Magnitude of the disease burden from neurocysticercosis in a developing country

The hidden threat of cysticercosis: A neglected public health problem

The parasitic infection known as cysticercosis is caused by the larvae of the Taenia solium (pork tapeworm). Cysticercosis is spread by food. Humans can serve as both definitive and intermediate hosts, whereas pigs serve as intermediate hosts. This illness is one of the neglected tropical diseases that affect the public health of people from low-income backgrounds. Cysticercosis is endemic to Africa, China, India, Southeast Asia, and Latin America. When humans consume pork that has been contaminated and cooked incorrectly, cysticerci enter the small intestine where they are evaginated by digestive enzymes and stick to the intestinal wall. Cysticerci can reside in the host tissues of both humans and pigs without causing illness or inflammation. Cysts are most frequently observed in the cerebral hemispheres, particularly where gray and white matter meet. Cysticerci typically build nests in the muscles and subcutaneous fat of pigs. This parasite typically causes neurocysticercosis, a pleomorphic clinical condition, in humans by infecting the central nervous system. Neuroimaging, serological tests, and a thorough clinical examination are good methods for diagnosing cysticercosis. An infection with T. solium tapeworm can be transmitted by eating raw or undercooked pork that has been infected. Individuals with pork tapeworms in their intestinal lumen, pigs, poverty, and cultural factors are the main causes of this disease. It is possible to treat human tapeworm infections with niclosamide. Cysticercosis has been eliminated in more through improved sanitation and restrictions on domestic pig husbandry.

Disseminated cysticercosis incidentally diagnosed in a patient with distal cholangiocarcinoma: A case report

Cysticercosis, a major health issue in developing countries, is caused by the larval stage of Taenia solium. Disseminated cysticercosis (DCC), which is characterized by widespread cysticerci in various tissues, is rare and often asymptomatic. Here, we report the case of a 50-year-old man from rural Nepal with distal cholangiocarcinoma and DCC involving the skin, brain, orbit, tongue, soft palate, heart, and abdominal organs. Despite the presence of abdominal pain, obstructive jaundice, anemia, and significant weight loss-symptoms indicative of biliary malignancy-there were no symptoms typical of DCC. Diagnostic imaging confirmed DCC and stomach-preserving pancreaticoduodenectomy was performed. Histopathological examination of the periampullary mass revealed distal cholangiocarcinoma. Postsurgical treatment for DCC included steroids, carbamazepine, and antiparasitic therapy with albendazole. The coexistence of cysticercosis and neoplasia, though uncommon, necessitates thorough diagnostic evaluation. This case underscores the clinical complexity and highlights the need for comprehensive management of concurrent conditions.

Neurocysticercosis Prevalence and Characteristics in Communities of Sinda District in Zambia: A Cross-Sectional Study

BACKGROUND

This study aimed at describing the epidemiology of (neuro)cysticercosis as well as its clinical and radiological characteristics in a Taenia solium endemic district of Zambia.

METHODS

This was part of a cross-sectional community-based study conducted in Sinda district to evaluate an antibody-detecting T. solium point-of-care (TS POC) test for taeniosis and (neuro)cysticercosis. All TS POC cysticercosis positive (CC+) participants and a subset of the TS POC cysticercosis negative (CC-) received a clinical evaluation and cerebral computed tomography (CT) examination for neurocysticercosis (NCC) diagnosis and staging.

RESULTS

Of the 1249 participants with a valid TS POC test result, 177 (14%) were TS POC CC+ . Cysticercosis sero-prevalence was estimated to be 20.1% (95% confidence intervals [CI] 14.6-27.0%). In total, 233 participants received a CT examination (151 TS POC CC+ , 82 TS POC CC-). Typical NCC lesions were present in 35/151 (23%) TS POC CC+ , and in 10/82 (12%) TS POC CC- participants. NCC prevalence was 13.5% (95% CI 8.4-21.1%) in the study population and 38.0% (95% CI 5.2-87.4%) among people reporting epileptic seizures. Participants with NCC were more likely to experience epileptic seizures (OR = 3.98, 95% CI 1.34-11.78, p = 0.01) than those without NCC, although only 7/45 (16%) people with NCC ever experienced epileptic seizures. The number of lesions did not differ by TS POC CC status (median: 3 [IQR 1-6] versus 2.5 [IQR 1-5.3], p = 0.64). Eight (23%) of the 35 TS POC CC+ participants with NCC had active stage lesions; in contrast none of the TS POC CC- participants was diagnosed with active NCC.

CONCLUSION

NCC is common in communities in the Eastern province of Zambia, but a large proportion of people remain asymptomatic.

Top-50 cited articles on cysticercosis and neurocysticercosis

BACKGROUND

Identifying the most highly cited papers in a given field can help researchers and professionals understand the milestones and research areas that are generating the most impact. This study aimed to identify and describe the 50 most frequently cited manuscripts on cysticercosis and neurocysticercosis.

METHODS

We identified the 50 most cited papers (articles and reviews) on cysticercosis and neurocysticercosis from the MEDLINE database and indexed in Web of Science-Core Collection, analyzing their bibliographic and content characteristics.

RESULTS

The most cited documents comprised 29 (58%) original articles and 21 (42%) reviews, the bulk of which were narrative reviews (n = 17), with a negligible presence of other types of reviews with high-level scientific evidence. Six journals published 42% of the articles. In addition to the USA, Mexico and Peru were prominent countries of origin among leading researchers. The main research topics were the central nervous system and epilepsy on the one hand, and diagnostic and therapeutic approaches on the other.

CONCLUSION

Our findings shed light on the dissemination of knowledge about cysticercosis and neurocysticercosis in recent decades, identifying the most highly cited contributions that have driven research in the field.

Multiantigen print immunoassay (MAPIA) for the diagnosis of neurocysticercosis: a single-center diagnostic optimization and accuracy study in Lima, Peru

Neurocysticercosis (NCC) is the most common helminthic infection of the human central nervous system. The antibody detection assay of choice is the enzyme-linked immunoelectrotransfer blot assay using lentil-lectin purified parasite antigens (LLGP-EITB, Western blot), an immunoassay with exceptional performance in clinical samples. However, its use is mainly restricted to a few research laboratories because the assay is labor-intensive and requires sophisticated equipment, expertise, and large amounts of parasite material for preparation of reagents. We report a new immunoprint assay (MAPIA) that overcomes most of these barriers. We initially compared the performance of five different antigen combinations in a subset of defined samples in the MAPIA format. After selecting the best-performing assay format (a combination of rGP50 + rT24H + sTs14 antigens), 148 archived serum samples were tested, including 40 from individuals with parenchymal NCC, 40 with subarachnoid NCC, and 68 healthy controls with no evidence of neurologic disease. MAPIA using three antigens (rGP50 + rT24H + sTs14) was highly sensitive and specific for detecting antibodies in NCC. It detected 39 out of 40 (97.5%) parenchymal NCC cases and 40/40 (100%) subarachnoid cases and was negative in 67 out of 68 (98.53%) negative samples. MAPIA using three recombinant and synthetic antigens is a simple and economical tool with a performance equivalent to the LLGP-EITB assay for the detection of specific antibodies to NCC. The MAPIA overcomes existing barriers to adoption of the EITG LLGP and is a candidate for worldwide use.

Does ensuring optimum vitamin D levels result in early resolution of neurocysticercosis?

BACKGROUND

Neurocysticercosis is a leading cause of acquired epilepsy. Calcified granulomas are known to cause seizure recurrence. Researchers have reported that vitamin D deficiency is associated with brain calcification and reduction in calcification occurs with vitamin D receptor agonist calcitriol through upregulation of SLC20A2. Based on these observations, a hypothesis was proposed that the occurrence of calcification could be reduced by optimizing vitamin D levels, resulting in early resolution of neurocysticercosis.

METHODOLOGY

A case-control (retrospective and prospective) study on 60 children with solitary intraparenchymal neurocysticercosis, 20 new cases prior to starting cysticidal therapy and other 40 resolved cases was carried out. Among new cases, children deficient in vitamin D were given megadose of vitamin D and vitamin D levels were rechecked after 30 days. Children having normal vitamin D were taken as cases and the deficient ones were taken as controls. Standard treatment for neurocysticercosis was given. Three monthly MRI scans were done. Outcome was evaluated as resolution/persistence of neurocysticercosis at 3, 6, 9 and 12 months.

