Journal articles: 'Schistosoma spp'

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Crego-Vicente, Beatriz, Pedro Fernández-Soto, Begoña Febrer-Sendra, Juan García-Bernalt Diego, Jérôme Boissier, Etienne K. Angora, Ana Oleaga, and Antonio Muro. "Application of a Genus-Specific LAMP Assay for Schistosome Species to Detect Schistosoma haematobium x Schistosoma bovis Hybrids." Journal of Clinical Medicine 10, no. 6 (March 22, 2021): 1308. http://dx.doi.org/10.3390/jcm10061308.

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Schistosomiasis is a disease of great medical and veterinary importance in tropical and subtropical regions caused by different species of parasitic flatworms of the genus Schistosoma. The emergence of natural hybrids of schistosomes indicate the risk of possible infection to humans and their zoonotic potential, specifically for Schistosoma haematobium and S. bovis. Hybrid schistosomes have the potential to replace existing species, generate new resistances, pathologies and extending host ranges. Hybrids may also confuse the serological, molecular and parasitological diagnosis. Currently, LAMP technology based on detection of nucleic acids is used for detection of many agents, including schistosomes. Here, we evaluate our previously developed species-specific LAMP assays for S. haematobium, S. mansoni, S. bovis and also the genus-specific LAMP for the simultaneous detection of several Schistosoma species against both DNA from pure and, for the first time, S. haematobium x S. bovis hybrids. Proper operation was evaluated with DNA from hybrid schistosomes and with human urine samples artificially contaminated with parasites’ DNA. LAMP was performed with and without prior DNA extraction. The genus-specific LAMP properly amplified pure Schistosoma species and different S. haematobium-S. bovis hybrids with different sensitivity. The Schistosoma spp.-LAMP method is potentially adaptable for field diagnosis and disease surveillance in schistosomiasis endemic areas where human infections by schistosome hybrids are increasingly common.

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MANNECK, THERESIA, JENNIFER KEISER, and JOACHIM MÜLLER. "Mefloquine interferes with glycolysis in schistosomula of Schistosoma mansoni via inhibition of enolase." Parasitology 139, no. 4 (February 6, 2012): 497–505. http://dx.doi.org/10.1017/s0031182011002204.

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SUMMARYThe antimalarial drug mefloquine has promising antischistosomal properties killing haematophagous adult schistosomes as well as schistosomula. The mode of action and involved drug targets of mefloquine in Schistosoma mansoni schistosomula are unknown. In order to identify mefloquine-binding proteins and thus potential drug targets, mefloquine affinity chromatography with S. mansoni schistosomula crude extracts was performed. We found one specific mefloquine-binding protein that was identified by mass spectrometry as the glycolytic enzyme enolase (Q27877). Enolase activity assays were performed on schistosomula crude extracts and on the recombinant enolase Q27877 expressed in Escherichia coli. In schistosomula crude extracts enolase activity was inhibited by mefloquine and by the enolase inhibitor sodium fluoride, while activity of the recombinant enolase was not affected. In contrast to enolase from crude extracts, recombinant Q27877 did not bind to mefloquine-agarose. Using isothermal microcalorimetry, we next investigated the metabolic inhibition of mefloquine and 3 known glycolytic inhibitors in Schistosoma spp., namely sodium fluoride, 3-bromopyruvate and menadione on schistosomula in the presence or absence of glucose. We found that in the presence of glucose, schistosomula were less affected by mefloquine, sodium fluoride and 3-bromopyruvate, whereas glucose had no protective effect when schistosomula had been exposed to menadione. These results suggest a potential role of mefloquine as an inhibitor of glycolysis, at least in stages where other targets like haem degradation are not relevant.

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Tuffour, Isaac, Irene Ayi, Theresa Manful Gwira, Edward Dumashie, Yvonne Ashong, and Regina Appiah-Opong. "Schistosoma Egg Antigen Induces Oncogenic Alterations in Human Prostate Cells." Analytical Cellular Pathology 2018 (December 9, 2018): 1–10. http://dx.doi.org/10.1155/2018/4675380.

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Schistosomiasis is a neglected tropical disease that affects 200 million people and accounts for 100,000 deaths annually. In endemic geographical areas, schistosomiasis has been implicated as an etiological agent in the pathogenesis of bladder, colorectal, and renal carcinoma largely due to Schistosoma eggs in tissues that comes with chronic infection. Several studies have also reported cases of association between Schistosoma infection and prostate cancer. The possible causal association is however poorly understood. We hypothesized in this study that infection of the prostate cells with Schistosoma spp promotes cancer. Urine samples from individuals living in Galilea, a schistosomiasis endemic community in the Ga South District of Ghana, were collected and screened for Schistosoma infection via microscopy and multiplex PCR. Soluble egg antigens (SEA) were prepared from Schistosoma egg-positive urine samples and assessed for the ability to induce cancer-like phenotypes including excessive proliferation, oxidative stress (reduced glutathione (GSH) depletion), and diminished apoptosis in cultured human prostate (PNT2) cells. Molecular analysis revealed infecting schistosome species to be S. haematobium and S. mansoni. Prostate cell proliferation was significantly induced by 12.5 μg/ml SEA (p=0.029). Also, SEA dose-dependently depleted cellular GSH. Flow cytometric analysis and fluorescence staining revealed that SEA dose-dependently diminished apoptosis, significantly, in prostate cells. Findings of this study suggest that schistosome infection may play a role in the pathogenesis of prostate cancer. In vivo studies are however needed to confirm this association.

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James, Stephanie L. "Schistosoma spp.: Progress toward a defined vaccine." Experimental Parasitology 63, no. 3 (June 1987): 247–52. http://dx.doi.org/10.1016/0014-4894(87)90170-6.

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Castillo, Jesus Rico, Diana Alame, Madalina Tuluc, Michelle Nagurney, and Noha Ghusson. "Acute Appendicitis Associated With Schistosoma Species." American Journal of Clinical Pathology 152, Supplement_1 (September 11, 2019): S60—S61. http://dx.doi.org/10.1093/ajcp/aqz113.058.

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Abstract Objectives Schistosomiasis is a public health problem in tropical regions of the world, highly endemic in sub-Saharan Africa but uncommon in the United States. It is considered second only to malaria as the most devastating human parasitic diseases, and it is mainly classified as urinary or intestinal. Here we report a rare case of acute appendicitis associated with Schistosoma spp. Case Presentation A 28-year-old male presented to our institution in October 2018 with a 2-day history of periumbilical and right lower quadrant abdominal pain associated with nausea, vomiting, fever, and chills. CT scan of the abdomen in the emergency department showed hyperenhancement of the appendix, with an increased diameter of 10 mm and infiltration of the adjacent fat, compatible with appendicitis. The patient was administered intravenous piperacillin-tazobactam and underwent an uncomplicated laparoscopic appendectomy. Histopathological examination of the appendectomy specimen reveals neutrophilic infiltrate of the wall consistent with acute appendicitis, with granulomatous inflammation surrounding parasitic eggs measuring 60 by 37 μm morphologically consistent with Schistosoma spp. within the wall. Additionally, Ziehl-Neelsen stained negative. Significant travel history included a trip to Lake Malawi approximately 9 years prior to this presentation where he frequently swam in freshwater lakes. He does not recall developing an acute illness associated with this travel. Discussion Chronic schistosomiasis is the result of host immune responses to schistosome eggs that become lodged in the capillaries or organs and cause granulomatous reactions. Chronic inflammation can lead to bowel wall ulceration, hyperplasia, and polyposis and, with massive infection, to periportal liver fibrosis, dysuria, and hematuria. Small bowel involvement is very unusual and only rare cases of appendicitis have been reported worldwide. Additionally, Ziehl-Neelsen stained negative favoring other Schistosoma species instead of S mansoni, S intercalatum, or S japonicum. Fortunately, the patient underwent surgery, received praziquantel, and achieved full recovery.

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Härter, Georg, Hagen Frickmann, Sebastian Zenk, Dominic Wichmann, Bettina Ammann, Peter Kern, Bernhard Fleischer, Egbert Tannich, and Sven Poppert. "Diagnosis of neuroschistosomiasis by antibody specificity index and semi-quantitative real-time PCR from cerebrospinal fluid and serum." Journal of Medical Microbiology 63, no. 2 (February 1, 2014): 309–12. http://dx.doi.org/10.1099/jmm.0.066142-0.

