Taenia Solium Cysticerci Research Articles

Epidemiology of infections with zoonotic pig parasites in Enugu State, Nigeria.

Pig production is an important component of animal agriculture in Nigeria but zoonotic parasites constrain the production and make pork unsafe for human consumption. This epidemiological study was therefore conducted, to ascertain the prevalence and determinants of Taenia solium cysticerci and Ascaris spp infections in pigs in Enugu State. Presence of cysticerci was determined by post-mortem examination of pig carcasses while pig faeces were coprologically examined for presence of Ascaris spp egg, according to standard parasitological protocol. Structured questionnaire was used to elicit information on pig farmers' involvement in practices predisposing to parasitic infections and deworming progammes in 107 piggeries surveyed. Cysticerci were detected in 3.51% (12/342) of pig carcasses inspected. Overall prevalence of Ascaris spp. infections were 38.3% (41/107) and 14.3% (63/441) at farm and individual pig levels respectively. Major determinants of the infection and the percentage of farmers involved were: eating on duty (66.4%), open defecation (35.5%) and semi-extensive husbandry system (62.3%). Others are non-availability of deworming programme (54.4%), rearing pigs of different ages together (41.9%), non-disinfection of feeding or water troughs (41.2%) and early weaning (54.3%). Cognizant of the zoonotic potentials of Ascaris spp and Taenia solium cysticerci, the prevalence found for the parasites are significant from public health and food safety points of view. This underscores the need for cost-effect control measures against the parasites, using a coordinated One Health approach; in order to boost pig production, limit spread of the zoonoses and hence, the public health consequences thereof.

Estimating the association between being seropositive for cysticercosis and the prevalence of epilepsy and severe chronic headaches in 60 villages of rural Burkina Faso.

BackgroundIndividuals diagnosed with neurocysticercosis often present with epilepsy and sometimes with progressively worsening severe chronic headaches (WSCH). While cross-sectional associations between seropositivity to cysticercal antigens and epilepsy have been reported, few large scale studies have been conducted in West Africa and none have measured the association between seropositivity to cysticercal antigens and headaches. This study aimed at filling these knowledge gaps by estimating the strength of the cross-sectional association between seropositivity to cysticercal antigens and the prevalence of epilepsy and WSCH in 60 villages of Burkina Faso, West Africa.Methodology/Principal findingsBaseline data from a cluster randomized controlled trial collected from January 2011 to February 2012 in 60 villages across three provinces in Burkina Faso were used. Between 78 and 80 individuals were screened for epilepsy and WSCH in each village, and those screened positive were confirmed by a physician. Seventy-five percent of all participants were asked to provide a blood sample to test for Taenia solium cysticercus circulating antigens. Hierarchical multivariable logistic models were used to measure the association between seropositivity to cysticercal antigens and epilepsy (lifetime and active) as well as WSCH. Among 3696 individuals who provided a blood sample, 145 were found to have epilepsy only, 140 WSCH only and 19 both. There were positive associations between seropositivity to cysticercal antigens and active epilepsy (prevalence odds ratio (POR): 2.40 (95%CI: 1.15–5.00)) and WSCH (POR: 2.59 (1.34–4.99)).Conclusions/SignificanceOur study is the first to demonstrate a cross-sectional association between seropositivity to cysticercal antigens and WSCH in a large community-based study conducted in West Africa. The measured cross-sectional association had a strength similar to the ones previously observed between seropositivity to cysticercal antigens and lifetime or active epilepsy. As a result, preventing new cysticercosis cases in communities may reduce the prevalence of these two important neurological disorders.

