Prevalence Of Neurocysticercosis Research Articles

Economic implications of three strategies for the control of taeniasis

To evaluate the cost-effectiveness of three strategies for the control of taeniasis in a community, in terms of cost per case treated. A study was conducted in South India to determine the prevalence of taeniasis by screening stool samples from 653 randomly chosen subjects, for coproantigens. The costs incurred in the project were used to estimate the cost per case screened and treated. A one-way sensitivity analysis was carried out for varying rates of taeniasis, different screening strategies and mass therapy. Further sensitivity analysis was carried out with different manpower and test costs. The rate of taeniasis as detected by ELISA for coproantigen was 3 per 1000 (2 of 653 samples). Our study showed that mass therapy without screening for taeniasis would be the most economical strategy in terms of cost per case treated if field workers are employed exclusively for either mass therapy or screening. For each strategy, costs per case treated are higher at low prevalence of taeniasis, with a sharp rise below 15%. In places that are endemic for taeniasis and neurocysticercosis, mass therapy or screening for taeniasis should be considered. Screening by stool microscopy is not cost-effective in terms of cost per case of taeniasis treated owing to its low sensitivity. Although the cost per case of taeniasis treated is high at low prevalence of taeniasis for all options, incorporating mass therapy into existing mass drug distribution programmes might prove to be the most cost-effective control strategy.

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

Neurocysticercosis (NCC) is the most frequent parasitic infection of the central nervous system caused by the larvae of Taenia solium. The prevalence of NCC is obscured due to variations in the methods used for epidemiological studies and often asymptomatic manifestation. The present study was conducted on 595 apparently healthy individuals belonging to the pig farming community of northern India to estimate the prevalence of asymptomatic NCC and to evaluate risk factors based on questionnaires. Diagnosis of NCC was based on neuroimaging, immunological and epidemiological criteria. Asymptomatic NCC was detected in 90 (15.1%) of 595 individuals. The evaluation of risk factors showed that age >15 years (P=0.001), intake of raw vegetables (P=0.025) and undercooked pork (P=0.005), lack of safe drinking water (P=0.003), inadequate drainage system (P=0.049), no separate place for pigs (P≤0.001), NCC related active epilepsy in the family (P≤0.001) were significantly associated with asymptomatic NCC. The present study shows high prevalence of asymptomatic NCC in pig farming community of northern India. Further, asymptomatic NCC is associated with most variables of poor socio-economic parameters.

Relative seroprevalence of cysticercus antigens and antibodies and antibodies to Taenia ova in a population sample in south India suggests immunity against neurocysticercosis

We evaluated the exposure of a community in Vellore district of south India to Taenia solium infection and its relationship to the prevalence of neurocysticercosis (NCC) causing active epilepsy. Seroprevalence of Taenia cysticercus antigens and antibodies were determined in 1064 randomly chosen asymptomatic individuals, antibodies to T. solium ova in 197 selected sera, and prevalence of taeniasis by a coproantigen test in 729 stool samples. The prevalence of NCC causing active epilepsy in Vellore district was determined in a population of 50 617. Coproantigens were detected in 0.8% (6 samples), Taenia cysticercus antigens in 4.5% (48 sera) and cysticercus IgG antibodies in 15.9% (169 sera) of the population. Cysticercus antibodies were directed against relatively low molecular weight cyst glycoprotein antigens in 14.9% (158 sera) of the population. IgG antibodies to Taenia ova were found in 81 (41.1%) of the selected samples. Prevalence of NCC causing active epilepsy was 1.3 per 1000 population. These results show high exposure of the population to the parasite and a relatively high prevalence of active infections (4.5% antigen positives) but a low prevalence of NCC causing active epilepsy (0.13%). These findings may indicate that the population is protected against developing neurocysticercosis. IgG antibodies directed against Taenia ova and low molecular weight cyst antigens may contribute to protection.

