An epidemiological study of asymptomatic neurocysticercosis in a pig farming community in northern India

Calcified Neurocysticercosis: Demographic, Clinical, and Radiological Characteristics of a Large Hospital-Based Patient Cohort

Neurocysticercosis (NCC), the infection of the central nervous system caused by Taenia solium larvae (cysticerci), is a major cause of acquired epilepsy worldwide. Calcification in NCC is the most common neuroimaging finding among individuals with epilepsy in T. solium-endemic areas. We describe the demographic, clinical, and radiological profiles of a large hospital cohort of patients with calcified NCC in Peru (during the period 2012-2022) and compared profiles between patients with and without a previous known diagnosis of viable infection. A total of 524 patients were enrolled (mean age at enrollment: 40.2 ± 15.2 years, mean age at symptom onset: 29.1 ± 16.1 years, 56.3% women). Of those, 415 patients (79.2%) had previous seizures (median time with seizures: 5 years, interquartile range (IQR): 2-13 years; median number of seizures: 7 (IQR: 3-32)), of which 333 (80.2%) had predominantly focal to bilateral tonic-clonic seizures; and 358 (68.3%) used antiseizure medication). Patients had a median number of three calcifications (IQR: 1-7), mostly located in the frontal lobes (79%). In 282 patients (53.8%) there was a previous diagnosis of viable infection, while 242 only had evidence of calcified NCC since their initial neuroimaging. Most patients previously diagnosed with viable infection were male, had previous seizures, had seizures for a longer time, had more calcifications, and had a history of taeniasis more frequently than patients without previously diagnosed viable infection (all p < 0.05). Patients with calcified NCC were heterogeneous regarding burden of infection and clinical manifestations, and individuals who were diagnosed after parasites calcified presented with milder disease manifestations.

H, Krovvidi S, Chennuru S. Prevalence of taeniosis in pig farming community in Andhra Pradesh, India

Taeniosis is one of the neglected zoonoses in India. Facts on taeniosis, compared to cysticercosis are scanty in India. Hence, this study is aimed to determine the occurrence of taeniosis in human beings in Andhra Pradesh, India. A total of 1380 stool samples were collected from people associated with pig farming and or had the habit of pork eating in certain districts (n = 7) of Andhra Pradesh. Prevalence of human taeniosis was determined using microscopic examination of stool samples and proglottds. The overall prevalence of taeniosis was found to be 0.79%. Morphology of gravid segments revealed lower number of lateral branches indicating T. solium segments. Age and gender of human were not associated with the occurrence of taeniosis. The low prevalence of taeniosis in human indicates good hygiene and sanitation practices in humans, and awareness about the disease and its transmission. Further studies involving more sensitive techniques on stool and serum samples are warranted.

What Causes Seizures in Neurocysticercosis?

Neurocysticercosis (NCC) is the most prevalent parasitic infection of the central nervous system. It is caused by the presence of larvae of the cestode Taenia solium in the brain. The most common symptom of NCC is seizures, and it is widely considered the world’s leading cause of preventable epilepsy. Despite the prevalence and impact of NCC, a thorough, mechanistic understanding of seizure generation is still lacking. In this review, we address the question “What causes seizures in NCC?” by summarizing and discussing the major theories that seek to explain the seizurogenic and epileptogenic processes in this disorder. In addition, we highlight the potential for recent advances in disease modeling to help accelerate progress in this area.

CystiHuman: A model of human neurocysticercosis

INTRODUCTION

The Taenia solium tapeworm is responsible for cysticercosis, a neglected tropical disease presenting as larvae in the body of a host following taenia egg ingestion. Neurocysticercosis (NCC), the name of the disease when it affects the human central nervous system, is a major cause of epilepsy in developing countries, and can also cause intracranial hypertension, hydrocephalus and death. Simulation models can help identify the most cost-effective interventions before their implementation. Modelling NCC should enable the comparison of a broad range of interventions, from treatment of human taeniasis (presence of an adult taenia worm in the human intestine) to NCC mitigation. It also allows a focus on the actual impact of the disease, rather than using proxies as is the case for other models.

METHODS

This agent-based model is the first model that simulates human NCC and associated pathologies. It uses the output of another model, CystiAgent, which simulates the evolution of pig cysticercosis and human taeniasis, adding human and cyst agents, including a model of cyst location and stage, human symptoms, and treatment. CystiHuman also accounts for delays in the appearance of NCC-related symptoms. It comprises three modules detailing cyst development, seizure probability and timing, and intracranial hypertension/hydrocephalus, respectively. It has been implemented in Java MASON and calibrated in three endemic villages in Peru, then applied to another village (Rica Playa) to compare simulation results with field data in that village.

RESULTS AND DISCUSSION

Despite limitations in available field data, parameter values found through calibration are plausible and simulated outcomes in Rica Playa are close to actual values for NCC prevalence and the way it increases with age and cases with single lesions. Initial simulations further suggest that short-term interventions followed by a rapid increase in taeniasis prevalence back to original levels may have limited impacts on NCC prevalence.

High prevalence of neurocysticercosis among patients with epilepsy in a tertiary care hospital of Assam, India

Background:

Neurocysticercosis (NCC) is a parasitic disease of the central nervous system, which is caused by the metacestode of the pork tapeworm, Taenia solium. The present unicentric, hospital-based, cross-sectional study was undertaken to assess the contribution of NCC as a cause of active epilepsy among patients attending a tertiary health care center in Assam, India.

Materials and Methods:

Over a period of 2 years, 152 active epilepsy patients were investigated based on clinical, epidemiological, neuroimaging (contrast-enhanced computerized tomography), and immunological techniques to establish the diagnosis of NCC. A precoded questionnaire was administered to patients and/or guardians to collect detailed medical history.

Results:

Ninety-three cases (61.2%) fulfilled either definitive or probable diagnostic criteria for NCC. Anti-cysticercus immunoglobulin G antibodies were detected by ELISA and enzyme electro-immune transfer blot in 69 (45.4%) active epilepsy patients. Seroprevalence was higher in males, 46.6% (54/116); than in females, 41.7% (15/36), and increased significantly with age; peaking in the 20–39 years age group (36/76; χ² = 5.64; P = 0.02). Among the seropositive cases, 54 (78.3%) were diagnosed with NCC. A significantly higher number of seropositive individuals were diagnosed with NCC in the 20–39 years age group as compared to the 40 years and above age group (χ² = 6.28; P = 0.01). The association between seropositivity for NCC, and the number of lesions in the brain was statistically significant (χ² = −8.33; P = 0.003).

Conclusions:

This study indicates that NCC is a major cause of active epilepsy in Assam. A high prevalence of pediatric NCC is also a major concern.

