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The pig is the natural intermediate host of Taenia solium , a parasite causing significant burden of disease in both humans and pigs. Porcine cysticercosis is traditionally detected via tongue palpation and slaughterhouse meat inspection, both with limited sensitivity. Serum antibody detection has a better performance; however, it does not discriminate past from present infection. Serum antigen detection can demonstrate viable infection and gives a good estimate of parasitic load. This study evaluated a sandwich antigen-detection ELISA using monoclonal antibodies (MoAbs) 158C11 and 60H8 for the diagnosis of viable cysticercosis in pigs. Serum samples were used from 35 naturally T. solium cysticerci-infected pigs, 31 cysticercosis-negative pigs, and 22 pigs with Taenia hydatigena infection (to assess cross-reactions). Positive cysticercosis samples were subcategorized at necropsy according to parasitic burden as mild (1-10 viable cysts, n = 10), moderate (11-100 cysts, n = 5), or severe infection (more than 100 cysts, n = 20). This Ag-ELISA showed a sensitivity of 82.9% and a specificity of 96.8% when not considering cross-reactions with T. hydatigena . Hundred percentage of severely infected, 80% of moderately infected, and 50% of mildly T. solium -infected pigs tested positive. Twenty of 22 pigs with only T. hydatigena infections were positive, with 13 reaching saturating levels in the ELISA. The Ag-ELISA revealed the presence of live cysts and is, thus, a fairly reliable test to monitor experimental infection, response to treatment, and follow-up in animal models of cysticercosis. It should, however, be carefully interpreted when used in regions where T. hydatigena is endemic in pigs.

Background: Infections with Taenia solium are the most common cause of adult acquired seizures worldwide, and are the leading cause of epilepsy in developing countries. A better understanding of the genetic diversity of T. solium will improve parasite diagnostics and transmission pathways in endemic areas thereby facilitating the design of future control measures and interventions. Microsatellite markers are useful genome features, which enable strain typing and identification in complex pathogen genomes. Here we describe microsatellite identification and characterization in T. solium, providing information that will assist in global efforts to control this important pathogen., Methods: For genome sequencing, T. solium cysts and proglottids were collected from Huancayo and Puno in Peru, respectively. Using next generation sequencing (NGS) and de novo assembly, we assembled two draft genomes and one hybrid genome. Microsatellite sequences were identified and 36 of them were selected for further analysis. Twenty T. solium isolates were collected from Tumbes in the northern region, and twenty from Puno in the southern region of Peru. The size-polymorphism of the selected microsatellites was determined with multi-capillary electrophoresis. We analyzed the association between microsatellite polymorphism and the geographic origin of the samples., Results: The predicted size of the hybrid (proglottid genome combined with cyst genome) T. solium genome was 111 MB with a GC content of 42.54%. A total of 7,979 contigs (>1,000 nt) were obtained. We identified 9,129 microsatellites in the Puno-proglottid genome and 9,936 in the Huancayo-cyst genome, with 5 or more repeats, ranging from mono- to hexa-nucleotide. Seven microsatellites were polymorphic and 29 were monomorphic within the analyzed isolates. T. solium tapeworms were classified into two genetic groups that correlated with the North/South geographic origin of the parasites., Conclusions/significance: The availability of draft genomes for T. solium represents a significant step towards the understanding the biology of the parasite. We report here a set of T. solium polymorphic microsatellite markers that appear promising for genetic epidemiology studies.