Ocular toxocariasis caused by toxocara canis in an adult woman. Case report

Introducción. La toxocariasis es una zoonosis producida por las larvas de los nematodos Toxocara canis y Toxocara cati, parásitos intestinales de los cánidos y los félidos, respectivamente.Presentación del caso. Paciente femenino de 22 años de edad, procedente de Caquetá, Colombia, con un cuadro de 3 meses de evolución con pérdida de visión en ojo izquierdo, acompañada de dolor ocular, diplopía, fotofobia y ojo rojo bilateral, quien presenta desprendimiento de retina en ojo izquierdo diagnosticado por ecografía. La mujer asiste a oftalmología, donde se hace diagnóstico diferencial con retinoblastoma y pars planitis. Se inicia manejo sintomático con corticoides orales y tópicos, con mejoría de la sintomatología, pero persistencia de pérdida de la agudeza visual.Discusión. Al revisar historial de antecedentes socioeconómicos, la paciente convive con perros y gatos, por lo que se piensa en toxocariasis ocular. En el cuadro hemático se observa ligera leucocitosis y linfocitosis, sin eosinofilia. La determinación de anticuerpos anti-Toxoplasma gondii y anti-cisticerco de Taenia solium resultaron negativas, al igual que el VDRL. El test de ELISA para T. canis fue positivo, con unos títulos IgG de 1:64 (positivo ≥1:32, especificidad >90%). Se inicia manejo con corticoide oftálmico, sistémico, albendazol y vitrectomía. Con la intervención quirúrgica se libera banda vítrea, logrando la desaparición de la diplopía, pero persiste granuloma periférico residual, el cual será intervenido por oftalmología.Conclusiones. Dada la posibilidad de ser confundida con un retinoblastoma —una neoplasia maligna que puede requerir la enucleación del ojo—, el conocimiento de esta forma de presentación de la toxocariasis es de suma importancia para los clínicos.

Evaluation of ELISA kit for detection of serum specific IgG antibodies against Taenia solium in diagnosis of human cysticercosis

To evaluate the ELISA kit for detection of IgG antibodies against Taenia solium cysticercus in humans, so as to provide a reference for its application in clinical practice. The sera collected from the patients with neurocysticercosis, echinococcosis, taeniasis and healthy people, respectively, were checked by ELISA for specific IgG antibodies against T. solium cysticercus, as described in the instruction of the kit. Of the 30 patients with neurocysticercosis at active stage, 28 showed seropositive reaction, indicating a sensitivity of 93.33%. There were no positive reactions in the 100 healthy people. Two of the 42 persons with taeniasis were seropositive with an infection rate of 4.76%. Forty-one of the 60 persons with echinococcosis showed positive reactions, suggesting that the cross reaction rate of the kit with echinococcosis was 68.33%. The assessed ELISA kit has a reasonably high sensitivity but a poor specificity, and the cross reaction rate with echinococcosis is very high. It is urgent to improve the sensitivity and specificity of the diagnostic kit for detection of T.solium cysticercosis in China.

Inflammation Caused by Praziquantel Treatment Depends on the Location of the Taenia solium Cysticercus in Porcine Neurocysticercosis.

BackgroundNeurocysticercosis (NCC), infection of the central nervous system by Taenia solium cysticerci, is a pleomorphic disease. Inflammation around cysticerci is the major cause of disease but is variably present. One factor modulating the inflammatory responses may be the location and characteristics of the brain tissue adjacent to cysticerci. We analyzed and compared the inflammatory responses to cysticerci located in the parenchyma to those in the meninges or cysticerci partially in contact with both the parenchyma and the meninges (corticomeningeal).Methodology/Principal FindingsHistological specimens of brain cysticerci (n = 196) from 11 pigs naturally infected with Taenia solium cysticerci were used. Four pigs were sacrificed after 2 days and four after 5 days of a single dose of praziquantel; 3 pigs did not receive treatment. All pigs were intravenously injected with Evans Blue to assess disruption of the blood-brain barrier. The degree of inflammation was estimated by use of a histological score (ISC) based on the extent of the inflammation in the pericystic areas as assessed in an image composed of several photomicrographs taken at 40X amplification. Parenchymal cysticerci provoked a significantly greater level of pericystic inflammation (higher ISC) after antiparasitic treatment compared to meningeal and corticomeningeal cysticerci. ISC of meningeal cysticerci was not significantly affected by treatment. In corticomeningeal cysticerci, the increase in ISC score was correlated to the extent of the cysticercus adjacent to the brain parenchyma. Disruption of the blood-brain barrier was associated with treatment only in parenchymal tissue.SignificanceInflammatory response to cysticerci located in the meninges was significantly decreased compared to parenchymal cysticerci. The suboptimal inflammatory response to cysticidal drugs may be the reason subarachnoid NCC is generally refractory to treatment compared to parenchymal NCC.