Neurocysticercosis and its impact on crude prevalence rate of epilepsy in an Indian community

Community-based studies of epilepsy in India have reported variable prevalence rates, 5-10/1000 population. Reasons for this wide variation in the prevalence rates are uncertain. Most of the earlier studies had not done appropriate investigations to establish the possible etiology. To study the prevalence and etiological profile of active epilepsy in the rural population of Uttarakhand. In this rural community-based study in the state of Uttarakhand, a door-to-door survey was conducted using validated questionnaire. All the suspected cases of epilepsy were examined by a neurologist to confirm the diagnosis of epilepsy and all the confirmed cases underwent contrast computed tomography (CT) scan and electroencephalography (EEG). Epilepsy and epilepsy syndromes were classified using the classifications proposed by the International League Against Epilepsy. Of the 14,086 population studied, 141 cases of active epilepsy were detected giving a crude prevalence rate of 1%. After clinical evaluation and scanning, 35 (24.8%) were found to have seizure disorder active neurocysticercosis (NCC) and 14 (9.9%) had remote symptomatic seizures related to calcified granuloma. After excluding acute and remote symptomatic cases related to NCC, prevalence rate of epilepsy was 6.5/1000. The study suggests that the region-specific prevalence rates of epilepsy in India are partly dependent on the prevalence of NCC in the given community. To some extent, this may be responsible for variable rates of epilepsy prevalence reported from different regions of the country.

A systematic review of the frequency of neurocyticercosis with a focus on people with epilepsy.

BackgroundThe objective of this study is to conduct a systematic review of studies reporting the frequency of neurocysticercosis (NCC) worldwide.Methods/Principal FindingsPubMed, Commonwealth Agricultural Bureau (CAB) abstracts and 23 international databases were systematically searched for articles published from January 1, 1990 to June 1, 2008. Articles were evaluated for inclusion by at least two researchers focusing on study design and methods. Data were extracted independently using standardized forms. A random-effects binomial model was used to estimate the proportion of NCC among people with epilepsy (PWE). Overall, 565 articles were retrieved and 290 (51%) selected for further analysis. After a second analytic phase, only 4.5% of articles, all of which used neuroimaging for the diagnosis of NCC, were reviewed. Only two studies, both from the US, estimated an incidence rate of NCC using hospital discharge data. The prevalence of NCC in a random sample of village residents was reported from one study where 9.1% of the population harboured brain lesions of NCC. The proportion of NCC among different study populations varied widely. However, the proportion of NCC in PWE was a lot more consistent. The pooled estimate for this population was 29.0% (95%CI: 22.9%–35.5%). These results were not sensitive to the inclusion or exclusion of any particular study.Conclusion/SignificanceOnly one study has estimated the prevalence of NCC in a random sample of all residents. Hence, the prevalence of NCC worldwide remains unknown. However, the pooled estimate for the proportion of NCC among PWE was very robust and could be used, in conjunction with estimates of the prevalence and incidence of epilepsy, to estimate this component of the burden of NCC in endemic areas. The previously recommended guidelines for the diagnostic process and for declaring NCC an international reportable disease would improve the knowledge on the global frequency of NCC.

How frequent is the association of neurocysticercosis and mesial temporal lobe epilepsy with hippocampal sclerosis?

To the Editors: In an interesting article, Chandra et al. (2010) quoted us to support the view that the association of neurocysticercosis (NCC) and mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) is rare. This is not our view. Instead, we believe that this association is rather frequent. NCC is endemic in the developing world, being a major cause of epilepsy worldwide (Garcia et al., 2005). Despite the fact that the epidemiology of the association of MTLE-HS with NCC is unknown, there are some clues regarding the real occurrence of this association. The prevalence of NCC plus MTLE-HS might be high in some world regions (Bianchin et al., 2005). In a cross-sectional study of 512 patients with refractory epilepsy, 281 (54.8%) of them had MTLE-HS and 104 (37.0% of the total of patients with MTLE-HS) presented MTLE-HS plus NCC. In comparison, the prevalence of NCC in patients with other epileptogenic lesions (cortical dysplasia, brain tumors, or gliosis) was only 15%, a significant difference (Velasco et al., 2006). Given the epidemiology of both diseases, if this association also occurs in other populations, then the prevalence of MTLE-HS plus NCC worldwide would be substantial. So far we believe that there are three possibilities for the association of NCC and MTLE-HS. First, there are patients who have NCC and MTLE-HS because of coincidence (Leite et al., 2000). Second, both diseases might share common predisposing factors, including socioeconomic-related factors (Velasco et al., 2006). Third, NCC might work as an initial precipitating injury leading to typical MTLE-HS, similarly to other infections (Wichert-Ana et al., 2004; Velasco et al.; 2006; Bianchin et al., 2006a). When associated with MTLE-HS, NCC is more common in women than in men, causes more bilateral temporal lobe interictal discharges, and patients tend to have a lower frequency of “classical” initial precipitating injury history (Bianchin et al., 2006b). In addition, NCC in MTLE-HS is anatomically related to the side of the hippocampal sclerosis (Bianchin et al., 2008). Despite these differences, when present, NCC has no major impact on MTLE-HS surgical prognosis (Bianchin et al., 2005), a finding that further supports the role of NCC as an initial precipitating injury. Based on these observations, we suggested that the mechanisms involved in hippocampal damage may be inflammation, repeated seizures involving specific neural networks, NCC-induced status epilepticus, gender-related factors, and possibly other molecular mechanisms (Wichert-Ana et al., 2004; Bianchin et al., 2006a; Velasco et al., 2006; Bianchin et al., 2010). In our view, each of these factors might act separately or together to cause hippocampal damage and MTLE-HS. Because NCC and MTLE-HS are common diseases, it would not be a surprise if their association were highly prevalent worldwide. Moreover, some data support the view that NCC might directly cause MTLE-HS, favoring this association. Considering its prevalence, NCC could well be a major cause of MTLE-HS. Consequently, it is not possible to state that the association of NCC and MTLE-HS is rare. Further studies are necessary to evaluate the epidemiology of this association and to clarify its mechanisms. We have no conflict of interest. We confirm that we have read the Journal’s position on issues involved in ethical publication and affirm that this report is consistent with those guidelines.