STATISTICS AND RESULTS

Pearson chi square/Fisher's exact test was used along with Kaplan Meier and log rank test. Of 60 patients, at 6 months 3 cases and 4 controls (p value 0.43), at 9 months 2 cases and 6 controls (p value 0.037) and at 12 months 3 cases and 6 controls (p value 0.029) had complete resolution of NCC.

CONCLUSION

The results do not show that adequate vitamin D levels result in early resolution of neurocysticercosis.

Recurrent syncopal episodes in a pregnant patient with neurocysticercosis

Neurocysticercosis (NCC) is the most common parasitic infection of the nervous system and acquired epilepsy in low-resource settings due to the pork tapeworm, Taenia solium. Humans contract the intestinal infection of the adult tapeworm (taeniasis) through the fecal-oral route after consuming undercooked food, particularly pork or water, contaminated with tapeworm eggs. When the larvae invades the central nervous system (CNS), the infection causes NCC, which often manifests as late-onset seizures, chronic headaches, and intracranial hypertension. We describe a 31-year-old Hispanic multigravida woman from Guatemala, at 33 weeks of gestation, who presented with multiple syncopal and hypotensive episodes prompting a Computed tomography (CT) image of the head revealing multiple small cerebral calcifications indicating NCC. In this article, we highlight the significance of early symptom recognition and diagnostic workup for NCC in areas with diverse immigrant populations. We also discuss the epidemiology, clinical manifestations, and current treatment modalities available for NCC.

Serological and molecular detection of neurocysticercosis among epileptic patients in Nagpur, Maharashtra state (India)

Neurocysticercosis (NCC), one of the most important neuroparasitic diseases in humans, is caused by Cysticercus cellulosae, the metacestode stage of digenetic zoonotic cestode Taenia solium. The present study aims at the detection of anti-cysticercus antibodies in the sera of epileptic patients (n=26) visiting a tertiary care hospital in Nagpur, Maharashtra state, India, by an in-house developed indirect IgG-ELISA and enzyme-linked immunoelectro transfer blot (EITB) assay using different antigens (namely, Whole Cyst Antigen (WCA), Cystic Fluid Antigen (CFA), Scolex Antigen (SA), Excretory-Secretory Antigen (ESA) and Membrane-Body Antigen (MBA)) prepared from T. solium metacestodes to find out the status of NCC. An attempt has also been made for molecular detection of NCC from blood samples of those patients by Polymerase Chain Reaction (PCR) assay targeted at large subunit rRNA gene of T. solium. The IgG ELISA level of anti-cysticercus antibodies against WCA, CFA, SA, ESA and MBA antigens were as follows: 19.23 %, 23.07 %, 38.46 %, 30.76 % and 15.38 %. The seroreactivity to CFA, SA and ESA was found in equal proportions in patients with ring-enhancing lesions. In the EITB assay, the lower and medium molecular weight protein bands of SA and ESA were immunodominant compared to the higher WCA and CFA peptides. PCR positivity could be observed in 34.6 % (9/26) of the patients under study. It is the first report of detecting NCC among epileptic patients of the Nagpur region of Maharashtra state in India using serological and molecular tools.

Consistent Measurement of Parasite-Specific Antigen Levels in Sera of Patients with Neurocysticercosis Using Two Different Monoclonal Antibody (mAb)-Based Enzyme-Linked Immunosorbent Assays

Monoclonal antibody (mAb)-based enzyme-linked immunosorbent assay (ELISA) is a complementary diagnosis technique for neurocysticercosis (NCC), which detects circulating parasite antigen (Ag) indicative of viable infection and Ag levels that correlate well with the parasite burden. In this study, we compared the performance of two Ag-ELISA techniques for the detection of NCC. We assessed the agreement between our in-house TsW8/TsW5 Ag-ELISA and the widely used B158/B60 Ag-ELISA for measuring T. solium antigen levels in the sera from 113 patients with calcified, parenchymal, and subarachnoid NCC. Concordance was demonstrated evaluating the limits of agreement (LoAs) stratified by the type of NCC. Both ELISA's detected 47/48 (97.8%) subarachnoid NCC cases. In parenchymal and calcified NCC, the B158/B60 Ag-ELISA detected 19/24 (79.2%) and 18/41 (43.9%) cases, while the TsW8/TsW5 Ag-ELISA detected 21/24 (87.5%) and 13/41 (31.7%), respectively. Parenchymal and calcified NCC obtained a perfect agreement (100%), indicating that all sample results were within the predicted LoA, while for subarachnoid NCC, the agreement was 89.6%. The high concordance between the assays was confirmed by Lin's concordance coefficient (LCC = 0.97). Patients with viable parenchymal NCC (LCC = 0.95) obtained the highest concordance between assays, followed by subarachnoid NCC (LCC = 0.93) and calcified NCC (LCC = 0.92). The TsW8/TsW5 Ag-ELISA and B158/B60 Ag-ELISA showed high Ag measurement correlations across diverse types of NCC.

Community-level prevalence of epilepsy and of neurocysticercosis among people with epilepsy in the Balaka district of Malawi: A cross-sectional study

Background

Epilepsy and neurocysticercosis (NCC) prevalence estimates in sub-Saharan Africa are still scarce but show important variation due to the population studied and different screening and diagnosis strategies used. The aims of this study were to estimate the prevalence of epileptic seizures and epilepsy in the sampled population, and the proportion of NCC among people with epilepsy (PWE) in a large cross-sectional study in a rural district of southern Malawi.

Methods

We conducted a community-based door-to-door screening study for epileptic seizures in Balaka, Malawi between October and December 2012. Past epileptic seizures were reported through a 15-item questionnaire answered by at least one person per household generating five major criteria. People who screened positive were further examined by a neurologist to establish diagnosis. Patients diagnosed with epilepsy were examined and offered Taenia solium cyst antigen and antibody serological tests, and a CT scan for the diagnosis of NCC.

Results

In total, screening information on 69,595 individuals was obtained for lifetime occurrence of epileptic seizures. 3,100 (4.5%) participants screened positive, of whom 1,913 (62%) could be followed-up and underwent further assessment. Lifetime prevalence was 3.0% (95% Bayesian credible interval [CI] 2.8 to 3.1%) and 1.2% (95%BCI 0.9 to 1.6%) for epileptic seizures and epilepsy, respectively. NCC prevalence among PWE was estimated to be 4.4% (95%BCI 0.8 to 8.5%). A diagnosis of epilepsy was ultimately reached for 455 participants.

Conclusion

The results of this large community-based study contribute to the evaluation and understanding of the burden of epilepsy in the population and of NCC among PWE in sub-Saharan Africa.

The prevalence of and contributors to neurocysticercosis in endemic regions

BACKGROUND

Neurocysticercosis is one of the most common causes of acquired epilepsy worldwide. Caused by Taenia solium, the infection uses pigs as an intermediate host and thus is often associated with proximity to and consumption of pigs.

OBJECTIVE

This review explores the epidemiology of neurocysticercosis in endemic regions across Africa, Asia, and Latin America and examines common risk factors in these areas.

METHODS

A literature review was conducted using pubmed to search for articles with key words including neurocysticercosis, Taenia, solium, epidemiology, and the names of countries and continents in the regions of interest.

FINDINGS

Multiple risk factors for neurocysticercosis were identified, including inadequate regulation of pig farms and food safety, poor sanitation, and water contamination. In addition, additional barriers to appropriate diagnosis and management were found, including resource limitations and poor health literacy.

CONCLUSION

Despite its global prevalence, effective limitation of neurocysticercosis is still achievable through projects which address common risk factors.

Seroepidemiological evidence for Taenia solium taeniasis/cysticercosis in three Venezuelan rural communities

Taenia solium is the most common parasite infection of the brain, causing neurocysticercosis and typically found in rural communities with free-ranging pigs. Identification of transmission in rural areas is essential for its control. Risk factors and transmission of the parasite were evaluated in three rural Venezuelan communities (Valle del Rio and Potrero Largo, Cojedes state; and Palmarito, Portuguesa state) by a questionnaire (112 households) and coprological (492 samples) and serological (433 human and 230 porcine sera) analysis, respectively. Typical risk factors were found in all three communities: free-foraging pig husbandry, deficient sanitary conditions, high open defecation and ignorance of the parasite life cycle. Coprological examinations revealed a high level of soil-transmitted parasites. Importantly, two T. solium adult worm carriers were identified in each of the three communities. Anti-metacestode antibodies and the HP10 secreted metacestode glycoprotein were detected at significant levels in human and porcine sera in Valle del Rio, Potrero Largo and Palmarito. In conclusion, these communities may be considered to be endemic for taeniasis/cysticercosis, and the instigation of an appropriate control programme is recommended.