Identification and quantification of host proteins in the vesicular fluid of porcine Taenia solium cysticerci

The host–parasite relationship in cestode infections is complex. One feature of this bidirectional molecular communication is the uptake of host proteins by the parasite. Here we describe the presence of several host proteins in the vesicular fluid of Taenia solium cysticerci dissected from the central nervous system and the skeletal muscle of naturally infected pigs. Using two-dimensional electrophoresis we compared the protein patterns of vesicular fluids of cysticerci vs. the sera of cysticercotic pigs. We found that the vesicular fluids of both groups of cysts showed 17 protein spots matching with the pig’s sera spots. After mass spectrometry sequencing of these spots, five host proteins were identified: hemoglobin, albumin, serpin A3–8, haptoglobin, rho GTPase-activating protein 36-like. Three of the 17 spots corresponded to host protein fragments: hemoglobin, albumin and serpin A3–8. IgG heavy and light chains were also identified by Western blot using a specific antibody. Quantitative estimations indicated that the host proteins represented 11–13% of the protein content in the vesicular fluids. We also calculated the relative abundance of these host proteins in the vesicular fluids; all were represented in similar relative abundances as in host sera. This suggests that uptake of host proteins by cysticerci proceeds through an unspecific mechanism such as non-specific fluid pinocytosis.

Oxfendazole flukicidal activity in pigs

Although oxfendazole (OFZ) is a well know broad-spectrum benzimidazole anthelmintic, the assessment of its potential trematodicidal activity remains unexplored. OFZ administration at single high doses has been recommended to control Taenia solium cysticercus in pigs. The current study investigated the flukicidal activity obtained after a single high (30mg/kg) oral dose of OFZ in pigs harbouring a natural Fasciola hepatica infection. Sixteen (16) local ecotype pigs were randomly allocated into two (2) experimental groups of 8 animals each named as follow: Untreated control and OFZ treated, in which animals received OFZ (Synanthic®, Merial Ltd., 9.06% suspension) orally at 30mg/kg. At seven (7) days post-treatment, all the animals were sacrificed and direct adult liver fluke counts were performed following the WAAVP guidelines. None of the animals involved in this experiment showed any adverse event during the study. OFZ treatment as a single 30mg/kg oral dose showed a 100% efficacy against F. hepatica. In conclusion, the trial described here demonstrated an excellent OFZ activity against F. hepatica in naturally infected pigs, after its administration at a single oral dose of 30mg/kg.

Cloning, characterization and functional expression of Taenia solium 17 beta-hydroxysteroid dehydrogenase

The 17β-hydroxysteroid dehydrogenases (17β-HSD) are key enzymes involved in the formation (reduction) and inactivation (oxidation) of sex steroids. Several types have been found in vertebrates including fish, as well as in invertebrates like Caenorhabditis elegans, Ciona intestinalis and Haliotis diversicolor supertexta. To date limited information is available about this enzyme in parasites. We showed previously that Taenia solium cysticerci are able to synthesize sex steroid hormones in vitro when precursors are provided in the culture medium. Here, we identified a T. solium 17β-HSD through in silico blast searches in the T. solium genome database. This coding sequence was amplified by RT-PCR and cloned into the pcDNA 3.1(+) expression vector. The full length cDNA contains 957bp, corresponding to an open reading frame coding for 319 aa. The highest identity (84%) at the protein level was found with the Echinococcus multilocularis 17β-HSD although significant similarities were also found with other invertebrate and vertebrate 17β-HSD sequences. The T. solium Tsol-17βHSD belongs to the short-chain dehydrogenase/reductase (SDR) protein superfamily.HEK293T cells transiently transfected with Tsol17β-HSD induced expression of Tsol17β-HSD that transformed 3H-androstenedione into testosterone. In contrast, 3H-estrone was not significantly transformed into estradiol. In conclusion, T. solium cysticerci express a 17β-HSD that catalyzes the androgen reduction. The enzyme belongs to the short chain dehydrogenases/reductase family and shares motifs and activity with the type 3 enzyme of some other species.

