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Blair D. Paragonimiasis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024; 1454:203-238. [PMID: 39008267 DOI: 10.1007/978-3-031-60121-7_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
Paragonimiasis is a zoonotic disease caused by lung flukes of the genus Paragonimus. Humans usually become infected by eating freshwater crabs or crayfish containing encysted metacercariae of these worms. However, an alternative route of infection exists: ingestion of raw meat from a mammalian paratenic host. Adult worms normally occur in pairs in cysts in the lungs from which they void their eggs via air passages. The pulmonary form is typical in cases of human infection due to P. westermani, P. heterotremus, and a few other species. Worms may occupy other sites in the body, notably the brain, but lung flukes have made their presence felt in almost every organ. Ectopic paragonimiasis is particularly common when infection is due to members of the P. skrjabini complex. Human paragonimiasis occurs primarily in the tropics and subtropics of Asia, Africa, and the Americas, with different species being responsible in different areas (Table 6.1).
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Affiliation(s)
- David Blair
- James Cook University, Townsville, QLD, Australia
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2
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Vasconcelos Miranda TA, Tsuchiya K, Lucato LT. Imaging of Central Nervous System Parasitic Infections. Neuroimaging Clin N Am 2023; 33:125-146. [DOI: 10.1016/j.nic.2022.07.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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3
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Abstract
Purpose of the review Neurocysticercosis (NCC) has been well recognized as a leading cause of epilepsy. More recently, studies of other parasitic diseases such as cerebral malaria (CM) and onchocerciasis are yielding novel insights into the pathogenesis of parasite-associated epilepsy. We compare the clinical and electrophysiological findings in epilepsy associated with these highly prevalent parasites and discuss the mechanisms involved in epileptogenesis. Recent Findings Electrophysiological and imaging biomarkers continue to emerge, and individuals who are at-risk of developing parasite-associated epilepsies are being identified with greater reliability. While both Taenia solium and Plasmodium falciparum directly affect the brain parenchyma, Onchocerca volvulus is not known to invade the central nervous system. Thus, the causal association between O. volvulus and epilepsy remains controversial. Summary Both NCC and CM have a well-defined acute phase when the parasites directly or indirectly invade the brain parenchyma and lead to local inflammatory changes. This is followed by a chronic phase marked by recurrent seizures. However, these stages of epileptogenic process have not been identified in the case of O. volvulus.
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Affiliation(s)
- Rajarshi Mazumder
- Department of Neurology, David Geffen School of Medicine, University of California, 710 Westwood Plaza, C109, Los Angeles, CA, 90095, USA.
| | - John K Lee
- Department of Neurology, David Geffen School of Medicine, University of California, 710 Westwood Plaza, C109, Los Angeles, CA, 90095, USA
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Alizadeh Khatir A, Sepidarkish M, Rajabalizadeh MR, Alizadeh Moghaddam S, Aghapour S, Mehravar S, Hotez PJ, Gasser RB, Rostami A. Case-Control Study to Assess the Association between Epilepsy and Toxocara Infection/Exposure. Microorganisms 2021; 9:microorganisms9102091. [PMID: 34683412 PMCID: PMC8537584 DOI: 10.3390/microorganisms9102091] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/29/2021] [Accepted: 10/01/2021] [Indexed: 11/16/2022] Open
Abstract
Although causes and etiology of epilepsy are mostly obscure, some zoonotic parasites, such as Toxocara species, have been proposed as a risk factor for this disease. Here, we conducted an age-matched case-control study to evaluate whether there is an association between epilepsy and the presence of serum antibodies to Toxocara in incident cases. We included 94 idiopathic epileptic patients as cases, and—from the same geographical region—88 people with no own history of epilepsy or neurological disease as control subjects. Epilepsy was confirmed by a physician using the International League Against Epilepsy (ILAE) definition. All participants were screened for the anti-Toxocara IgG serum antibody by enzyme-linked immunosorbent assay (ELISA). Univariate and mutltivariate statistical analyses were applied to calculate the crude and adjusted odds ratios (OR) and 95% confidence intervals (CIs). Anti-Toxocara serum antibody was detected in 37 epileptic patients and in 23 control subjects, giving respective seroprevalences of 39.3% (95% CI, 29.4–49.9%) and 26.1% (95% CI, 17.3–36.5%), respectively. Adjusted multivariate logistic regression analysis estimated an OR of 2.38 (95% CI, 1.25–4.63), indicating a significant association between epilepsy and Toxocara seropositivity. There was also a significant association between seropositivity to Toxocara and partial (OR, 2.60; 95% CI, 1.14–6.04) or generalized (OR, 2.17; 95% CI, 1.09–4.40%) seizures. Findings from the present study of incident epileptic cases support previous studies proposing that Toxocara infection/exposure is a risk factor for epilepsy. However, further well-designed population-based surveys and mechanistic/experimental studies in animal models are required to better understand the reason(s) for this association.