Human taeniasis as well as porcine and human cysticercosis--caused by the pork tapeworm Taenia solium--are ancient diseases. The fact that pigs were considered impure in the ancient Greece and that the Koran prohibited the consumption of pork, were likely related to the knowledge that cysticercosis may affect swine. Evidence suggests that human cysticercosis was also present in the ancient Egypt and Rome. During the Renaissance, the causative agent was properly identified and human cases were recognized. Confirmation that both taeniasis and cysticercosis were caused by the same parasite was provided during the 19th Century by German pathologists. During the 20th Century, bouts of human cysticercosis in non-endemic regions left us valuable lessons on the mechanisms of disease acquisition and spread. These included a large series of neurocysticercosis cases in the United Kingdom that occurred after the return of troops stationed in India (which demonstrated that symptoms may occur years after infection), the epidemic of cysticercosis-related epilepsy in the Ekari people of Papua New Guinea occurring after the gift of pigs with cysticercosis received from Indonesia (demonstrating the fast establishment of endemic transmission and the impact of cysticercosis in epilepsy frequency), and the occurrence of neurocysticercosis among members of an Orthodox Jewish community of New York City, related to Latin American Taenia carriers working in their houses (highlighting the fact that cysticercosis transmission do not require the presence of infected pigs). These lessons of history have significantly contributed to our current knowledge on this disease., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Background: Human cysticercosis is a zoonotic disease causing severe health disorders and even death. While prevalence data become available worldwide, incidence rate and cumulative incidence figures are lacking, which limits the understanding of the Taenia solium epidemiology., Methodology/principal Findings: A seroepidemiological cohort study was conducted in a south-Ecuadorian community to estimate the incidence rate of infection with and the incidence rate of exposure to T. solium based on antigen and antibody detections, respectively. The incidence rate of infection was 333.6 per 100,000 person-years (95% CI: [8.4-1,858] per 100,000 person-years) contrasting with a higher incidence rate of exposure 13,370 per 100,000 person-years (95% CI: [8,730-19,591] per 100,000 person-years). The proportion of infected individuals remained low and stable during the whole study year while more than 25% of the population showed at least one antibody seroconversion/seroreversion during the same time period., Conclusions/significance: Understanding the transmission of T. solium is essential to develop ad hoc cost-effective prevention and control programs. The estimates generated here may now be incorporated in epidemiological models to simulate the temporal transmission of the parasite and the effects of control interventions on its life cycle. These estimates are also of high importance to assess the disease burden since incidence data are needed to make regional and global projections of morbidity and mortality related to cysticercosis.

Background: Cysticercosis is caused by the invasion of human or pig tissues by the metacestode larval stage of Taenia solium. In Europe, the disease was endemic in the past but the autochthonous natural life cycle of the parasite is currently completed very rarely. Recently, imported cases have increased in parallel to the increased number of migrations and international travels. The lack of specific surveillance systems for cysticercosis leads to underestimation of the epidemiological and clinical impacts., Objectives: To review the available data on epidemiology and management of cysticercosis in Europe., Methods: A review of literature on human cysticercosis and T. solium taeniasis in Europe published between 1990-2011 was conducted., Results: Out of 846 cysticercosis cases described in the literature, 522 cases were autochthonous and 324 cases were imported. The majority (70.1%) of the autochthonous cases were diagnosed in Portugal from 1983 and 1994. Imported cases of which 242 (74.7%) diagnosed in migrants and 57 (17.6%) in European travellers, showed an increasing trend. Most of imported cases were acquired in Latin America (69.8% of migrants and 44.0% of travellers). The majority of imported cases were diagnosed in Spain (47.5%), France (16.7%) and Italy (8.3%). One third of neurosurgical procedures were performed because the suspected diagnosis was cerebral neoplasm. Sixty eight autochthonous and 5 imported T. solium taeniasis cases were reported., Conclusions: Cysticercosis remains a challenge for European care providers, since they are often poorly aware of this infection and have little familiarity in managing this disease. Cysticercosis should be included among mandatory reportable diseases, in order to improve the accuracy of epidemiological information. European health care providers might benefit from a transfer of knowledge from colleagues working in endemic areas and the development of shared diagnostic and therapeutic processes would have impact on the quality of the European health systems.