Management of neurocysticercosis

Background: Neurocysticercosis is a parasitic infection of the central nervous system caused by the larval stage of the tapeworm Taenia solium and is the most common parasitic infection involving the human nervous system. Neurocysticercosis represents one of the most common causes of symptomatic epilepsy in developing countries and is an increasing concern in industrialized nations.Methods: We conducted a review of the medical literature regarding the current management of neurocysticercosis in Latin American countries.Results: Mexico and Brazil report the highest incidence of neurocysticercosis in Latin America. However, major obstacles interfere with an accurate determination of the prevalence of neurocysticercosis, including the lack of standardized and comprehensive epidemiological systems, intrinsic limitations of current immunological studies, the high cost of neuroimaging studies in rural communities and the presence of asymptomatic patients with neuroimaging characteristic compatible with neurocysticercosis. As such, the real prevalence of the disease and its burden are likely underestimated in Latin America. There is no universal consensus or guidelines for the management of different forms of the disease, but most experts agree in the use of antihelminthic therapy when viable cysts are encountered and with the use of corticosteroids in patients presenting with encephalitis.Discussion: Neurocysticercosis is a pleomorphic disease, with a broad spectrum of clinical and radiographic features. The medical management of neurocysticercosis is complex and needs to be individualized.

Epilepsy and neurocysticercosis in sub-Saharan Africa

Over the last decades, studies in sub-Saharan Africa have indicated that epilepsy is a highly prevalent neurological disorder. Causes may be varied with infections of the central nervous system playing an important role. Neurocysticercosis (NCC) has recently been recognised as an emerging public health problem and a growing concern throughout sub-Saharan Africa and has been estimated to be responsible for 30-50% of acquired epilepsy. NCC is closely linked with porcine cysticercosis and human taeniosis, the former reaching a prevalence of almost 50% in some pig populations. In this review, we first summarize prevalence data on epilepsy and highlight some special aspects of the disorder within sub-Saharan Africa. We then focus on the prevalence of NCC, clinical signs and symptoms and diagnostic criteria for NCC with special reference to sub-Saharan Africa. This is followed by a section on the latest developments regarding serodiagnosis of cysticercosis and a section on care management of people infected with NCC. NCC clearly represents a major risk factor of epilepsy, thus detecting and treating NCC may help cure epilepsy in millions of people in sub-Saharan Africa.

Prevalência de neurocisticercose em pacientes atendidos no setor de neurologia do Hospital Universitário Regional de Maringá, Estado do Paraná, Brasil

Register books of ambulatory patients and of the ones in hospital, assisted at the neurology sector of the Hospital Universitário Regional de Maringá, State of Paraná, from January, 2000 to June, 2003, were evaluated with the purpose of estimating the neurocysticercosis prevalence. Out of the 1,713 individuals attended, 13 (0.8%) patients were given the diagnosis of neurocysticercosis. In four patients, such a diagnosis was established during the study period, and the others were evaluated from 1993 to 1999. Concerning sex, the prevalence of neurocysticercosis was of 0.8% in males and 0.7% in females. As for age, the prevalence was greater in 11-30-year-old patients (1.3%) and in individuals who were above 50 years old (1.2%). With respect to the municipal districts that presented cases of neurocysticercosis, Ângulo, Marialva, Floresta and Mandaguaçu showed the greatest prevalence. Epileptic crises and headaches were the main complaint of the diagnosed patients. The observation of one active case and of a transitional one, among the four cases diagnosed in the study period, indicates that the infection is still active in our environment and that it deserves a constant vigilance from the sanitary authorities.