Comorbidities of epilepsy in low and middle-income countries: systematic review and meta-analysis

Epilepsy is a major public health concern in low and middle-income countries (LMICs) and comorbidities aggravate the burden associated with the disease. The epidemiology of these comorbidities has not been well described, although, identifying the main comorbidities of epilepsy, and their relative importance, is crucial for improving the quality of care. Comorbidities were defined as disorders coexisting with or preceding epilepsy, or else compounded or directly attributed to epilepsy or to its treatment. A meta-analysis of the proportion of main comorbidities by subcontinent as well as overall was also conducted. Out of the 2,300 papers identified, 109 from 39 countries were included in this systematic review. Four groups of comorbidities were identified: parasitic and infectious diseases (44% of comorbid conditions), somatic comorbidities (37%), psychosocial (11%), as well as psychiatric comorbidities (8%). Heterogeneity was statistically significant for most variables then random effect models were used. The most frequently studied comorbidities were: neurocysticercosis (comorbid proportion: 23%, 95% CI: 18-29), head trauma (comorbid proportion: 9%, 95% CI: 5-15) malnutrition (comorbid proportion: 16%, 95% CI: 28-40), stroke (comorbid proportion: 1.3%, 95% CI: 0.2-7.0), and discrimination for education (comorbid proportion: 34%, 95% CI: 28-40). Many comorbidities of epilepsy were identified in LMICs, most of them being infectious.

Unique Characteristics of Epilepsy Development in Neurocysticercosis

The parasitic helminth infection neurocysticercosis (NCC) is the most common cause of adult-acquired epilepsy in the world. Despite the serious consequences of epilepsy due to this infection, an in-depth review of the distinct characteristics of epilepsy due to neurocysticercosis has never been conducted. In this review, we evaluate the relationship between NCC and epilepsy and the unique characteristics of epilepsy caused by NCC. We also discuss recent advances in our understanding of NCC-related epilepsy, including the importance of anti-inflammatory therapies, the association between NCC and temporal lobe epilepsy, and the recent discovery of biomarkers of severe epilepsy development in individuals with NCC and seizures.

Disseminated cysticercosis in an immunocompetent individual

Cysticercosis is a major public health problem, particularly in developing countries. It is caused by the larvae of the cestode Taenia solium (pork tapeworm). It usually presents as a solitary lesion in the muscle or brain (neurocysticercosis). Disseminated cysticercosis is an uncommon manifestation, especially in an immunocompetent individual. We hereby report the case of a 31-year-old male who presented with new-onset generalized tonic-clonic seizures and who also had multiple soft-tissue swellings all over his body. Imaging studies revealed multiple cysticerci in the brain parenchyma, extraocular muscles, and muscles of all the four limbs, which was subsequently established by histopathology also. The patient was started on anticonvulsants, steroids, and albendazole following which he made a complete recovery.

Antibody Banding Patterns of the Enzyme-Linked Immunoelectrotransfer Blot and Brain Imaging Findings in Patients With Neurocysticercosis

Background

The enzyme-linked immunoelectrotransfer blot (EITB) assay is the reference serological test for neurocysticercosis (NCC). A positive result on EITB does not always correlate with the presence of active infections in the central nervous system (CNS), and patients with a single viable brain cyst may be EITB negative. Nonetheless, EITB antibody banding patterns appears to be related with the expression of 3 protein families of Taenia solium, and in turn with the characteristics of NCC in the CNS (type, stage, and burden of viable cysts).

Methods

We evaluated EITB antibody banding patterns and brain imaging findings of 548 NCC cases. Similar banding patterns were grouped into homogeneous classes using latent class analysis. The association between classes and brain imaging findings was assessed.

Results

Four classes were identified. Class 1 (patients negative or only positive to the GP50 band, related to the protein family of the same name) was associated with nonviable or single viable parenchymal cysticerci; class 2 (patients positive to bands GP42-39 and GP24, related to the T24-42 protein family, with or without anti-GP50 antibodies) was associated with intraparenchymal viable and nonviable infections; classes 3 and 4 (positive to GP50, GP42-39, and GP24 but also responding to low molecular weight bands GP21, GP18, GP14, and GP13, related to the 8 kDa protein family) were associated with extraparenchymal and intraparenchymal multiple viable cysticerci.

Conclusions

EITB antibody banding patterns correlate with brain imaging findings and complement imaging information for the diagnosis of NCC and for staging NCC patients.

Epidemiology of central nervous system infectious diseases: a meta-analysis and systematic review with implications for neurosurgeons worldwide

OBJECTIVE

Central nervous system (CNS) infections cause significant morbidity and mortality and often require neurosurgical intervention for proper diagnosis and treatment. However, neither the international burden of CNS infection, nor the current capacity of the neurosurgical workforce to treat these diseases is well characterized. The objective of this study was to elucidate the global incidence of surgically relevant CNS infection, highlighting geographic areas for targeted improvement in neurosurgical capacity.

METHODS

A systematic literature review and meta-analysis were performed to capture studies published between 1990 and 2016. PubMed, EMBASE, and Cochrane databases were searched using variations of terms relating to CNS infection and epidemiology (incidence, prevalence, burden, case fatality, etc.). To deliver a geographic breakdown of disease, results were pooled using the random-effects model and stratified by WHO region and national income status for the different CNS infection types.

RESULTS

The search yielded 10,906 studies, 154 of which were used in the final qualitative analysis. A meta-analysis was performed to compute disease incidence by using data extracted from 71 of the 154 studies. The remaining 83 studies were excluded from the quantitative analysis because they did not report incidence. A total of 508,078 cases of CNS infections across all studies were included, with a total sample size of 130,681,681 individuals. Mean patient age was 35.8 years (range: newborn to 95 years), and the male/female ratio was 1:1.74. Among the 71 studies with incidence data, 39 were based in high-income countries, 25 in middle-income countries, and 7 in low-income countries. The pooled incidence of studied CNS infections was consistently highest in low-income countries, followed by middle- and then high-income countries. Regarding WHO regions, Africa had the highest pooled incidence of bacterial meningitis (65 cases/100,000 people), neurocysticercosis (650/100,000), and tuberculous spondylodiscitis (55/100,000), whereas Southeast Asia had the highest pooled incidence of intracranial abscess (49/100,000), and Europe had the highest pooled incidence of nontuberculous vertebral spondylodiscitis (5/100,000). Overall, few articles reported data on deaths associated with infection. The limited case fatality data revealed the highest case fatality for tuberculous meningitis/spondylodiscitis (21.1%) and the lowest for neurocysticercosis (5.5%). In all five disease categories, funnel plots assessing for publication bias were asymmetrical and suggested that the results may underestimate the incidence of disease.

CONCLUSIONS

This systematic review and meta-analysis approximates the global incidence of neurosurgically relevant infectious diseases. These results underscore the disproportionate burden of CNS infections in the developing world, where there is a tremendous demand to provide training and resources for high-quality neurosurgical care.

A novel enolase from Taenia solium metacestodes and its evaluation as an immunodiagnostic antigen for porcine cysticercosis

Cysticercosis is a worldwide parasitic disease of humans and pigs principally caused by infection with the larvae of the pork tapeworm Taenia solium. Through the use of the recently-made-available T. solium genome, we identified a gene within a novel 1448 bp ORF that theoretically encodes for a 433 amino acid-long protein and predicted to be an α-enolase closely related to enolases of other flatworms. Additional bioinformatic analyses revealed a putative plasminogen-binding region on this protein, suggesting a potential role for this protein in pathogenesis. On this basis, we isolated the mRNA encoding for this presumptive enolase from T. solium metacestodes and reverse-transcribed it into cDNA before subsequently cloning and expressing it in both E. coli (rEnoTs) and insect cells (rEnoTsBac), in a 6xHis tagged manner. The molecular weights of these two recombinant proteins were ∼48 and ∼50 kDa, respectively, with the differences likely attributable to differential glycosylation. We used spectrophotometric assays to confirm the enolase nature of rEnoTs as well as to measure its enzymatic activity. The resulting estimates of specific activity (60.000 U/mg) and K_m (0.091 mM) are quite similar to the catalytic characteristics of enolases of other flatworms. rEnoTs also exhibited high immunogenicity, eliciting a strong polyclonal antibody response in immunized rabbits. We subsequently employed rEnoTsBac for use in an ELISA aimed at discriminating between healthy pigs and those infected with T. solium. This diagnostic assay exhibited a sensitivity of 88.4% (95% CI, 74.92%-96.11%) and a specificity of 83.7% (95% CI: 69.29%-93.19%). In conclusión, this study reports on and enzymatically characterizes a novel enolase from T. solium metacestode, and shows a potential use as an immunodiagnostic for porcine cysticercosis.

