Neurocysticercosis in radiographically imaged seizure patients in U.S. emergency departments

Neurocysticercosis: An Uncommon Cause of New-Onset Seizure in the United States

Neurocysticercosis is predominantly a disease in tropical countries. However, with increasing migration, it is now more frequently reported in developed countries as well. We are reporting a case of new-onset seizures due to underlying neurocysticercosis in a 31-year-old male migrant patient. Initial imaging revealed two cystic lesions in the left parietal lobe and another small lesion in the right parietal lobe. The imaging findings were highly suggestive of neurocysticercosis. Our case highlights the important issue of neurocysticercosis as an etiology for new-onset seizures in the United States.

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.

Treatment of Toxin-Related Status Epilepticus With Levetiracetam, Fosphenytoin, or Valproate in Patients Enrolled in the Established Status Epilepticus Treatment Trial

STUDY OBJECTIVE

We describe a subset of patients with toxin-related precipitants of seizures/status epilepticus enrolled in the Established Status Epilepticus Treatment Trial (ESETT).

METHODS

The ESETT was a prospective, double-blinded, adaptive trial evaluating levetiracetam, valproate, and fosphenytoin as second-line agents in benzodiazepine-refractory status epilepticus in adults and children. The primary outcome was the absence of seizures and improvement in the level of consciousness 1 hour after study drug administration. In this post hoc analysis, the safety and efficacy of second-line agents in a subset of patients with toxin-related seizures are described.

RESULTS

A total of 249 adults and 229 children were enrolled in the ESETT. Toxin-related seizures occurred in 29 (11.6%) adults and 1 child (0.4%). In adults, men were more likely to have toxin-related seizures than women (25 of 145, 17.2% versus 4 of 104, 3.9%). The most common toxin-related precipitants were alcohol withdrawal and cocaine, 11(37%) of 30 patients each. Cocaine was used with other substances by most patients 10 (91%) of 11, most commonly with an opioid 7 (64%) of 11. For alcohol withdrawal-related seizures, treatment successes with levetiracetam, valproate, and fosphenytoin were 3 (100%) of 3, 3 (50%) of 6, and 1 (50%) of 2, respectively. For cocaine-related seizures, treatment success was 1 (14%) of 7 for levetiracetam, 0 (0%) of 1 for valproate, and 1 (33%) of 3 for fosphenytoin. One patient who used cocaine and an opioid received fosphenytoin and developed life-threatening hypotension.

CONCLUSION

In the ESETT, approximately 1 in 10 adult patients with status epilepticus presented with a toxin-related seizure. Alcohol withdrawal and cocaine/opioid use were the most common toxin-related precipitants. Toxin-related benzodiazepine-refractory status epilepticus was successfully treated with a single dose of second-line antiseizure medication in 42% of the patients.

Paediatric neurocysticercosis in high income countries

BACKGROUND

Neurocysticercosis (NCC) is an unusual cause of seizures in high income settings. It typically presents as an afebrile seizure in a previously well child and can occur years after migration or travel.

METHODS

Children diagnosed with neurocysticercosis from 01 July 2005 to 30 June 2020 were identified from the electronic medical records of a tertiary children's hospital in Australia. Additionally, a 10-year compilation of case reports of paediatric NCC in high income settings was performed by medline search (publication years 2011-2021). Diagnosis and treatment of neurocysticercosis were reviewed with reference to diagnostic criteria of Del Brutto et al., and the 2017 Infectious Diseases Society of America treatment guidelines.

RESULTS

Over a fifteen-year period, eight children were diagnosed with NCC at our hospital in Sydney, Australia. Seizures and history of travel to or migration from South Asia were the two most frequently occurring findings. Children diagnosed after 2016 all received antiparasitic therapy. Outcomes were generally favorable, though long-term epilepsy resulted in some cases. Compiled case reports from high income settings revealed migration and travel exposures commensurate with local demographic patterns, and treatment approaches conforming with 2017 Infectious Diseases Society of America guidelines.

CONCLUSIONS

Clinicians should be aware of NCC as a differential diagnosis in children from endemic areas presenting with unprovoked seizures as misdiagnosis can occur. Expert review of neuroimaging facilitates diagnosis and can avert unnecessary neurosurgery. In Australia, India was a key exposure country for NCC, reflecting its endemic burden of disease and local travel and migration patterns.