My experience on taeniasis and neurocysticercosis

Taeniasis and neurocysticercosis (NCC) are major public health problems in developing countries. NCC is the leading cause of community-acquired active epilepsy. NCC may present as a medical emergency, especially when there is cysticercotic encephalitis or raised intracranial hypertension. Systematic community-based studies on taeniasis and NCC are lacking. We studied taeniasis and NCC-related active epilepsy disease burden in the pig farming community of Lucknow district, Uttar Pradesh, India. Based on the 30 cluster sampling approach as recommended by the World Health Organization, we estimated the prevalence of taeniasis, NCC-related active epilepsy, and silent NCC in the community. We also estimated the prevalence of swine cysticercosis. Taeniasis was detected in 18.6% of populations. Expulsions of tapeworm segments in stool, consumption of undercooked pork, age above 15 years, and handwash with clay or plain water after defecation were associated with taeniasis. On molecular analyses of positive stool samples, T. solium was identified in 40% and Taenia asiatica in 60% of cases. Active epilepsy was identified in 5.8% of subjects; 48% of them had NCC. On neuroimaging, NCC was detected in 15% of asymptomatic individuals. We observed that host genetic factors such as toll-like receptor-4, matrix metalloproteinase-9, intercellular adhesion molecule-1, and glutathione-S transferase gene polymorphisms were associated with seizure in NCC. When peripheral blood mononuclear cells (PBMCs) from NCC subjects were exposed to cysticerci fluid antigens in-vitro, PBMCs from symptomatic and asymptomatic subjects showed significantly higher Th 1 and Th 2 cytokines response respectively, symptomatic patients had significant Th-1 cytokines response, while asymptomatic individuals showed Th-2 response. Porcine cysticercosis was detected in 26% of swine; 38% of them had cysticerci in the brain. Swine with brain involvement showed clinical signs such as excessive salivation, excessive blinking and tearing, and subconjunctival nodule. On molecular analysis, 15% of cysticerci in swine were identified as T. asiatica. Infected swine when treated with albendazole plus/minus steroid, the response rate of cysticerci (either dead or resolved lesion) was 100% in albendazole-treated group and 71% in albendazole plus steroid-treated group. The above studies suggest that taeniasis and NCC are alarmingly high in the pig farming community of North India. Taeniasis in human and cysticercosis in swine due to T. asiatica call for further studies on this parasite.

A Large Case Series of Neurocysticercosis in Kuwait, a Nonendemic Arabian Gulf Country in the Middle East Region

Neurocysticercosis (NCC), a leading global cause of severe progressive headache and epilepsy, in developed or affluent countries is mostly diagnosed among immigrants from poor or developing Taenia solium taeniasis-endemic countries. Taeniasis carriers in Kuwait are routinely screened by insensitive stool microscopy. In this study, enzyme-linked immunoelectrotransfer blot (EITB) was used as a confirmatory test for NCC. Screening was performed on 970 patients referred for suspected NCC on the basis of relevant history and/or ring-enhancing lesions on computed tomography and/or magnetic resonance imaging during a 14-year period in Kuwait. Demographic data and clinical details were retrieved from laboratory or hospital records. EITB was positive in 150 subjects (15.5%), including 98 expatriates mostly originating from taeniasis-endemic countries and, surprisingly, 52 Kuwaiti nationals. The clinical details of 48 of 50 NCC cases diagnosed during 2014–2019 were available. Most common symptoms included seizures, persistent headache with/without fever, and fits or loss of consciousness. Cysticercal lesions were located at various brain regions in 39 of 48 patients. Multiple members of 3 families with NCC were identified; infection was linked to domestic workers from taeniasis-endemic countries and confirmed in at least 1 family. Our data show that NCC is predominantly imported in Kuwait by expatriates originating from taeniasis-endemic countries who transmit the infection to Kuwaiti citizens.

Neurocysticercosis in patients with active epilepsy in the tea garden community of Assam, Northeast India

Neurocysticercosis is a significant cause of epilepsy in the tropics. The present cross-sectional survey was conducted in the socioeconomically backward tea garden community of Assam to gauge the prevalence of neurocysticercosis in patients with active epilepsy and to determine the associated risk factors. In a door to door survey, a total of 1028 individuals from every fifth household of the study Teagarden were enrolled to identify self-reported seizure cases, followed by a neurological examination to confirm the diagnosis of active epilepsy. Patients with active epilepsy underwent clinical, epidemiological, neuroimaging (contrast-enhanced computerized tomography) and immunological evaluations to establish the diagnosis of neurocysticercosis. Clinically confirmed 53 (5.16%) active epilepsy were identified; 45 agreed to further assessment for neurocysticercosis and 19 (42.2%) cases fulfilled either definitive or probable diagnostic criteria for neurocysticercosis. Patients with epilepsy due to neurocysticercosis were more likely to suffer from taeniasis (20.0% vs 0.0%), rear pigs (57.9% vs 15.4%) or have pigs in their neighbourhood (78.9% vs 53.8%) relative to epileptic patients without neurocysticercosis. Rearing pigs (aOR 14.35, 95% CI: 3.98–51.75) or having pigs in the neighbourhood (aOR 12.34, 95% CI: 2.53–60.31) were independent risk factors of neurocysticercosis. In this community, the prevalence of taeniasis (adult worm infection) was 6.6% based on microscopy. The study reports a high prevalence of active epilepsy in the tea garden community of Assam and neurocysticercosis as its primary cause. The high prevalence of taeniasis is also a significant concern.

Psychiatric Disorders of Neurocysticercosis: Narrative Review

Neurocysticercosis, the most common type of neuroparasitosis, is a condition in which the central nervous system (CNS) is infested with the pork tapeworm Taenia solium cysticercosis' larvae. Neurocysticercosis is the most widespread parasitic CNS disease worldwide, affecting more than 50 million individuals. As neurocysticercosis is prevalent in developing countries, the growing number of migrants and travelers increases prevalence in developed countries. Possible neuropsychiatric manifestations are depression, cognitive dysfunction, dementia, and visual hallucinations. Depending on the cysts' location in the CNS, focal neurology or psychiatric symptoms manifest. The diagnosis of neurocysticercosis is based on neuroimaging and serology. The correlation between specific symptoms and the cyst's location might help better understand psychiatric disorders' pathophysiology. Nonetheless, the exact prevalence of neurocysticercosis is seldom reported in patients with psychiatric disorders, which may be due to the lack of imaging availability in developing countries with a high prevalence.

Neurocysticercosis: An Easy to Miss Diagnosis in Non-Endemic Regions

A 29-year-old male presented with swollen gums and stomatitis for the past two months. History revealed that he had moved to the United States from India six years ago and had a first episode of generalized tonic-clonic seizure with confusion and loss of consciousness. Meningioma of the brain was diagnosed, and a Gamma Knife excision of the meningioma was planned. The patient refused to proceed with the surgery and came back to India for a second opinion. Upon repeat MRI scan, the neurosurgeon revised the diagnosis to neurocysticercosis (NCC), and the patient was treated with albendazole, prednisolone, and phenytoin and recovered completely. Hence an unnecessary brain surgery was avoided. The complaint of stomatitis and gingival hypertrophy was due to the side effects of phenytoin. NCC remains a major public health problem in developing countries, and it should be considered as a differential diagnosis in patients from NCC endemic regions.