Neurocysticercosis in a European Traveler Returning From India, Primarily Suspected as Neoplasia

The case reported by Salzer and colleagues1 shows a typical problem that is observed during the evaluation and management of patients with suspected neurocysticercosis in nonendemic areas. According to their description, a woman—with history of frequent travel to India—was evaluated because of a subcutaneous nodule that was confirmed to be a Taenia solium cysticercus after biopsy and histopathological examination. Then, …

The effect of glucocorticoids on sex steroid synthesis in cultured Taenia crassiceps Wake Forest University (WFU) cysticerci

We have shown previously that cultured Taenia crassiceps Wake Forest University (WFU) and Taenia solium cysticerci, as well as the adult worms, synthesize sex steroid hormones from [3H]steroid precursors and that androgens and oestrogens influence the in vitro development of the parasites. Glucocorticoids (GCs) are used to control the inflammation caused by T. solium cysticerci in the brain. These steroids stimulate oestrogen synthesis in several tissues. Since there is no information on the effect of GC on the endocrine function of cysticerci, we investigated the effect of natural and synthetic GCs on the synthesis of oestrogens in cultured T. crassiceps WFU cysticerci. The cysticerci were obtained from the peritoneal cavity of infected female BALB/c mice; the cysts were washed extensively and pre-cultured in Dulbecco's Modified Eagle's Medium (DMEM) plus antibiotics for 5 days. The parasites were further cultured with different doses of corticosterone, dexamethasone or the vehicle for 5 days. [3H]Dehydroepiandrosterone (3H-DHEA) was added to the media and the cysticerci were further incubated for 6 or 24 h. Media were then removed and the steroids ether-extracted. Aliquots of the media were seeded on silica gel plates and developed in solvent systems. Parasites incubated in the presence of 3H-DHEA synthesized [3H]androstenediol, [3H]testosterone and [3H]17β-oestradiol ([3H]17β-E2). The addition of 100 nm or higher corticosterone doses to the media increased [3H]17β-E2 synthesis fourfold after 24 h. Dexamethasone also increased [3H]17β-E2 synthesis. The experiments presented here show for the first time that corticosterone and the synthetic GC dexamethasone modulate the synthesis of oestrogens by cysticerci.

Evaluation of the protective potential of a Taenia solium cysticercus mimotope on murine cysticercosis

An NC-1 mimotope from Taenia solium cysticerci can help identify patients with neurocysticercosis through immunoassay. After chemical synthesis, an NC-1 peptide was coupled to bovine serum albumin (NC-1/BSA) for used as an immunogen in murine Taenia crassiceps cysticercosis, which is an experimental model of cysticercosis caused by T. solium. NC-1/BSA immunisation decreased parasitaemia by inducing 74% protection compared to the 77% protection obtained with T. crassiceps crude antigen. The influence of immunisation was also observed on the size and stage of development of the parasite. Antibodies from NC-1/BSA-immunised mice recognised proteins from the tegument and from the buddings, and intense immunostaining was observed in the final stage of the metacestode. The capacity of NC-1/BSA to induce protective antibodies which are reactive to proteins from the tegument of the metacestode suggests that this mimotope is a potential candidate for a vaccine against human and animal cysticercosis.

TsAg5, a Taenia solium cysticercus protein with a marginal trypsin-like activity in the diagnosis of human neurocysticercosis

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.