Neglected Parasitic Infections: What Family Physicians Need to Know-A CDC Update

Chagas disease, cysticercosis, and toxoplasmosis affect millions of people in the United States and are considered neglected parasitic diseases. Few resources are devoted to their surveillance, prevention, and treatment. Chagas disease, transmitted by kissing bugs, primarily affects people who have lived in Mexico, Central America, and South America, and it can cause heart disease and death if not treated. Chagas disease is diagnosed by detecting the parasite in blood or by serology, depending on the phase of disease. Antiparasitic treatment is indicated for most patients with acute disease. Treatment for chronic disease is recommended for people younger than 18 years and generally recommended for adults younger than 50 years. Treatment decisions should be individualized for all other patients. Cysticercosis can manifest in muscles, the eyes, and most critically in the brain (neurocysticercosis). Neurocysticercosis accounts for 2.1% of all emergency department visits for seizures in the United States. Diagnosing neurocysticercosis involves serology and neuroimaging. Treatment includes symptom control and antiparasitic therapy. Toxoplasmosis is estimated to affect 11% of people older than six years in the United States. It can be acquired by ingesting food or water that has been contaminated by cat feces; it can also be acquired by eating undercooked, contaminated meat. Toxoplasma infection is usually asymptomatic; however, people who are immunosuppressed can develop more severe neurologic symptoms. Congenital infection can result in miscarriage or adverse fetal effects. Diagnosis is made with serologic testing, polymerase chain reaction testing, or parasite detection in tissue or fluid specimens. Treatment is recommended for people who are immunosuppressed, pregnant patients with recently acquired infection, and people who are immunocompetent with visceral disease or severe symptoms.

Mortality in Parenchymal and Subarachnoid Neurocysticercosis

Neurocysticercosis (NCC) is endemic in many parts of the world, carrying significant neurological morbidity that varies according to whether lesions are located inside the cerebral parenchyma or in extraparenchymal spaces. The latter, in particular subarachnoid NCC, is assumed to be more severe, but no controlled studies comparing mortality between types of NCC exist. The aim of this study was to compare all-cause mortality between patients with intraparenchymal NCC and those with subarachnoid NCC. Vital status and sociodemographic characteristics were evaluated in patients with intraparenchymal viable, intraparenchymal calcified, and subarachnoid NCC attending a neurological referral hospital in Lima, Perú. Survival analyses using Kaplan-Meier curves and Cox proportional regression models were carried out to compare mortality rates between groups. From 840 NCC patients followed by a median time of 82.3 months, 42 (5.0%) died, six (1.8%) in the intraparenchymal viable group, four (1.3%) in the calcified group, and 32 (16.6%) in the subarachnoid group (P < 0.001). Older age and lower education were significantly associated with mortality. The age-adjusted hazard ratio for death in the subarachnoid group was 13.6 (95% CI: 5.6-33.0, P < 0.001) compared with the intraparenchymal viable group and 10.7 (95% CI: 3.7-30.8, P < 0.001) when compared with the calcified group. We concluded that subarachnoid disease is associated with a much higher mortality in NCC.

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 Presenting With a New-Onset Seizure: A Case Report

Neurocysticercosis (NCC) is a common infection that is found worldwide but is often neglected in the United States (US). This case report aims to illustrate the presentation of the disease, provide information on this globally prevalent pathogen, and shed light on the diagnostic workup and treatment of the infection. We discuss the case of a 31-year-old male patient of Central American origin presenting with a new-onset seizure. He had no significant past medical history and had never experienced similar events before. The diagnosis was made through neuroimaging, serum antibody testing, and biopsy of the brain lesion. This case highlights the importance of performing a good clinical history and a proper diagnostic workup that would help in the prompt recognization and treatment of this common worldwide illness that may not be endemic to the clinician's geographical area.

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.

Axonal swellings and spheroids: a new insight into the pathology of neurocysticercosis

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

Neurocysticercosis in Pregnancy

The normal physiologic changes during pregnancy contribute to nutritional, metabolic, and immunologic adjustments, which can have an impact on the presentation of several diseases. New onset seizures during pregnancy and the postpartum can be attributed to several etiologies. Patient demographic data as well as personal and social histories are key in determining the etiology of new onset seizures. Neurocysticercosis (NCC), a commonly overlooked etiology, must be included in the differential diagnosis of patients with new onset seizures coming from NCC endemic areas. The diagnosis is based on a combination of clinical findings, exposure history, imaging, and serology. We present two cases of patients with NCC that became symptomatic during pregnancy or postpartum period. We will review the epidemiology, clinical manifestations, and management of NCC in pregnancy.

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".

Two glutathione transferase isoforms isolated from juvenile cysts of Taenia crassiceps: identification, purification and characterization

We identified and characterized the first two glutathione transferases (GSTs) isolated from juvenile cysts of Taenia crassiceps (EC 2.5.1.18). The two glutathione transferases (TcGST1 and TcGST2) were purified in a single-step protocol using glutathione (GSH)-sepharose chromatography in combination with a GSH gradient. The specific activities of TcGST1 and TcGST2 were 26 U mg-1 and 19 U mg-1, respectively, both at 25°C and pH 6.5 with 1-chloro-2,4-dinitrobenzene (CDNB) and GSH as substrates. The Km(CDNB) and Kcat(CDNB) values for TcGST1 and TcGST2 (0.86 μm and 62 s-1; 1.03 μm and 1.97 s-1, respectively) and Km(GSH) and Kcat(GSH) values for TcGST1 and TcGST2 (0.55 μm and 11.61 s-1; 0.3 μm and 32.3 s-1, respectively) were similar to those reported for mammalian and helminth GSTs. Mass spectrometry analysis showed that eight peptides from each of the two parasite transferases were a match for gi|29825896 glutathione transferase (Taenia solium), confirming that both enzymes are GSTs. The relative molecular masses were 54,000 ± 0.9 for the native enzymes and 27,500 ± 0.5 for the enzyme subunits. Thus, TcGST1 and TcGST2 are dimeric proteins. Optimal TcGST1 and TcGST2 activities were observed at pH 8.5 in the range of 20-55°C and pH 7.5 at 35-40°C, respectively. TcGST1 and TcGST2 were inhibited by cibacron blue (CB), bromosulphophthalein (BST), rose bengal (RB), indomethacin and haematin (Hm) with 50% inhibitory concentrations (IC50) in the μm range. TcGST1 was inhibited in a non-competitive manner by all tested inhibitors with the exception of indomethacin, which was uncompetitive. The discovery of these new GSTs facilitates the potential use of T. crassiceps as a model to investigate multifunctional GSTs.

