The protozoan parasite Trypanosoma cruzi causes Chagas disease, an important public health problem throughout Latin America. Current therapeutic options are characterised by limited efficacy, long treatment regimens and frequent toxic side-effects. Advances in this area have been compromised by gaps... in our knowledge of disease pathogenesis, parasite biology and drug activity. Nevertheless, several factors have come together to create a more optimistic scenario. Drug-based research has become more systematic, with increased collaborations between the academic and commercial sectors, often within the framework of not-for-profit consortia. High-throughput screening of compound libraries is being widely applied, and new technical advances are helping to streamline the drug development pipeline. In addition, drug repurposing and optimisation of current treatment regimens, informed by laboratory research, are providing a basis for new clinical trials. Here, we will provide an overview of the current status of Chagas disease drug development, highlight those areas where progress can be expected, and describe how fundamental research is helping to underpin the process.
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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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The sub-Saharan African region, carries 90% of the over 250 million cases of schistosomiasis occurring worldwide. In this region, after Nigeria, Tanzania is second country having the highest cases of schistosomiasis and approximately 51.5%0 of the Tanzanian population is either exposed or live in ar...eas with high risk of exposure. The country is endemic to both Schistosoma mansoni and Schistosoma haematobium, these infections are common in communities characterised with limited access to water, sanitation, hygienic practices and health services. Schistosoma mansoni infection is associated with hepatosplenic disease characterised with hepatomegaly, splenomegaly, progressive periportal fibrosis (PPF) which can lead to portal hypertension and its related sequelae, mainly ascites, liver surface irregularities, oesophageal varices and haematemesis. The main consequences of S. haematobium infection are haematuria, dysuria, nutritional deficiencies, urinary bladder lesions, hydronephrosis, urinary bladder squamous cell carcinoma and in children, growth retardation. Preventive chemotherapy using mass drug administration (MDA) of praziquantel targeting primary school aged children is the main strategy for controlling schistosomiasis in Tanzania.
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Urogenital schistosomiasis is a common neglected tropical disease in many rural communities in African countries, with patches of infection in the Eastern Mediterranean Region. Globally, an estimated 239 million people are currently infected, with burden estimated at more than 3.5 million disability...-adjusted life years (DALYs). In many endemic areas, severely infected individuals may suffer fibrosis of the bladder, kidney damage, bladder cancer, and death if untreated. This, however, depends on several factors such as host-parasite genetics, degree and length of exposure, intensity of infection, host immune response to the parasites, and coinfections with other tropical diseases such as malaria and HIV-1.
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Human schistosomiasis otherwise called bilharzia, is a fresh- water snail transmitted intravascular debilitating disease resulting from infection by the parasitic dimorphic Schistosoma trematode worms, which lives in the bloodstream of humans. The World Health Organization (WHO) regards the disease ...as a neglected tropical disease, with an estimated 732 million persons being vulnerable to infection worldwide in renowned transmission areas. Steinmann and co-workers documented that over 200 million individuals from Africa, Asia, and South America are infected with this disease. The WHO further estimated that schistosome infections and geohelminths accounts for over 40% of the world tropical disease burden with the exclusion of malaria. Humans get infected with this disease when they make contact with water contaminated with the skin-penetrating cercariae. Prevalence of schistosomiasis, at present, is still high in sub-Saharan Africa. In 2008, 17.5 million people were treated globally for schistosomiasis, 11.7 million of those from sub-Saharan Africa only. Approximately 120 million individuals in sub-Saharan Africa have schistosomiasis-related symptoms while about 20 million undergo hardship as a result of chronic presentations of the disease.
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Schistosomiasis, commonly known as bilharzia, is an acute and chronic tropical disease caused by trematodes of the genus Schistosoma. The schistosome parasite is transmitted through a snail intermediate host with the human being the definitive host. Worldwide, schistosomiasis continues to cause a pu...blic health problem with 779 million people exposed to the infection. The disease is present in 78 countries and endemic in 52 of those countries where an estimated 90% of people need treatment. Schistosomiasis has been successfully controlled in many countries but its burden remains high in Africa, particularly in sub-Saharan countries.
