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The Parasitic Protozoa and Helminth Worms
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
Immunity to schistosomiasis in humans does occur but is slow to develop. Most of what we know has come from studies on S. mansoni. On penetrating the host′s skin, part of the outer surface, or tegument, is shed and a new tegument formed. The tegument absorbs a number of host molecules, including red blood cell and histocompatibility antigens, that effectively disguise the worm as its host, so it is able to travel through the body and to live in its final immunologically exposed site unrecognized hence its ability to survive for five years or more. However, the worm produces a number of molecules that are immunogenic and elicit antibody responses as do eggs produced by the female worm that do not reach the outside world but are deposited locally or are carried around the body and deposited in the liver.
The Pathology of Human Schistosoma Haematobium Infection
Published in Max J. Miller, E. J. Love, Parasitic Diseases: Treatment and Control, 2020
Schistosomiasis comprises a group of chronic diseases caused by schistosomes, a genus of digenetic parasitic worms which cohabitate the venous plexes of the viscera. Schistosoma haematobium dwells principally in the perivesical venous plexus in humans and causes urinary schistosomiasis (bilharziasis), which is endemic in many parts of Africa and the Middle East, and is now considered a major public health problem.1–6
An Overview of Helminthiasis
Published in Venkatesan Jayaprakash, Daniele Castagnolo, Yusuf Özkay, Medicinal Chemistry of Neglected and Tropical Diseases, 2019
Leyla Yurttaș, Betül Kaya Çavușoğlu, Derya Osmaniye, Ulviye Acar Çevik
Schistosomiasis is a disease caused by blood flukes (trematodes) belonging to the genus Schistosoma. First described by Theodor Bilharz in the 19th century, schistosomiasis is one of the most common parasitic infections in humans. S. intercalatum, S. mansoni, S. japonicum, S. haematobium and S. mekongi species are the most common etiologic agents. The World Health Organization (WHO) estimates that more than 200 million people are infected by these parasites, making schistosomiasis the second most destructive parasitic disease after malaria. Schistosomiasis affects a large proportion of children under the age of 14 years. Humans are infected when in contact with schistosoma-infested water. Infection is developed when the cercariae, the larval form of the parasite, penetrates the skin during contact with fresh water while bathing, wading or doing laundry. Eggs, larvae, or antigen-antibody immunecomplex deposits of the Schistosoma spp. can settle in any organ or body tissue, including the eyes. The symptoms of human schistosomiasis are mainly due to immune reaction against the invading and migrating larvae and later against the parasite eggs present in the host tissue (Leutscher and Magnussen 2017, Orefice et al. 2016, Kim et al. 2016, Linquist and Cross 2017).
Modeling the transmission phenomena of water-borne disease with non-singular and non-local kernel
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
Wejdan Deebani, Rashid Jan, Zahir Shah, Narcisa Vrinceanu, Mihaela Racheriu
It is well-known that schistosomiasis is a parasite illness transmitted by water that affects people as well as other animals including dogs, sheep, buffaloes, cattle and pigs (Kabatereine et al. 2014). It is a zoonotic illness spread by the dioecious schistosoma intravascular resident fluke (Gao et al. 2014; Walz et al. 2015); furthermore, it is a parasitic trematodiasis produced by schistosoma species, among which S. intercalatum and S. mekongi are of local concern while S. haematobium, S. japonicum and S. mansoni are of worldwide public health significance (Ismail et al. 2014). We focus on schistosoma haematobium which is the common schistosoma species in Sub-Saharan Africa and has been related to increased HIV prevalence and cancer development. It is known that urogenital schistosomiasis is caused by S. haematobium and is transmitted by Bulinus snails (Liu et al. 2011). By coming into touch with cercariae-infested freshwater, the parasite is spread to both human and nonhuman animal populations. Cercariae enters the epidermis and changes into an adaptable schistosomula that can evade the immune system of the host. The schistosomula move to the lungs in humans, where it matures and produce eggs (Adenowo et al. 2015). After the hatching of eggs in urine, the miracidia infect amphibious snails after entrance, resulting in the formation of sporocysts. The larval cercariae are then produced asexually by sporocysts (Ismail et al. 2014).
Mass spectrometry based metabolomics for small molecule metabolites mining and confirmation as potential biomarkers for schistosomiasis – case of the Okavango Delta communities in Botswana
Published in Expert Review of Proteomics, 2022
Sedireng M. Ndolo, Matshediso Zachariah, Lebotse Molefi, Nthabiseng Phaladze, Kwenga F. Sichilongo
MS is usually interfaced with a variety of separation techniques to provide high selectivity and specificity for the qualitative identification of appropriate metabolites. On the other hand, NMR is nondestructive, noninvasive, and fast. However, while MS can be coupled to LC, GC, or CE to enhance its robustness, NMR is limited by its lower sensitivity and unaccounted loss of low concentration metabolites, or overlay of signals in some regions that interfere with metabolite identification [76]. The key focus of both platforms is the identification of metabolites in infected versus non-infected control samples for possible diagnostic biomarkers using data processing and multivariate techniques. These techniques, though not labor-intensive, require stringent and laborious data manipulation procedures that often employ a combination of software packages for data filtration. Data filtration enables the removal of false positives, and uses multivariate statistical analysis and comparison with databases for identification purposes. In the area of biomedical research, the evolution of schistosomiasis diagnostics has been advancing with technological platforms capable of diagnosing the disease at different stages of infection [77]. However, this evolution is mostly evident in low-endemic or imported-schistosomiasis areas inhabited by high-income dwellers.
Controlled human infection models to evaluate schistosomiasis and hookworm vaccines: where are we now?
Published in Expert Review of Vaccines, 2021
Jan Pieter R. Koopman, Emmanuella Driciru, Meta Roestenberg
Schistosomiasis affects the lives of more than 200 million people. The most significant health risks related to schistosomiasis are caused by eggs that get trapped in tissue triggering a local granulomatous, inflammatory response. The subsequent scarring and fibrosis is a safety concern for a controlled human infection with schistosomes (CHI-S). One way of minimizing egg-associated pathology is using male or female worms only. Molecular techniques make it possible to reliably determine the sex of the infective larval stage [12]. Highly sensitive assays can be used to detect worm-derived circulating anodic antigen (CAA) [13]. So far, 17 healthy, Schistosoma-naïve volunteers were exposed to 10, 20, or 30 male Schistosoma mansoni cercariae. Infection was detectable in 82% of participants exposed to 20 male cercariae [14]. Multiple systemic symptoms, such as (nocturnal) fever, myalgia, and headache, were reported, indicating that acute schistosomiasis syndrome can occur even without the presence of eggs [14].