Needs of exploring the burden of recent onset seizures due to neurocysticercosis and challenges in southeast Asia focusing on scenario in Malaysia

Seizures due to neurocysticercosis (NCC) is a neglected human-to-human transmitted disorder and an emerging problem worldwide. A substantial portion of recent onset seizures is known to be attributed to NCC in Taenia solium (T. solium) endemic areas where populations which neither raise pigs nor eat pig meat are also at risk. High prevalence of NCC causing epilepsy has been reported in the underdeveloped areas of Southeast Asia (SEA) however, only fragmentary information on its incidence is available in countries like Malaysia. In Malaysia T. solium infection was previously thought to be infrequent due to Muslim population majority and the religious prohibition of consuming pork, but it is not totally absent. There is an evident lack of knowledge and awareness of the actual burden, routes of transmission, and the impact of NCC in this region. The problem is assumed to be more prevalent particularly in cities because of the frequent inflow of possibly T. solium infected individuals or carriers among those who migrate from neighboring endemic countries to Malaysia. The issue of imported cases that are likely to be emerging in Malaysia is highlighted here. An accurate quantification of regional burdens of epilepsy due to NCC in Malaysia is warranted considering the disease emergence in its neighboring countries. It is suggested that the importance of NCC be recognized through quantification of its burden, and also to collect epidemiological data for its subsequent elimination in line of World Health Organization's mission for control of cysticercosis as a neglected tropical disease. In this review the need as well as a strategy for neuro-care center screening of epilepsy cases, and various issues with possible explanations are discussed. It is also proposed that NCC be declared as a reportable disease which is one of the eradicable public health problems in SEA.

Simultaneous densitometric determination of anthelmintic drug albendazole and its metabolite albendazole sulfoxide by HPTLC in human plasma and pharmaceutical formulations

A new, simple, accurate and precise high-performance thin-layer chromatographic method has been developed and validated for simultaneous determination of an anthelmintic drug, albendazole, and its active metabolite albendazole, sulfoxide. Planar chromatographic separation was performed on aluminum-backed layer of silica gel 60G F₂₅₄ using a mixture of toluene-acetonitrile-glacial acetic acid (7.0:2.9:0.1, v/v/v) as the mobile phase. For quantitation, the separated spots were scanned densitometrically at 225 nm. The retention factors (R_f ) obtained under the established conditions were 0.76 ± 0.01 and 0.50 ± 0.01 and the regression plots were linear (r²  ≥ 0.9997) in the concentration ranges 50-350 and 100-700 ng/band for albendazole and albendazole sulfoxide, respectively. The method was validated for linearity, specificity, accuracy (recovery) and precision, repeatability, stability and robustness. The limit of detection and limit of quantitation found were 9.84 and 29.81 ng/band for albendazole and 21.60 and 65.45 ng/band for albendazole sulfoxide, respectively. For plasma samples, solid-phase extraction of analytes yielded mean extraction recoveries of 87.59 and 87.13% for albendazole and albendazole sulfoxide, respectively. The method was successfully applied for the analysis of albendazole in pharmaceutical formulations with accuracy ≥99.32%.

Under seize: neurocysticercosis in an immigrant woman and review of a growing neglected disease

Neurocysticercosis (NCC) is a significantly neglected tropical disease and, with increasing globalisation, a notable emerging infection in the developed world. We describe a case of ventricular NCC in a 22-year-old Mexican-American woman with a history of seizures, who presented with 2 weeks of headaches and intermittent fevers progressing to altered mental status and vomiting. Initial imaging revealed a cystic mass at the posteroinferior aspect of the third ventricle superior to the aqueduct of Sylvius, calcifications scattered throughout the parenchyma, and enlargement of the lateral and third ventricles. Initial laboratories were unrevealing and serum investigations for Taenia solium antibody were negative, but T. solium antibody was subsequently returned positive from cerebrospinal fluid. This case highlights important issues regarding the clinical presentation, diagnostic evaluation and treatment of NCC relevant to providers not only in areas with endemic disease but, importantly, in locales with diverse immigrant populations.