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We describe the case of a 16-year-old German male expatriate from Ghana who presented with obstipation, dysuria, dysaesthesia of the gluteal region and the lower limbs, bilateral plantar hypaesthesia and paraesthesia without pareses. A serum–cerebrospinal fluid (CSF) Schistosoma spp. specific antibody specificity index of 3.1 was considered highly suggestive of intrathecal synthesis of anti-Schistosoma spp. specific antibodies, although standardization of this procedure has not previously been described. Diagnosis was confirmed by detection of Schistosoma DNA in CSF by semi-quantitative real-time PCR at 100-fold concentration compared with serum. Accordingly the two diagnostic procedures, which have not previously been applied for routine diagnosis, appear to be useful for the diagnosis of neuroschistosomiasis. Clinical symptoms resolved following anthelmintic and anti-inflammatory therapy.

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Pereira, Tiago Campos, Cláudia Carolina Silva Evangelista, Gustavo Borges, Eliana Maria Zanotti-Magalhães, Luiz Augusto Magalhães, and Iscia Lopes-Cendes. "Applications of RNA Interference in Schistosomiasis: Gene Function Identification and Development of New Therapies." ISRN Parasitology 2013 (December 31, 2013): 1–10. http://dx.doi.org/10.5402/2013/247036.

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The study of Schistosoma species has undergone a dramatic change in recent years mainly due to transcriptome, proteome, and genome analyses. In order to better understand the biology of the parasite and to develop new and more efficient/specific drugs, scientists have now the task to translate genetic information into functional data. The present paper aims to review the use of RNA interference (RNAi), a versatile technique used in gene silencing, for the dissection of the cellular/molecular biology of Schistosoma spp. In addition, we will review information on the recent development of a new generation of RNA-based drugs. Examples of specific experimental approaches will be presented and discussed, such as identification of gene function, development of therapies by targeting eggs, miracidia (as a strategy for environmental use), sporocysts (for infestation control in the intermediate host), and schistosomula/adult worms (as a treatment strategy). Furthermore, some of the main advantages, drawbacks, and future directions of these new applications and techniques will also be discussed.

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Navarro, Rohani C., Aleyla E. de Cadiz, Jordan M. Fronda, Lynnell Alexie D. Ong, and Vicente Y. Belizario Jr. "Prevalence of Schistosoma japonicum infection in water buffaloes in selected areas in Davao del Norte and Davao de Oro, the Philippines." January-July 7, no. 1 (February 16, 2021): 12–18. http://dx.doi.org/10.14202/ijoh.2021.12-18.

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Background and Aim: Schistosomiasis (SCH) japonica is a zoonotic disease that can infect several mammalian hosts. Bovines, particularly water buffaloes, are considered the most important reservoir hosts due to the high levels of schistosome eggs, they excrete into the environment. In the Philippines, the previous studies have revealed a high prevalence of SCH in bovines in selected provinces in Luzon, Visayas, and Mindanao. However, there is a lack of studies on SCH in the Davao Region, Mindanao, where the infection remains a public health concern. This study aimed to determine the prevalence of SCH in water buffaloes in four barangays (villages) each in Braulio Dujali, Davao del Norte and Maragusan, Davao de Oro, Southeastern Mindanao, the Philippines. Materials and Methods: Fecal samples from 91 water buffaloes were collected intrarectally, processed using the formalin-ethyl acetate sedimentation technique, and examined microscopically to determine the prevalence of SCH. Results: A total of three water buffaloes (8.6%) in Maragusan were determined to be positive for Schistosoma japonicum, while none in Braulio Dujali. The prevalence of other parasites (Fasciola spp. [53.8%], Paramphistome spp. [20.9%], Amphistome spp. [16.5%], Strongyle spp. [11.0%], Balantidium spp. [9.9%], Eurytrema spp. [2.2%], and Gongylonema pulchrum [1.1%]) was also observed. Conclusion: The results of the study provide baseline data on the presence of S. japonicum in water buffaloes in the Davao Region, Mindanao. Strategies for controlling and eliminating SCH in animal reservoir hosts, especially in water buffaloes, are necessary for the long-term control and elimination of SCH in humans.

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Jones, Isabel J., Susanne H. Sokolow, Andrew J. Chamberlin, Andrea J. Lund, Nicolas Jouanard, Lydie Bandagny, Raphaël Ndione, et al. "Schistosome infection in Senegal is associated with different spatial extents of risk and ecological drivers for Schistosoma haematobium and S. mansoni." PLOS Neglected Tropical Diseases 15, no. 9 (September 27, 2021): e0009712. http://dx.doi.org/10.1371/journal.pntd.0009712.

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Schistosome parasites infect more than 200 million people annually, mostly in sub-Saharan Africa, where people may be co-infected with more than one species of the parasite. Infection risk for any single species is determined, in part, by the distribution of its obligate intermediate host snail. As the World Health Organization reprioritizes snail control to reduce the global burden of schistosomiasis, there is renewed importance in knowing when and where to target those efforts, which could vary by schistosome species. This study estimates factors associated with schistosomiasis risk in 16 villages located in the Senegal River Basin, a region hyperendemic for Schistosoma haematobium and S. mansoni. We first analyzed the spatial distributions of the two schistosomes’ intermediate host snails (Bulinus spp. and Biomphalaria pfeifferi, respectively) at village water access sites. Then, we separately evaluated the relationships between human S. haematobium and S. mansoni infections and (i) the area of remotely-sensed snail habitat across spatial extents ranging from 1 to 120 m from shorelines, and (ii) water access site size and shape characteristics. We compared the influence of snail habitat across spatial extents because, while snail sampling is traditionally done near shorelines, we hypothesized that snails further from shore also contribute to infection risk. We found that, controlling for demographic variables, human risk for S. haematobium infection was positively correlated with snail habitat when snail habitat was measured over a much greater radius from shore (45 m to 120 m) than usual. S. haematobium risk was also associated with large, open water access sites. However, S. mansoni infection risk was associated with small, sheltered water access sites, and was not positively correlated with snail habitat at any spatial sampling radius. Our findings highlight the need to consider different ecological and environmental factors driving the transmission of each schistosome species in co-endemic landscapes.

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Boes, J., A. L. Willingham, Shi Fuhui, Hu Xuguang, L. Eriksen, P. Nansen, and T. B. Stewart. "Prevalence and distribution of pig helminths in the Dongting Lake Region (Hunan Province) of the People's Republic of China." Journal of Helminthology 74, no. 1 (March 2000): 45–52. http://dx.doi.org/10.1017/s0022149x00000068.

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AbstractThe prevalence of helminths in pigs was investigated in five rural communities situated on the embankment of Dongting Lake in Zhiyang County, Hunan Province, People's Republic of China, in an area known to be endemic for Schistosoma japonicum. The helminth prevalences identified on the basis of faecal egg count analysis were: Oesophagostomum spp. (86.7%), Ascaris suum (36.7%), Metastrongylus spp. (25.8%), Strongyloides spp. (25.8%), Trichuris suis (15.8%), Globocephalus spp. (6.7%), Gnathostoma spp. (4.2%), Schistosoma japonicum (5.0%) and Fasciola spp. (1.3%). Post mortem examinations of a small number of pigs depositing eggs of different helminth species revealed the presence of Oesophagostomum dentatum, O. quadrispinulatum, A. suum, Metastrongylus apri, M. pudendotectus, T. suis, G. hispidum and Ascarops dentata. Prevalences of all helminths, with the exception of Oesophagostomum spp., were higher in young pigs (< 8 months old) compared with adult pigs. Prevalences of trematodes were very low, especially for S. japonicum which had decreased dramatically compared with previous reports from this area of P.R. China, whereas prevalences of nematodes were generally in agreement with those reported from other Yangtze River Provinces. Results from helminth prevalence studies in pigs, conducted in other provinces of P.R. China between 1987 and 1997, are presented and discussed. It was concluded that a government helminth control programme, implemented in 1995 to control S. japonicum infection in pigs in Hunan Province, may have resulted in a greatly reduced prevalence of S. japonicum in pigs in this region.

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Shahi, M. K., and K. P. Gairhe. "Prevalence of Helminths in Wild Asian Elephant and Indian Rhinoceros in Chitwan and Bardia National Park, Nepal." Nepalese Veterinary Journal 36 (December 1, 2019): 60–74. http://dx.doi.org/10.3126/nvj.v36i0.27755.