Barriers to Participation in a Community-Based Program to Control Transmission of Taenia solium in Peru

Infection of the brain with Taenia solium larvae (neurocysticercosis) is a leading cause of preventable epilepsy worldwide. Effective and sustainable strategies to control parasite transmission in rural endemic communities are needed to prevent the disease. Surveillance and targeted intervention around infected pigs (ring control strategy) have been shown to be effective when carried out by research teams. However, this strategy has not been implemented or tested as a community-based program. In this small trial in northern Peru, eight villages were randomly assigned to community-led surveillance and treatment (five villages, 997 residents) or control (three villages, 1,192 residents). In intervention villages, community-led surveillance and reporting were promoted by community health workers, radio advertisement, and school and household education. Each suspected pig infection was verified, with confirmed cases resulting in treatment with niclosamide for taeniasis and oxfendazole for pigs in clusters of homes nearby. No incentives beyond human and pig treatment were offered. Control villages received basic disease education but no treatment intervention in response to reports. Despite 14 case reports, community-based replication of ring control strategy did not replicate prior results. After 12 months, there was no change in seroincidence in intervention villages between the baseline and study end, and no difference compared with control villages. There was no difference in prevalence of taeniasis or porcine cysticercosis at study end. Community members described lack of knowledge as the main reason for not reporting infected pigs. Further exploration of methods to transfer ring strategy and other control interventions for cysticercosis to the community is needed.

Clinical Cysticercosis epidemiology in Spain based on the hospital discharge database: What's new?

BACKGROUND

Cysticercosis (CC) is a tissue infection caused by the larval cysts of the pork tapeworm Taenia solium. It is usually acquired by eating contaminated food or drinking water. CC Cysts can develop in the muscles, the eyes, the brain, and/or the spinal cord. T. solium is found worldwide, but its prevalence has decreased in developed countries due to stricter meat inspection and better hygiene and sanitation. Nevertheless, CC is still a leading cause of seizures and epilepsy. In Spain, The disease is not nationally reportable and data on CC infected animals are also missing, despite the European Directive 2003/99/EC.

METHODOLOGY/PRINCIPAL FINDINGS

We performed a retrospective descriptive study using the Spanish Hospitalization Minimum Data Set (CMBD). Data with ICD-9 CM cysticercosis code ("123.1") placed in first or second diagnostic position from 1997 to 2014 were analyzed. Hospitalization rates were calculated and clinical characteristics were described. Spatial distribution of cases and their temporal behavior were also assessed. A total of 1,912 hospital discharges with clinical cysticercosis were identified. From 1998 to 2008, an increasing trend in the number of CC hospitalizations was observed, decreasing afterwards, in parallel with a decrease in the external migration rate. The Murcia region had the highest median hospitalization rate (13.37 hospitalizations/100,000 population), followed by Navarra and Madrid. The 16-44 age group was the most represented (63.6%). The three most frequent associated diagnoses were epilepsy and convulsions (49.5%), hydrocephalus (11.8%) and encephalitis/myelitis/meningitis (11.6%).

CONCLUSIONS/SIGNIFICANCE

There is a need for a common strategy on data collection, monitoring and reporting, which would facilitate a more accurate picture on the CC epidemiological scenario. Even if most cases might be imported, improving the human and animal CC surveillance will result useful both in gaining extended disease knowledge and reducing morbidity and related-costs.

Identification and control of sources of Taenia solium infection – the attempts to eradicate the parasite

Taenia solium is a parasite causing porcine cysticercosis and human taeniosis and cysticercosis, parasitic zoonoses with a serious public health and economic influence. It has been globally ranked as the top foodborne parasite by the Food and Agriculture Organisation of the United Nations (FAO) and the World Health Organisation (WHO). This parasite is transmitted mainly in countryside regions where animals are free roaming, having access to human faeces, and infected pork is widely available. More developed countries eliminated cysticercosis; nonetheless, there are insufficient data about the current endemicity status of T. solium, due to increased human migration from endemic areas. Formally submitted statistics on cysticercosis in pigs are extremely inadequate. This is the result of not reporting all cases of the disease by some countries and lack of molecular verification during identification of the parasite. There is a need to develop diagnostic tests with increased sensitivity and specificity. The purpose of the present review is to summarise current knowledge about diagnostic and control methods concerning T. solium infection. The article does not address the diagnostics of human cysticercosis, since there is a distinct medical field which should be discussed separately. The paper focuses mainly on identifying the sources of T. solium infection, presenting the methods to detect and control porcine cysticercosis and taeniosis in humans.

Identification and Control of Sources of Taenia Solium Infection - the Attempts To Eradicate the Parasite

Taenia solium is a parasite causing porcine cysticercosis and human taeniosis and cysticercosis, parasitic zoonoses with a serious public health and economic influence. It has been globally ranked as the top foodborne parasite by the Food and Agriculture Organisation of the United Nations (FAO) and the World Health Organisation (WHO). This parasite is transmitted mainly in countryside regions where animals are free roaming, having access to human faeces, and infected pork is widely available. More developed countries eliminated cysticercosis; nonetheless, there are insufficient data about the current endemicity status of T. solium, due to increased human migration from endemic areas. Formally submitted statistics on cysticercosis in pigs are extremely inadequate. This is the result of not reporting all cases of the disease by some countries and lack of molecular verification during identification of the parasite. There is a need to develop diagnostic tests with increased sensitivity and specificity. The purpose of the present review is to summarise current knowledge about diagnostic and control methods concerning T. solium infection. The article does not address the diagnostics of human cysticercosis, since there is a distinct medical field which should be discussed separately. The paper focuses mainly on identifying the sources of T. solium infection, presenting the methods to detect and control porcine cysticercosis and taeniosis in humans.

Dynamic contrast-enhanced (DCE) MRI derived kinetic perfusion indices may help predicting seizure control in single calcified neurocysticercosis

BACKGROUND

The factors responsible for seizure recurrence in patients with Solitary calcified neurocysticercosis (NCC) are not well understood. Blood brain barrier (BBB) breach may be associated with seizure recurrence. Dynamic contrast enhanced (DCE) MRI derived indices k_ep, k^trans and v_e are useful in quantifying BBB permeability. In this study, we assessed the possible role of DCE-MRI and matrix metalloproteinases (MMP)-9 levels in predicting seizure recurrence.

METHODS

In this prospective-observational study, patients with new-onset seizures and a solitary calcified NCC were included. DCE-MRI was done to quantify BBB integrity. DCE-MRI parameters were measured as k_ep, k^trans and v_e. MMP-9 levels were estimated. Patients were followed for 1 year, when DCE-MRI and MMP-9 levels were repeated. Patients were classified into two groups on the basis of seizure recurrence, which was defined as the recurrence of an episode of seizure at least 1 week after the initiation of the anti-epileptic drugs. Logistic regression analysis was done.

RESULTS

At 1-year of follow up, 8 out of 32 patients had seizure recurrence. Baseline DCE-MRI derived k_ep (p = 0.015) and MMP-9 levels (p = 0.019) were significantly higher in the seizure "recurrence" group compared with the "no recurrence" group. On within-group analysis, a significant increase in k_ep (p = 0.012), v_e (p = 0.012), and MMP-9 levels (p = 0.017) was observed in the seizure "recurrence" group while a decrease was seen in v_e and MMP-9 levels in the "no recurrence" group.

CONCLUSION

Higher values of DCE-MRI indices and MMP-9 levels, with a corresponding trend in the follow-up, can be useful in predicting lesions with a higher propensity for seizure recurrence.