Proteomic study of activated Taenia solium oncospheres

Taenia solium cysticerci are a major cause of human seizures and epilepsy in the world. In the gastrointestinal tract of infected individuals, taeniid eggs release the oncospheres, which are then activated by intestinal stimuli, getting ready to penetrate the gut wall and reach distant locations where they transform in cysticerci. Information about oncospheral molecules is scarce, and elucidation of the oncosphere proteome could help understanding the host–parasite relationship during the first steps of infection. In this study, using liquid chromatography and tandem mass spectrometry (LC–MS/MS) analysis, we could identify a set of oncospheral proteins involved in adhesion, protein folding, detoxification and proteolysis, among others. In addition, we have characterized one of the identified molecules, the parasite 14-3-3, by immunoblot and immunolocalization. The identification of these oncospheral proteins represents the first step to elucidate their specific roles in the biology of the host–parasite relationship.

Elimination of Taenia solium transmission to pigs in a field trial of the TSOL18 vaccine in Cameroon

A pilot field trial of the TSOL18 vaccine was undertaken in Cameroon. Two hundred and forty, 2–3month-old piglets were distributed to 114 individual households in pairs. Vaccinated animals received three immunisations with 200μg TSOL18 plus 5mg Quil A and 30mg/kg oxfendazole at the time of the second immunisation. Necropsies were undertaken when the pigs were approximately 12months of age. Viable Taenia solium cysticerci were identified in 20 control pigs (prevalence 19.6%); no cysticerci were found in any of the vaccinated animals (P<0.0001). Combined application of TSOL18 vaccination and a single oxfendazole treatment in pigs may be a relatively simple and sustainable procedure that has the potential to control T. solium transmission in endemic areas and, indirectly, reduce the number of new cases of neurocysticercosis in humans.

Low Degree of Genetic Diversity Within and Among Taenia solium Cysticerci from Natural Infected Pigs of Central Mexico

Low Degree of Genetic Diversity Within and Among Taenia solium Cysticerci from Natural Infected Pigs of Central Mexico

The immune response in Taenia solium neurocysticercosis in pigs is associated with astrogliosis, axonal degeneration and altered blood–brain barrier permeability

Immunohistochemistry was used to examine the immuno-pathological changes and the extent of neuronal damage caused by either viable or dead Taenia solium cysticerci during porcine neurocysticercosis. Thirty pig brains with cerebral cysticercosis and 5 brains from T. solium free pigs were used in this study. Results revealed extensive astrogliosis, neuronal and mostly axonal damage in both early (grade I) and late (grades III and V) lesions as evidenced by an increased expression of glial fibrillary acidic protein (GFAP) and neurofilament protein (NFP). In many late lesions, astrocyte end-feet formed glial scars that surrounded the dead parasite. Rapid angiogenesis resulted in blood vessels lacking astrocyte end-feet suggesting loss of blood–brain barrier (BBB) hence allowing an influx of peripheral blood immune cells such as eosinophils, macrophages, CD3+ T cells, B lymphocytes and plasma cells into lesions. This study showed that porcine NCC was associated with severe nervous tissue damage, the host response of which is a collaborative effort between the local and peripheral immune responses comparable to that observed in human NCC. Results further implied that porcine NCC could be a useful model for understanding the course of NCC in human as well as provide useful information for therapeutic and/or immune strategies.

Evaluation of lower molecular mass (20–24 kDa) Taenia solium cysticercus antigen fraction by ELISA and dot blot for the serodiagnosis of neurocysticercosis in children