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The Nepalese elephant (Elephas maximus maximus) and rhinoceros (Rhinoceros unicornis), are an important part of Nepal’s heritage, culture and wildlife conservation. Despite its importance, not much is known about the helminth parasites that affect elephant and rhinoceros. This study investigates the prevalence of helminth parasites in wild Asian Elephant and wild Indian Rhinoceros.A study was conducted from November 2011 to April 2012 to screen helminth parasites of wild asian elephant and wild Indian Rhinoceros at Chitwan and Bardia National Park of Nepal. Total of 80 samples, 40 each taken from the Wild Asian Elephants and Indian Rhinoceros. The study showed 88.75% overall prevalence of helminthes. The prevalence in Wild Asian Elephant and Indian Rhinoceros was 95% and 82.5% respectively. 97.37% and 72.73% infection were mixed infections in elephant and rhinoceros respectively.Among 38 positive samples of the elephant of CNP and BNP, 9 different types of helminth eggs were found. 15 (39.47%) were positive for Fasciola Spp. With 450 EPG count, 11 (28.95%) for Paramphistomum spp. with 600 EPG, 27 (71.05%) for Schistosoma spp. with 500 EPG, 3 (7.89%) for Dicrocoelium spp. with 900 EPG, 12 (30.16%) for Moniezia spp. with 433.3 EPG, 17 (44.74%) for Oesophagostomum spp. with 1025 EPG, 10 (26.31%) for Chabartia spp. with 1141.65 EPG, 17 (44.74) for Strongyloides spp. with 15558.335 EPG and 23 (60.53%) for Strongylus spp. with 1700 EPG.Similarly out of the 33 positive samples of Rhinoceros of CNP and BNP, 8 different types of helminth eggs were found. 11 (33.33%) were positive for Fasciola Spp. With 558.34 EPG, 10 (30.30%) for Paramphistomum spp. with 525 EPG, 7 (21.21%) for Schistosoma spp. with 475 EPG, 4 (12.12%) for Moniezia spp. with 650 EPG, 6 (18.18%) for Strongyloides spp. with 1466.67 EPG, 4 (12.12%) for Strongylus spp. with 1625 EPG, 9 (27.27%) for Toxocara spp. with 699.98 EPG and 20 (60.61%) for Trychostrongylus spp. with 1149.98 were found to be positive.

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Gaye, Papa Mouhamadou, Souleymane Doucoure, Bruno Senghor, Babacar Faye, Ndiaw Goumballa, Mbacké Sembène, Coralie L’Ollivier, et al. "Bulinus senegalensis and Bulinus umbilicatus Snail Infestations by the Schistosoma haematobium Group in Niakhar, Senegal." Pathogens 10, no. 7 (July 8, 2021): 860. http://dx.doi.org/10.3390/pathogens10070860.

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Thorough knowledge of the dynamics of Bulinus spp. infestation could help to control the spread of schistosomiasis. This study describes the spatio-temporal dynamics of B. senegalensis and B. umbilicatus infestation by the Schistosoma haematobium group of blood flukes in Niakhar, Senegal. Molecular identification of the S. haematobium group was performed by real-time PCR, targeting the Dra 1 gene in 810 samples of Bulinus spp. collected during the schistosomiasis transmission season in 2013. In addition to Dra 1 PCR, a rapid diagnostic-PCR was performed on a sub-group of 43 snails to discriminate S. haematobium, S. bovis, and S. mattheei. Out of 810 snails, 236 (29.1%) were positive for Dra 1 based on the PCR, including 96.2% and 3.8% of B. senegalensis and B. umbilicatus, respectively. Among the sub-group, 16 samples were confirmed to be S. haematobium while one was identified as a mixture of S. haematobium and S. bovis. Snails infestations were detected in all villages sampled and infestation rates ranged from 15.38% to 42.11%. The prevalence of infestation was higher in the north (33.47%) compared to the south (25.74%). Snail populations infestations appear early in the rainy season, with a peak in the middle of the season, and then a decline towards the end of the rainy season. Molecular techniques showed, for the first time, the presence of S. bovis in the Bulinus spp. population of Niakhar. The heterogeneity of snail infestations at the village level must be taken into account in mass treatment strategies. Further studies should help to improve the characterizations of the schistosome population.

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Pardo, J., C. Carranza, M. C. Turrientes, J. L. Pérez Arellano, R. López Vélez, V. Ramajo, and A. Muro. "Utility of Schistosoma bovis Adult Worm Antigens for Diagnosis of Human Schistosomiasis by Enzyme-Linked Immunosorbent Assay and Electroimmunotransfer Blot Techniques." Clinical Diagnostic Laboratory Immunology 11, no. 6 (November 2004): 1165–70. http://dx.doi.org/10.1128/cdli.11.6.1165-1170.2004.

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ABSTRACT Immunodiagnostic methods based on the detection of antibodies continue to be the most effective and practical methods for the diagnosis of imported schistosomiasis. Schistosoma bovis is a species whose final natural hosts are bovines, ovines, caprines, and small wild ruminants. Different studies have demonstrated the analogies existing between S. bovis and other Schistosoma species which affect humans. The objective of this work was to evaluate the utility of S. bovis adult worm antigens (AWA) for the diagnosis of imported human schistosomiasis by enzyme-linked immunosorbent assay (ELISA) and electroimmunotransfer blotting (EITB) techniques. By detecting eggs, the ELISA for S. bovis AWA was able to definitively detect imported cases with a sensitivity of 94%. The specificity of the ELISA for S. bovis AWA was 97%. There were no differences between the results of the S. bovis AWA ELISA for patients infected with Schistosoma mansoni and those infected with Schistosoma haematobium. The EITB technique showed bands of 85, 37, and 20 kDa, which are characteristic of infections with Schistosoma spp. Specific bands to indicate infection by different species of Schistosoma have not been detected. The combined use of the ELISA for S. bovis AWA and EITB increased the global sensitivity of the study to 97%. Our findings suggest that the ELISA for S. bovis AWA is a useful test for the immunodiagnosis of imported schistosomiasis and that EITB for detecting S. bovis AWA permits the confirmation of diagnosis when the ELISA for S. bovis AWA is positive.

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Halfter, Matthias, Ulrich Müseler, Ralf Matthias Hagen, and Hagen Frickmann. "Enteric pathogens in German police officers after predominantly tropical deployments – A retrospective assessment over 5 years." European Journal of Microbiology and Immunology 10, no. 3 (October 14, 2020): 172–77. http://dx.doi.org/10.1556/1886.2020.00026.

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AbstractIntroductionThe study was performed to assess the infection risk of German police officers on predominantly tropical deployments, mostly United Nations missions, with gastrointestinal pathogens.MethodsPolice officers were offered PCR-based screening for gastrointestinal pathogens before and after deployment. The screening panel comprised enteroinvasive bacteria (Salmonella spp., Shigella spp./enteroinvasive Escherichia coli, Campylobacter jejuni, and Yersinia spp.), enteropathogenic protozoa (Entamoeba histolytica, Giardia duodenalis, Cryptosporidium spp., and Cyclospora cayetanensis), as well as enteric helminths (Ancyclostoma spp., Ascaris lumbricoides, Enterobius vermicularis, Hymenolepis nana, Necator americanus, African Schistosoma spp., Strongyloides stercoralis, Taenia saginata, Taenia solium, and Trichuris trichiura).ResultsG. duodenalis (n = 3), C. jejuni (n = 2), Salmonella spp. (n = 1), Shigella spp./enteroinvasive E. coli (n = 3), and S. stercoralis (n = 3) were detect in 12 out of 133 (9.0%) police officers. The majority had shown gastrointestinal symptoms on deployment and all were asymptomatic at the time of medical assessment. The major infection sites were Sub-Saharan Africa followed by Northern Africa and the Middle East.ConclusionsDeployment of police officers to tropical deployment sites on United Nations missions is associated with a considerable acquisition risk of gastrointestinal pathogens in a quantitatively relevant minority. Post-deployment screening is advisable to facilitate therapeutic and hygiene-related consequences.

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Saelens, Ganna, and Sarah Gabriël. "Currently Available Monitoring and Surveillance Systems for Taenia spp., Echinococcus spp., Schistosoma spp., and Soil-Transmitted Helminths at the Control/Elimination Stage: A Systematic Review." Pathogens 9, no. 1 (January 6, 2020): 47. http://dx.doi.org/10.3390/pathogens9010047.