Cathepsin L-like proteases are secreted by several parasites including Taenia solium. The mechanism used by T. solium oncospheres to degrade and penetrate the intestine and infect the host is incompletely understood. It is assumed that intestinal degradation is driven by the proteolytic activity of enzymes secreted by the oncosphere. Blocking the proteolytic activity by an antibody response would prevent the oncosphere penetration and further infection. Serine and cysteine proteases including chymotrypsin, trypsin, elastase, and cathepsin L, are secreted by T. solium and Taenia saginata oncospheres when cultured in vitro, being potential vaccine candidates. However, the purification of a sufficient quantity of proteases secreted by oncospheres to conduct a vaccine trial is costly and lengthy. A 53/25 kDa cathepsin L-like fraction partially purified from T. solium cyst fluid was described previously as an important antigen for immunodiagnostics. In this study we found that this antigen is present in the T. solium oncosphere and is also secreted by the cysticercus. This protein fraction was tested for its ability to protect pigs against an oral challenge with T. solium oncospheres in a vaccine trial. IgG antibodies against the 53/25 kDa cathepsin L-like protein fraction were elicited in the vaccinated animals but did not confer protection., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Neurocysticercosis is an endemic parasitic disease caused by Taenia solium larva. Although the mechanism of infection is not completely understood, it is likely driven by proteolytic activity that degrades the intestinal wall to facilitate oncosphere penetration and further infection. We analyzed the publicly available T. solium EST/DNA library and identified two contigs comprising a full-length cDNA fragment very similar to Echinococcus granulosus Ag5 protein. The T. solium cDNA sequence included a proteolytic trypsin-like-domain in the C-terminal region, and a thrombospondin type-1 adherence-domain in the N-terminal region. Both the trypsin-like and adherence domains were expressed independently as recombinant proteins in bacterial systems. TsAg5 showed marginal trypsin-like activity and high sequence similarity to Ag5. The purified antigens were tested in a Western immunoblot assay to diagnose human neurocysticercosis. The sensitivity of the trypsin-like-domain was 96.36% in patients infected with extraparenchymal cysts, 75.44% in patients infected with multiple cysts, and 39.62% in patients with a single cyst. Specificity was 76.70%. The thrombospondin type-1 adherence-domain was not specific for neurocysticercosis., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Objective: To determine whether Ziehl-Neelsen staining can differentiate Taenia solium from Taenia saginata eggs., Methods: Tapeworm proglottids (33 specimens, 23 T. solium and 10 T. saginata) and eggs (31 specimens, 13 T. solium and 18 T. saginata) were stained. Four eggs from each sample were measured and average diameters were recorded., Results: Taenia saginata eggs stained entirely magenta in seven of 13 cases. Taenia solium eggs stained entirely blue/purple in 4/18 cases and entirely magenta in one. Eggs of T. saginata were slightly larger and always ovoid, while T. solium eggs were smaller and mostly spheric., Conclusions: Ziehl-Neelsen staining can occasionally distinguish fully mature T. solium from T. saginata eggs, but this distinction is neither very sensitive nor completely specific. Differential staining suggests differences in embryophore components between species which become evident with egg maturation. In this small series, egg morphology (shape, maximal diameter) provided appropriate differentiation between T. solium and T. saginata eggs., (© 2010 Blackwell Publishing Ltd.)

Neurocysticercosis, an endemic parasitic disease in most developing countries, is caused by Taenia solium and compromises the human central nervous system. Cathepsin L-like proteases are secreted by several parasites including T. solium and constitute important antigens for immunodiagnostics. A protein fraction with cathepsin L-like activity was purified from the cysticercus fluid by size exclusion and ion exchange chromatography. Cathepsin L-like activity was measured fluorometrically by detecting the hydrolysis of the fluorogenic substrate Z-Phe-Arg-AMC. The purified protein fraction included antigens of 53 and 25 kD that were tested in a Western immunoblot and in an enzyme-linked immunosorbent assay (ELISA) for detection of human cysticercosis. The sensitivity of the Western immunoblot was 96% for patients infected with multiple cysts and 78% for patients with a single cyst. Specificity was 98%. The sensitivity of the ELISA was 98% in patients with multiple cysts and 84% in patients with a single cyst. Specificity was 92.7%.

The prevalence and characteristics of human taeniasis/cysticercosis and porcine cysticercosis were assessed in an endemic area of the Peruvian highlands. Individuals from 10 communities had stool examinations (N = 2,951) and serologic testing for Taenia solium antibodies (N = 2,583). The total porcine population present (N = 703) was also examined by serology. Cysticercosis is hyperendemic in this area and is associated with an important number of seizure cases. Human seroprevalence by village ranged from 7.1-26.9% (mean, 13.9%). Seroprevalence was higher among individuals with a history of seizures but not in those reporting a history of headache or intestinal taeniasis. Prevalence of taeniasis ranged from 0-6.7% (median, 2.5%). Coproantigen detection found 2.4 times more taeniasis cases than did microscopy (direct and after concentration). Age distribution for taeniasis showed a peak at younger ages than for seroprevalence. Porcine seroprevalence ranged from 42-75%. Random effects logistic regression models for human seropositivity demonstrated both in-house clustering of cases and a large increase in risk associated with a tapeworm carrier in the house. Besides confirming the close relationship between taeniasis and cysticercosis cases, this large-scale field study demonstrated early age of tapeworm and cysticercosis infections in humans, and short duration of taeniasis infections.