Clinical diagnosis of human neurocysticercosis (NCC) is often presumptive and serodiagnosis usually substantiates clinical findings and radiological reports. A battery of highly sensitive immunodiagnostic techniques have been applied to detect specific antibody response in NCC patients. Taenia solium (Tso) cysticerci crude antigen and antigen B have frequently led to low specificity due to cross reactions (Espinoza et al. 1986; Estrada et al. 1989; Katti and Chandramukhi 1991; Malla et al. 1992; Das et al. 2002; Mandal et al. 2006) and use of lower molecular mass (LMM) antigen fractions are reported to have high specificity (Grogl et al. 1985; Gottstein et al. 1986; Tsang et al. 1989; Kaur et al. 1995; Kaur et al. 1996; Lissiane et al. 1999)). In our earlier study, in adults, detection of antibody response to LMM antigen fraction (20–24 kDa) of Tso cysticerci, by ELISA had shown a sensitivity and specificity of 95.23% and 100%, respectively (Kaur et al. 1996). Nearly two-thirds of the Indian patients have single lesion disease, therefore, there is need to identify the serodiagnostic tests with high sensitivity and specificity which can detect single lesion disease as well as multilesion disease with equal efficacy and high specificity (Rajshekhar and Chandy 1997; Prabhakar et al. 2004). The present study was aimed to evaluate the efficacy of Tso cysticercus LMM antigen fraction (20–24 kDa) by ELISA and dot blot for the diagnosis of NCC in children and to compare the results of the present study with our previous study conducted in the same samples with the use of crude soluble extract (CSE) antigen (Mandal et al. 2006). An attempt was also made to correlate the results of antibody response with radiological findings (single vs. multiple lesions).

Annexin B1 at the host–parasite interface of the Taenia solium cysticercus: Secreted and associated with inflammatory reaction

Annexin B1 is a novel member of annexin family firstly cloned by immunological screening a Taenia solium cysticercus library. To investigate the histological distribution and physiological role(s) of this protein, we first prepared a specific monoclonal antibody against annexin B1. Western blot analysis indicated that annexin B1 could be detected in cystic fluid of T. solium cysticercus and sera of pigs/humans with cysticercosis. Thus, annexin B1 might belong to the secreted members of annexins. Immunohistochemical analysis revealed that annexin B1 was mainly present in the tegument of bladders, but not in the scolex and neck; it was also detected in the surrounding host-derived layer with granulomatous infiltration. Together with previous, the presented data suggested that the protein inhibited mammalian PLA2 in vitro, and might down regulate host inflammatory responses.

Lack of specificity of a single positive 50-kDa band in the electroimmunotransfer blot (EITB) assay for cysticercosis

Diagnosis of the parasitic infection cysticercosis is usually confirmed by serological assays. The electroimmunotransfer blot (EITB) for cysticercosis is a sensitive and specific assay, which uses six glycoprotein antigens on a strip to detect antibodies to Taenia solium cysticerci. Although the appearance of bands at any of these six sites is considered to be a positive result, a growing body of evidence suggests that the presence of a single 50-kDa band in this assay may not indicate infection. An audit of 984 samples tested over a 3-year period showed that only two (15.4%) of 13 samples with a single 50-kDa band were associated with a diagnosis of cysticercosis. Possible reasons for this include technical problems, cross-reactivity with other parasites or other diseases, or the presence of a non-specific band. The results suggest that the finding of a single 50-kDa band should be interpreted with caution.

Inhibitory role of antibodies in the development of Taenia solium and Taenia crassiceps toward reproductive and pathogenic stages.

Untreated Taenia solium cysticerci obtained from different naturally infected pigs vary notably in their capacity to develop into intestinal tapeworms in prednisolone-treated hamsters, whereas cells derived from Taenia crassiceps cysticerci after 2 mo of infection almost always develop to cysticerci in the peritoneal cavity of susceptible BALB/cAnN mice. Preincubation of whole cysticerci or parasite cells with mice immunoglobulins raised against an 18-mer peptide epitope (GK-1) common to both parasites significantly interferes with both transformations. These crippling effects of antiparasite antibodies suggest new forms of immunological interference with parasite biology other than simple killing. Antibodies that cripple biological functions of the parasite, e.g., their development to reproductive or pathogenic stages, make them important protagonists in taeniasis/cysticercosis disease as classic parasitocidal antibodies. Different serum levels of crippling antibodies in the infected pigs could be responsible for the varied ability of cysticerci to convert to tapeworms. Antigens capable of inducing crippling antibodies, e.g., GK-1, could be useful as a therapeutic vaccine for pigs in order to reduce parasite transmission.