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An increasing global focus on neglected tropical diseases (NTDs) has resulted in the set up of numerous control and elimination activities worldwide. This is partly true for Taenia solium taeniasis/cysticercosis, the most important foodborne parasitic infection. Despite substantial progress, adequate monitoring and surveillance (M&S) are required to sustain a status of control/elimination. This is often lacking, especially for T. solium. Therefore, the objective was to conduct a systematic literature review of the currently available M&S systems at the control/elimination stage of the four top-ranked helminth NTDs. Specifically, Taenia spp., Echinococcus spp., Schistosoma spp., and soil-transmitted helminths (STHs) were considered to determine if there are any similarities between their M&S systems and whether certain approaches can be adopted from each other. The systematic review demonstrated that rigorous M&S systems have been designed for the control/elimination stage of both STHs and schistosomiasis, particularly in China. On the other hand, a concept of M&S for Taenia spp. and Echinococcus spp. has not been fully developed yet, due to a lack of epidemiological data and the fact that many endemic countries are far away from reaching control/elimination. Moreover, accurate diagnostic tools for all four diseases are still imperfect, which complicates proper M&S. Finally, there is an urgent need to develop and harmonize/standardize M&S activities in order to reliably determine and compare the epidemiological situation worldwide.

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Zhao, Guang-Hui, Juan Li, David Blair, Xiao-Yan Li, Hany M. Elsheikha, Rui-Qing Lin, Feng-Cai Zou, and Xing-Quan Zhu. "Biotechnological advances in the diagnosis, species differentiation and phylogenetic analysis of Schistosoma spp." Biotechnology Advances 30, no. 6 (November 2012): 1381–89. http://dx.doi.org/10.1016/j.biotechadv.2012.02.008.

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Abera, Bayeh, Genetu Alem, Mulat Yimer, and Zaida Herrador. "Epidemiology of soil-transmitted helminths, Schistosoma mansoni, and haematocrit values among schoolchildren in Ethiopia." Journal of Infection in Developing Countries 7, no. 03 (March 14, 2013): 253–60. http://dx.doi.org/10.3855/jidc.2539.

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Introduction: This study aimed to determine the prevalence of intestinal helminths, risk factors and haematocrit values among primary schoolchildren. Methodology: Across-sectional study was conducted in 12 primary schools in March 2011. Stool samples were randomly selected from 778 children and were microscopically examined using Kato-Katz and formal-ether concentration methods. Haematocrit values were measured using heparinized capillary tubes. Results: The overall prevalence of intestinal helminths was 51.5% (rural = 68.3%, urban = 36.2%). Hookworm spp., Schistosoma mansoni and Schistosoma stercoralis were more prevalent in rural schools, whereas Hymenolepis nana was higher in urban schools (p = 0.0001). With regard to haematocrit, 34% of rural and 21.7% of urban schoolchildren had haematocrit values below the median (40.5%) (p=0.001). Hookworm spp. and S. mansoni infected children had lower haematocrit values than non-infected children (p = 0.001). Lack of footwear was positively associated with intestinal helminths infection in rural schools [OR = 2.5 (95% CI: 1.5-4.1)], and having dirty fingernails and untrimmed fingernails were positively associated with the prevalence of intestinal helminths in urban samples [OR = 1.58 (95% CI: 1.03-2.5)]. Conclusion: The prevalence of soil-transmitted helminths and S. mansoni differs by geographical area of the schools and social determinants. Primary school de-worming and health education on proper hygiene are recommended.

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Odoya, E. M., E. U. Edosomwa, O. I. Iribhogbe, A. A. Damina, and O. A. Asojo. "Intestinal schistosomiasis in an apparently healthy rural population in Bayelsa State, Nigeria." African Journal of Clinical and Experimental Microbiology 22, no. 2 (April 8, 2021): 187–95. http://dx.doi.org/10.4314/ajcem.v22i2.11.

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Background: Schistosomiasis is endemic in Nigeria and three species; Schistosoma haematobium, Schistosoma mansoni, and Schistosoma intercalatum have been reported in Niger Delta, Nigeria. This study aimed to determine the prevalence of schistosomiasis in rural communities of Bayelsa State, Nigeria.Methodology: Four rural homogeneous communities; Otuegala, Immiringi, Otuesega, and Ibelebiri in Ogbia Local Government Area of Bayelsa State, Nigeria, were randomly selected for the study. A structured questionnaire was administered to each participant in their native language and used to collect participant’s biodata and swimming history. Stool samples collected from all participants were examined qualitatively by wet preparation and after formolethol concentration. Data were analyzed using SPSS version 20.0 software and results presented in proportion and tables.Results: A total of 829 participants (age range 1 - 80 years) were recruited for the study. Helminth ova were identified in the stool samples of 218 (26.3%) participants. Among 380 males examined, 82 (21.6%) were infected, while out of 449 females examined, 138 (30.3%) were infected. The ova of seven helminths identified and their frequency of occurrence were; S. intercalatum 86 (10.4%), Ascaris lumbricoides 53 (6.4%), S. mansoni 35 (4.2%), Trichuris trichiura 22 (2.6%), hookworm 20 (2.4%) and Taenia spp 2 (0.2%). Schistosoma haematobium was identified in non-urine contaminated stool sample of an eight-year old boy. A total of 11 (1.3%) participants had double infections, affecting 7 (63.6%) females and 4 (36.4%) males, with the commonest combination being S. intercalatum and A.lumbricoides 6 (0.7%), followed by S. intercalatum and hookworm 4 (0.5%), and S. mansoni and hookworm 1(0.1%).Conclusion: S. intercalatum was the most prevalent intestinal helminthic infection in this study, which is a rare finding in most epidemiological investigations. The affinity of Schistosoma species to establish double infections with hookworm and other intestinal helminths should be taken into account during chemoprophylaxis. Keywords: Schistosomiasis, Chemoprophylaxis, Prevalence, Rural Population

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Scholte, Ronaldo G. C., Omar S. Carvalho, John B. Malone, Jürg Utzinger, and Penelope Vounatsou. "Spatial distribution of Biomphalaria spp., the intermediate host snails of Schistosoma mansoni, in Brazil." Geospatial health 6, no. 3 (September 1, 2012): 95. http://dx.doi.org/10.4081/gh.2012.127.

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Gh. Suliman, E., and S. S. Aghwan. "Diagnostic study of infection with Schistosoma spp in sheep and cattle in Ninevah Governorate." Iraqi Journal of Veterinary Sciences 21, no. 2 (December 28, 2007): 215–27. http://dx.doi.org/10.33899/ijvs.2007.46965.

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Wang, Yu, Chun-Ren Wang, Guang-Hui Zhao, Jun-Feng Gao, Ming-Wei Li, and Xing-Quan Zhu. "The complete mitochondrial genome of Orientobilharzia turkestanicum supports its affinity with African Schistosoma spp." Infection, Genetics and Evolution 11, no. 8 (December 2011): 1964–70. http://dx.doi.org/10.1016/j.meegid.2011.08.030.

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Kann, Simone, Daniela Bruennert, Jessica Hansen, Gustavo Andrés Concha Mendoza, José José Crespo Gonzalez, Cielo Leonor Armenta Quintero, Miriam Hanke, Ralf Matthias Hagen, Joy Backhaus, and Hagen Frickmann. "High Prevalence of Intestinal Pathogens in Indigenous in Colombia." Journal of Clinical Medicine 9, no. 9 (August 28, 2020): 2786. http://dx.doi.org/10.3390/jcm9092786.

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Background: Intestinal infections remain a major public health burden in developing countries. Due to social, ecological, environmental, and cultural conditions, Indigenous peoples in Colombia are at particularly high risk. Materials: 137 stool samples were analyzed by microscopy and real-time-Polymerase Chain Reaction (RT-PCR), targeting protozoan parasites (Giardia intestinalis, Entamoeba histolytica, Cryptosporidium spp., and Cyclospora cayetanensis), bacteria (Campylobacter jejuni, Salmonella spp., Shigella ssp./enteroinvasive E. coli (EIEC), Yersinia spp., enterohemorrhagic E. coli (EHEC), enteropathogenic E. coli (EPEC), enterotoxin-producing E. coli (ETEC), enteroaggregative E. coli (EAEC), and Tropheryma whipplei), and helminths (Necator americanus, Strongyloides stercoralis, Ascaris lumbricoides, Ancylostoma spp., Trichuris. trichiura, Taenia spp., Hymenolepis nana, Enterobius vermicularis, and Schistosoma spp.). Microscopy found additional cases of helminth infections. Results: At least one pathogen was detected in 93% of the samples. The overall results revealed protozoa in 79%, helminths in 69%, and bacteria in 41%. G. intestinalis (48%), Necator/hookworm (27%), and EAEC (68%) were the most common in each group. Noteworthy, T. whipplei was positive in 7% and T. trichirua in 23% of the samples. A significant association of one infection promoting the other was determined for G. intestinalis and C. jejuni, helminth infections, and EIEC. Conclusions: The results illustrate the high burden of gastrointestinal pathogens among Indigenous peoples compared to other developing countries. Countermeasures are urgently required.