Mapping the residual incidence of taeniasis and cysticercosis in Colombia, 2009-2013, using geographical information systems: Implications for public health and travel medicine

BACKGROUND

In Colombia, taeniasis and cysticercosis have been significantly reduced over the past decades, however still reported with implications for public health and travel medicine.

METHODS

An observational, retrospective study, in which the incidence of taeniasis and cysticercosis (ICD-10 codes B68s/B69s) in Colombia, 2009-2013, was estimated based on data extracted from the Individual Health Records System (Registro Individual de Prestación de Servicios, RIPS) was performed. The Geographic Information System (GIS) generated national maps showing the distribution of taeniasis and cysticercosis by department by year.

RESULTS

During the period, 3626 cases were reported (median 796/year), for a cumulative crude national rate of 7.7 cases/100,000pop; 58.2% corresponded to male; 57% were <40 year-old (10.2% < 9.9 year-old). Cases were 57.6% neurocysticercosis, the rest were taeniasis due to T. solium, T. saginata, ocular cysticercosis and cysticerci in other organs. Bolivar, a touristic department, had the highest cumulated incidence rate (16.17 cases/100,000pop), as also evident across the map series developed in this study.

CONCLUSION

Despite the limitations of this study, data presented provide recent estimates of national taeniasis and cysticercosis incidence in the country useful in public health and for travel medicine practitioners, as some highly touristic areas presented higher disease incidence. Improved control, particularly of taeniasis, should be an attainable goal, which among other strategies would require improved sanitation and health education to prevent transmission, but also enhanced surveillance.

Neurocysticercosis among People Living Near Pigs Heavily Infected with Cysticercosis in Rural Endemic Peru

Neurocysticercosis causes substantial neurologic morbidity in endemic regions around the world. In this cross-sectional study, we describe the frequency of neurocysticercosis among a presumed high-risk group of people in an endemic community in northern Peru. Participants who screened positive on a nine-question seizure survey were evaluated clinically to diagnose epilepsy using International League Against Epilepsy criteria. Those with epilepsy were offered a noncontrast computerized tomography (CT) of the head. We also tested sera from all participants using the lentil lectin-bound glycoprotein enzyme-linked immunoelectrotransfer blot (EITB) to detect anti-cysticercus antibodies and enzyme-linked immunosorbent assay (ELISA) B60/B158 to detect cysticercosis antigens. Participants with strongly positive ELISA (ratio ≥ 3) were offered a noncontrast magnetic resonance imaging (MRI) of the brain. We diagnosed 16 cases of epilepsy among 527 people screened (lifetime prevalence 30 per 1,000). Twelve with epilepsy accepted CT scan and five (41.7%) had parenchymal calcifications. None had viable cysts. Of the 514 who provided a blood sample, 241 (46.9%) were seropositive by EITB and 12 (2.9%) were strongly positive by ELISA (ratio ≥ 3). Eleven accepted MRI and eight (72.3%) had neurocysticercosis, including five with extraparenchymal cysts, five with parenchymal vesicular cysts, and two with parenchymal granulomas. These findings show that clinically relevant forms of neurocysticercosis and epilepsy can be found by applying screening interventions in communities endemic to Taenia solium. Longitudinal controlled studies are needed to better understand which subgroups are at highest risk and which are most likely to have improved prognosis as a result of screening.

[Seroprevalence of cysticercosis and associated risk factors in a group of patients examined at the Regional Referral Hospital in Antsirabe]

Introduction

In Madagascar, cysticercosis, a disease caused by Taenia Solium's larval form, is a public health problem. In 2003, the seroprevalence of cysticercosis ranged between 7% and 21% with a higher rate in the central regions of the island. However, epidemiological data on human cysticercosis have been limited over the last dozen years. The objective of our study aimed to determine the seroprevalence of cysticercosis Western blot as well as its associated risk factors in patients from the region of Vakinankaratra with clinical suspicion.

Methods

We conducted a cross-sectional, descriptive study at the Regional Referral Hospital in Antsirabe over a period of 6 months. All the patients included in the study answered a clinic questionnaire collecting their socio-demographic and cultural features as well as their dietary habits and their clinical symptoms.

Results

The seroprevalence of cysticercosis in the study population was 14.8% (35/237). These rates did not differ significantly according to sex, age, pork consumption or meat preparation (p > 0.05). However, a significant difference (p < 0.05) was observed among patients with subcutaneous nodules or positive for cysticercosis.

Conclusion

In our study, the high index of exposure to Taenia solium justifies the strengthening of control and prevention measures already set up in our country.

Seroprevalence and awareness of porcine cysticercosis across different pig production systems in south-central Cambodia

Background

Taeniasis/cysticercosis, caused by the pork tapeworm Taenia solium, represents an important public health and economic burden in endemic countries. However, there is a paucity of data on infection among pigs in many parts of Southeast Asia, particularly Cambodia. We aimed to estimate seroprevalence of porcine cysticercosis, and investigate husbandary practices and knowledge of the disease among livestock workers, across different pig sector units in south-central Cambodia.

Methods

A cross sectional survey was conducted among pig smallholders, commercial farms, slaughterhouses and traders/middlemen from south-central Cambodia, selected through multistage sampling in proportion to local pig populations sizes. Questionnaires were administered to 163 pig workers to obtain data pig production, trading and slaughtering practices. Sera from 620 pigs were tested for Taenia antigens using a commercial ELISA-based test. Associations between seroprevalence and pig husbandry practices were assessed using generalised linear mixed models, adjusting for random-effects at herd-level.

Results

Of 620 pigs sampled, 29 (4.7%) tested positive for Taenia antigens. Seropositivity was associated with type of pig sector unit (P = 0.008), with the highest seroprevalence among pigs sampled from traders/middlemen (16.7%; 95% CI: 4.4%-37.8%), smallholders (7.6%; 95% CI: 3.8%-14.1%) and slaughterhouses (4.1%; 95% CI: 2.0%-7.5%), while none of the pigs sampled from small/medium or large commercial farms tested positive. Although the vast majority of pigs were penned, practices that might facilitate human-to-pig transmission, such as use of household waste and surface water sources to feed pigs, were prevalent among smallholders. However these were not found to be significantly associated with infection. Of 163 interviewed pig workers, 115 (70.5%) were aware of porcine cysticercosis, and 78 (47.8%) also knew it could affect humans. Twenty-six (16.0%) reported having noticed lesions typical of cysticercosis in their pigs.

Conclusions

Despite most pigs being kept confined in pens rather than raised in free-roaming systems, porcine cysticercosis appears to be endemic in south-central Cambodia and is associated with smallholder production. Further investigation is needed to identify which Taenia species are causing infections among pigs, and how seroprevalence and zoonotic risk may vary across the country, to understand the risks to public health and assess where interventions might be needed.

Spatial relationship between Taenia solium tapeworm carriers and necropsy cyst burden in pigs

BACKGROUND

Taenia solium, a parasite that affects humans and pigs, is the leading cause of preventable epilepsy in the developing world. Geographic hotspots of pigs testing positive for serologic markers of T. solium exposure have been observed surrounding the locations of human tapeworm carriers. This clustered pattern of seropositivity in endemic areas formed the basis for geographically targeted control interventions, which have been effective at reducing transmission. In this study, we further explore the spatial relationship between human tapeworm carriers and infected pigs using necroscopic examination as a quantitative gold-standard diagnostic to detect viable T. solium cyst infection in pigs.

METHODOLOGY/PRINCIPAL FINDINGS

We performed necroscopic examinations on pigs from 7 villages in northern Peru to determine the number of viable T. solium cysts in each pig. Participating humans in the study villages were tested for T. solium tapeworm infection (i.e., taeniasis) with an ELISA coproantigen assay, and the distances from each pig to its nearest human tapeworm carrier were calculated. We assessed the relationship between proximity to a tapeworm carrier and the prevalence of light, moderate, and heavy cyst burden in pigs. The prevalence of pig infection was greatest within 50 meters of a tapeworm carrier and decreased monotonically as distance increased. Pigs living less than 50 meters from a human tapeworm carrier were 4.6 times more likely to be infected with at least one cyst than more distant pigs. Heavier cyst burdens, however, were not more strongly associated with proximity to tapeworm carriers than light cyst burdens.

CONCLUSION/SIGNIFICANCE

Our study shows that human tapeworm carriers and pigs with viable T. solium cyst infection are geographically correlated in endemic areas. This finding supports control strategies that treat humans and pigs based on their proximity to other infected individuals. We did not, however, find sufficient evidence that heavier cyst burdens in pigs would serve as improved targets for geographically focused control interventions.