Managing neurocysticercosis: challenges and solutions

Taenia solium neurocysticercosis (NCC) is a major cause of neurological morbidity in the world. Variability in the neuropathology and clinical presentation of NCC often make it difficult to diagnose and manage. Diagnosis of NCC can be challenging especially in endemic and resource-limited countries where laboratory and imaging techniques are often lacking. NCC management can also be challenging as current treatment options are limited and involve symptomatic agents, antiparasitic agents, or surgery. Although antiparasitic treatment probably reduces the number of active lesions and long-term seizure frequency, its efficacy is limited and strategies to improve treatment regimens are warranted. Treatment decisions should be individualized in relation to the type of NCC. Initial measures should focus on symptomatic management, with antiparasitic therapy only to be considered later on, when appropriate. Symptomatic treatment remains the cornerstone in NCC management which should not only focuses on epilepsy, but also on other manifestations that cause considerable burden (recurrent headaches, cognitive decline). Accurate patients’ categorization, better antiparasitic regimens, and definition of new clinical outcomes for trials on NCC could improve management quality and prognosis of NCC. Prevention strategies targeting tapeworm carriers and infected pigs are yielding good results in local models. If local elimination of transmission is confirmed and replicated, this will open the door to cysticercosis eradication efforts worldwide.

Intraventricular Taenia solium cysts presenting with Bruns syndrome and indications for emergent neurosurgery

Bruns syndrome is an unusual phenomenon, characterized by attacks of sudden and severe headache, vomiting, and vertigo, triggered by abrupt movement of the head. The presumptive cause of Bruns syndrome is a mobile deformable intraventricular mass leading to an episodic obstructive hydrocephalus. Intraventricular tumors have been associated with Bruns syndrome; however, few cases of intraventricular neurocysticercosis have been reported to present with Bruns syndrome. We report the first series of fourth ventricular neurocysticercosis presenting with Bruns syndrome in the United States and review the other published cases where surgery was indicated.

Clinical symptoms, diagnosis, and treatment of neurocysticercosis

The infection of the nervous system by the cystic larvae of Taenia solium (neurocysticercosis) is a frequent cause of seizure disorders. Neurocysticercosis is endemic or presumed to be endemic in many low-income countries. The lifecycle of the worm and the clinical manifestations of neurocysticercosis are well established, and CT and MRI have substantially improved knowledge of the disease course. Improvements in immunodiagnosis have further advanced comprehension of the pathophysiology of this disease. This knowledge has led to individualised treatment approaches that account for the involvement of parenchymal or extraparenchymal spaces, the number and form of parasites, and the extent of degeneration and associated inflammation. Clinical investigations are focused on development of effective treatments and reduction of side-effects induced by treatment, such as seizures, hydrocephalus, infarcts, and neuroinjury.

Cysticercosis-related hospitalizations in the United States, 1998-2011

Cysticercosis has become increasingly recognized as an important infection in the United States in recent decades. Despite its potential impact, there is a lack of comprehensive information on the nationwide burden of disease. To better define the burden of cysticercosis in the United States, we analyzed in-patient records using the Nationwide Inpatient Sample for 1998-2011 to estimate cysticercosis-related hospitalizations and patient/institutional characteristics. There were an estimated 33,060 (95% confidence interval [95% CI] = 29,610.5-36,510.3) cysticercosis-related hospitalizations nationwide, representing a hospitalization rate of 8.03 per million population. The highest proportion of cases were male (54.8%), Hispanic (62.0%), aged 18-44 (58.8%), and occurred in the West (45.1%). An estimated 459 deaths occurred, representing an in-hospital case-fatality rate of 1.4%. These findings indicate the burden of cysticercosis-related hospitalizations in the United States is considerable and may be greater than currently appreciated. Cysticercosis should be a nationally reportable disease.

Computed tomography abnormalities and epidemiology of adult patients presenting with first seizure to the emergency department in Qatar

OBJECTIVES

There is little information available from the Middle Eastern region on adult patients presenting with first seizure. The objectives of this study were to describe epidemiological characteristics of patients presenting to the emergency department (ED) in Doha, Qatar, with first seizure and to determine the incidence of computed tomographic (CT) scan abnormalities.

METHODS

A retrospective cohort study was conducted on all adult patients with first seizure presenting to Hamad General Hospital ED over a 1-year period (June 2012 through May 2013). Electronic patient records were reviewed for demographics, neuroimaging, electroencephalography, laboratory test results, and medications administered.

RESULTS

There were 439 patients who satisfied inclusion criteria. Patients were aged a mean of 35.3 years (95% confidence interval [CI] = 33.92 to 36.69 years) with a male-to-female ratio of five to one. CT abnormalities were detected in 154 patients (35.3%; 95% CI = 30.81% to 39.82%). Out of reported abnormal scans, 14.7% patients had significant abnormalities such as neurocysticercosis (9.2%); brain metastasis and neoplasm (3.4%); and subarachnoid and subdural hemorrhage, cavernous sinus thrombosis, acute stroke, and brain edema (2.0%). None of the patients had any electrolyte abnormalities, and three patients had hypoglycemia. Patients with initial abnormal CT brain results were more likely to have recurrent seizures (OR = 1.65; 95% CI = 1.11 to 2.45) within 6 months.

CONCLUSIONS

Adults who presented with first seizure to the ED in Qatar had a young male predominance, and a high proportion of brain CT scans were reported as abnormal. It is recommended that all such patients in this population should undergo prompt CT scanning in the ED, but the utility of routine electrolyte tests requires further investigation.