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Affiliation(s)
- Ali Alizadeh Khatir
- Mobility Impairment Research Center, Health Research Institute, Babol University of Medical Sciences, Babol 4714871167, Iran;
| | - Mahdi Sepidarkish
- Department of Biostatistics and Epidemiology, School of Public Health, Babol University of Medical Sciences, Babol 4714871167, Iran;
| | - Mohammad Reza Rajabalizadeh
- Student Research Committee, Babol University of Medical Sciences, Babol 4714871167, Iran; (M.R.R.); (S.A.M.)
| | - Solmaz Alizadeh Moghaddam
- Student Research Committee, Babol University of Medical Sciences, Babol 4714871167, Iran; (M.R.R.); (S.A.M.)
| | - Saeed Aghapour
- Department of Neurosurgery, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari 1353447416, Iran;
| | - Saeed Mehravar
- Department of Epidemiology and Statistics, School of Public Health, Tehran University of Medical Science, Tehran 1666663111, Iran;
| | - Peter J. Hotez
- Texas Children’s Hospital Center for Vaccine Development, Department of Pediatrics and Molecular Virology and Microbiology, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX 77030, USA;
| | - Robin B. Gasser
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, VIC 3010, Australia
- Correspondence: (R.B.G.); (A.R.); Tel.: +98-11-32190557 (A.R.)
| | - Ali Rostami
- Infectious Diseases and Tropical Medicine Research Center, Health Research Institute, Babol University of Medical Sciences, Babol 4714871167, Iran
- Correspondence: (R.B.G.); (A.R.); Tel.: +98-11-32190557 (A.R.)
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Carpio A, Romo ML, Hauser WA, Kelvin EA. New understanding about the relationship among neurocysticercosis, seizures, and epilepsy. Seizure 2021; 90:123-129. [DOI: 10.1016/j.seizure.2021.02.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 01/26/2021] [Accepted: 02/12/2021] [Indexed: 02/08/2023] Open
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Bhatia R, Dev T, Kandasamy D, Arava S, Sethuraman G. Antiparasitic agents in disseminated cysticercosis: a double-edged sword. Int J Dermatol 2021; 60:e512-e514. [PMID: 33934352 DOI: 10.1111/ijd.15626] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 03/06/2021] [Accepted: 04/06/2021] [Indexed: 11/28/2022]
Affiliation(s)
- Riti Bhatia
- Department of Dermatology and Venereology, All India Institute of Medical Sciences, New Delhi, India
| | - Tanvi Dev
- Department of Dermatology and Venereology, All India Institute of Medical Sciences, New Delhi, India
| | | | - Sudhir Arava
- Department of Pathology, All India Institute of Medical Sciences, New Delhi, India
| | - Gomathy Sethuraman
- Department of Dermatology and Venereology, All India Institute of Medical Sciences, New Delhi, India
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Douglas B, Oyesola O, Cooper MM, Posey A, Tait Wojno E, Giacomin PR, Herbert DR. Immune System Investigation Using Parasitic Helminths. Annu Rev Immunol 2021; 39:639-665. [PMID: 33646858 DOI: 10.1146/annurev-immunol-093019-122827] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Coevolutionary adaptation between humans and helminths has developed a finely tuned balance between host immunity and chronic parasitism due to immunoregulation. Given that these reciprocal forces drive selection, experimental models of helminth infection are ideally suited for discovering how host protective immune responses adapt to the unique tissue niches inhabited by these large metazoan parasites. This review highlights the key discoveries in the immunology of helminth infection made over the last decade, from innate lymphoid cells to the emerging importance of neuroimmune connections. A particular emphasis is placed on the emerging areas within helminth immunology where the most growth is possible, including the advent of genetic manipulation of parasites to study immunology and the use of engineered T cells for therapeutic options. Lastly,we cover the status of human challenge trials with helminths as treatment for autoimmune disease, which taken together, stand to keep the study of parasitic worms at the forefront of immunology for years to come.