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Schistosomiasis, which is the second most important parasitic infection after malaria in terms of its socioeconomic impact, is responsible for the loss of an estimated 4.5 million disability-adjusted life years (DALYs) worldwide. Schistosomiasis, including both intestinal and urinary forms of the di...sease, occurs in 78 countries across the globe. An estimated 240 million people are infected, with more than 779 million living at risk globally. The majority of those infected and those at risk for infection live in low-income countries, and approximately 80% of the morbidity occurs in impoverished communities and households in sub-Saharan Africa. Within Uganda, 91 of the 134 districts are endemic for intestinal schistosomiasis caused by Schistosoma mansoni, and the eastern region, especially along Lake Victoria, has one of the highest S. mansoni burdens worldwide. Schistosoma haematobium is only endemic in the five districts of the Lango region in northern Uganda.
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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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Schistosomiasis is a prevalent parasitic, neglected tropical disease (NTD) affecting over 220 million people globally, especially in sub-Saharan Africa (SSA). The pathology of this disease in terms of intestinal, liver and urinary presentations is well-known, yet its chronic effect on host genitalia... is often ignored or overlooked. Male genital schistosomiasis (MGS) is a gender-specific manifestation of urogenital schistosomiasis (UGS), associated with the presence of Schistosoma haematobium eggs and related pathologies in genitalia of men inhabiting or visiting endemic areas in SSA. Despite the first reported by Madden, the epidemiology, diagnostic testing and case management of MGS are not well-described owing to limited research and diminishing focus over several decades.
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HIV-1 infection disproportionately affects women in sub-Saharan Africa, where areas of high HIV-1 prevalence and Schistosoma haematobium endemicity largely overlap. Female genital schistosomiasis (FGS), caused most frequently by S. haematobium egg deposition in the genital tract, has been associated... with prevalent HIV-1 infection in cross-sectional studies. The presence of S. haematobium eggs in genital tissue is also associated with vascularization and the accumulation of CD4+ lymphocytes and macrophages, making the granuloma-associated environment a potential contributor to HIV-1 vulnerability. In addition to modulation of the local cervicovaginal environment, FGS has also been associated with a higher frequency of systemic CD4 T-cells expressing the chemokine receptor CCR5. Tissue-entrapped eggs are also associated with clinically visible FGS-associated manifestations in the cervicovaginal mucosa. FGS lesions may breach the intact cervicovaginal immune barrier and are hypothesized to provide an entry point for HIV-1 infection. However, the underlying mechanism for potential HIV-1 vulnerability in FGS has not been fully characterized and requires further investigation.
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PLoS Neglected Tropical diseases August 16, 2021 https://doi.org/10.1371/journal.pntd.0009697
Chagas disease, also known as American trypanosomiasis, is a neglected tropical disease transmitted by triatomine insects, first identified in 1909. Chagas disease affects approximately 6–7 million peop...le globally and is highly prevalent in Latin America where most cases are reported. However, there is increasing evidence that Chagas disease is now an important public health issue outside the “classical” endemic countries due to population migration. Our understanding of Chagas disease, including its pathologies and factors relating to progression, remains to date limited, and is also challenged by lack of diagnosis and highly effective treatment. This systematic review aims to describe studies with Chagas patients receiving antiparasitic treatment. Databases were searched for relevant studies published after 1997, and the results of these searches were screened.
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A qualitative assessment of knowledge gaps about female genital schistosomiasis among communities living in Schistosoma haematobium endemic districts of Zanzibar and Northwestern Tanzania.
PloS Neglected Tropical Diseases September 30, 2021 https://doi.org/10.1371/journal.pntd.0009789
Schistosoma... haematobium causes urogenital schistosomiasis and is widely distributed in Tanzania. In girls and women, the parasite can cause Female Genital Schistosomiasis (FGS), a gynecological manifestation of schistosomiasis that is highly neglected and overlooked by public health professionals and policy makers. This study explored community members’ knowledge, attitudes and perceptions (KAP) on and health seeking behavior for FGS.