A prospective cohort study to assess the frequency and risk factors for calcification in single lesion parenchymal neurocysticercosis

BACKGROUND

Calcified neurocysticercosis (NCC) predisposes patients to an enduring state of epilepsy. The predictors for calcification in parenchymal neurocysticercosis are not well defined.

METHOD

In this prospective cohort study, consecutive children with single-lesion parenchymal NCC were enrolled and followed up for one year. All patients were investigated with brain 3 T-MRI and electroimmunotransfer blot (EITB). Clinical follow-ups were performed every 3 months. Radiology was repeated at the 6-month and one-year follow-ups. The proportion of calcified lesions at one year and the predictors of calcification were studied.

RESULT

During the study period from June 2013 to December 2015, 93 children with single lesion parenchymal NCC were enrolled. At presentation, 90 % of the lesions were in the colloidal stage, and 71 % of the lesions had moderate to severe perilesional oedema. All children had 6 months of follow-up, and 86 (92.5 %) had one year of follow-up. Seizure recurrence was present in 13 (14 %) children. Follow-up radiology at one year showed lesion resolution in 51 (59 %) lesions and calcification in 28 (32.5 %) lesions. Children with calcified lesions during follow-up had a higher odds of seizure recurrences {OR, 95 % CI 3.6(2.3-5.6)}. The presence at baseline of diffusion restriction {OR, 95% CI 2.9 (1.01-8.8)}, scolex or wall calcification in the T2 Star weighted angiography MRI images {OR, 95% CI 3.7 (1.7-8.2)} and >10 mm size of the lesion {OR, 95 % CI 2.4 (1.2-5.01)} predicted lesion calcification.

CONCLUSION

Children with calcification of the parenchymal NCC lesions have a higher risk for seizure recurrence during follow-up. The presence of diffusion restriction, calcified nidus in the colloidal nodular stage, and >10 mm size of the lesion at baseline predicted calcification of the lesion during follow-up.

Population Screening for Urine Antigens to Detect Asymptomatic Subarachnoid Neurocysticercosis: A Pilot Study in Northern Peru

Subarachnoid neurocysticercosis (SANCC) is a severe and progressive brain infection with Taenia solium. We performed a pilot study of noninvasive screening for SANCC in two endemic villages in northern Peru using a urine antigen screen followed by brain magnetic resonance imaging for participants with elevated levels of antigen. Among the 978 participants screened, we identified eight individuals with SANCC, many of whom were asymptomatic. This represents a minimum prevalence of 0.8% of SANCC, a level higher than expected based on prior studies, and a positive predictive value of 62% for our novel urine screening test. Future studies should confirm whether early detection and management improve clinical outcomes.

Taenia solium Cysticercosis and Its Impact in Neurological Disease

Taenia solium neurocysticercosis (NCC) is endemic in most of the world and contributes significantly to the burden of epilepsy and other neurological morbidity. Also present in developed countries because of immigration and travel, NCC is one of few diseases targeted for eradication. This paper reviews all aspects of its life cycle (taeniasis, porcine cysticercosis, human cysticercosis), with a focus on recent advances in its diagnosis, management, and control. Diagnosis of taeniasis is limited by poor availability of immunological or molecular assays. Diagnosis of NCC rests on neuroimaging findings, supported by serological assays. The treatment of NCC should be approached in the context of the particular type of infection (intra- or extraparenchymal; number, location, and stage of lesions) and has evolved toward combined symptomatic and antiparasitic management, with particular attention to modulating inflammation. Research on NCC and particularly the use of recently available genome data and animal models of infection should help to elucidate mechanisms of brain inflammation, damage, and epileptogenesis.

An Ambispective Cohort Study to Assess Seizure Recurrences in Children with Calcified Parenchymal Neurocysticercosis

Calcified neurocysticercosis (NCC), previously thought to be a dead end, is an important risk factor for seizure recurrences. We studied the pattern of seizure recurrences and associated radiological findings in children with calcified NCC. In this ambispective cohort study, we enrolled children (age 1-15 years) with calcified NCC attending the pediatric NCC clinic between January 2017 and December 2017. Retrospective data were collected from the hospital records, and all enrolled children were prospectively followed up till June 2018. The study group divided into two groups: 1) children first presenting with calcified granuloma and 2) children presented with ring-enhancing lesion (REL) and transformed into the calcified lesion during follow-up imaging. During the study period (January 2017-December 2017), 520 children with NCC were screened and 128 with calcified NCC were enrolled. The mean age was 10.8 ± 3.2 years, and 63% were boys. Among 128 children, 40 (31%) had calcified granuloma and 88 (69%) had REL transformed to calcified granuloma. Sixty-one (49%) children had seizure recurrence: 22 (58%) within calcified granuloma group and 39 (45%) within REL transformed to calcified granuloma group (P = 0.18). Seizure recurrence was associated with the presence of perilesional edema (PE) in 35 (57.4%) children on computed tomography scan. The median interval between two seizure recurrences was 30 (17-56) months, and the median antiepileptic drug-free interval was 17 (12-22) months. The total duration of continued seizures was 42 (26-58) months, slightly longer in children with REL transformed to calcified granuloma group (42, 95% CI: 18-66 months) in comparison to calcified granuloma group (35, 95% CI: 10-60 months, P = 0.32). To conclude, children with calcified NCC have seizure recurrences over a prolonged period. Seizure recurrences are intermittent and may be interspersed with a prolonged period of quiescence in between. The presence of PE and contrast enhancement around the lesion during seizure recurrence suggests lesion reactivation.

Screening for neurocysticercosis in internationally adopted children: yield, cost and performance of serological tests, Italy, 2001 to 2016

Neurocysticercosis (NCC) is one of the leading causes of epilepsy worldwide. The majority of cases in Europe are diagnosed in immigrants. Currently in Italy, routine serological screening for cysticercosis is recommended for internationally adopted children (IAC) coming from endemic countries. Methods: We retrospectively analyse the results of the serological screening for cysticercosis in IAC 16 years old or younger, attending two Italian third level paediatric clinics in 2001–16. Results: Of 2,973 children included in the study, 2,437 (82.0%) were screened by enzyme-linked immune electro transfer blot (EITB), 1,534 (51.6%) by ELISA, and 998 (33.6%) by both tests. The seroprevalence of cysticercosis ranged between 1.7% and 8.9% according to EITB and ELISA, respectively. Overall, 13 children were diagnosed with NCC accounting for a NCC frequency of 0.4% (95% confidence interval (CI): 0.2–0.6%). Among the 168 seropositive children, only seven (4.2%) were diagnosed with NCC. Of these children, three were asymptomatic and four presented epilepsy. Among seronegative children (n = 2,805), seven presented with neurological symptoms that lead to the diagnosis of NCC in six cases. The sensitivity, specificity, positive and negative predictive value for the diagnosis of NCC were 54.5%, 98.6%, 14.6%, 99.8% for EITB and 22.2%, 91.1%, 1.4%, 99.5% for ELISA. The yield of the screening programme was 437 NCC cases per 100,000. The number needed to screen to detect one NCC case was 228. The cost per NCC case detected was EUR 10,372. Conclusion: On the base of our findings we suggest the ongoing serological screening for cysticercosis to be discontinued, at least in Italy, until further evidence in support will be available.