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.

Third-ventricular neurocysticercosis: hydraulic maneuvers facilitating endoscopic resection

BACKGROUND

Neurocysticercosis, an infection of the central nervous system with the larval cysts of the pork tapeworm, Taenia solium, is the most common parasitic disease of the central nervous system. The disease is a major global cause of acquired epilepsy and may also manifest as intracranial hypertension due to mass effect from large cysts or to cerebrospinal fluid flow obstruction by intraventricular cysts or inflammation of the subarachnoid space. While the condition is endemic in several regions of the world and has been appreciated as a public health problem in such regions for several decades, its emergence in the USA in areas far from the Mexican border is a more recent phenomenon.

METHODS

We present a case of surgically corrected acute hydrocephalus in a recent Haitian emigrant child due to a third ventricular neurocysticercal cyst complex.

RESULTS

We describe the endoscope-assisted en bloc removal of the complex, together with hydraulic maneuvers facilitating the removal of the intact cyst.

CONCLUSIONS

Simple hydraulic maneuvers can facilitate the endoscopic en bloc removal of third ventricular neurocysticercal cysts.

Recombinant protein- and synthetic peptide-based immunoblot test for diagnosis of neurocysticercosis

One of the most well-characterized tests for diagnosing neurocysticercosis (NCC) is the enzyme-linked immunoelectrotransfer blot (EITB) assay developed at the CDC, which uses lentil lectin-bound glycoproteins (LLGP) extracted from Taenia solium cysticerci. Although the test is very reliable, the purification process for the LLGP antigens has been difficult to transfer to other laboratories because of the need for expensive equipment and technical expertise. To develop a simpler assay, we previously purified and cloned the diagnostic glycoproteins in the LLGP fraction. In this study, we evaluated three representative recombinant or synthetic antigens from the LLGP fraction, individually and in different combinations, using an immunoblot assay (recombinant EITB). Using a panel of 249 confirmed NCC-positive and 401 negative blood serum samples, the sensitivity of the recombinant EITB assay was determined to be 99% and the specificity was 99% for diagnosing NCC. We also tested a panel of 239 confirmed NCC-positive serum samples in Lima, Peru, and found similar results. Overall, our data show that the performance characteristics of the recombinant EITB assay are comparable to those of the LLGP-EITB assay. This new recombinant- and synthetic antigen-based assay is sustainable and can be easily transferred to other laboratories in the United States and throughout the world.

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.

Neurocysticercosis in the United States

Neurocysticercosis (NCC) is typically considered a disease of the developing world. Nonetheless, NCC is also diagnosed in the developed world. The rise in the number of cases of NCC in developed countries, especially in the United States of America, has largely been driven by the influx of immigrants from endemic to non-endemic regions and the widespread access to neuroimaging. Cases of local transmission have also been documented particularly in the setting of a tapeworm carrier present in the household, which highlights the relevance of NCC as a public health problem in the USA. Although accurate incidence data in the USA are not available, estimates range from 0·2 to 0·6 cases per 100 000 general population and 1·5-5·8 cases per 100 000 Hispanics. We estimate that between 1320 and 5050 new cases of NCC occur every year in the USA. The number of NCC cases reported in the literature in the USA increased from 1494 prior to 2004 to 4632 after that date. Parenchymal cases remain the most commonly reported form of the disease; however, a slight increase in the percentage of extraparenchymal cases has been described in the most recent series. NCC is associated with significant morbidity resulting from hydrocephalus, cerebral edema, and seizures. Although uncommon, NCC is also a cause of premature death in the USA with a calculated annual age-adjusted mortality rate of at least 0·06 per million population.

Intramedullary spinal neurocysticercosis presenting as brown-sequard syndrome

Cysticercosis is an emerging disease in the United States. Neurocysticercosis may rarely cause disease within the spinal cord, but the occurrence of such pathology can produce debilitating symptoms for patients. We present the second report in the literature of intramedullary spinal neurocysticercosis presenting with a Brown-Sequard syndrome.

Drug therapy for solitary cysticercus granuloma: a systematic review and meta-analysis

OBJECTIVE

The effectiveness of anthelminthic and corticosteroid drug therapy in parenchymal neurocysticercosis is well established. The treatment of parenchymal solitary cysticercus granuloma (SCG), however, remains controversial. We attempted to obtain a consistent estimate of the efficacy of anthelminthic and corticosteroid drug treatment in SCG.

METHODS

Randomized-controlled trials (RCTs) comparing rates of seizure freedom, granuloma resolution, and residual calcification in individuals with SCG treated with anthelminthic or corticosteroid drugs with those treated with antiepileptic drugs (AEDs) alone were systematically reviewed and quantified using fixed- or random-effects meta-analysis.

RESULTS

Fifteen RCTs were identified for inclusion. Ten RCTs assigned 765 people with SCG to AED treatment with or without anthelminthic drug (albendazole) treatment. A further 5 RCTs assigned 457 people with SCG to AED treatment with or without corticosteroid drugs. Anthelminthic treatment was associated with significantly increased rates of seizure freedom (nonevent odds ratio: 2.45; 95% confidence interval: 1.49-4.03; p = 0.0004) and significantly higher rates of granuloma resolution (odds ratio: 2.09; 95% confidence interval: 1.41-3.00; p = 0.0003), but did not alter the risk of residual calcification. Corticosteroid treatment was not significantly associated with any outcome.