Cisticercosis subcutánea

Se presenta el caso de una paciente de 57 años de edad, natural del distrito de San Martín de Porres en Lima, quien acude a emergencias en el Hospital II Lima Norte-Callao Luis Negreiros Vega de EsSalud por presentar una tumoración en el muslo derecho. La paciente refiere dolor al palpar el muslo y al ponerse en marcha, por lo que se realizan estudios y se procede a la exéresis quirúrgica de dicha tumoración. El análisis macroscópico indicó fragmento de tejido de 5x4x11cm con losange de piel de 4x1.5cm y superficie irregular compuesta de tejido adiposo; al corte a 0.8cm de la piel presenta formación nodular de color pardo amarillento de 1.5x1.8cm con formación quística de 0.6cm, bien delimitada por el tejido fibroso. Además, presenta otras tres formaciones quísticas de 0.3 a 0.8cm de diámetro. De igual forma, el diagnóstico histológico señaló formaciones quísticas en tejido celular subcutáneo de paredes fibrosas recubiertas en su parte interna por macrófagos y células epitelioides a cuerpo extraño, compatible con cisticercosis subcutánea.

Estimation of the health and economic burden of neurocysticercosis in India

Taenia solium is an endemic parasite in India which occurs in two forms in humans: cysticercosis (infection of soft tissues) and taeniosis (intestinal infection). Neurocysticercosis (NCC) is the most severe form of cysticercosis in which cysts develop in the central nervous system. This study was conducted to estimate health and economic impact due to human NCC-associated active epilepsy in India. Input data were sourced from published research literature, census data and other official records. Economic losses due to NCC-associated active epilepsy were estimated based on cost of treatment, hospitalisation and severe injury as well as loss of income. The disability-adjusted life years (DALYs) due to NCC were estimated by combining years of life lost due to early death and the number of years compromised due to disability taking the disease incidence into account. DALYs were estimated for five age groups, two genders and four regions, and then combined. To account for uncertainty, probability distributions were used for disease incidence data and other input parameters. In addition, sensitivity analyses were conducted to determine the impact of certain input parameters on health and economic estimates. It was estimated that in 2011, human NCC-associated active epilepsy caused an annual median loss of Rupees 12.03 billion (uncertainty interval [95% UI] Rs. 9.16-15.57 billion; US $ 185.14 million) with losses of Rs. 9.78 billion (95% UI Rs. 7.24-13.0 billion; US $ 150.56 million) from the North and Rs. 2.22 billion (95% UI Rs. 1.58-3.06 billion; US $ 34.14 million) from the South. The disease resulted in a total of 2.10 million (95% UI 0.99-4.10 million) DALYs per annum without age weighting and time discounting with 1.81 million (95% UI 0.84-3.57 million) DALYs from the North and 0.28 million (95% UI 0.13-0.55 million) from the South. The health burden per thousand persons per year was 1.73 DALYs (95% UI 0.82-3.39). The results indicate that human NCC causes significant health and economic impact in India. Programs for controlling the disease should be initiated to reduce the socio-economic impact of the disease in India.

Neurocysticercosis in a Rhesus Macaque (Macaca mulatta)

An 8-y-old, intact, male rhesus macaque (Macaca mulatta) was sedated to undergo MRI in preparation for the implantation of cranial hardware. During imaging, 9 focal lesions were noted in the brain and musculature of the head. The lesions were hyperechoic with hypoechoic rims. The animal was deemed inappropriate for neuroscience research, and euthanasia was elected. Gross examination revealed multiple round, thick-walled, fluid-filled cysts (diameter, approximately 0.5 cm) in multiple tissues: one each in the left caudal lung lobe, left masseter muscle, and the dura overlying the brain and 8 throughout the gray and white matter of the brain parenchyma. Formalin-fixed sections of cyst-containing brain were stained with hematoxylin and eosin. Microscopic examination and molecular analysis of the COX1 (COI) gene recognized the causative organism as Taenia solium at 99.04% identity.

Analysis of cerebrospinal fluid in racemose form of neurocysticercosis

The present work aimed to evaluate the pattern of CSF alterations in patients diagnosed with neurocysticercosis (NCC) in racemose form.Method This is a retrospective cohort study of patients with diagnosis of NCC in racemose form. CSF samples from 26 patients were analyzed. After patient-chart analysis was performed descriptive analysis of case studies and comparison between sexes in relation to variables were obtained with CSF by Mann-Whitney and Student's t-tests.Results The sexes did not differ statistically when compared to pleocytosis in CSF. Eosinophils were present in 31% in samples while the ELISA test presented 80% sensitivity in this case series. Of the patient total, 24 presented a meningitis pattern with lymphocytic predominance.Conclusion There was no difference in inflammatory pattern between the sexes, with predominance of lymphocytic meningitis and 80% sensitivity by ELISA test of CSF patients with racemose form of NCC.

Imaging and Serological-Evidence of Neurocysticercosis Among Patients with Seizures in Odisha, an Unexplored Eastern Coastal Province in India

INTRODUCTION

Neurocysticercosis being a potential to human transmitted disease, is the major cause of seizures and a public health problem in tropical countries. Though India is known to be highly endemic, there are many provinces where reports are still unavailable thereby underestimating its actual burden.

MATERIALS AND METHODS

Anti-Cysticercus IgG antibodies in sera from cases presenting with seizures were screened by ELISA in a preliminary study in Odisha state which is a province in Eastern coastal India that was never explored before. Patients presenting with recent onset of seizures within age group 5 to 50 years, either local residents of Odisha or inhabitants from other parts of the country living for at least one year period in the study area were included.

RESULTS

The present study showed 43.75% cases with seizures to be confirmed neurocysticercosis (NCC) based on serology and brain imaging. However, statistically no association was established between anti-Cysticercus antibody detection and radio imaging characteristics (location, number of lesions, and stage).

CONCLUSION

This is the first study in Odisha presenting a series of cases with serological evidence of exposure to the parasite along with imaging characteristics which was consistent with NCC. It is recommended that NCC must be considered for a differential diagnosis in each active epilepsy case irrespective of prior prevalence information in all unexplored provinces in India and other endemic regions; also a compulsory reporting is warranted in order to aid in quantifying its actual burden.

Cysticercosis and epilepsy in rural Tanzania: a community-based case-control and imaging study

OBJECTIVE

To assess the contribution of neurocysticercosis (NCC) to the burden of epilepsy in a rural Tanzanian population.

METHODS

We identified adult people with epilepsy (PWE) in a door-to-door study in an established demographic surveillance site. PWE and community controls were tested for antibodies to Taenia solium, the causative agent of NCC, and all PWE were offered a computed tomography (CT) head scan. Data on household occupancy and sanitation, pig-keeping and pork consumption were collected from PWE and controls and associations with epilepsy were assessed using chi-square or Fisher's exact tests.

RESULTS

Six of 218 PWE had antibodies to T. solium (2.8%; 95% CI 0.6-4.9), compared to none of 174 controls (Fisher's exact test, P = 0.04). Lesions compatible with NCC were seen in eight of 200 CT scans (4.0%; 95% CI 1.3-6.7). A total of 176 PWE had both investigations of whom two had positive serology along with NCC-compatible lesions on CT (1.1%; 95% 0.3-4.0). No associations between epilepsy and any risk factors for NCC were identified.

CONCLUSIONS

Neurocysticercosis is present in this population but at a lower prevalence than elsewhere in Tanzania and sub-Saharan Africa. Insights from low-prevalence areas may inform public health interventions designed to reduce the burden of preventable epilepsy.

Fine-needle aspiration cytology as a diagnostic modality for cysticercosis: A clinicocytological study of 137 cases

BACKGROUND

Cysticercosis, a parasitic tissue infection caused by the larva of Taenia solium, is quite a common disease in our part of the world, but its incidence is often underestimated. Fine-needle aspiration cytology (FNAC) plays an important role in early detection of this disease, especially when the lesion is located in anatomically approachable superficial locations.

AIMS

The aim was to study role of FNAC in the diagnosis of cysticercosis.

MATERIALS AND METHODS

In this retrospective study, the data of 137 patients with palpable nodules, who were diagnosed as having or suspicious of cysticercosis on FNAC, were retrieved and analyzed.