Exploring the complex associations over time among albendazole treatment, cyst evolution, and seizure outcomes in neurocysticercosis

OBJECTIVE

To develop a causal model for the occurrence of neurocysticercosis (NC)-related seizures and test hypotheses generated from the model.

METHODS

We used data from a randomized controlled trial comparing albendazole with placebo among patients newly diagnosed with NC. Based on our causal model, we explored the associations among albendazole treatment, NC cyst evolution, and seizure outcomes over 24 months of follow-up using generalized linear mixed effect models.

RESULTS

We included 153 participants, of whom 51% received albendazole. The association between seizure outcomes and treatment over time demonstrated lack of linearity and heterogeneity, requiring the inclusion of time-treatment interaction terms for valid modeling. Participants in the albendazole group had fewer seizures overall and of partial onset at all time points compared with the placebo group, but the difference increased over the first few months following treatment, then decreased over time. Generalized seizures exhibited a more complex association; those in the albendazole group had fewer seizures compared with those in the placebo group for the first few months after treatment, and then the association reversed and those in the placebo arm had fewer seizures. Adjusting for the number of NC cysts in each phase resulted in an attenuation of the strength of association between albendazole and seizure outcomes, consistent with mediation. Among participants in whom all cysts had disappeared (n = 21), none continued to have seizures.

SIGNIFICANCE

Albendazole treatment is associated with a possible reduction in focal seizures in the short term (3-6 months), perhaps by hastening the resolution of the cysts. However, the effect is not discernible over the long term, because most cysts either calcify or resolve completely, regardless of whether treated with albendazole. The stage of evolution of the cysticercus is an important consideration in the evaluation of albendazole effect on seizure outcome.

Pediatric Neurocysticercosis

Neurocysticercosis is the most common helminth infection of nervous system in humans caused by the encysted larvae of Taenia solium. It is a major cause of epilepsy in tropical areas and the most common cause of focal-onset seizures in North Indian children. Children with neurocysticercosis have pleomorphic manifestations depending on the location, number and viability of the cysts and host response. In endemic areas, neurocysticercosis should be clinically suspected in any child with recent-onset seizures, headache or focal motor deficits where there is no other suggestion of an underlying neurological disorder. Diagnosis of neurocysticercosis is essentially based on neuroimaging; visualization of a scolex is diagnostic. Management includes use of cysticidal drugs usually albendazole, which seems to be effective for lesion resolution and seizure remission, use of steroids and anti-epileptic drugs. Single lesions portend good prognosis with resolution of lesions in >60% of the cases within 6 mo and good seizure control. Prognosis is guarded in cysticercus encephalitis, racemose and extraparenchymal neurocysticercosis.

The epidemiology of Taenia spp. infection and Taenia solium cysticerci exposure in humans in the Central Highlands of Vietnam

BACKGROUND

Vietnam is endemic for taeniasis and T. solium cysticercosis. Despite this, information on the epidemiological characteristics of the diseases in the Central Highlands of Vietnam are poorly described. The aims of this study were to determine the epidemiological characteristics of taeniasis (Taenia spp.) and T. solium cysticerci exposure in humans in Dak Lak province in the Central Highlands, Vietnam.

METHODS

This cross-sectional study was carried out in six villages in three districts of Dak Lak. A total of 190 households were visited. From each household, between one and five individuals were asked to donate a single faecal and blood sample and respond to a questionnaire. Serum samples were subjected to lentil lectin purified glycoprotein enzyme-linked immunoelectrotransfer blot assay to detect antibodies against T. solium cysticerci. Multiplex real-time PCR was used to detect Taenia spp. infection in faecal samples. A fixed-effects logistic regression model was developed to identify factors associated with the probability of Taenia spp. infection or T. solium cysticerci exposure risk. The contribution of each of identified factor was quantified using population attributable fractions.

RESULTS

The prevalence of seroexposure to T. solium in Dak Lak was 5% (95% CI 3% to 8%). Consumption of raw vegetables, sourcing drinking water from lakes, streams or ponds and the practice of outdoor defaecation were identified as primary risk factors for the prevalence of T. solium cysticerci exposure, while consuming undercooked pork and beef, pork tongue and observing Taenia proglottids in stool were associated with Taenia spp. infection. Consumption of raw vegetables attributed to 74% of T. solium cysticerci exposure-positive cases and consumption of undercooked beef attributed to 77% of taeniasis cases in these communities.

CONCLUSIONS

The prevalence of T. solium seroexposure in Dak Lak is consistent with those reported in other regions of Vietnam. The identified risk factors associated with the prevalence of T. solium seroexposure and taeniasis infection in Dak Lak are modifiable and thus advocate for targeted community intervention programs to mitigating these risks.

Animal influence on water, sanitation and hygiene measures for zoonosis control at the household level: A systematic literature review

INTRODUCTION

Neglected zoonotic diseases (NZDs) have a significant impact on the livelihoods of the world's poorest populations, which often lack access to basic services. Water, sanitation and hygiene (WASH) programmes are included among the key strategies for achieving the World Health Organization's 2020 Roadmap for Implementation for control of Neglected Tropical Diseases (NTDs). There exists a lack of knowledge regarding the effect of animals on the effectiveness of WASH measures.

OBJECTIVES

This review looked to identify how animal presence in the household influences the effectiveness of water, hygiene and sanitation measures for zoonotic disease control in low and middle income countries; to identify gaps of knowledge regarding this topic based on the amount and type of studies looking at this particular interaction.

METHODS

Studies from three databases (Medline, Web of Science and Global Health) were screened through various stages. Selected articles were required to show burden of one or more zoonotic diseases, an animal component and a WASH component. Selected articles were analysed. A narrative synthesis was chosen for the review.

RESULTS

Only two studies out of 7588 met the inclusion criteria. The studies exemplified how direct or indirect contact between animals and humans within the household can influence the effectiveness of WASH interventions. The analysis also shows the challenges faced by the scientific community to isolate and depict this particular interaction.