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Pathogens . 2021 Nov 16;10(11):1493.doi: 10.3390/pathogens10111493
.Chronic manifestations of Chagas disease present as disabling and life-threatening condi-tions affecting mainly the cardiovascular and gastrointestinal systems. Although meaningful research has outlined the different molecular mech...anisms underlying Trypanosoma cruzi’s infection and the host-parasite interactions that follow, prompt diagnosis and treatment remain a challenge, particu-larly in developing countries and also in those where the disease is considered non-endemic. This review intends to present an up-to-date review of the parasite’s life cycle, genetic diversity, virulence factors, and infective mechanisms, as well as the epidemiology, clinical presentation, diagnosis, and treatment options of the main chronic complications of Chagas disease.
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Rev. Panam Salud Publica. 2017;41:e153. doi: 10.26633/RPSP.2017.153
Worldwide, over 6 million people are infected with Trypanosoma cruzi, the pathogen that causes Chagas disease (CD). In the Americas, CD creates the greatest burden in disability-adjusted life years of any parasitic infection. In Co...lombia, 437 000 people are infected with T. cruzi, of whom 131 000 suffer from cardiomyopathy. Colombia’s annual costs for treating patients with advanced CD reach US$ 175 016 000. Although timely etiological treatment can significantly delay or prevent development of cardiomyopathy—and costs just US$ 30 per patient—fewer than 1% of people with CD in Colombia and elsewhere receive it.
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This is a summary of the following peer-reviewed, scientific article:
Comparative Evaluation of Immunoassays to Improve Access to Diagnosis for Chagas Disease in Colombia.
Microorganisms . 2022 Jul 14;10(7):1427.
Chagas disease (CD) is endemic in about 21 countries of the Americas. The disease has spread to recently Chagas-free regions, mainly due to migration, and can now also be diagnosed in countries such as the USA, Canada, many European and some African, eastern... Mediterranean and western Pacific countries. About 6 million people are infected and 70 million live with a daily risk of infection. Although many efforts have been made to control the disease, and some improvements were achieved, still, less than about 1% of the infected have access to diagnosis and treatment. This causes high morbidity and mortality rates with more than 12,000 deaths per year
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Research and Reports in Tropical Medicine 2022:13 25–40
Chagas disease (CD) or American trypanosomiasis is a neglected parasitic disease associated with significant mortality and morbidity that includes long-term disability, social stigma and a mental health toll. Perceived as a disease of the ve...ry poor, this infection, once limited to rural areas of Latin America (LA), has now spread via migration to non-endemic areas and countries, where transmission is maintained via non-vectorial routes.
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J Clin Med . 2020 May 18;9(5):1517. doi: 10.3390/jcm9051517.
Chagas disease (CD) is a major burden in Latin America, expanding also to non-endemic countries. A gold standard to detect the CD causing pathogen Trypanosoma cruzi is currently not available. Existing real time polymerase chain reaction...s (RT-PCRs) lack sensitivity and/or specificity. We present a new, highly specific RT-PCR for the diagnosis and monitoring of CD.
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Revista Médica del Hospital General de México, Vol. 81. Issue 3.Pages 154-164 (July - September 2018)
Chagas disease is a parasitic zoonosis caused by Trypanosoma cruzi, a protozoan whose transmission to humans is primarily vector-borne. It is estimated that 6–8 million people worldwide are inf...ected and that 65–100 million people are at risk of becoming infected. Its clinical spectrum is very broad. During the acute phase, non-specific manifestations develop that may go unnoticed. During the chronic phase, specific manifestations develop that are diagnosed late and increase the morbidity and mortality of those suffering from it.
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Lymphatic filariasis (LF) infection if untreated results in fluid accumulation in the limbs or breasts (lymphedema) or genitalia (hydrocele) that is painful and causes great discomfort. Morbidity management and disability prevention (MMDP) strategies such as surgery for hydrocele, treatment of acute... attacks and management of lymphedema are necessary for the management of the advanced stages of LF. However, very few countries including Zambia, have adequate information on the health beliefs and health seeking behavior of communities living in endemic areas towards MMDP services for LF. This study sought to explore community and health provider perspectives towards MMDP services for LF in a highly endemic region, Luangwa District, Zambia, between February and April 2019.
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