RESULTS

In 129 (94.2%) cases, a definitive diagnosis of cysticercosis was obtained in the form of parts of parasite tegument, hooklets, parenchymatous portion and calcareous corpuscles. In the background, giant cells, mixed inflammatory cells, and epithelioid cells were present. In remaining 8 (5.8%) cases, larval fragments could not be identified on the aspirates, and the diagnosis of parasitic inflammation was suggested on the basis of other cytological findings such as clear fluid aspirate, presence of eosinophils, histiocytes, foreign body giant cells, a typical granular dirty background, etc. Follow-up biopsy in these 8 cases confirmed the diagnosis of cysticercosis in 7 (87.5%) while in 1 (12.5%) case, histopathology was suggestive of parasitic cyst.

CONCLUSION

Fine-needle aspiration cytology in cysticercosis is a low-cost outpatient procedure. The cytological diagnosis is quite straightforward in cases where the actual parasite structures are identified in the smears. In other cases, a cytological diagnosis of suspicious of cysticercosis can be given if the cytological findings suggest the same.

Ring-screening to control endemic transmission of Taenia solium

BACKGROUND

Taenia solium is a major cause of preventable epilepsy in developing nations. Screening and treatment of human intestinal stage infection (taeniasis) within high-risk foci may reduce transmission and prevent epilepsy by limiting human exposure to infective eggs. We piloted a ring-strategy that involves screening and treatment for taeniasis among households located nearby pigs heavily-infected with the larval stage (cysticercosis). These pigs mark areas of increased transmission and can be identified by tongue examination.

METHODOLOGY

We selected two villages in northern Peru for a controlled prospective interventional cohort pilot study. In the intervention village (1,058 residents) we examined the tongues of all pigs every 4 months for nodules characteristic of cysticercosis. We then screened all residents living within 100-meters of any tongue-positive pig using enzyme-linked immunosorbent assay to detect Taenia antigens in stool. Residents with taeniasis were treated with niclosamide. In both the intervention and control (753 residents) we measured incidence of exposure by sampling the pig population every 4 months for serum antibodies against cysticercosis using enzyme-linked immunoelectrotransfer blot.

PRINCIPAL FINDINGS

Baseline seroincidence among pigs born during the study was 22.6 cases per 100 pigs per-month (95% confidence interval [CI] 17.0-30.0) in the intervention and 18.1 (95% CI 12.7-25.9) in the control. After one year we observed a 41% reduction in seroincidence in the intervention village compared to baseline (incidence rate ratio 0.59, 95% CI 0.41-0.87) while the seroincidence in the control village remained unchanged. At study end, the prevalence of taeniasis was nearly 4 times lower in the intervention than in the control (prevalence ratio 0.28, 95% CI 0.08-0.91).

CONCLUSIONS/SIGNIFICANCE

Ring-screening reduced transmission of T. solium in this pilot study and may provide an effective and practical approach for regions where resources are limited. However, this strategy requires validation in larger populations over a greater period of time.

Neurocysticercosis in children presenting with afebrile seizure: clinical profile, imaging and serodiagnosis

Neurocysticercosis (NCC) is one of the major causes of childhood seizures in developing countries including India and Latin America. In this study neurological pediatric cases presenting with afebrile seizures were screened for anti-Cysticercus antibodies (IgG) in their sera in order to estimate the possible burden of cysticercal etiology. The study included a total of 61 pediatric afebrile seizure subjects (aged one to 15 years old); there was a male predominance. All the sera were tested using a pre-evaluated commercially procured IgG-ELISA kit (UB-Magiwell Cysticercosis Kit ^™). Anti-Cysticercus antibody in serum was positive in 23 of 61 (37.7%) cases. The majority of cases with a positive ELISA test presented with generalized seizure (52.17%), followed by complex partial seizure (26.08%), and simple partial seizure (21.73%). Headaches were the major complaint (73.91%). Other presentations were vomiting (47.82%), pallor (34.78%), altered sensorium (26.08%), and muscle weakness (13.04%). There was one hemiparesis case diagnosed to be NCC. In this study one child without any significant findings on imaging was also found to be positive by serology. There was a statistically significant association found between the cases with multiple lesions on the brain and the ELISA-positivity (p = 0.017). Overall positivity of the ELISA showed a potential cysticercal etiology. Hence, neurocysticercosis should be suspected in every child presenting with afebrile seizure especially with a radio-imaging supportive diagnosis in tropical developing countries or areas endemic for taeniasis/cysticercosis.

Neglected parasitic infections in the United States: cysticercosis

Cysticercosis is a potentially fatal and preventable neglected parasitic infection caused by the larval form of Taenia solium. Patients with symptomatic disease usually have signs and symptoms of neurocysticercosis, which commonly manifest as seizures or increased intracranial pressure. Although there are many persons living in the United States who emigrated from highly disease-endemic countries and there are foci of autochthonous transmission of the parasite in the United States, little is known about burden and epidemiology of the disease in this country. In addition, despite advances in the diagnosis and management of neurocysticercosis, there remain many unanswered questions. Improving our understanding and management of neurocysticercosis in the United States will require improved surveillance or focused prospective studies in appropriate areas and allocation of resources towards answering some of the key questions discussed in this report.

Evaluation of the non-catalytic binding function of Ts26GST a glutathione transferase isoform of Taenia solium

Taenia solium glutathione transferase isoform of 26.5 kDa (Ts26GST) was observed to bind non-catalytically to porphyrins, trans-trans-dienals, bile acids and fatty acids, as assessed by inhibition kinetics, fluorescence spectroscopy and competitive fluorescence assays with 8-anilino-1-naphthalene sulfonate (ANS). The quenching of Ts26GST intrinsic fluorescence allowed for the determination of the dissociation constants (KD) for all ligands. Obtained data indicate that Ts26GST binds to all ligands but with different affinity. Porphyrins and lipid peroxide products inhibited Ts26GST catalytic activity up to 100% in contrast with only 20-30% inhibition observed for bile acids and two saturated fatty acids. Non-competitive type inhibition was observed for all enzyme inhibitor ligands except for trans-trans-2,4-decadienal, which exhibited uncompetitive type inhibition. The dissociation constant value KD = 0.7 μM for the hematin ligand, determined by competitive fluorescence assays with ANS, was in good agreement with its inhibition kinetic value Ki = 0.3 μM and its intrinsic fluorescence quenching KD = 0.7 μM. The remaining ligands did not displace ANS from the enzyme suggesting the existence of different binding sites. In addition to the catalytic activity of Ts26GST the results obtained suggest that the enzyme exhibits a ligandin function with broad specificity towards nonsubstrate ligands.

Further characterization of Tsol-p27 as a diagnostic antigen in sub-Saharan Africa

Commercial antigens used to diagnose human neurocysticercosis are obtained from either a soluble parasite extract or a parasite-derived glycoprotein fraction. The aim of the present study was to identify antigenic proteins as potential diagnostic candidates in Mozambique. Soluble proteins from Taenia solium cysticerci were separated by two-dimensional electrophoresis and blotted onto nitrocellulose membranes. Subtracted hybridization was performed with serum samples obtained from patients with neurocysticercosis (NCC) and from a NCC-negative control group. Six antigenic proteins were identified and sequenced by liquid chromatography–mass spectrometry. Among these we found Tsol-p27, which was previously identified as a diagnostic candidate in a study conducted in Nicaragua, Central America. Here, we evaluated Tsol-p27 and the antigen cC1 as potential recombinant diagnostic reagents, and also investigated the localization and partial function of Tsol-p27. Immunoblotting demonstrated that Tsol-p27 was recognized by all 10 serum samples from NCC-positive individuals, whereas cC1 was identified by only five of the 10 positive sera. None of the antigens were recognized by negative control sera. Despite the limited number of serum samples evaluated in this study, the results suggest that Tsol-p27 can be a suitable candidate for diagnosis of human NCC, not only in Central America but also in sub-Saharan Africa.

Neurocysticercosis in a European traveler returning from India primarily suspected as neoplasia

A woman with a history of cured breast cancer and multiple trips to India presented with a cervical nodule. Primarily suspected as metastasis of breast cancer, histopathology, however, showed the scolex of Taenia solium. Although the patient was neurologically asymptomatic neuroimaging showed multiple cysts. During treatment with praziquantel, albendazole, and dexamethason the patient developed seizures.