CONCLUSION

The dearth of studies examining animal-WASH interactions is explained by the difficulties associated with studying environmental interventions and the lack of collaboration between the WASH and Veterinary Public Health research communities. Further tailored research under a holistic One Health approach will be required in order to meet the goals set in the NTDs Roadmap and the 2030 Agenda for Sustainable Development.

Clinical topography relationship in patients with parenchymal neurocysticercosis and seizures

OBJECTIVE

Discordances between imaging findings of parenchymal neurocysticercosis and seizure expression have been reported, and as such the possibility that neurocysticercosis and seizures may frequently coexist by chance has been raised. In this study, we evaluate the topographic relationship between seizure foci based on semiology and electroencephalography with the location of parenchymal neurocysticercotic lesions.

METHODS

Seizure information, neuroimaging (computed tomography and magnetic resonance imaging [MRI]) and electroencephalographic data from three randomized clinical trials of individuals with parenchymal neurocysticercosis and focal seizures were analyzed. Blinded epileptologists defined a potential seizure onset zone and a symptomatogenic zone for each individual based on semiology. The topographic relationship between semiology, either lesion location or areas of perilesional edema on baseline MRI, and electroencephalographic abnormalities were assessed.

RESULTS

Fifty-eight patients with one or two parenchymal neurocysticercotic lesions were included in this study. From them, 50 patients (86%; 95% CI, 75%-93%) showed a clinical-topography relationship with the potential seizure onset zone, and 44 (76%) also with the symptomatogenic zone. From the eight patients with no topographic relationship, five had focal seizures 30 days before or after the baseline MRI and showed perilesional edema. All of these five patients showed a clinical-topography relationship between such seizures and an area of perilesional edema, making a total of 55 patients (95%; 95% CI, 85%-99%) with clinical-topography relationship when perilesional edema is considered. Most patients with focal epileptiform discharges (7/8, 88%) had a topographic association between electroencephalographic focality, the potential seizure onset zone and a cysticercotic lesion.

CONCLUSION

Seizure semiology and focal epileptiform discharges are topographically related to neurocysticercotic lesions in most patients. These data strongly support seizure origin in the cortex surrounding these lesions.

Calcified Neurocysticercosis and Headache in an Endemic Village: A Case-Control Study Nested to a Population-Based Cohort

Headache in patients with calcified neurocysticercosis (NCC) is probably common but has been largely overlooked. We aimed to assess the presence, characteristics, and diagnosis of headache across patients with calcified NCC and their matched controls. In this case-control study nested to a population-based cohort, Atahualpa residents aged ≥ 20 years with calcified NCC were identified as case patients and paired 1:1 to age- and gender-matched randomly selected controls. A culturally adapted questionnaire was derived from the EUROLIGHT. Headache diagnosis was established according to the International Classification of Headache Disorders, 3rd edition. Conditional logistic regression models for matched paired data were fitted to assess the independent association between calcified NCC (as the exposure) and headache variables, after adjusting for education, alcohol intake, depression, and epilepsy. The selection process generated 106 case patients and their matched controls. Lifetime headache prevalence (odds ratio [OR]: 4.18; 95% Confidence Interval [CI]: 1.79-9.75; P = 0.001), current headaches (OR: 4.19; 95% CI: 1.92-9.16; P < 0.001), and intense headaches (OR: 9.47; 95% CI: 2.88-31.19; P < 0.001) were more frequent among cases than in controls. In addition, migraine (but not other forms of headache) was more frequent among subjects with calcified NCC (OR: 4.89; 95% CI: 2.36-11.39; P < 0.001). This study shows a robust epidemiological association between headache-particularly migraine-and calcified NCC.

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.

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

OBJECTIVECentral 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.METHODSA 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.RESULTSThe 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.CONCLUSIONSThis 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.

Neurocysticercosis in Bhutan: a cross-sectional study in people with epilepsy

BACKGROUND

We sought to provide an assessment of the burden of neurocysticercosis among people with epilepsy (PWE) in Bhutan and evaluate the yield of various tests for Taenia solium.

METHODS

PWE were enrolled at the National Referral Hospital in Thimphu (2014-2015). Serum was tested for anti-Taenia solium IgG using ELISA (Ab-ELISA), enzyme-linked immunoelectrotransfer blot (EITB), and parasite antigen. Results were compared to brain MRI. Participants were categorized as definite neurocysticercosis (MRI and EITB positive), probable neurocysticercosis (MRI or EITB positive), or without neurocysticercosis. Logistic regression models were constructed to explore clinicodemographic associations.

RESULTS

There were 12/205 (6%, 95% CI 2%, 9%) definite and 40/205 (20%, 95% CI 14%, 25%) probable neurocysticercosis cases. 25/205 (12%) with positive EITB did not have neurocysticercosis on MRI, and 15/205 (7%) participants with positive MRI had negative EITB. Participants with neurocysticercosis-suggestive lesions on MRI had an average of 1.2 cysts (parenchymal 26/27; nodular/calcified stage 21/27). In a multivariable analysis, present age (OR 1.05, 95% CI 1.01,1.09, p=0.025) was positively associated with (combined probable or definite) neurocysticercosis while mesial temporal sclerosis on MRI (OR 0.294, 95% CI 0.144, 0.598, p=0.001) was negatively associated.

CONCLUSIONS

Neurocysticercosis was associated with 6-25% of epilepsy in a Bhutanese cohort. Combining EITB and MRI would aid the diagnosis of neurocysticercosis among PWE since no test identified all cases.

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.

An outbreak of classical swine fever in pigs in Bangladesh, 2015

In a group of 22 healthy pigs aged between 4 and 6 months, 2 pigs became ill with high fever, complete anorexia, cough and abnormal swaying movements on 22 June 2015. One of them died on June 24 and the second died on July 3. Shortly after, the remaining pigs also fell ill and died from the same illness by 10 August 2015. We investigated the aetiology, epidemiological and clinical features of the outbreak. We recorded the clinical signs and symptoms for each pig with the date of onset of illness. Veterinarians conducted post-mortem examinations on the 12 dead pigs, they collected tissue samples from the dead pigs and placed them in a tube containing 1 mL of nucleic acid extraction buffer (lysis buffer). We tested all the tissue samples by real-time reverse transcription polymerase chain reaction (rRT-PCR) to detect classical swine fever virus (CSFV) because the animals' symptoms matched those of this disease. We also conducted a phylogentic analysis of the nucleotide sequence of the E2 gene segment of CSFV detected in a lung tissue sample. The attack rate (22/22) and the case fatality were 100%. The predominant symptoms of the disease included high fever, cough, diarrhoea and swaying movements of the hind legs prior to death. Of the 12 pigs tissue samples tested, all had evidence of the presence of CSFV RNA by rRT-PCR. The phylogenetic analysis indicated that the virus belongs to genotype 2.2, which is closely related to CSFV genotype 2.2 reported in India. Our investigation suggests that CSF is circulating in pigs, posing a risk for communities in Bangladesh that rely on pigs for economic income and dietary protein. Future research could focus on estimating the disease and economic burden of CSFV in pig rearing areas to determine if interventions might be warranted or cost-effective.