Active epilepsy as an index of burden of neurocysticercosis in Vellore district, India

To determine the contribution of neurocysticercosis (NCC) to the causation of active epilepsy (AE) in a south Indian community. We conducted a door-to-door survey of 50,617 people between the ages of 2 and 60 years in a rural (38,105 people) and urban setting (12,512 people) in the Vellore district of the south Indian state of Tamil Nadu to identify patients with AE. Patients with AE were investigated with a contrast-enhanced CT scan and serologic study using enzyme-linked immunotransfer blot (EITB) for cysticercal antibodies. We identified 194 patients with AE. The prevalence of AE was 3.83 per 1,000 people, with the prevalence in the urban clusters more than twice that in the rural clusters (6.23 vs 3.04 per 1,000) (p < 0.0001). A diagnosis of NCC was made in 46 (28.4%) of the 162 patients undergoing a CT scan, and EITB was positive in 21 (13%) patients. Overall, 55 (34%) patients were diagnosed with NCC (11 definitive NCC and 44 probable NCC). There was no significant difference in the prevalence of NCC causing AE in the urban (1.28 per 1,000) and rural (1.02 per 1,000) communities. NCC is the cause of nearly one-third of all cases of AE in both the urban and rural regions. Extrapolating our results to the country as a whole leads to an estimated disease burden of 1 million patients in India with AE attributable to NCC.

A neurocisticercose humana na Baixada Fluminense, Estado do Rio de Janeiro, Brasil

The objective of this manuscript was to know the neurocysticercosis prevalence and some epidemiological aspects in Baixada Fluminense, State of Rio de Janeiro, Brazil. The data came from the service of computerized tomography of the Nova Iguaçu General Hospital from 1996 to 2002 and from neuroimage "D'IMAGEM" Center from 1992 to 2002. We analyzed 36,379 tomographies identifying 72 cases of the parasitoses, the majority in women (62.5%, p>0.05) and in the chronic phase (93.1%). The neurocysticercosis had occurred in all age groups and increase with age (r=0.84, p<0.05), being that 45.8% of them up to 50 years. The 20 interviewed cases were origin from several municipal districts of Baixada Fluminense, the monthly per capita income was 366 R dollars. The growing urbanization, deficient sanitary vigilance, absence of sewage systems and sanitary education are the main factors that potentially the transmission of cysticercosis and taeniasis in the Baixada Fluminense.

EMERGEncy ID NET: an emergency department-based emerging infections sentinel network.

Acute infectious disease presentations among many at-risk patient groups (eg, uninsured, homeless, and recent immigrants) are frequently seen in emergency departments. Therefore EDs may be useful sentinel sites for infectious disease surveillance. This article describes the background, development, and implementation of EMERGE ncy ID NET, an interdisciplinary, multicenter, ED-based network for research of emerging infectious diseases. EMERGE ncy ID NET was established in cooperation with the National Center for Infectious Diseases, Centers for Disease Control and Prevention (CDC) as part of the CDC's strategy to expand and complement existing disease detection and control activities. The network is based at 11 university-affiliated, urban hospital EDs with a combined annual patient visit census of more than 900,000. Data are collected during ED evaluation of patients with specific clinical syndromes, and are electronically stored, transferred, and analyzed at a central receiving site. Current projects include investigation of bloody diarrhea and the prevalence of Shiga toxin-producing Escherichia coli, animal exposures and rabies postexposure prophylaxis practices, seizures and prevalence of neurocysticercosis, nosocomial ED Mycobacterium tuberculosis transmission, and hospital isolation bed use for adults admitted for pneumonia or suspected tuberculosis. EMERGE ncy ID NET also was developed to be a mechanism for rapidly responding to new diseases or epidemics. Future plans include study of antimicrobial use, meningitis, and encephalitis, and consideration of other public health concerns such as injury and national and international network expansion.

