Chagas disease (American trypanosomiasis) is caused by the protozoan parasite Trypanosoma cruzi, and transmitted to humans by infected triatomine bugs, and less commonly by transfusion, organ transplant, from mother to infant, and in rare instances, by ingestion of contaminated food or drink.1-4 The... hematophagous triatomine vectors defecate during or immediately after feeding on a person. The parasite is present in large numbers in the feces of infected bugs, and enters the human body through the bite wound, or through the intact conjunctiva or other mucous membrane.
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Theodor Bilharz, a German professor of anatomy and chief of surgery at the Kasr El Ani Hospital of Cairo from 1850, first identified an infective organism, Distomum hematobium in 1851, which was renamed Schistosoma haematobium in 1858. It arose from a cestode worm, Hymenoleptis nana, lying in the sm...all colon of an Egyptian patient. He also discovered a trematode worm at the same time from an autopsy, thought to be the cause of urinary Schistosomiasis. Bilharz died from typhoid fever in 1862 at the age of 37. The Theodor Bilharz Research Institute in Giza, Egypt, stands as a tribute to him today. F. Milton published the first recorded peer-reviewed article report on Schistosomiasis in 1914.
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Schistosomiasis is a neglected tropical disease of global medical and veterinary importance. As efforts to eliminate schistosomiasis as a public health problem and interrupt transmission gather momentum, the potential zoonotic risk posed by livestock Schistosoma species via viable hybridisation in s...ub-Saharan Africa have been largely overlooked. We aimed to investigate the prevalence, distribution, and multi-host, multiparasite transmission cycle of Haematobium group schistosomiasis in Senegal, West Africa.
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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.
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Human schistosomiasis, a parasitic and often chronic illness, is one of the major neglected tropical diseases worldwide. It is estimated that 240 million people suffer from schistosomiasis, with more than 200000 fatalities recorded each year. Schistosomiasis is caused by an infection of the blood fl...uke Schistosoma and is transmitted to humans through direct contact with infected water.
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In support of the London Declaration goals, PATH aims to catalyze engagement of the diagnostics industry and product development efforts. As part of this work, PATH conducted a diagnostic landscape analysis to identify gaps and evaluated current and nascent HAT diagnostics that may provide solutions....
We conducted literature reviews and interviews with key stakeholders to identify use cases for HAT diagnostics, understand current practices, and analyze progress toward more robust diagnostics across
different biomarkers.
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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
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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.
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This analysis focused on the chronic form of HAT caused by T. b. gambiense, as it contributes to the majority of disease burden. Information from the literature review,
product development landscape, and stakeholder interviews was compiled to:
- Identify use cases and understand current diagnosti...c practices and tools associated with each use case.
- Analyze progress toward robust diagnostics for HAT across different biomarkers.
- Develop recommendations for steps to improve the availability, access, and adoption of HAT diagnostic tools.
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Taenia saginata is a zoonotic tapeworm that is of economic importance in countries where cattle are kept. The parasite is transmitted from human tapeworm carriers (taeniosis) to bovines (cysticercosis) by excretion of eggs or proglottids containing eggs into the environment via the stool. Bovines ca...n then ingest the eggs through contaminated feed or water. After ingestion, the eggs hatch and release oncospheres in the small intestines, where the oncospheres penetrate the intestinal wall to reach the blood circulation. This distributes them throughout the body, but primarily to muscle tissue, where they develop into cysticerci. For humans to become infected with T. saginata, raw or undercooked bovine meat or offal containing infective cysts must be consumed. Bovine cysticercosis has been associated with various environmental factors related to water sources, such as animals having access to surface water, flooding of pastures and proximity to wastewater sources.
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The epidemiology of the disease is mediated by the interaction of the parasite (trypanosome) with the vectors (tsetse flies), as well as with the human and animal hosts within a particular environment. Related to these interactions, the disease is confined in spatially limited areas called “foci..., which are located
in Sub-Saharan Africa, mainly in remote rural areas. The risk of contracting HAT is, therefore, determined by the possibility of contact of a human being with an infected tsetse fly. Epidemics of HAT were described at the beginning of the 20th century; intensive activities have been set up to confront the disease, and it was under control in the 1960s, with fewer than 5,000 cases reported in the whole continent.
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Frequently Asked Questions on Visceral Leishmaniasis
Diabetes mellitus (DM) is a global epidemic with significant morbidity. Diabetic
retinopathy (DR) is the specific microvascular complication of DM and affects 1 in 3 persons with DM. DR remains a leading cause of vision loss in working adult populations. Patients with severe levels of DR are report...ed to have poorer quality of life and reduced levels of physical, emotional, and social well-being, and they utilize more health care resources.
Epidemiological studies and clinical trials have shown that optimal control of blood glucose, blood pressure, and blood lipids can reduce the risk of developing retinopathy and slow its progression. Timely treatment with laser photocoagulation, and increasingly, the appropriate use of intraocular administration of vascular endothelial growth factor (VEGF) inhibitors can prevent visual loss in vision- threatening retinopathy, particularly diabetic macular edema (DME). Since visual loss may not be present in the earlier stages of retinopathy, regular screening of persons with diabetes is essential to enable early intervention.
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Chagas disease is currently endemic and also predicted to be at increased transmission risk under future climate change scenarios. Similarly, an expansion of areas in the United States at increased risk for Chagas disease transmission is also expected over the next several decades under climate chan...ge scenarios. Of particular interest is the predicted northern shift of triatomine species to central regions of the United States with historically unsuitable climates for T. cruzi vectors. The weight of evidence regarding the influences climate change may pose on T. cruzi vector species distributions demonstrates the sensitivity of Chagas disease transmission to future climate variability. In order to advance forecasts for the impact climate change may have on Chagas disease transmission in the Americas, it is imperative to
further develop, utilize, and perhaps combine predictive species distribution modeling approaches that integrate accurate, long term data on climate variables, vector species distributions, Chagas disease incidence, as well as other socio-ecological variables.
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Diagnosis, Case Management Prevention and Control of Leptospirosis
I examine the effectiveness of donors in targeting the highest burden of malaria in the Democratic Republic of Congo when health information structure is fragmented. I exploit local variations in the burden of malaria induced by mining activities as well as financial and epidemiological data from he...alth facilities to estimate how local aid is matching local health needs. Using a regression discontinuity design, I find significant but quantitatively small variations in aid to health facilities located within mining areas. Comparing local aid with the additional cost of treatment and prevention associated with the increased risk of malaria transmission, I find suggestive evidence that local populations with the highest burden of the disease receive a proportionately lower share of aid compared to neighbouring areas with reduced exposure to malaria infection. The evidence of disparities in the allocation of aid for malaria supports the view that donors may have inaccurate information about local population needs.
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Buruli ulcer (BU) is a bacterial skin infection that is caused by Mycobacterium ulcerans and mainly affects people who reside in the rural areas of Africa and in suburban and beach resort communities in Australia.