Clinical presentation of neurocysticercosis-related epilepsy

Neurocysticercosis (NCC) is the most common parasitic infection of the central nervous system and a major risk factor for seizures and epilepsy. Seizure types in NCC vary largely across studies and seizure semiology is poorly understood. We discuss here the studies regarding seizure types and seizure semiology in NCC, and examine the clinical presentation in patients with NCC and drug-resistant epilepsy. We also provide evidence of the role of MRI and EEG in the diagnosis of NCC-related epilepsy. Focal seizures are reported in 60-90% of patients with NCC-related epilepsy, and around 90% of all seizures registered prospectively are focal not evolving to bilateral tonic-clonic seizures. A great number of cases suggest that seizure semiology is topographically related to NCC lesions. Patients with hippocampal sclerosis and NCC have different clinical and neurophysiological characteristics than those with hippocampal sclerosis alone. Different MRI protocols have allowed to better differentiate NCC from other etiologies. Lesions' stages might account on the chances of finding an interictal epileptiform discharge. Studies pursuing the seizure onset in patients with NCC are lacking and they are specially needed to determine both whether the reported events of individual cases are seizures, and whether they are related to the NCC lesion or lesions. This article is part of a Special Issue entitled "Neurocysticercosis and Epilepsy".

On the relationship between calcified neurocysticercosis and epilepsy in an endemic village: A large-scale, computed tomography-based population study in rural Ecuador

OBJECTIVE

Using a large-scale population-based study, we aimed to assess prevalence and patterns of presentation of neurocysticercosis (NCC) and its relationship with epilepsy in community-dwellers aged ≥20 years living in Atahualpa (rural Ecuador).

METHODS

In a three-phase epidemiological study, individuals with suspected seizures were identified during a door-to-door survey and an interview (phase I). Then, neurologists evaluated suspected cases and randomly selected negative persons to estimate epilepsy prevalence (phase II). In phase III, all participants were offered noncontrast computed tomography (CT) for identifying NCC cases. The independent association between NCC (exposure) and epilepsy (outcome) was assessed by the use of multivariate logistic regression models adjusted for age, sex, level of education, and alcohol intake. CT findings were subsequently compared to archived brain magnetic resonance imaging in a sizable subgroup of participants.

RESULTS

Of 1,604 villagers aged ≥20 years, 1,462 (91%) were enrolled. Forty-one persons with epilepsy (PWE) were identified, for a crude prevalence of epilepsy of 28 per 1,000 population (95% confidence interval [CI] = 20.7-38.2). A head CT was performed in 1,228 (84%) of 1,462 participants, including 39 of 41 PWE. CT showed lesions consistent with calcified parenchymal brain cysticerci in 118 (9.6%) cases (95% CI = 8.1-11.4%). No patient had other forms of NCC. Nine of 39 PWE, as opposed to 109 of 1,189 participants without epilepsy, had NCC (23.1% vs. 9.2%, p = 0.004). This difference persisted in the adjusted logistic regression model (odds ratio = 3.04, 95% CI = 1.35-6.81, p = 0.007).

SIGNIFICANCE

This large CT-based study demonstrates that PWE had three times the odds of having NCC than those without epilepsy, providing robust epidemiological evidence favoring the relationship between NCC and epilepsy.

Seroprevalence and risk factors of human cysticercosis and taeniasis prevalence in a highly endemic area of epilepsy in Bangoua, west Cameroon

Cysticercosis caused by the larvae of Taenia solium is a serious and emerging threat to public health in the endemic areas as well as in the non-endemic areas.　Neurocysticercosis, an affection of the central nervous system is a leading cause of epilepsy in endemic areas. This study was carried out to investigate human cysticercosis, taeniasis and risk factors, and also their association with epilepsy in Bangoua, west Cameroon where epilepsy is highly prevalent. Out of 384 people investigated, 12 (3.1%) exhibited antibody response against low molecular weight antigens of T. solium by ELISA. Immunoblot revealed that six persons (1.6%) were seropositive with the same antigens. Among 61 epileptic patients, only one was seropositive by immunoblot and the study did not find any statistically significant difference (P>0.05) in seropositivity to T. solium between epileptic persons (1/61, 1.6%) and non-epileptic group (5/323, 1.5%). In addition, cysticercosis was associated with households eating pork meat from pigs slaughtered at home, but not with other factors. The risk factors including pig farming, the consumption of pork meat, vegetables, and non-drinkable water were attenuated by the relatively good hygiene and pig husbandry practices of the population. No egg of Taenia was found in stool by microscopic examination. All data obtained in this study suggested that cysticercosis might not be the principal causative agent of epilepsy in this area.

High Prevalence of Asymptomatic Neurocysticercosis in an Endemic Rural Community in Peru

Background

Neurocysticercosis is a common helminthic infection of the central nervous system and an important cause of adult-onset epilepsy in endemic countries. However, few studies have examined associations between neurologic symptoms, serology and radiographic findings on a community-level.

Methodology

We conducted a population-based study of resident’s ≥2 years old in a highly endemic village in Peru (pop. 454). We applied a 14 -question neurologic screening tool and evaluated serum for antibodies against Taenia solium cysticercosis using enzyme-linked immunoelectrotransfer blot (LLGP-EITB). We invited all residents ≥18 years old to have non-contrast computerized tomography (CT) of the head.

Principal findings

Of the 385 residents who provided serum samples, 142 (36.9%) were seropositive. Of the 256 residents who underwent CT scan, 48 (18.8%) had brain calcifications consistent with NCC; 8/48 (17.0%) reported a history of headache and/or seizures. Exposure to T. solium is very common in this endemic community where 1 out of 5 residents had brain calcifications. However, the vast majority of people with calcifications were asymptomatic.

Conclusion

This study reports a high prevalence of NCC infection in an endemic community in Peru and confirms that a large proportion of apparently asymptomatic residents have brain calcifications that could provoke seizures in the future.

Neurocysticercosis is a parasitic infection of the brain and a common cause of epilepsy in many countries in Latin America, Asia and Africa. In this study, we applied a combination of head CT, serology and symptoms screening in a rural village in northern Peru. We found that the infection was very common in this community, where nearly one in five adults had calcified lesions in the brain. While the majority of these people reported never had experienced seizures, brain calcifications are known to result in chronic intermittent seizures in some. Follow-up studies are needed to help understand how many people with calcifications will go on to experience seizures in their lifetime, and to better predict those who are at greatest risk so that preventive intervention can be offered.