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R. Southgate, D. de Clercq, M. Sene, V. "Observations on the compatibility between Bulinus spp. and Schistosoma haematobium in the Senegal River basin." Annals of Tropical Medicine And Parasitology 94, no. 2 (March 1, 2000): 157–64. http://dx.doi.org/10.1080/00034980057491.

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Southgate, V. R., D. De Clercq, M. Sène, D. Rollinson, A. Ly, and J. Vercruysse. "Observations on the compatibility between Bulinus spp. and Schistosoma haematobium in the Senegal River basin." Annals of Tropical Medicine & Parasitology 94, no. 2 (March 2000): 157–64. http://dx.doi.org/10.1080/00034983.2000.11813524.

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Ahmed, Saad A., Umar Mohammed, Robert B. Sanda, Jerry Makama, Mohammed S. Shehu, Emmanuel A. Ameh, and Ahmed A. Mayun. "Schistosomiasis of the Appendix in a Tertiary Hospital in Northern Nigeria: A 22-Year Review." Journal of Laboratory Physicians 6, no. 01 (January 2014): 018–21. http://dx.doi.org/10.4103/0974-2727.129085.

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ABSTRACT Background: Schistosomiasis is one of the neglected tropical diseases caused by a trematode, Schistosoma spp, and affects many systems in the body including the gastrointestinal tract. Schistosomiasis of the appendix is a well-recognized disease and presents as a chronic granulomatous inflammation. This study aims to document the frequency and pattern of distribution of schistosomal appendicitis in our environment. Materials and Methods: This is a retrospective histopathological review of schistosomiasis of the appendix in the Department of Pathology, Ahmadu Bello University Teaching Hospital, Zaria - Nigeria, between January 1, 1991 to December 31, 2012. Results: Within the study period, there were 1,464 appendectomy specimens histologically examined in the Pathology Laboratory. Thirty of these, representing 2.1%, were diagnosed as schistosomiasis of the appendix. The male:female ratio was 6.5:1 and peak age incidence was in the 20-29 years age group. Abdominal pains, vomiting and fever were seen in 23 (76.7%) and altered bowel motion in seven (23.3%) patients. Conclusion: This study showed that schistosomiasis of the appendix is not rare and that its presentation is similar to other forms of appendicitis. There is a need to focus on the prevention of schistosomiasis in order to reduce morbidity among these economically viable age groups.

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Sangma, A., N. Begum, BC Roy, and MO Gani. "Prevalence of helminth parasites in sheep (Ovis aries) in Tangail district, Bangladesh." Journal of the Bangladesh Agricultural University 10, no. 2 (May 13, 2013): 235–44. http://dx.doi.org/10.3329/jbau.v10i2.14913.

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Prevalence of helminths of sheep in relation to age, sex, nutritional status, management system and flock size was studied at Tangail district, Bangladesh from July to December 2010 by fecal examination. A total of 190 sheep were examined of which 154 (81.1%) were positive for one or more species of helminth parasites. Seven species of helminths were identified, of them three species were trematodes, namely, Fasciola gigantica (8.4%), Paramphistomum spp. (44.2%) and Schistosoma indicum (3.7%); four species were nematodes, namely, Bunostomum sp (19.0%), Trichuris spp. (2.1%), Strongyles (62.6%) and Strongyloides spp. (9.5%). No cestodes were identified. Prevalence of helminths was significantly (p<0.01) higher in young sheep aged >1-2 year (92.7%) than adult aged > 2 years (83.3%) and lamb aged ? 1 year (63.6%). Higher prevalence was recorded in female than in male sheep. In relation to nutritional status and flock size, prevalence of helminths were significantly (p<0.01) higher in poor health and large flock sized animals. It is suggested that helminth infection is widely prevalent in sheep in Tangail district of Bangladesh.DOI: http://dx.doi.org/10.3329/jbau.v10i2.14913 J. Bangladesh Agril. Univ. 10(2): 235-244, 2012

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McManus, Donald P. "Recent Progress in the Development of Liver Fluke and Blood Fluke Vaccines." Vaccines 8, no. 3 (September 22, 2020): 553. http://dx.doi.org/10.3390/vaccines8030553.

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Liver flukes (Fasciola spp., Opisthorchis spp., Clonorchis sinensis) and blood flukes (Schistosoma spp.) are parasitic helminths causing neglected tropical diseases that result in substantial morbidity afflicting millions globally. Affecting the world’s poorest people, fasciolosis, opisthorchiasis, clonorchiasis and schistosomiasis cause severe disability; hinder growth, productivity and cognitive development; and can end in death. Children are often disproportionately affected. F. hepatica and F. gigantica are also the most important trematode flukes parasitising ruminants and cause substantial economic losses annually. Mass drug administration (MDA) programs for the control of these liver and blood fluke infections are in place in a number of countries but treatment coverage is often low, re-infection rates are high and drug compliance and effectiveness can vary. Furthermore, the spectre of drug resistance is ever-present, so MDA is not effective or sustainable long term. Vaccination would provide an invaluable tool to achieve lasting control leading to elimination. This review summarises the status currently of vaccine development, identifies some of the major scientific targets for progression and briefly discusses future innovations that may provide effective protective immunity against these helminth parasites and the diseases they cause.

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Esonu, D. O., G. S. N. Kia, O. Evelyn, and S. Mathias. "Occurrence of Cryptosporidium Oocysts and Helminth Ova on Dried Crayfish (Procambarus clarkii) Sold in Kaduna State, Nigeria." Folia Veterinaria 65, no. 1 (March 1, 2021): 29–36. http://dx.doi.org/10.2478/fv-2021-0004.

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Abstract Cryptosporidium spp. and helminths are responsible for diarrhoal illness in humans and many other animals. The transmission routes of these parasites suggest a risk for human infection through contaminated foods. In order to determine the occurrence of Cryptosporidium oocysts and helminth ova on dried crayfish (Procambarus clarkii) sold in Zaria and Kaduna Central market, Kaduna State, 100 crayfish samples were examined using the modified Ziehl-Neelsen staining technique for Cryptosporidium oocyst and the flotation technique for helminth ova. The measurements of the oocysts from the positive samples were estimated by using a calibrated microscope eyepiece. The prevalence of Cryptosporidium oocysts in dried crayfish was 20.0 % while the location-based prevalence was 43.3 %, 5.0 %, and 12.0 % for Sabo, Samaru and Kaduna central market, respectively. Micrometry revealed that the oocysts size ranged from 3.68 µm to 4.7 µm. Also, the prevalence of helminth ova in dried crayfish was 19 %, while the specific prevalence based on location showed a higher prevalence in Sabo (30.0 %) than in Kaduna central market (18.0 %) and Samaru (5.0 %). The helminth eggs recovered from this study included: Toxocara spp. (4.0 %), Ascaris spp. (7.0 %), Trichuris spp. (4.0 %), Schistosoma spp. (2.0 %), Ancylostoma spp. (1.0 %), and Capillaria spp. (1.0 %). The analysis of the questionnaires revealed that 71 (71.0 %) of the respondents ate uncooked cray-fish and 44.0 % used their bare hands to handle the cray-fish. There was no statistically significant association (P > 0.05) between the prevalence of Cryptosporidium oocysts or helminth ova and the locations sampled. This study has shown that dried crayfish obtained from markets within the study area were contaminated with parasite ova and oocysts, thus public enlightenment on the dangers of the consumption of raw or undercooked dried crayfish should be well publicized.

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Osada, Yoshio, Takashi Kumagai, Kyoko Masuda, Tomoyuki Suzuki, and Tamotsu Kanazawa. "Mutagenicity evaluation of Schistosoma spp. extracts by the umu-test and V79/HGPRT gene mutation assay." Parasitology International 54, no. 1 (March 2005): 29–34. http://dx.doi.org/10.1016/j.parint.2004.08.004.