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Affiliation(s)
- Bonnie Douglas
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA; ,
| | - Oyebola Oyesola
- Department of Immunology, University of Washington, Seattle, Washington 98109, USA; ,
| | - Martha M Cooper
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland 4878, Australia; ,
| | - Avery Posey
- Parker Institute for Cancer Immunotherapy, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA; .,Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.,Corporal Michael J. Crescenz VA Medical Center, Philadelphia, Pennsylvania 19104, USA
| | - Elia Tait Wojno
- Department of Immunology, University of Washington, Seattle, Washington 98109, USA; ,
| | - Paul R Giacomin
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland 4878, Australia; ,
| | - De'Broski R Herbert
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA; ,
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Toxoplasma gondii: AnUnderestimated Threat? Trends Parasitol 2020; 36:959-969. [PMID: 33012669 DOI: 10.1016/j.pt.2020.08.005] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 08/17/2020] [Accepted: 08/21/2020] [Indexed: 02/08/2023]
Abstract
Traditionally, the protozoan parasite Toxoplasma gondii has been thought of as relevant to public health primarily within the context of congenital toxoplasmosis or postnatally acquired disease in immunocompromised patients. However, latent T.gondii infection has been increasingly associated with a wide variety of neuropsychiatric disorders and, more recently, causal frameworks for these epidemiological associations have been proposed. We present assimilated evidence on the associations between T.gondii and various human neuropsychiatric disorders and outline how these may be explained within a unifying causal framework. We argue that the occult effects of latent T.gondii infection likely outweigh the recognised overt morbidity caused by toxoplasmosis, substantially raising the public health importance of this parasite.
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Nicoletti A, Gomez-Puerta LA, Arroyo G, Bustos J, Gonzalez AE, Garcia HH, For The Cysticercosis Working Group In Peru. Toxocara Brain Infection in Pigs is Not Associated with Visible Lesions on Brain Magnetic Resonance Imaging. Am J Trop Med Hyg 2020; 103:273-275. [PMID: 32431279 DOI: 10.4269/ajtmh.19-0912] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Human exposure to Toxocara spp. is very frequent, and its larvae can cross the blood-brain barrier and invade the central nervous system (CNS), causing neurotoxocariasis. We aimed to establish a neurotoxocariasis animal model in pigs confirmed by necropsy. Also, the presence of larvae in the CNS was assessed using magnetic resonance imagings (MRIs), to establish brain lesions caused by the larvae migration. Ten pigs were infected intraperitoneally with 3,000 Toxocara larvae. Cerebral toxocariasis was evaluated using MRIs at days 7, 14, 21, and 49, and pigs were euthanized after the examination. Brain tissues were examined by microscopy, and five pigs presented Toxocara, most frequently at day 21 after infection. None of the 10 pigs showed alterations on MRIs. Our study confirms that intraperitoneal Toxocara infection produces neurotoxocariasis in pigs. Toxocara larvae passage through the brain does not seem to produce lesions detectable at MRIs.