Disease Centered Around Calcified Taenia solium Granuloma

Taenia solium (the pork tapeworm) is present in most developing countries, where it is a frequent cause of seizures and other neurological disease. Parasitic larvae invade the human brain, establish, and eventually resolve, leaving a calcified scar. While these lesions are common in endemic regions, and most of these are clinically silent, a proportion of individuals with calcified cysticerci develop seizures from these lesions, and 30-65% of these cases are associated with perilesional edema (PE), likely due to host inflammation. This manuscript summarizes the importance, characteristics, natural history, and potential prevention and treatments of symptomatic calcified neurocysticercosis (NCC).

Antiepileptic drug therapy and recommendations for withdrawal in patients with seizures and epilepsy due to neurocysticercosis

INTRODUCTION

Neurocysticercosis (NCC) is a leading causes of secondary epilepsy worldwide. There is increasing evidence on the epileptogenic role of NCC, and the presence of edema, calcified scars, gliosis and hippocampal sclerosis support this phenomenon.

AREAS COVERED

We summarized principles of antiepileptic drug (AED) therapy as well as risk factors associated with seizure recurrence after AED withdrawal in patients with NCC. Expert commentary: First-line AED monotherapy is effective as a standard approach to control seizures in most NCC patients. Risks and benefits of AED withdrawal have not been systematically studied, and this decision must be individualized. However, a seizure-free period of at least two years seem prudent before attempting withdrawal. Risk factors for seizure recurrence after AED withdrawal include a history of status epilepticus, poor seizure control during treatment, neuroimaging evidence of perilesional gliosis, hippocampal sclerosis and calcified lesions, as well as persistence of paroxysmal activity in the EEG.

Human Glutathione S-Transferase Enzyme Gene Polymorphisms and Their Association With Neurocysticercosis

Neurocysticercosis (NCC), caused by cysticerci of Taenia solium is the most common helminthic infection of the central nervous system. Some individuals harboring different stages of cysticerci in the brain remain asymptomatic, while others with similar cysticerci lesions develop symptoms and the reasons remain largely unknown. Inflammatory response to antigens of dying parasite is said to be responsible for symptomatic disease. Reactive oxygen species (ROS) that are generated in inflammatory conditions can damage cellular macromolecules such as lipids, DNA, and proteins. The glutathione S-transferases (GSTs) are critical for the protection of cells from ROS. A total of 250 individuals were included in the study: symptomatic NCC = 75, asymptomatic NCC = 75, and healthy controls = 100. The individuals carrying the deletions of GSTM1 and GSTT1 were at risk for NCC (OR = 2.99, 95 %CI = 1.31-6.82, p = 0.0073 and OR = 1.94, 95 %CI = 0.98-3.82, p = 0.0550 respectively). Further, the individuals with these deletions were more likely to develop symptomatic disease (OR = 5.08, 95 % CI = 2.12-12.18, p = 0.0001 for GSTM1 and OR = 3.25, 95 %CI = 1.55-6.82, p = 0.0018 for GSTT1). Genetic variants of GSTM3 and GSTP1 were not associated with NCC. The total GST activity and levels of GSTM1, GSTT1, and GSTM3 were significantly higher in asymptomatic subjects than in symptomatic and healthy controls. Lower GST activity was observed in individuals with GSTM1 and GSTT1 deletions. The present study suggests that the individuals with GSTM1 and GSTT1 deletions are at higher risk to develop symptomatic disease. The higher GST activity and levels of GSTM1, GSTT1, and GSTM3 are likely to play role in maintaining asymptomatic condition.

Pediatric neurocysticercosis: current challenges and future prospects

Neurocysticercosis (NCC) is an acquired infection of the nervous system caused by encysted larvae of Taenia solium. It is a major cause of epilepsy in the tropics and the commonest cause of focal seizures in North Indian children. T. solium teniasis-cysticercosis is considered a parasitic "Neglected Tropical Diseases" endemic throughout Southeast Asia. NCC in children has pleomorphic manifestations depending on the location, number and viability of the cysts, and host response. Even with advancing knowledge of the disease manifestations, many aspects related to diagnosis and treatment, particularly in children, still remain controversial and pose challenges to clinical practice. There is no gold standard test to diagnose NCC and the management recommendations are still emerging. This review provides an overview of diagnosis of NCC in children and its management with special focus on current challenges and future prospects.

The Increase of Exotic Zoonotic Helminth Infections: The Impact of Urbanization, Climate Change and Globalization

Zoonotic parasitic diseases are increasingly impacting human populations due to the effects of globalization, urbanization and climate change. Here we review the recent literature on the most important helminth zoonoses, including reports of incidence and prevalence. We discuss those helminth diseases which are increasing in endemic areas and consider their geographical spread into new regions within the framework of globalization, urbanization and climate change to determine the effect these variables are having on disease incidence, transmission and the associated challenges presented for public health initiatives, including control and elimination.

Cultural and Economic Motivation of Pig Raising Practices in Bangladesh

The interactions that pig raisers in Bangladesh have with their pigs could increase the risk of zoonotic disease transmission. Since raising pigs is a cultural taboo to Muslims, we aimed at understanding the motivation for raising pigs and resulting practices that could pose the risk of transmitting disease from pigs to humans in Bangladesh, a predominantly Muslim country. These understandings could help identify acceptable strategies to reduce the risk of disease transmission from pigs to people. To achieve this objective, we conducted 34 in-depth interviews among pig herders and backyard pig raisers in eight districts of Bangladesh. Informants explained that pig raising is an old tradition, embedded in cultural and religious beliefs and practices, the primary livelihood of pig herders, and a supplemental income of backyard pig raisers. To secure additional income, pig raisers sell feces, liver, bile, and other pig parts often used as traditional medicine. Pig raisers have limited economic ability to change the current practices that may put them at risk of exposure to diseases from their pigs. An intervention that improves their financial situation and reduces the risk of zoonotic disease may be of interest to pig raisers.

Epilepsy in India I: Epidemiology and public health

Of the 70 million persons with epilepsy (PWE) worldwide, nearly 12 million PWE are expected to reside in India; which contributes to nearly one-sixth of the global burden. This paper (first of the two part series) provides an in-depth understanding of the epidemiological aspects of epilepsy in India for developing effective public health prevention and control programs. The overall prevalence (3.0-11.9 per 1,000 population) and incidence (0.2-0.6 per 1,000 population per year) data from recent studies in India on general population are comparable to the rates of high-income countries (HICs) despite marked variations in population characteristics and study methodologies. There is a differential distribution of epilepsy among various sociodemographic and economic groups with higher rates reported for the male gender, rural population, and low socioeconomic status. A changing pattern in the age-specific occurrence of epilepsy with preponderance towards the older age group is noticed due to sociodemographic and epidemiological transition. Neuroinfections, neurocysticercosis (NCC), and neurotrauma along with birth injuries have emerged as major risk factors for secondary epilepsy. Despite its varied etiology (unknown and known), majority of the epilepsy are manageable in nature. This paper emphasizes the need for focused and targeted programs based on a life-course perspective and calls for a stronger public health approach based on equity for prevention, control, and management of epilepsy in India.