From seizures to epilepsy and its substrates: neurocysticercosis

Neurocysticercosis (NCC) is the main risk factor for late-onset seizures in many Taenia solium endemic countries and is also increasingly recognized in high income countries, where it was once thought to have been eliminated. The course and outcome of NCC-associated seizures and epilepsy are poorly understood. Substrates underlying NCC-associated seizures and epilepsy are unknown. Another unknown is if there is an association between NCC and hippocampal sclerosis (HS) and if it leads to intractable epilepsy. We review evidence regarding the structural basis of seizures and epilepsy in NCC and its association with HS. There are only a limited number of prospective studies of NCC-associated seizures and epilepsy. From these, it can be inferred that the risk of seizure recurrence is high following a first seizure, even though seizures are well-controlled with antiepileptic drugs. The single most important risk factor for ongoing or recurrent seizures is the persistence of either degenerating or residual calcified cysticercus cysts in the brain parenchyma on follow-up imaging studies. Medically intractable epilepsy requiring surgical treatment appears to be rare in people with NCC. In few cases that have been operated, gliosis around the cysticerci is the principal pathologic finding. Reports of the association between NCC and HS might be categorized into those in which the calcified cysticercus is located within the hippocampus and those in which the calcified cysticercus is located remote from the hippocampus. The former are convincing cases of medically intractable epilepsy with good seizure control following hippocampal resection. In the remaining, it is unclear whether a dual pathology relationship exists between HS and the calcified cysticercus. Carefully planned, follow-up studies incorporating high-resolution and quantitative imaging are desirable in order to clarify the outcome, the structural basis of NCC-associated epilepsy, and also its association with HS.

On the relationship between neurocysticercosis and mesial temporal lobe epilepsy associated with hippocampal sclerosis: coincidence or a pathogenic relationship?

Neurocysticercosis (NCC) and mesial temporal lobe epilepsy associated with hippocampal sclerosis (MTLE-HS) are two common worldwide forms of focal epilepsy. In regions where NCC is endemic, both diseases can be observed in the same patient. There is recent and growing evidence suggesting that NCC might contribute to or even cause MTLE-HS. In this article, we review the literature regarding NCC and temporal lobe epilepsy, specifically addressing the relationship between NCC and MTLE-HS. In addition, we review some scenarios where NCC seems to emerge as a causative agent or contributor to the development of MTLE-HS in some patients. This association is important because it may have an impact on the evaluation and treatment of a sizable proportion of patients with epilepsy. Insights from these clinical observations might also contribute to the understanding of the neurobiology of both NCC and MTLE-HS. We hope that our review might shed some light on this interesting interplay between two of the most common worldwide conditions associated with human focal epilepsy.

The economic impact of pig-associated parasitic zoonosis in Northern Lao PDR

The parasitic zoonoses human cysticercosis (Taenia solium), taeniasis (other Taenia species) and trichinellosis (Trichinella species) are endemic in the Lao People's Democratic Republic (Lao PDR). This study was designed to quantify the economic burden pig-associated zoonotic disease pose in Lao PDR. In particular, the analysis included estimation of the losses in the pork industry as well as losses due to human illness and lost productivity. A Markov-probability based decision-tree model was chosen to form the basis of the calculations to estimate the economic and public health impacts of taeniasis, trichinellosis and cysticercosis. Two different decision trees were run simultaneously on the model's human cohort. A third decision tree simulated the potential impacts on pig production. The human capital method was used to estimate productivity loss. The results found varied significantly depending on the rate of hospitalisation due to neurocysticerosis. This study is the first systematic estimate of the economic impact of pig-associated zoonotic diseases in Lao PDR that demonstrates the significance of the diseases in that country.

Eosinophilic meningitis

Eosinophilic meningitis is defined by the presence of at least 10% eosinophils in the total cerebrospinal fluid (CSF) leukocyte count. Although there are several possible causes of eosinophils in the CSF, parasitic infection is the main cause. The three common parasites causing eosinophilic meningitis include Angiostrongylus cantonensis, Gnathostoma spinigerum, and Taenia solium. Even though these parasites are endemic in tropical countries, they are now spreading globally due to extensive traveling, and physicians worldwide should pay more attention to this condition. This chapter will review risk factors, clinical manifestations, and treatment of these three parasites.

Neurocysticercosis

Cysticercosis, an infection caused by the cystic larvae of the pork tapeworm Taenia solium, is one of the most frequent parasitic infections of the human nervous system (neurocysticercosis). It is endemic in most of Latin America, the sub-Saharan Africa, and vast parts of Asia, including the Indian subcontinent. It has also been increasingly diagnosed in developed countries because of migration of people from endemic zones and exposure in travelers. The life cycle involves the development of the adult tapeworm in the human small intestine (after ingesting infected pork with cysts) and larval infection in pig tissues (after ingesting human stools containing the eggs of the tapeworm). Humans get infected by the fecal-oral route, most often from a direct contact with an asymptomatic Taenia carrier. Most common clinical presentations are seizures (particularly late-onset seizures), chronic headaches, and intracranial hypertension. However, cysticerci can locate anywhere in the human nervous system, thus potentially causing almost any neurological syndrome and making clinical diagnosis a difficult task. Neuroimaging is the main diagnostic tool, and specific serology confirms the diagnosis and helps to define the diagnosis when images are unclear. Factors such as location (extraparenchymal versus intraparenchymal), number, size and evolutive stage of the parasites determine the clinical manifestations, therapeutic approach, and prognosis. Management includes symptomatic drugs (analgesics, antiepileptic drugs, anti-inflammatory agents) and in many cases cysticidal drugs, either albendazole or praziquantel. In recent years, efforts have focused on transmission control and potential elimination in endemic regions.

Geographic correlation between tapeworm carriers and heavily infected cysticercotic pigs

Background

Neurocysticercosis is a leading cause of preventable epilepsy in the developing world. Sustainable community-based interventions are urgently needed to control transmission of the causative parasite, Taenia solium. We examined the geospatial relationship between live pigs with visible cysticercotic cysts on their tongues and humans with adult intestinal tapeworm infection (taeniasis) in a rural village in northern Peru. The objective was to determine whether tongue-positive pigs could indicate high-risk geographic foci for taeniasis to guide targeted screening efforts. This approach could offer significant benefit compared to mass intervention.

Methods

We recorded geographic coordinates of all village houses, collected stool samples from all consenting villagers, and collected blood and examined tongues of all village pigs. Stool samples were processed by enzyme-linked immunosorbent assay (ELISA) for presence of Taenia sp. coproantigens indicative of active taeniasis; serum was processed by enzyme-linked immunoelectrotransfer blot for antibodies against T. solium cysticercosis (EITB LLGP) and T. solium taeniasis (EITB rES33).

Findings

Of 548 pigs, 256 (46.7%) were positive for antibodies against cysticercosis on EITB LLGP. Of 402 fecal samples, 6 (1.5%) were positive for the presence of Taenia sp. coproantigens. The proportion of coproantigen-positive individuals differed significantly between residents living within 100-meters of a tongue-positive pig (4/79, 5.1%) and residents living >100 meters from a tongue-positive pig (2/323, 0.6%) (p = 0.02). The prevalence of taeniasis was >8 times higher among residents living within 100 meters of a tongue-positive pig compared to residents living outside this range (adjusted PR 8.1, 95% CI 1.4–47.0).

Conclusions

Tongue-positive pigs in endemic communities can indicate geospatial foci in which the risk for taeniasis is increased. Targeted screening or presumptive treatment for taeniasis within these high-risk foci may be an effective and practical control intervention for rural endemic areas.

Taenia solium, aka the pork tapeworm, is an important cause of epilepsy in developing nations. People with intestinal tapeworms, a condition known as taeniasis, pass infectious eggs in their feces which contaminate the environment. These eggs can cause serious disease in both humans and pigs if they are ingested. Treating taeniasis is one way to potentially control transmission of the parasite in affected communities. However, this is difficult because people with taeniasis usually have no symptoms and therefore don't know they are infected. As a result, control programs may resort to offering treatment to entire communities in order to reach a few tapeworm carriers. Focusing detection and treatment on high-risk subgroups is another approach which might reduce unnecessary treatments. In this study, we found that people with taeniasis are more likely to be found living nearby pigs with visible signs of infection, specifically tapeworm cysts on their tongues. This suggests that routine tongue examination by pig owners and buyers could identify neighborhoods where detection and treatment of taeniasis may be more efficient.