CONCLUSIONS

Anthelminthic treatment with albendazole provides improved rates of seizure freedom and hastens resolution of the granuloma. The role of corticosteroid treatment remains uncertain. The benefits (or lack thereof in the case of corticosteroids) are consistent when measured across different time points after treatment.

Immunodiagnosis of CNS parasitic infections

The nature of many parasitic infections of the central nervous system (CNS) requires immunodiagnosis to confirm presumptive diagnoses. The CNS is the primary site of parasite infection for some parasitic organisms and for others, neurological infection occurs only in immunocompromised hosts. Still other parasites cause ectopic infections of the CNS and occur very rarely. This review concentrates on laboratory diagnosis of diseases that are caused by parasites with a primary predilection for the CNS. Emphasis is placed on laboratory diagnostic methods that are used and suitable for clinical diagnosis, rather than a comprehensive review of all the experimental methods that have been reported in the literature. Immunodiagnosis is not appropriate for the diagnosis of all parasitic infections of the CNS; in those cases, alternative diagnostic methods are presented, but not discussed in detail. In some instances potential new antigens or methods are presented, particularly if adoption of these methods is expected in the near future.

Transient cortical blindness as a manifestation of solitary cysticercus granuloma

Neurocysticercosis is recognised as a significant cause of neurological morbidity in endemic regions. The wide range of pleomorphic and non-specific neurological manifestations of neurocysticercosis must be kept in mind by physicians, as the disease has shown resurgence in developed countries. When an atypical presentation of an unusual tropical disease occurs in non-endemic regions, the diagnosis is often missed. We describe a case of a 4-year-old girl who presented with a history of transient bilateral loss of vision with headache and vomiting. Brain MRI revealed the presence of a single cysticercus granuloma in the occipital lobe. A diagnosis of symptomatic occipital lobe seizure secondary to neurocysticercosis was made. She was given a course of albendazole. There was no recurrence of symptoms at 3 years follow-up. Occipital seizures that are associated with ictal amaurosis closely mimic basilar migraine. Such cases benefit from neuroimaging in order to rule out the underlying structural causes.

Epilepsy across the spectrum: promoting health and understanding. A summary of the Institute of Medicine report

Approximately 1 in 26 people will develop epilepsy at some point in their lives. Although epilepsy is one of the nation's most common neurological disorders, public understanding is limited. A complex spectrum of disorders, epilepsy affects an estimated 2.2 million people in the United States. Living with epilepsy is about more than just seizures; it is often defined in practical terms, such as challenges, uncertainties, and limitations in school, social situations, employment, driving, and independent living. People with epilepsy are also faced with health and community services that are fragmented, uncoordinated, and difficult to obtain. The Institute of Medicine's report (2012) [1], Epilepsy across the spectrum: promoting health and understanding, examines the public health dimensions of epilepsy with a focus on (a) public health surveillance and data collection and integration; (b) population and public health research; (c) health policy, health care, and human services; and (d) education for providers, people with epilepsy and their families, and the public. The report's recommendations range from the expansion of collaborative epilepsy surveillance efforts to the independent accreditation of epilepsy centers, to the coordination of public awareness efforts, and to the engagement of people with epilepsy and their families in education, dissemination, and advocacy activities. Given the current gaps in epilepsy knowledge, care, and education, there is an urgent need to take action-across multiple dimensions-to improve the lives of people with epilepsy and their families. The realistic, feasible, and action-oriented recommendations in this report can help enable short- and long-term improvements for people with epilepsy.

Prevalence case-control study of epilepsy in three Burkina Faso villages

PURPOSE

To estimate the association between the prevalence of epilepsy and potential risk factors in three Burkina Faso villages.

METHODS

Three villages were selected based on local reports of high numbers of epilepsy cases and pig-rearing practices. One person aged 7 or older was selected at random from all households of selected concessions for epilepsy screening and blood sampling. Epilepsy was confirmed by a physician using the ILAE definition. The cross-sectional associations between epilepsy and selected factors and seroresponse to the antigens of Taenia solium were estimated using a Bayesian hierarchical logistic regression. Prevalence odds ratios (POR) and their 95% Bayesian Credible Intervals (95% BCI) were estimated.

RESULTS

Of 888 individuals interviewed, 39 of 70 screened positive were confirmed to have epilepsy for a lifetime prevalence of 4.5% (95% CI: 3.3; 6.0). The prevalence of epilepsy was associated with a positive reaction to cysticercosis Ag-ELISA serology (POR = 3.1, 95% BCI = 1.0; 8.3), past pork consumption (POR = 9.7, 95% BCI = 2.5; 37.9), and being salaried or a trader compared to a farmer or housewife (POR = 2.9, 95% BCI = 1.2; 6.4).

DISCUSSION

Several factors were associated with prevalent epilepsy, with Ag-ELISA suggesting the presence of neurocysticercosis. The association between epilepsy and some occupations may reflect differences in local attitudes toward epilepsy and should be further explored.