Neurocysticercosis is a parasitic brain disease caused by the larval form (Cysticercus cellulosae) of Taenia solium and is the leading cause of preventable epilepsy worldwide. However, the pathophysiology and relation to the wide range of clinical features remains poorly understood. Axonal swelling is emerging as an important early pathological finding in multiple neurodegenerative diseases and as a cause of brain injury, but has not been well described in neurocysticercosis. Histological analysis was performed on human, rat and porcine NCC brain specimens to identify axonal pathology. Rat infection was successfully carried out via two routes of inoculation: direct intracranial injection and oral feeding. Extensive axonal swellings, in the form of spheroids, were observed in both humans and rats and to a lesser extent in pigs with NCC. Spheroids demonstrated increased immunoreactivity to amyloid precursor protein and neurofilament indicating probable impairment of axonal transport. These novel findings demonstrate that spheroids are present in NCC which is conserved across species. Not only is this an important contribution toward understanding the pathogenesis of NCC, but it also provides a model to analyze the association of spheroids with specific clinical features and to investigate the reversibility of spheroid formation with antihelminthic treatment. [ABSTRACT FROM AUTHOR]

Neurocysticercosis is a nervous system infection caused by the larvae (cysticercus) of the pork tapeworm (Taenia solium). Neurocysticercosis is the primary cause of acquired epilepsy worldwide and, therefore, a global public health problem. On the other hand, T. solium taeniasis/cysticercosis is one of very few infectious diseases considered to be potentially eradicable. Recently, a large-scale elimination program in Tumbes, Peru, demonstrated the feasibility of interrupting transmission. Based on these advances, a series of initial guidelines are proposed aimed at setting out the foundations for regional and national taeniasis/cysticercosis control programs, with simple and feasible local interventions as a starting point. [ABSTRACT FROM AUTHOR]

Background: A recent hypothesis suggested that in many cases cysticercal granulomas represent recently established Taenia solium metacestodes rapidly destroyed by the host's immune system. Here, we attempted to determine whether patients with cysticercal granulomas are younger than those with other forms of parenchymal brain cysticercosis. Methods: Series of 185 patients with single parenchymal brain cysticercus, classified according to the stage of the parasite at the moment of diagnosis in cysts without inflammation, cysts with inflammation, granular lesions, and calcifications. We correlated the age of the patients with the parasite evolutive stage. Results: Patients with cysticercus granulomas were significantly younger than those with vesicular cysts (17.7±12.9 versus 36.8±15.1 years, P<0.005) or calcifications (17.7±12.9 versus 40.8±19.7 years, P<0.0001). There was also a non-significant trend for patients with granulomas to be younger than those with coloidal cysts (17.7±12.9 versus 26.7±15.6 years, P=0.367). Conclusions: Results from this study argued against the classical hypothesis that granulomas are the end result from long-established vesicular cysts destroyed by the host's immune system. Vesicular (viable) cysticerci must be treated with cysticidal drugs as it is unlikely that they will be spontaneously destroyed. [ABSTRACT FROM AUTHOR]

Taenia solium is a cestode parasite that causes cysticercosis in both humans and pigs. A serological survey was undertaken to assess the seroprevalence and risk factors associated with porcine cysticercosis in the rural district of Morropon, Peru. Pigs aged between 2 and 60 months were assessed by the Enzyme-linked Immunoelectrotransfer blot (EITB) assay to determine their serological status against porcine cysticercosis in a cross-sectional study. A total of 1,153 pigs were sampled. Porcine seroprevalence was 45.19% (42.31–48.06). The information about the animals and households was analyzed and risk factors associated with seroprevalence were determined by a multivariate logistic regression analysis. In the porcine population, the risk of being seropositive increased by 7% with every month of age (OR 1.07, 95% CI 1.05–1.09), and by 148% for pigs living in East Morropon (OR 2.48, 95% CI 1.82–3.37). Whereas, the presence of latrines in a household decreased the risk of being seropositive by 49% (OR 0.51; 95% CI 0.39–0.67). Sex and rearing system did not represent either risk or protective factors associated with the seroprevalence of porcine cysticercosis. The findings of this study could be used for further development of control programs that might focus on similar population groups within rural communities of developing countries where cysticercosis is endemic. Author Summary: Taenia solium causes taeniasis in humans and cysticercosis in humans and pigs. In humans the parasite may infect the central nervous system and cause neurocysticercosis. The World Health Organization (WHO) estimated that over 50,000 deaths per year are due to neurocysticercosis and the disease is also the main cause of acquired epilepsy. Pigs act as intermediate hosts for the parasite's transmission. Porcine cysticercosis causes economic losses to farmers of developing countries, because infected pork has reduced value or may be condemned. Previous studies have identified risk factors for T. solium infection in pigs in various parts of the world; however, findings are contradictory or not consistent. In this study, particular areas in which pigs lived and age (older pigs were at higher risk) increased the risk of being seropositive; whereas the use of latrines decreased their risk of being seropositive. The results of this study contribute to epidemiology of porcine cysticercosis in rural areas, which is relevant for establishing effective control programs in rural locations with similar characteristics. [ABSTRACT FROM AUTHOR]