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Affiliation(s)
| | - Luis A Gomez-Puerta
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru.,Center for Global Health, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Gianfranco Arroyo
- Center for Global Health, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Javier Bustos
- Cysticercosis Unit, Instituto Nacional de Ciencias Neurologicas, Lima, Peru.,Center for Global Health, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Armando E Gonzalez
- Center for Global Health, Universidad Peruana Cayetano Heredia, Lima, Peru.,School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Hector H Garcia
- Cysticercosis Unit, Instituto Nacional de Ciencias Neurologicas, Lima, Peru.,Center for Global Health, Universidad Peruana Cayetano Heredia, Lima, Peru
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Abstract
Human toxocariasis, caused by larvae of the Toxocara spp., is one of the most prevalent zoonosis with a worldwide distribution. Toxocara larvae can cross the blood-brain barrier, invading the central nervous system (CNS), leading to neurotoxocariasis. The clinical presentation consists of a wide spectrum of neurological manifestations such as meningitis, encephalitis, myelitis and cerebral vasculitis, but asymptomatic CNS infection is common. Despite the high seroprevalence, neurotoxocariasis is thought to be rare, even if in many animal models larvae usually migrate to the brain. Indeed, diagnosis of neurotoxocariasis is rarely considered, and the exact prevalence of CNS involvement is still unknown. Diagnosis of neurotoxocariasis is generally based on the detection of specific antibodies to Toxocara excretory-secretory antigens by ELISA in CSF or serum, and clinical and radiological improvement after anthelmintic therapy, but definitive diagnosis is given by histological confirmation, which is rarely available. Treatment is based on anti-helminthic drugs, commonly albendazole, generally administered with concomitant corticosteroids coverage. At the population level, serological studies suggest an association between Toxocara infections and epilepsy, as well as with other neurodegenerative and psychiatric disorders. Nonetheless the possible role of Toxocara spp. in the pathogenesis of these disorders is still matter of debate.
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Affiliation(s)
- Alessandra Nicoletti
- Department G.F. Ingrassia, Section of Neurosciences, University of Catania, Catania, Italy.
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Bayesian Methods for Exposure Misclassification Adjustment in a Mediation Analysis: Hemoglobin and Malnutrition in the Association Between Ascaris and IQ. Epidemiology 2019; 30:659-668. [PMID: 31205289 DOI: 10.1097/ede.0000000000001051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND Soil-transmitted helminth infections have been found to be associated with child development. The objective was to investigate hemoglobin levels and malnutrition as mediators of the association between Ascaris infection and intelligence quotient (IQ) scores in children. METHODS We conducted a longitudinal cohort study in Iquitos, Peru, between September 2011 and July 2016. A total of 1760 children were recruited at 1 year of age and followed up annually to 5 years. We measured Ascaris infection and malnutrition at each study visit, and hemoglobin levels were measured as of age 3. The exposure was defined as the number of detected Ascaris infections between age 1 and 5. We measured IQ scores at age 5 and used Bayesian models to correct exposure misclassification. RESULTS We included a sample of 781 children in the analysis. In results adjusted for Ascaris misclassification, mean hemoglobin levels mediated the association between Ascaris infection and IQ scores. The natural direct effects (not mediated by hemoglobin) (95% CrI) and natural indirect effects (mediated by hemoglobin) (95% CrI) were compared with no or one infection: -0.9 (-4.6, 2.8) and -4.3 (-6.9, -1.6) for the effect of two infections; -1.4 (-3.8, 1.0) and -1.2 (-2.0, -0.4) for three infections; and -0.4 (-3.2, 2.4) and -2.7 (-4.3, -1.0) for four or five infections. CONCLUSION Our results are consistent with the hypothesis that hemoglobin levels mediate the association between Ascaris infection and IQ scores. Additional research investigating the effect of including iron supplements in STH control programs is warranted.