Extraparenchymal neurocysticercosis in the United States

Neurocysticercosis (NCC) is endemic in the developing world but is becoming more common in the United States because of immigration. Although NCC is pleomorphic in its presentation, extraparenchymal NCC may be challenging to diagnose and treat. Extraparenchymal NCC is probably more frequent than previously thought. Neurologists and neuroradiologists in the United States are often unaware of the pretreatment/post-treatment radiographic patterns of extraparenchymal NCC and the potentially poor prognosis if not correctly diagnosed and managed. The review of this condition is important given increasing incidence in the United States.

Substance P causes seizures in neurocysticercosis

Neurocysticercosis (NCC), a helminth infection of the brain, is a major cause of seizures. The mediators responsible for seizures in NCC are unknown, and their management remains controversial. Substance P (SP) is a neuropeptide produced by neurons, endothelial cells and immunocytes. The current studies examined the hypothesis that SP mediates seizures in NCC. We demonstrated by immunostaining that 5 of 5 brain biopsies from NCC patients contained substance P (SP)-positive (+) cells adjacent to but not distant from degenerating worms; no SP+ cells were detected in uninfected brains. In a rodent model of NCC, seizures were induced after intrahippocampal injection of SP alone or after injection of extracts of cysticercosis granuloma obtained from infected wild type (WT), but not from infected SP precursor-deficient mice. Seizure activity correlated with SP levels within WT granuloma extracts and was prevented by intrahippocampal pre-injection of SP receptor antagonist. Furthermore, extracts of granulomas from WT mice caused seizures when injected into the hippocampus of WT mice, but not when injected into SP receptor (NK1R) deficient mice. These findings indicate that SP causes seizures in NCC, and, suggests that seizures in NCC in humans may be prevented and/or treated with SP-receptor antagonists.

Neurocysticercosis--retrospective study of autopsy reports, a 17-year experience

Neurocysticercosis (NCC) is a common central nervous system (CNS) infection caused by Taenia solium metacestodes. The objective of this study is to describe the incidence of cysticercosis diagnosed at autopsies and describe the epidemiological and clinical characteristics of NCC. Retrospective study analyzing 6,500 reports of autopsies between 1977 and 1994 from a school hospital in Curitiba, PR, southern of Brazil. The following data was obtained, age, gender, site of cysticercosis, NCC as cause of death. The diagnosis of cysticercosis was established in 52 (0.8%) autopsies. From 1977 to 1987 (0.7%) and from 1988 to 1994 (1.1%). In the autopsies with cysticercosis 75% were male; age (mean ± SD) was 43 ± 20. NCC was present in 96% of cases, and seizures was the most frequent clinical manifestation. Asymptomatic cases in 54%. These data classify our area as hiperendemic, according with OMS criteria. The present study reinforces the necessity to develop adequate control programs.

Hydrocephalus in neurocysticercosis

INTRODUCTION

Cysticercosis (CC) is the most important of the parasitic diseases of the central nervous system due to its high incidence in the world. CC is the infection with the larval cysts of Taenia solium. It is the most common helminthic infection of the nervous system and is endemic in most underdeveloped countries as well as in industrialized nations. It is estimated that approximately 50,000 people die every year from neurocysticercosis (NCC) worldwide.

DISCUSSION

Humans with CC are incidental intermediate hosts, which replace the pig in the life cycle of the T. solium. Children are more frequently affected by parenchyma infestation of cysticercus, of which the main clinical manifestation is epilepsy. Hydrocephalus is more common in adults and is caused by cerebrospinal fluid blockage by ventricular cysts and inflammatory reactions (ependimitis/arachnoiditis). Treatment should be individualized based on clinical presentation, degree of infestation, location and viability of cysticercus, and host response. Hydrocephalus can be controlled only by removal of obstructive intraventricular cysts or associated with either ventriculoperitoneal shunt or endoscopic third ventriculostomy. The degree of infestation and complications related to the shunt represents the most important prognostic factors in the outcome of NCC.

Extraparenchymal neurocysticercosis in Albuquerque, New Mexico

BACKGROUND

neurocysticercosis (NCC) prevalence is increasing throughout the United States mainly because of immigration from Latin America. Clinicians may fail to recognize the extraparenchymal disease because they do not consider the diagnosis.

METHODS

to analyze neuroimaging and clinical characteristics of extraparenchymal NCC, we retrospectively reviewed all such cases presenting to a major general medical school hospital in the State of New Mexico.

RESULTS

eleven (30%) of our 37 cases of NCC diagnosed using standard criteria from 1998 through 2004 had extraparenchymal disease. On neuroimaging, 36% of the patients lacked parenchymal cysts, 64% had intraventricular cysticerci, 64% had subarachnoid cysticerci, and 64% had hydrocephalus due to either basal arachnoiditis or direct obstruction of intraventricular pathways. Lumbar puncture was performed in 6 patients. All had a cerebrospinal fluid (CSF) pleocytosis, none had CSF or blood eosinophilia, and CSF antibody to NCC could be absent while present in serum. Response to treatment was frequently suboptimal.