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Pointier, Jean-Pierre, and Fergus McCullough. "Biological control of the snail hosts of Schistosoma mansoni in the Caribbean area using Thiara spp." Acta Tropica 46, no. 3 (May 1989): 147–55. http://dx.doi.org/10.1016/0001-706x(89)90031-4.

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Faixová, D., G. Hrčková, T. Mačák Kubašková, and D. Mudroňová. "Antiparasitic effects of selected isoflavones on flatworms." Helminthologia 58, no. 1 (February 10, 2021): 1–16. http://dx.doi.org/10.2478/helm-2021-0004.

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Summary Medicinal plants have been successfully used in the ethno medicine for a wide range of diseases since ancient times. The research on natural products has allowed the discovery of biologically relevant compounds inspired by plant secondary metabolites, what contributed to the development of many chemotherapeutic drugs. Flavonoids represent a group of therapeutically very effective plant secondary metabolites and selected molecules were shown to exert also antiparasitic activity. This work summarizes the recent knowledge generated within past three decades about potential parasitocidal activities of several flavonoids with different chemical structures, particularly on medically important flatworms such as Schistosoma spp., Fasciola spp., Echinococcus spp., Raillietina spp., and model cestode Mesocestoides vogae. Here we focus on curcumin, genistein, quercetin and silymarin complex of flavonolignans. All of them possess a whole spectrum of biological activities on eukaryotic cells which have multi-therapeutic effects in various diseases. In vitro they can induce profound alterations in the tegumental architecture and its functions as well as their activity can significantly modulate or damage worm´s metabolism directly by interaction with enzymes or signaling molecules in dose-dependent manner. Moreover, they seem to differentially regulate the RNA activity in numbers of worm´s genes. This review suggests that examined flavonoids and their derivates are promising molecules for antiparasitic drug research. Due to lack of toxicity, isoflavons could be used directly for therapy, or as adjuvant therapy for diseases caused by medically important cestodes and trematodes.

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Hoffmann, Tanja, Imke Carsjens, Raphaël Rakotozandrindrainy, Mirko Girmann, Njary Randriamampionona, Oumou Maïga-Ascofaré, Andreas Podbielski, Andreas Hahn, Hagen Frickmann, and Norbert Georg Schwarz. "Serology- and Blood-PCR-Based Screening for Schistosomiasis in Pregnant Women in Madagascar—A Cross-Sectional Study and Test Comparison Approach." Pathogens 10, no. 6 (June 8, 2021): 722. http://dx.doi.org/10.3390/pathogens10060722.

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This work was conducted as a cross sectional study to define the disease burden of schistosomiasis in pregnant Madagascan women and to evaluate serological and molecular diagnostic assays. A total of 1154 residual EDTA blood samples from pregnant Madagascan women were assessed. The nucleic acid extractions were subjected to in-house real-time PCRs specifically targeting S. mansoni complex, S. haematobium complex, and African Schistosoma spp. on genus level, while the EDTA plasma samples were analyzed using Schistosoma-specific IgG and IgM commercial ELISA and immunofluorescence assays. The analyses indicated an overall prevalence of schistosomiasis in Madagascan pregnant women of 40.4%, with only minor regional differences and differences between serology- and blood PCR-based surveillance. The S. mansoni specific real-time PCR showed superior sensitivity of 74% (specificity 80%) compared with the genus-specific real-time PCR (sensitivity 13%, specificity 100%) in blood. The laborious immunofluorescence (sensitivity IgM 49%, IgG 87%, specificity IgM 85%, IgG 96%) scored only slightly better than the automatable ELISA (sensitivity IgM 38%, IgG 88%, specificity IgM 78%, IgG 91%). Infections with S. mansoni were detected only. The high prevalence of schistosomiasis recorded here among pregnant women in Madagascar calls for actions in order to reduce the disease burden.

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Taylor, M. B., P. J. Becker, E. Janse Van Rensburg, B. N. Harris, I. W. Bailey, and W. O. K. Grabow. "A serosurvey of water-borne pathogens amongst canoeists in South Africa." Epidemiology and Infection 115, no. 2 (October 1995): 299–307. http://dx.doi.org/10.1017/s0950268800058428.

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SummaryCertain health risks have been associated with recreational exposure to faecally polluted water. Canoeing in certain South African waters is considered to be a high risk activity with regard to schistosomiasis. gastroenteritis and possibly hepatitis. In a cross-sectional study, a serosurvey was conducted amongst canoeists to ascertain whether or not they had a higher seroprevalence to hepatitis A virus. Norwalk virus andSchistosomaspp. than non-canoeists. In comparisons between the two groups, a significant association could not be demonstrated between canoeing and antibody response to hepatitis A and Norwalk viruses (P-values for age-adjustedχ2were 0·083 and 0·219 respectively), but a significant association could be demonstrated between canoeing and the antibody response to Schistosoma spp. (P> 0·001: age-adjusted).

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Fernández-Soto, Pedro, Virginia Velasco Tirado, Cristina Carranza Rodríguez, José Luis Pérez-Arellano, and Antonio Muro. "Long-Term Frozen Storage of Urine Samples: A Trouble to Get PCR Results in Schistosoma spp. DNA Detection?" PLoS ONE 8, no. 4 (April 16, 2013): e61703. http://dx.doi.org/10.1371/journal.pone.0061703.

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Githui, Elijah K., Raymond T. Damian, Rashid A. Aman, Mohamed A. Ali, and Joseph M. Kamau. "Schistosoma spp.: Isolation of microtubule associated proteins in the tegument and the definition of dynein light chains components." Experimental Parasitology 121, no. 1 (January 2009): 96–104. http://dx.doi.org/10.1016/j.exppara.2008.10.007.

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Ponte, Eduardo Vieira, José Ângelo Rizzo, and Álvaro Augusto Cruz. "Inter-relação entre asma, atopia e infecções helmínticas." Jornal Brasileiro de Pneumologia 33, no. 3 (June 2007): 335–42. http://dx.doi.org/10.1590/s1806-37132007000300016.

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Este estudo teve como objetivo descrever as principais evidências encontradas na literatura acerca da inter-relação entre infecções helmínticas, atopia e asma. Foi feita uma revisão não sistemática da literatura. Encontramos numerosas publicações sobre o tema nas quais se verifica controvérsia quanto à capacidade das infecções por geohelmintos de inibir a reatividade ao teste alérgico cutâneo e os sintomas das doenças alérgicas. Por outro lado, estudos em pacientes infectados por Schistosoma spp., apesar de escassos, sugerem que estes helmintos são capazes de inibir a reatividade ao teste alérgico cutâneo e os sintomas de asma. Nos estudos in vitro, as evidências sugerem que as helmintíases inibem as respostas imunes mediadas por linfócitos T auxiliares do tipo 1 e 2, o que abre novas possibilidades terapêuticas para o tratamento de doenças do sistema imunológico.

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Harris, R. A., T. M. Preston, and V. R. Southgate. "Purification of an agglutinin from the haemolymph of the snail Bulinus nasutus and demonstration of related proteins in other Bulinus spp." Parasitology 106, no. 2 (February 1993): 127–35. http://dx.doi.org/10.1017/s0031182000074928.

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SUMMARYThe snail Bulinus nasutus 1214 possesses a potent haemagglutinin (end-point titre with human erythrocytes, 2−18) in its cell-free haemolymph which also binds to the miracidia (but not other larvae) of the incompatible parasite Schistosoma margrebowiei. We have purified a protein possessing this haemagglutinating property from the plasma of this snail. The native Mr of this protein was estimated by SDS polyacrylamide gel electrophoresis to be 210 kDa; under denaturing conditions in a 7.5% PAGE gel it ran as a major band of 135 kDa. Proteins of similar Mr were also found in the haemolymph of 16 other Bulinus spp. (the major intermediate hosts of human and veterinary schistosomiasis in Africa) although the plasma of none of these agglutinated human erythrocytes. Nonetheless, Cleveland mapping of the Mr 135 kDa bands from these different Bulinus spp. revealed 4 identical major peptide fragments (30, 28, 19 and 16 kDa) in each, thus demonstrating a similarity in the primary structure of these plasma proteins. Antisera from Balb/C mice immunized with the 135 kDa polypeptide from Bulinus truncatus 1521 cross-reacted in Western blots with the 135 kDa band of other members of the same truncatus/tropicus species complex but not with species from the africanus or forskalii species groups.