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Abstract
Paragonimiasis is a zoonotic disease caused by lung flukes of the genus Paragonimus. Humans usually become infected by eating freshwater crabs or crayfish containing encysted metacercariae of these worms. However, an alternative route of infection exists: ingestion of raw meat from a mammalian paratenic host. Adult worms normally occur in pairs in cysts in the lungs from which they void their eggs via air passages. The pulmonary form is typical in cases of human infection due to P. westermani, P. heterotremus, and a few other species (Table 5.1). Worms may occupy other sites in the body, notably the brain, but lung flukes have made their presence felt in almost every organ. Ectopic paragonimiasis is particularly common when infection is due to members of the P. skrjabini complex (Table 5.1). Human paragonimiasis occurs primarily in the tropics and subtropics of Asia, Africa, and the Americas, with different species being responsible in different areas (Table 5.1).
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Affiliation(s)
- David Blair
- College of Science and Engineering, James Cook University, Townsville, QLD, Australia.
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Updated evidence of the association between toxocariasis and epilepsy: Systematic review and meta-analysis. PLoS Negl Trop Dis 2018; 12:e0006665. [PMID: 30028858 PMCID: PMC6070292 DOI: 10.1371/journal.pntd.0006665] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 08/01/2018] [Accepted: 07/05/2018] [Indexed: 01/07/2023] Open
Abstract
Objective To gain further insight on the association between human toxocariasis and epilepsy in light of the new evidence in the last years. Methods A systematic review was conducted without date and language restriction in the following electronic databases: MEDLINE (PubMed), Ingenta Connect, Science Direct (Elsevier), RefDoc, Scopus, HighWire, Scielo and the database of the Institute of Neuroepidemiology and Tropical Neurology of the Limoges University (IENT). Two investigators independently conducted the search up to November 2017. A pooled odds ratio (OR) was estimated using a random effects model. Meta-regression was conducted to investigate potential sources of heterogeneity. Results Database search produced 204 publications. Eleven case-control studies were included that were carried out in 13 countries worldwide. A total number of 4740 subjects were considered (2159 people with epilepsy and 2581 people without epilepsy). The overall pooled OR was 1.69 (95% CI 1.42–2.01) for the association between epilepsy and Toxocara spp. seropositivity. A positive association was constantly reported in the restricted analysis (WB as confirmatory or diagnostic test, younger population, and population–based studies). Meta-regression showed no statistically significant association between covariates and outcome. Conclusion The updated meta-analysis provides epidemiological evidence of a positive association between Toxocara seropositivity and epilepsy. New surveys supported the association, mainly population-based studies. On this basis, health strategies to reduce the impact of Toxocara spp are strongly advised. Further research should be performed to understand the physiopathological mechanisms of toxocara-associated epileptogenesis. Human toxocariasis is a parasitic zoonosis caused by the larval stages of Toxocara canis (T. canis), the common roundworm of dogs, and by the roundworm of cats, Toxocara cati (T. cati). Toxocariasis is one of the most prevalent helminthiasis worldwide. Humans become infected by the ingestion of contaminated food or soil or by direct contact with dogs and cats. Epilepsy is the most common chronic neurological disorder worldwide with a global estimate of about 70 million cases of lifetime epilepsy. Early studies suggested high rate of toxocara exposure (toxocara seropositivity) among people with epilepsy. Despite several studies support the possible role of toxocariasis in the incidence of epilepsy, this association is still debated. We updated our previous research to gain further insight on the association. This study provides new evidence of a positive association between the two diseases. On this basis, health strategies to reduce the impact of Toxocara spp are strongly advised. Further studies are necessary to clarify the role of certain parasites in epilepsy.