CONCLUSIONS

extraparenchymal NCC is more frequent than previously thought. Because clinicians outside the Southwest United States are often unfamiliar with NCC as a cause of chronic meningitis, chronic ventriculitis, or hydrocephalus without obvious cysts, the diagnosis of extraparenchymal NCC often depends on the correct interpretation of neuroimaging.

A cross-sectional study of people with epilepsy and neurocysticercosis in Tanzania: clinical characteristics and diagnostic approaches

Neurocysticercosis (NCC) is a major cause of epilepsy in regions where pigs are free-ranging and hygiene is poor. Pork production is expected to increase in the next decade in sub-Saharan Africa, hence NCC will likely become more prevalent. In this study, people with epilepsy (PWE, n = 212) were followed up 28.6 months after diagnosis of epilepsy. CT scans were performed, and serum and cerebrospinal fluid (CSF) of selected PWE were analysed. We compared the demographic data, clinical characteristics, and associated risk factors of PWE with and without NCC. PWE with NCC (n = 35) were more likely to be older at first seizure (24.3 vs. 16.3 years, p = 0.097), consumed more pork (97.1% vs. 73.6%, p = 0.001), and were more often a member of the Iraqw tribe (94.3% vs. 67.8%, p = 0.005) than PWE without NCC (n = 177). PWE and NCC who were compliant with anti-epileptic medications had a significantly higher reduction of seizures (98.6% vs. 89.2%, p = 0.046). Other characteristics such as gender, seizure frequency, compliance, past medical history, close contact with pigs, use of latrines and family history of seizures did not differ significantly between the two groups. The number of NCC lesions and active NCC lesions were significantly associated with a positive antibody result. The electroimmunotransfer blot, developed by the Centers for Disease Control and Prevention, was more sensitive than a commercial western blot, especially in PWE and cerebral calcifications. This is the first study to systematically compare the clinical characteristics of PWE due to NCC or other causes and to explore the utility of two different antibody tests for diagnosis of NCC in sub-Saharan Africa.

Neurocysticercosis, a preventable and treatable disease, is one of the main causes of epilepsy in low income countries. In these countries, the diagnosis of epilepsy is often based on clinical presentation and interviews as neuroimaging is rarely available. It is crucial to distinguish people with epilepsy due to neurocysticercosis from other people with epilepsy by clinical symptoms and/or serology, because the former warrants a specific approach both in terms of diagnosis and treatment. The authors compared the demographic and clinical data of the two groups and found that people with epilepsy due to neurocysticercosis are older, more likely to consume pork, and respond better to anti-epileptic treatment. Additionally, the authors compared two antibody tests for cysticercosis with computed tomography images, which showed a higher sensitivity of the CDC electroimmunotransfer blot compared to a commercial western blot. The number of neurocysticercosis lesions was significantly associated with a positive antibody result in both tests. In summary, this research describes clinical characteristics of people with epilepsy and neurocysticercosis and assesses the usefulness of two immunoblots in those patients. This has implications not only for the diagnosis of neurocysticercosis in low income countries, but also for future epidemiological research.

A diagnostic and therapeutic scheme for a solitary cysticercus granuloma

BACKGROUND

Solitary cysticercus granuloma (SCG) is one of the most common forms of presentation of neurocysticercosis (NCC). The diagnostic workup and management approach to this condition remain uncertain and controversial.

OBJECTIVE

To review evidence and develop a consensus approach to the diagnosis and treatment of SCG.

METHODS

A multidisciplinary expert group meeting was convened in order to review and discuss various aspects of management of patients with SCG. Evidence reviewed was classified and a consensus was evolved according to standard protocols.

RESULTS

SCG is commonly recognized on CT as an enhancing lesion measuring <20 mm. Further evaluation with MRI does not add much information. The use of antihelminthic agents (specifically, albendazole in combination with corticosteroids) and corticosteroids alone have been shown to improve radiologic resolution and seizure outcome in patients with SCG. However, the sizes of the effects are modest. By convention, all patients with SCG presenting with seizures are initiated on antiepileptic drugs (AEDs). Available evidence suggests that withdrawal of AEDs after complete resolution of the SCG is safe. There is a high risk of seizure relapse after AED withdrawal in patients with calcific residue following resolution of the SCG. The duration of AED prophylaxis in these individuals is unclear.

CONCLUSIONS

It is desirable to have large, multicenter trials with sufficiently long follow-up, comparing outcomes with the use of antihelminthics with or without corticosteroids and corticosteroids alone in order to dissect out the benefits accrued due to each of these classes of drugs.

An uncommon cause of seizures in children living in developed countries: neurocysticercosis--a case report

Neurocysticercosis represents an important cause of seizures in children in endemic countries, such as Latin America, Asia and sub-Saharan Africa, while in Europe, especially in Italy, the cases of neurocysticercosis are anectodal. We report the case of a 6 year old boy, born and lived for four years in Cameroon, who presented a right emiconvulsion. The diagnosis was neurocysticercosis. This case accentuates the need to consider neurocysticercosis in a child presenting with non febrile seizures, mainly if he emigrated from an area of high prevalence or if he had long-term stay in endemic regions.