Neurocysticercosis

Neurocysticercosis is the commonest parasitic disease of the nervous system in humans, and constitutes a major public health problem for most of the developing world. The clinical manifestations of Neurocysticercosis (NCC) largely depend on number of lesions, site, and host immune response against the parasite. Diagnosis is mainly based upon neuro imaging studies and is supported by antibody/antigen detection in the serum and occasionally the cerebrospinal fluid. Randomized controlled trials evaluating the clinical benefit of treatment with cysticidal agents have shown hastened resolution of lesions in most, and reduced seizure recurrence in some studies. Outcome is favourable in single lesion parenchymal NCC but is guarded in multiple lesion and extra parenchymal NCC.

Association of ICAM-1 K469E polymorphism with neurocysticercosis

Neurocysticercosis (NCC), a central nervous system (CNS) disease is caused by the larval stage of Taenia solium. The disease is heterogeneous in clinical presentation; some infected individuals develop symptoms and others may remain symptom free. Impaired blood brain barrier allows recruitment of immune cells in the CNS during infection and soluble intercellular adhesion molecule-1 (sICAM-1) plays an important role in the recruitment of immune cells. We studied ICAM-1 K469E polymorphism among symptomatic and asymptomatic NCC patients. The study revealed that individuals with variant (EE) genotype were more susceptible to symptomatic NCC and also had an elevated level of sICAM-1.

Food-safety hazards in the pork chain in Nagaland, North East India: implications for human health

Pork occupies an important place in the diet of the population of Nagaland, one of the North East Indian states. We carried out a pilot study along the pork meat production chain, from live animal to end consumer. The goal was to obtain information about the presence of selected food borne hazards in pork in order to assess the risk deriving from these hazards to the health of the local consumers and make recommendations for improving food safety. A secondary objective was to evaluate the utility of risk-based approaches to food safety in an informal food system. We investigated samples from pigs and pork sourced at slaughter in urban and rural environments, and at retail, to assess a selection of food-borne hazards. In addition, consumer exposure was characterized using information about hygiene and practices related to handling and preparing pork. A qualitative hazard characterization, exposure assessment and hazard characterization for three representative hazards or hazard proxies, namely Enterobacteriaceae, T. solium cysticercosis and antibiotic residues, is presented. Several important potential food-borne pathogens are reported for the first time including Listeria spp. and Brucella suis. This descriptive pilot study is the first risk-based assessment of food safety in Nagaland. We also characterise possible interventions to be addressed by policy makers, and supply data to inform future risk assessments.

Neurocysticercosis in infants and toddlers: report of seven cases and review of published patients

Neurocysticercosis in infants and toddlers has received little attention in the literature, and little is known about the mechanisms of disease acquisition and clinical forms of presentation of the disease in this age group. All patients aged ≤3 years with neurocysticercosis evaluated at Hospital-Clínica Kennedy, Guayaquil, over a 22-year period were included in this study. Their household contacts were screened to detect Taenia solium carriers, which may represent the source of infection. A literature search on neurocysticercosis in infants and toddlers was also performed to compare personal cases with those described elsewhere. A total of 25 infants and toddlers with neurocysticercosis were included (seven from our institution and 18 from the literature). All patients had seizures as the primary manifestation of the disease, and neuroimaging studies showed one or two parenchymal brain cysticerci in the colloidal stage in 88% of patients. The source of infection was investigated in 11 houses, including the seven households of the present series, and only four of the 18 reported in the literature. A Taenia carrier was found in five (45%) of these households, including three from the present series and two from the literature. A sizable proportion of infants and toddlers with neurocysticercosis have been infected at home. Compulsory search of Taenia carriers among household contacts will allow the detection of the potential source of infection and will reduce further spread of the disease. The search must not be limited to family members, but also extended to domestic employees who are in daily contact with the children.

Serodiagnosis of human neurocysticercosis using antigenic components of Taenia solium metacestodes derived from the unbound fraction from jacalin affinity chromatography

The aim of the present study was to analyse Taenia solium metacestode antigens that were derived from the unbound fraction of jacalin affinity chromatography and subsequent tert-octylphenoxy poly (oxyethylene) ethanol Triton X-114 (TX-114) partitioning in the diagnosis of human neurocysticercosis (NCC). Immunoassays were designed to detect T. solium-specific IgG antibodies by ELISA and immunoblot. Serum samples were collected from 132 individuals who were categorised as follows: 40 had NCC, 62 presented Taenia spp or other parasitic diseases and 30 were healthy individuals. The jacalin-unbound (J unbound ) fraction presented higher sensitivity and specificity rates than the jacalin-bound fraction and only this fraction was subjected to subsequent TX-114 partitioning, resulting in detergent (DJ unbound ) and aqueous (AJ unbound ) fractions. The ELISA sensitivity and specificity were 85% and 84.8% for J unbound , 92.5% and 93.5% for DJ unbound and 82.5% and 82.6% for AJ unbound . By immunoblot, the DJ unbound fraction showed 100% sensitivity and specificity and only serum samples from patients with NCC recognised the 50-70 kDa T. solium-specific components. We conclude that the DJ unbound fraction can serve as a useful tool for the differential immunodiagnosis of NCC by immunoblot.

Improved detection of parenchymal cysticercal lesions in neurocysticercosis with T2*-weighted angiography magnetic resonance imaging

RATIONALE AND OBJECTIVES

Magnetic resonance imaging (MRI) is an important tool for the diagnosis and management of various central nervous system infections. In the present study, we investigated the role of T2*-weighted angiography (SWAN) imaging in the diagnosis of neurocysticercosis (NCC) viz-a-viz conventional MRI.

METHODS

Symptomatic (n = 46) and asymptomatic (n = 88) cases from a pig-farming community were imaged using both conventional and SWAN MRI between July 2009 and May 2011. Two experienced neuroradiologists independently reviewed all the images to characterize the lesions as well as detection of the scolex.

RESULTS

A total of 250 lesions were detected in 70 individuals. On conventional MRI, the lesion and scolex visibility was 82.4% (206/250) and 60% (150/250), respectively, which increased to 96.8% and 81%, respectively, using SWAN imaging. On combining SWAN with conventional MRI, the scolex visibility increased to 85% (213/250) of the total 250 lesions detected. Overall, adding SWAN to conventional MRI increased the lesion detection and scolex visibility up to 18% (206 vs. 250) and 30% (150 vs. 213), respectively.

CONCLUSION

SWAN imaging when added to the conventional MRI protocol for population screening for NCC in endemic regions improves both lesion detection and definitive diagnosis of neurocysticercosis.