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Reddy DS, Volkmer R. Neurocysticercosis as an infectious acquired epilepsy worldwide. Seizure 2017; 52:176-181. [DOI: 10.1016/j.seizure.2017.10.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 10/05/2017] [Accepted: 10/07/2017] [Indexed: 10/18/2022] Open
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Differing Methods and Definitions Influence DALY estimates: Using Population-Based Data to Calculate the Burden of Convulsive Epilepsy in Rural South Africa. PLoS One 2015; 10:e0145300. [PMID: 26697856 PMCID: PMC4689490 DOI: 10.1371/journal.pone.0145300] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 12/02/2015] [Indexed: 11/20/2022] Open
Abstract
Background The disability adjusted life year (DALY) is a composite measure of disease burden that includes both morbidity and mortality, and is relevant to conditions such as epilepsy that can limit productive functioning. The 2010 Global Burden of Disease (GBD) study introduced a number of new methods and definitions, including a prevalence-based approach and revised disability weights to calculate morbidity and new standard life expectancies to calculate premature mortality. We used these approaches, and local, population-based data, to estimate the burden of convulsive epilepsy in rural South Africa. Methods & Findings Comprehensive prevalence, incidence and mortality data on convulsive epilepsy were collected within the Agincourt sub-district in rural northeastern South Africa between 2008 and 2012. We estimated DALYs using both prevalence- and incidence-based approaches for calculating years of life lived with disability. Additionally, we explored how changing the disease model by varying the disability weights influenced DALY estimates. Using the prevalence-based approach, convulsive epilepsy in Agincourt resulted in 332 DALYs (95% uncertainty interval (UI): 216–455) and 4.1 DALYs per 1,000 individuals (95%UI: 2.7–5.7) annually. Of this, 26% was due to morbidity while 74% was due to premature mortality. DALYs increased by 10% when using the incidence-based method. Varying the disability weight from 0.072 (treated epilepsy, seizure free) to 0.657 (severe epilepsy) caused years lived with disability to increase from 18 (95%UI: 16–19) to 161 (95%UI: 143–170). Conclusions DALY estimates are influenced by both the methods applied and population parameters used in the calculation. Irrespective of method, a significant burden of epilepsy is due to premature mortality in rural South Africa, with a lower burden than rural Kenya. Researchers and national policymakers should carefully interrogate the methods and data used to calculate DALYs as this will influence policy priorities and resource allocation.
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Cassim S, Qulu L, Mabandla MV. Prenatal stress and early life febrile convulsions compromise hippocampal genes MeCP2/REST function in mid-adolescent life of Sprague-Dawley rats. Neurobiol Learn Mem 2015; 125:195-201. [DOI: 10.1016/j.nlm.2015.09.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 08/06/2015] [Accepted: 09/01/2015] [Indexed: 02/08/2023]
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Incidence, Remission and Mortality of Convulsive Epilepsy in Rural Northeast South Africa. PLoS One 2015; 10:e0129097. [PMID: 26053071 PMCID: PMC4459982 DOI: 10.1371/journal.pone.0129097] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 05/06/2015] [Indexed: 11/25/2022] Open
Abstract
Background Epilepsy is one of the most common neurological conditions globally, estimated to constitute 0.75% of the global burden of disease, with the majority of this burden found in low- and middle- income countries (LMICs). Few studies from LMICs, including much of sub-Saharan Africa, have described the incidence, remission or mortality rates due to epilepsy, which are needed to quantify the burden and inform policy. This study investigates the epidemiological parameters of convulsive epilepsy within a context of high HIV prevalence and an emerging burden of cardiovascular disease. Methods A cross-sectional population survey of 82,818 individuals, in the Agincourt Health and Socio-demographic Surveillance Site (HDSS) in rural northeast South Africa was conducted in 2008, from which 296 people were identified with active convulsive epilepsy. A follow-up survey was conducted in 2012. Incidence and mortality rates were estimated, with duration and remission rates calculated using the DISMOD II software package. Results The crude incidence for convulsive epilepsy was 17.4/100,000 per year (95%CI: 13.1-23.0). Remission was 4.6% and 3.9% per year for males and females, respectively. The standardized mortality ratio was 2.6 (95%CI: 1.7-3.5), with 33.3% of deaths directly related to epilepsy. Mortality was higher in men than women (adjusted rate ratio (aRR) 2.6 (95%CI: 1.2-5.4)), and was significantly associated with older ages (50+ years versus those 0-5 years old (RR 4.8 (95%CI: 0.6-36.4)). Conclusions The crude incidence was lower whilst mortality rates were similar to other African studies; however, this study found higher mortality amongst older males. Efforts aimed at further understanding what causes epilepsy in older people and developing interventions to reduce prolonged seizures are likely to reduce the overall burden of ACE in rural South Africa.
