Goal and objectives of the guideline
The goal of this guideline is to provide evidence-based recommendations to countries in their efforts to accomplish schistosomiasis morbidity control and elimination as a public health problem, and to move towards interruption of transmission.
The recommendatio...ns contained herein will help countries to implement national schistosomiasis control and elimination programmes and support efforts to verify the interruption of transmission.
The specific objectives are to provide guidance on:
prevalence thresholds, target age groups and frequency of preventive chemotherapy for schistosomiasis;
establishment of water, sanitation and hygiene (WASH) and snail control activities to support control and elimination of schistosomiasis;
use of diagnostic tests in humans in low transmission areas and for moving to, and evaluating the interruption of transmission of schistosomiasis;
tools for the assessment of Schistosoma spp. infection in snail hosts; and
diagnostic tests for the assessment of schistosomiasis infection in animal reservoirs of infection
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Schistosomiasis is a helminthic infection and one of the neglected tropical diseases (NTDs). It is caused by blood flukes of the genus Schistosoma. It is an important public health problem, particularly in poverty-stricken areas, especially those within the tropics and subtropics. It is estimated th...at at least 236 million people worldwide are infected, 90% of them in sub-Saharan Africa, and that this disease causes approximately 300,000 deaths annually. The clinical manifestations are varied and affect practically all organs. There are substantial differences in the clinical presentation, depending on the phase and clinical form of schistosomiasis in which it occurs. Schistosomiasis can remain undiagnosed for a long period of time, with secondary clinical lesion. Here, we review the clinical profile of schistosomiasis. This information may aid in the development of more efficacious treatments and improved disease prognosis.
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Schistosomiasis is an infectious disease caused by helminth parasites of the genus Schistosoma. Worldwide, an estimated 250 million people are infected with these parasites with the majority of cases occurring in sub-Saharan Africa. Within Asia, three species of Schistosoma cause disease. Schistosom...a japonicum is the most prevalent, followed by S. mekongi and S. malayensis. All three species are zoonotic, which causes concern for their control, as successful elimination not only requires management of the human definitive host, but also the animal reservoir hosts. With regard to Asian schistosomiasis, most of the published research has focused on S. japonicum with comparatively little attention paid to S. mekongi and even less focus on S. malayensis. In this review, we examine the three Asian schistosomes and their current status in their endemic countries: Cambodia, Lao People’s Democratic Republic, Myanmar, and Thailand (S. mekongi); Malaysia (S. malayensis); and Indonesia, People’s Republic of China, and the Philippines (S. japonicum). Prospects for control that could potentially lead to elimination are highlighted as these can inform researchers and disease control managers in other schistosomiasis-endemic areas, particularly in Africa and the Americas.
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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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Schistosomiasis is widely recognized as a disease that is socially determined. An understanding of the social and behavioural factors linked to disease transmission and control should play a vital role in designing policies and strategies for schistosomiasis prevention and control. To this must be a...dded the awareness that schistosomiasis is also a disease of poverty. It still survives in poverty-stricken, remote areas where there is little or no safe water or sanitation, and health care is scarce or non-existent. For a variety of complex reasons, many of which are addressed in this book, the disease is particularly prevalent in sub-Saharan Africa, and persists in certain areas of rural China. This concern for human behaviour in an environment of poverty echoes the concerns of the new research priority for “diseases of poverty” identified by the Special Programme for Research & Training in Tropical Diseases.
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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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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, 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, also known as bilharzia, is a disease caused by parasitic worms that require two hosts: humans and certain species of snails. There are two forms of the disease, namely, intestinal schistosomiasis, caused by Schistosoma mansoni and S. japonicum, and urogenital schistosomiasis, cause...d by S. haematobium. There are less common schistosome species in some parts of the world, e.g. S. mekongi and S. intercalatum. Schistosomiasis ranks second only to malaria as the most common parasitic disease worldwide.
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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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Schistosomiasis is an acute and chronic parasitic disease caused by blood flukes (trematode
worms) of the genus Schistosoma. At least 249 million people required preventive treatment in
2012. Preventive treatment, which should be repeated over a number of years, will reduce and
prevent morbidity.
Schistosoma haematobium is a parasitic digenetic trematode responsible for schistosomiasis (also known as bilharzia). The disease is caused by penetration of the skin by the parasite, spread by intermediate host molluscs in stagnant waters, and can be treated by administration of praziquantel. Schis...tosomiasis is considered to be an important but neglected tropical disease.
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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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Health ministries currently lack effective tools for monitoring and evaluation of schistosomiasis control programmes. Egg detection can be used, but the cost, challenges of obtaining samples, and the need for trained personnel and equipment limit the frequency of monitoring. The purpose of this TPP ...is to guide the development of new diagnostic tools to reliably measure when prevalence is above or below a cut-off of 10% in school-aged children. Communities remaining above 10% require annual MDA, while communities below 10% can reduce MDA frequency as long as < 10% prevalence can be maintained. However, the lack of a reliable test has hindered the development of maintenance strategies. The test is also needed to track changes of prevalence > 10% to ensure that annual MDA is reducing overall prevalence.
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PLoS ONE 13(8): e0202499. https://doi.org/10.1371/journal.pone.0202499
This was a school-based cross-sectional study conducted in 2015 among 305 school children aged 7–16 years from two primary schools located in Ilemela and Magu Districts, north-western Tanzania. Single stool and urine samples w...ere collected from each participant and examined for the presence of Schistosoma mansoni eggs, parasite antigen, and parasite DNA using KK thick smears, POC-CCA tests, and real-time PCR, respectively.
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