EMERGEncy ID NET: An Emergency Department–Based Emerging Infections Sentinel Network

Acute infectious disease presentations among many at-risk patient groups (eg, uninsured, homeless, and recent immigrants) are frequently seen in emergency departments. Therefore EDs may be useful sentinel sites for infectious disease surveillance. This article describes the background, development, and implementation of EMERGE ncy ID NET, an interdisciplinary, multicenter, ED-based network for research of emerging infectious diseases. EMERGE ncy ID NET was established in cooperation with the National Center for Infectious Diseases, Centers for Disease Control and Prevention (CDC) as part of the CDC’s strategy to expand and complement existing disease detection and control activities. The network is based at 11 university-affiliated, urban hospital EDs with a combined annual patient visit census of more than 900,000. Data are collected during ED evaluation of patients with specific clinical syndromes, and are electronically stored, transferred, and analyzed at a central receiving site. Current projects include investigation of bloody diarrhea and the prevalence of Shiga toxin–producing Escherichia coli , animal exposures and rabies postexposure prophylaxis practices, seizures and prevalence of neurocysticercosis, nosocomial ED Mycobacterium tuberculosis transmission, and hospital isolation bed use for adults admitted for pneumonia or suspected tuberculosis. EMERGE ncy ID NET also was developed to be a mechanism for rapidly responding to new diseases or epidemics. Future plans include study of antimicrobial use, meningitis, and encephalitis, and consideration of other public health concerns such as injury and national and international network expansion. [Talan DA, Moran GJ, Mower WR, Newdow M, Ong S, Slutsker L, Jarvis WR, Conn LA, Pinner RW, for the EMERGE ncy ID Net Study Group: EMERGE ncy ID Net: An emergency department–based emerging infections sentinel network. Ann Emerg Med December 1998;32:703-711]

Neurocysticercosis in persons with epilepsy in Medellín, Colombia. The Neuroepidemiological Research Group of Antioquia.

A prospective series of 643 persons with epilepsy attending a reference neurologic center in Medellín, Colombia, was examined by computed tomography (CT scan) or serology or both with the enzyme-linked immunoelectrotransfer blot assay (EITB) to assess the prevalence of Taenia solium cysticercosis. All presenting patients were consecutively enrolled in the study. Five hundred forty-six persons underwent cerebral CT scans; 376 of them also had serum EITB performed. Prevalence of neurocysticercosis by CT scan was 13.92%. Overall prevalence of T. solium antibodies with EITB was 9.82%, but for those with late-onset epilepsy (onset after age 30 years), prevalence increased to 17.5% and 19% for those who originated from outside urban Medellín. Seroprevalence in individuals with mixed lesions (cysts and calcifications) was 88.2% and 64.10% in those with live cysts. Conversely, only 2.72% of persons with CT findings not related to neurocysticercosis had positive EITB tests. Our study shows that an important proportion of individuals with epilepsy have radiologic or serologic evidence of T. solium infection, suggesting that neurocysticercosis is an important etiology for epilepsy in Colombia.

1-17-14 Prevalence of neurocysticercosis in individuals affected with epilepsy in Antioquia, Colombia

1-17-14 Prevalence of neurocysticercosis in individuals affected with epilepsy in Antioquia, Colombia

2-47-06 Brain CT for determination of neurocysticercosis prevalence a field study in rural Mexico

2-47-06 Brain CT for determination of neurocysticercosis prevalence a field study in rural Mexico

Human Subcutaneous Taenia solium Cysticercosis in an Andean Population with Neurocysticercosis *

Subcutaneous involvement by the larval stages of the pork tapeworm Taenia solium in patients suffering from neurocysticercosis (neurocysticercosis) is well-described. It has been a clinical but undocumented impression that subcutaneous nodules are less common in cases of neurocysticercosis in Latin American than in Africa or Asia. We report on the absence of subcutaneous nodules found in a screened population of 2,891 residents of an Andean village in Ecuador with a prevalence rate for neurocysticercosis of 144 per thousand. Thirty-four patients with multiple intracranial calcifications and or cystic or encephalitic parenchymal lesions of neurocysticercosis were examined and questioned about subcutaneous nodules. Only one patient described nodules and this computed tomography plain films are presented. Several hypotheses are presented as to why nodules may be less common in this Andean community with a high prevalence of neurocysticercosis.

Neurocysticercosis an epidemiological survey in two small rural communities

The authors describe the epidemiological findings related to human taeniasis and cysticercosis, and swine cysticercosis in two small rural communities, Postinho (P) and Tigre (T), of South Brazil. The prevalence of epilepsy was 2.04% (P) and 2.25% (T). The prevalence of neurocysticercosis was 0.47% (P) and 0.93% (T), and prevalence of swine cysticercosis was 12.8% (P) and 27.8% (T). Taenia sp. infestation was detected in 4.3% (P) and 4.6% (T) of stool examinations. The hyperendemic human taeniasis and cysticercosis and swine cysticercosis seems to be related to poor hygienic habits of the population, and the free access to human excreta by the pigs.