immunity, Innate; Mice; Rabbits; Trypanosomiasis, African
PubMed: 7010695
DOI: 10.1016/0035-9203(80)90185-6 -
Nanomedicine (London, England) 2015
Topics: Animals; Drug Delivery Systems; Drug Resistance; Humans; Nanoparticles; Polymers; Trypanosoma brucei gambiense; Trypanosomiasis, African
PubMed: 26652768
DOI: 10.2217/nnm.15.167