The diagnosis of neurocysticercosis was greatly improved by the introduction of computed tomography (CT) and magnetic resonance imaging (MRI). These techniques demonstrate the number and topography of lesions, their stage of involution, and the degree of inflammatory reaction of the host against the parasites and have largely replaced previous radiological procedures such as plain roentgenograms, pneumoencephalograms, cerebral angiography and myelography. In general, MRI provides better image detection and definition. The possibility of multiplanar reconstruction of images, its capability to visualize the posterior fossa without bone artifacts, and its high contrast resolution (far superior to that of CT) allow MRI to recognize many forms of cysticercosis not visualized on CT. However, the costs of MRI are high and the equipment is scarcely available in many endemic countries, and its sensitivity for the detection of calcified lesions is poor. CT remains the best screening neuroimaging procedure for patients with suspected neurocysticercosis, and MRI is the imaging modality of choice for the evaluation of patients with intraventricular cysticercosis, brainstem cysts and small cysts located over the convexity of cerebral hemispheres. Its better image definition also suggests that MRI is superior to CT in the follow-up of the patients after therapy. [Copyright &y& Elsevier]

One-hundred and sixty-four migrants from Sub-Saharan Africa to Italy were screened with the Taenia solium specific enzyme-linked immunosorbent assay coproantigen (ELISA CoAg) and four (2.4%) were recorded as positive, but with optical density values near to the cut-off. No ELISA CoAg positive samples were confirmed by parasitological methods. Low positivity could be attributed to false positive result or cross-reaction with other Taenia species. Further studies are needed to assess the role of migration on sporadic autochthonous transmission of T. solium taeniasis/cysticercosis in Europe. [ABSTRACT FROM AUTHOR]

Background: Cysticercosis is caused by the invasion of human or pig tissues by the metacestode larval stage of Taenia solium. In Europe, the disease was endemic in the past but the autochthonous natural life cycle of the parasite is currently completed very rarely. Recently, imported cases have increased in parallel to the increased number of migrations and international travels. The lack of specific surveillance systems for cysticercosis leads to underestimation of the epidemiological and clinical impacts. Objectives: To review the available data on epidemiology and management of cysticercosis in Europe. Methods: A review of literature on human cysticercosis and T. solium taeniasis in Europe published between 1990–2011 was conducted. Results: Out of 846 cysticercosis cases described in the literature, 522 cases were autochthonous and 324 cases were imported. The majority (70.1%) of the autochthonous cases were diagnosed in Portugal from 1983 and 1994. Imported cases of which 242 (74.7%) diagnosed in migrants and 57 (17.6%) in European travellers, showed an increasing trend. Most of imported cases were acquired in Latin America (69.8% of migrants and 44.0% of travellers). The majority of imported cases were diagnosed in Spain (47.5%), France (16.7%) and Italy (8.3%). One third of neurosurgical procedures were performed because the suspected diagnosis was cerebral neoplasm. Sixty eight autochthonous and 5 imported T. solium taeniasis cases were reported. Conclusions: Cysticercosis remains a challenge for European care providers, since they are often poorly aware of this infection and have little familiarity in managing this disease. Cysticercosis should be included among mandatory reportable diseases, in order to improve the accuracy of epidemiological information. European health care providers might benefit from a transfer of knowledge from colleagues working in endemic areas and the development of shared diagnostic and therapeutic processes would have impact on the quality of the European health systems. Key words: cysticercosis, neurocysticercosis, Taenia solium, taeniasis, Europe, travellers, migrants. [ABSTRACT FROM AUTHOR]

Objective. To explore the feasibility of developing a sheep model of neurocysticercosis (NCC) by intracranial infection with T. solium oncospheres. Materials and methods. We carried out an experimental infection model of NCC in sheep. Approximately 10 T. solium oncospheres previously cultured for 30 days were inoculated intracranially into ten sheep. The oncospheres, in 0.1 mL of physiological saline, were injected into the parietal lobe through an 18-gauge needle. Results. After three months, granulomas were found in two sheep. In a third sheep we identified a 5 mm diameter cyst in the right lateral ventricle and histological evaluation confirmed that the cyst corresponded to a T. solium larva. Immunohistochemistry with monoclonal antibodies directed against membrane components and excretory/secretory antigens of the T. solium cyst was also used to confirm the etiology of the found granulomas. One of them showed reactivity to the monoclonal antibodies used, thus confirming that it was a cysticercus. Conclusion. This experiment is the proof of concept that it is possible to infect sheep with cysticercosis by intracranial inoculation. [ABSTRACT FROM AUTHOR]