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Adekiya, Tayo Alex, Raphael Taiwo Aruleba, Babatunji Emmanuel Oyinloye, Kazeem Oare Okosun, and Abidemi Paul Kappo. "The Effect of Climate Change and the Snail-Schistosome Cycle in Transmission and Bio-Control of Schistosomiasis in Sub-Saharan Africa." International Journal of Environmental Research and Public Health 17, no. 1 (December 26, 2019): 181. http://dx.doi.org/10.3390/ijerph17010181.

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In the next century, global warming, due to changes in climatic factors, is expected to have an enormous influence on the interactions between pathogens and their hosts. Over the years, the rate at which vector-borne diseases and their transmission dynamics modify and develop has been shown to be highly dependent to a certain extent on changes in temperature and geographical distribution. Schistosomiasis has been recognized as a tropical and neglected vector-borne disease whose rate of infection has been predicted to be elevated worldwide, especially in sub-Saharan Africa; the region currently with the highest proportion of people at risk, due to changes in climate. This review not only suggests the need to develop an efficient and effective model that will predict Schistosoma spp. population dynamics but seeks to evaluate the effectiveness of several current control strategies. The design of a framework model to predict and accommodate the future incidence of schistosomiasis in human population dynamics in sub-Saharan Africa is proposed. The impact of climate change on schistosomiasis transmission as well as the distribution of several freshwater snails responsible for the transmission of Schistosoma parasites in the region is also reviewed. Lastly, this article advocates for modelling several control mechanisms for schistosomiasis in sub-Saharan Africa so as to tackle the re-infection of the disease, even after treating infected people with praziquantel, the first-line treatment drug for schistosomiasis.

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Zhou, Xiao-Nong, and Thomas K. Kristensen. "Relationship between susceptibility and genotype frequency of Oncomelania spp. to Schistosoma japonicum from mainland China analysed by logistic regression." Journal of Molluscan Studies 61, no. 4 (November 1995): 500–503. http://dx.doi.org/10.1093/mollus/61.4.500.

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Marks, N. J., D. W. Halton, A. G. Maule, G. P. Brennan, C. Shaw, V. R. Southgate, and C. F. Johnston. "Comparative analyses of the neuropeptide F (NPF)- and FMRFamide-related peptide (FaRP)-immunoreactivities in Fasciola hepatica and Schistosoma spp." Parasitology 110, no. 4 (May 1995): 371–81. http://dx.doi.org/10.1017/s0031182000064714.

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SUMMARYImmunochemical techniques were used to determine the distribution, chemical characteristics and relative abundance of immunoreactivity (IR) to two native platyhelminth neuropeptides, neuropeptide F (NPF) (Moniezia expansa) and the FMRFamide-related peptide (FaRP), GNFFRFamide, in the trematodes, Fasciola hepatica and Schistosoma mansoni; the larger S. margrebowiei was used in the chemical analysis. Extensive immunostaining for the two peptides was demonstrated throughout the nervous systems of both F. hepatica and S. mansoni, with strong IR also in the innervation of muscular structures, including those associated with the egg-forming apparatus. The patterns of immunostaining were similar to those previously described for the vertebrate neuropeptide Y superfamily of peptides and for FMRFamide. Ultra-structurally, gold labelling of NPF- and GNFFRFamide-IRs was localized exclusively to the contents of secretory vesicles in the axons and somatic cytoplasm of neurones. Double-labelling experiments showed an apparent homogeneity of antigenic sites, in all probability due to the demonstrated cross-reactivity of the FaRP antiserum with NPF. Radio-immunoassay of acid-ethanol extracts of the worms detected 8·3 pmol/g and 4·7 pmol/g equivalents of NPF- and FMRFamide-IRs, respectively, for F. hepatica, and corresponding values of 4·9 pmol/g and 4·3 pmol/g equivalents for S. margrebowiei. Gel-permeation chromatography resolved IR to both peptides in discrete peaks and these eluted in similar positions to synthetic NPF (M. expansa) and GNFFRFamide, respectively.

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Mutombo, Ngoy, Aly Landouré, Wing Young Man, Alan Fenwick, Robert Dembélé, Moussa Sacko, Adama D. Keita, Mamadou S. Traoré, Joanne P. Webster, and Mary-Louise McLaws. "The association between child Schistosoma spp. infections and morbidity in an irrigated rice region in Mali: A localized study." Acta Tropica 199 (November 2019): 105115. http://dx.doi.org/10.1016/j.actatropica.2019.105115.

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Kalinda, Chester, Tafadzwa Mindu, and Moses John Chimbari. "A systematic review and meta-analysis quantifying schistosomiasis infection burden in pre-school aged children (PreSAC) in sub-Saharan Africa for the period 2000–2020." PLOS ONE 15, no. 12 (December 29, 2020): e0244695. http://dx.doi.org/10.1371/journal.pone.0244695.

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Introduction Following the adoption of the World Health Assembly Resolution WHA 65.21 and Neglected Tropical Diseases road map 2021–2030, schistosomiasis control programmes have shifted from morbidity control to disease elimination. However, several gaps continue to be observed in the implementation of control programmes with certain age groups omitted from these campaigns increasing health inequalities and risks of reinfections to previously treated groups. We used the Inverse Variance Heterogeneity (IVhet) model to estimate the prevalence of schistosomiasis infection among preschool-aged children. Methods We did a systematic review of peer-reviewed literature on schistosomiasis in sub-Saharan Africa for the period January 1, 2000 to November 30, 2020. Quantitative data for cases of schistosomiasis infection were extracted, including country and region where the studies were done, year of publication and specific schistosome species observed. The IVhet model was used to estimate the pooled prevalence estimate (PPE), the heterogeneity and publication bias. Results We screened 2601 articles to obtain 47 eligible studies containing quantitative data on preschool-aged children. Of the selected studies, 44.7% (n = 22) were from East Africa while the least number of studies obtained (2.1%, n = 1) was from Central Africa. 21712 subjects were screened for infection due to Schistosoma spp; 13924 for S. mansoni and 7788 for S. haematobium. The PPE for schistosomiasis among PreSAC was 19% (95% CI: 11–28). Infection due to S. mansoni (IVhet PPE: 22% (95% CI: 9–36) was higher than that due to S. haematobium (15%; 95% CI: 6–25). A Luis Furuya–Kanamori index of 1.83 indicated a lack of publication bias. High level of heterogeneity was observed (I2 > 90%) and this could not be reduced through subgroup analysis. Conclusion Schistosomiasis infection among pre-school aged children 6 years old and below is high. This indicates the importance of including this age group in treatment programmes to reduce infection prevalence and long-term morbidities associated with prolonged schistosome infection.

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Neves, M. Inês, Charlotte M. Gower, Joanne P. Webster, and Martin Walker. "Revisiting density-dependent fecundity in schistosomes using sibship reconstruction." PLOS Neglected Tropical Diseases 15, no. 5 (May 13, 2021): e0009396. http://dx.doi.org/10.1371/journal.pntd.0009396.

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The stability of parasite populations is regulated by density-dependent processes occurring at different stages of their life cycle. In dioecious helminth infections, density-dependent fecundity is one such regulatory process that describes the reduction in egg production by female worms in high worm burden within-host environments. In human schistosomiasis, the operation of density-dependent fecundity is equivocal and investigation is hampered by the inaccessibility of adult worms that are located intravascularly. Current understanding is almost exclusively limited to data collected from two human autopsy studies conducted over 40 years ago, with subsequent analyses having reached conflicting conclusions. Whether egg production is regulated in a density-dependent manner is key to predicting the effectiveness of interventions targeting the elimination of schistosomiasis and to the interpretation of parasitological data collected during monitoring and evaluation activities. Here, we revisit density-dependent fecundity in the two most globally important human Schistosoma spp. using a statistical modelling approach that combines molecular inference on the number of parents/adult worms in individual human hosts with parasitological egg count data from mainland Tanzania and Zanzibar. We find a non-proportional relationship between S. haematobium egg counts and inferred numbers of female worms, providing the first clear evidence of density-dependent fecundity in this schistosome species. We do not find robust evidence for density-dependent fecundity in S. mansoni because of high sensitivity to some modelling assumptions and the lower statistical power of the available data. We discuss the strengths and limitations of our model-based analytical approach and its potential for improving our understanding of density dependence in schistosomiasis and other human helminthiases earmarked for elimination.

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Igbinosa, I. B., C. Isaac, H. O. Adamu, and G. Adeleke. "Parasites of edible land snails in Edo State, Nigeria." Helminthologia 53, no. 4 (December 1, 2016): 331–35. http://dx.doi.org/10.1515/helmin-2016-0031.

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Summary Land snails are sources of protein to man and are hosts to a number of parasites. It is imperative that the roles of the snail hosts and parasites are clearly defined. Before then however, the parasites of the different land snails collected in any locality should be identified. Land snails were collected in the wild in both dry and wet seasons. The internal organs and the faeces were examined for the presence of parasite. In the rainy season of 2015, a total of 272 snails were collected across four major towns (Benin, Uromi, Ekpoma and Auchi) in Edo State, Nigeria, while in the dry season, fewer snails (n=91) were handpicked. The snail species seen are: Achatina achatina (Linnaeus, 1758), Achatina fulica (Férussac, 1821), Acharchatina marginata (Swainson, 1982), Limicolaria aurora (Jay, 1839), L. flammea (Müller, 1774) and Limicolariopsis spp. The larvae of Strongyloides stercoralis were isolated from the various snail species with overall prevalence of 54.04 %. Snails positive with Alaria mesocercariae were L. aurora, L. flammea and Limicolariopsis spp. Additionally, few L. flammea were positive of the cercariae of Drocoelium dedriticum. Meanwhile, some samples of A. fulica harboured larvae of Angiostrongylus cantonesis, sporocysts of Fasciola gigantica and Schistosoma mansoni. Therefore, these edible snails could pose serious health hazard to man and animals by serving as a possible alternative parasite transmission route.

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Habib, Mohamed R., Azza H. Mohamed, Gamalat Y. Osman, Ahmed T. Sharaf El-Din, Hanan S. Mossalem, Nadia Delgado, Grace Torres, Solymar Rolón-Martínez, Mark W. Miller, and Roger P. Croll. "Histamine Immunoreactive Elements in the Central and Peripheral Nervous Systems of the Snail, Biomphalaria spp., Intermediate Host for Schistosoma mansoni." PLOS ONE 10, no. 6 (June 18, 2015): e0129800. http://dx.doi.org/10.1371/journal.pone.0129800.

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Isah, H., M. S. Abdulsalam, and N. E. Egbe. "Population dynamics of fresh water snail intermediate hosts of Schistosoma spp., in the Federal Capital Territory, Abuja, Nigeria." Nigerian Journal of Parasitology 40, no. 2 (September 30, 2019): 210. http://dx.doi.org/10.4314/njpar.v40i2.16.

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Miranda, G. S., B. S. Miranda, J. G. M. Rodrigues, M. G. S. Lira, R. A. Nogueira, D. Viegas-Melo, and N. Silva-Souza. "Research Note. The wild water-rats and their relevance in the context of schistosomiasis mansoni in Brazil: what we know and recommendations for further research." Helminthologia 54, no. 2 (June 27, 2017): 165–69. http://dx.doi.org/10.1515/helm-2017-0013.

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Summary Schistosomiasis is a parasitic and endemic disease in several parts of the world. Its mortality rate reaches alarming proportions, which makes emergency the control of this disease. In Brazil, only the species Schistosoma mansoni was adapted to the climatic conditions and to the presence of appropriate hosts. This species shows a life cycle involving mollusks Biomphalaria spp. and humans. However, it has been shown that wild rodents with semi-aquatic habits are capable to establish a productive infection of this parasite. In addition, they are likely also to be capable to spread the disease in endemic areas. Due to the selective pressure exerted by the successive infections in these animals, we may be watching the development of a new strain of the parasite, which is not yet fully defined and understood. With the intention of directing new studies to this problem, we tried to establish main lines of research to demonstrate the real importance of these wild rodents in the epidemiology of schistosomiasis mansoni in Brazil.

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Nguyen, Karena H., Philipp H. Boersch-Supan, Rachel B. Hartman, Sandra Y. Mendiola, Valerie J. Harwood, David J. Civitello, and Jason R. Rohr. "Interventions can shift the thermal optimum for parasitic disease transmission." Proceedings of the National Academy of Sciences 118, no. 11 (March 8, 2021): e2017537118. http://dx.doi.org/10.1073/pnas.2017537118.

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Temperature constrains the transmission of many pathogens. Interventions that target temperature-sensitive life stages, such as vector control measures that kill intermediate hosts, could shift the thermal optimum of transmission, thereby altering seasonal disease dynamics and rendering interventions less effective at certain times of the year and with global climate change. To test these hypotheses, we integrated an epidemiological model of schistosomiasis with empirically determined temperature-dependent traits of the human parasite Schistosoma mansoni and its intermediate snail host (Biomphalaria spp.). We show that transmission risk peaks at 21.7 °C (Topt), and simulated interventions targeting snails and free-living parasite larvae increased Topt by up to 1.3 °C because intervention-related mortality overrode thermal constraints on transmission. This Topt shift suggests that snail control is more effective at lower temperatures, and global climate change will increase schistosomiasis risk in regions that move closer to Topt. Considering regional transmission phenologies and timing of interventions when local conditions approach Topt will maximize human health outcomes.

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Hatta, Muhammad Nur Adam, Ezanee Azlina Mohamad Hanif, Siok-Fong Chin, and Hui-min Neoh. "Pathogens and Carcinogenesis: A Review." Biology 10, no. 6 (June 15, 2021): 533. http://dx.doi.org/10.3390/biology10060533.

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Cancer is a global health problem associated with genetics and unhealthy lifestyles. Increasingly, pathogenic infections have also been identified as contributors to human cancer initiation and progression. Most pathogens (bacteria, viruses, fungi, and parasites) associated with human cancers are categorized as Group I human carcinogens by the International Agency for Research on Cancer, IARC. These pathogens cause carcinogenesis via three known mechanisms: persistent infection that cause inflammation and DNA damage, initiation of oncogene expression, and immunosuppression activity of the host. In this review, we discuss the carcinogenesis mechanism of ten pathogens, their implications, and some future considerations for better management of the disease. The pathogens and cancers described are Helicobacter pylori (gastric cancer), Epstein-Barr virus (gastric cancer and lymphoma), Hepatitis B and C viruses (liver cancer), Aspergillus spp. (liver cancer), Opisthorchis viverrine (bile duct cancer), Clonorchis sinensis (bile duct cancer), Fusobacterium nucleatum (colorectal cancer), Schistosoma haematobium (bladder cancer); Human Papillomavirus (cervical cancer), and Kaposi’s Sarcoma Herpes Virus (Kaposi’s sarcoma).

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Kaiglová, A., M. J. S. Changoma, J. Špajdelová, D. Jakubcová, and K. Bírová. "Urinary schistosomosis in patients of rural medical health centers in Kwale county, Kenya." Helminthologia 57, no. 1 (January 25, 2020): 19–27. http://dx.doi.org/10.2478/helm-2020-0001.

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SummaryUrinary schistosomosis is a serious public health problem prevalent in low-income rural regions of sub-Saharan Africa, including coastal part of Kenya. Praziquantel administration to school-aged children is the prevailing tool of schistosomosis control in these regions. The aim of our study was to find out if this control strategy can lead to interruption of parasite trasmission and disease elimination. During February and March 2018, the occurrence of urinary schistosomosis in volunteers of primary health care facilities in Kwale County, Kenya was examined and the occurrence of infected intermediate hosts Bulinus globosus in local water resources was monitored. Participants completed a questionnaire concerning source of water for household purposes, type of housing and health status and were asked to provide urine samples. Diagnosis of urinary schistosomosis was established by detection of Schistosoma haematobium eggs in urine specimens microscopically, using filtration method. Infected B. globosus snails were detected using cercaria shedding tests. From the hemolymph of snails, prepatent period of infection was identified by polymerase chain reaction (PCR). The presence of urinary schistosomosis was detected in 15.07 % (69 out of 451) of study participants. Cercaria shedding test was positive in 2 particular sites of river Pengo and Tsanganyiko. Genetic material (haemolymph) of 68 B. globosus snails tested by DraI PCR revealed 7 Schistosoma spp. positive samples. Six of seven DraI positive snails were infected by S. haematobium, as it was detected by Sh110/SmS1 PCR. The study revealed, that the disease was still present in the region studied and the transmission was not interrupted. The rate of infection was significantly influenced by the water supplies used for household purposes and the type of housing.

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Journal articles on the topic 'Schistosoma spp'

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