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ALLAHDIN S, KHADEMVATAN S, RAFIEI A, MOMEN A, RAFIEI R. Frequency of Toxoplasma and Toxocara Sp. Antibodies in Epileptic Patients, in South Western Iran. IRANIAN JOURNAL OF CHILD NEUROLOGY 2015; 9:32-40. [PMID: 26664439 PMCID: PMC4670975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Epilepsy is a disorder of the brain characterized by an enduring predisposition to generate seizures. Infectious agents are mentioned in its etiology. With identifying and appropriate treatment of these infectious agents, preventing their secondary outcomes, including seizure is possible. This study was conducted to determine frequency of anti-Toxoplasma antibodies (IgG, IgM) and anti-Toxocara antibody (IgG) in epileptic patients. MATERIALS & METHODS Study sample consisted of 141 epileptic patients and 144 healthy people. After obtaining informed consents and completing demographic questionnaire, serum samples were taken from participants. The diagnostic test of Toxoplasma IgG & IgM and Toxocara antibodies was performed under the same conditions using ELISA method in a qualified private laboratory. Samples from patients and control groups with positive ELISA test in terms of anti-Toxocara antibody were also used for confirmatory Western blot test. RESULT According to ELISA results, 28 (19.85%) epileptic patients and 2(1.38%) of healthy people had anti-Toxocara antibodies (P<001), while 39 (30.46%) of the control group people and 14.18% of patients had anti-Toxoplsma antibodies (P=0.001). CONCLUSION Frequency of anti-Toxoplasma gondii is lower in epileptic than healthy individuals and this result is contrary to investigations that have reported higher levels of this antibody in such patient groups. ELISA results for Toxocara showed that the frequency of anti-Toxocara antibody in epileptic patients might empower the probability that this parasite may cause central nervous system damage. Western blotting has high specificity and is a proper confirmative method for diagnosis of toxocariasis.
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Affiliation(s)
- Sudabeh ALLAHDIN
- Cellular and Molecular Research Center & Dept. Parasitology, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Shahram KHADEMVATAN
- Department of Medical Parasitology and Mycology & Cellular and Molecular Research Center, Urmia University of Medical Sciences, Urmia, Iran ,Cellular and Molecular Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Abdollah RAFIEI
- Dept. of Medical Parasitology &Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Aliakbar MOMEN
- Dept. of Pediatrics, Neurology Ward, Golestan Teaching Hospital, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Reza RAFIEI
- Dept. of Medical Parasitology &Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
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Kamuyu G, Bottomley C, Mageto J, Lowe B, Wilkins PP, Noh JC, Nutman TB, Ngugi AK, Odhiambo R, Wagner RG, Kakooza-Mwesige A, Owusu-Agyei S, Ae-Ngibise K, Masanja H, Osier FHA, Odermatt P, Newton CR. Exposure to multiple parasites is associated with the prevalence of active convulsive epilepsy in sub-Saharan Africa. PLoS Negl Trop Dis 2014; 8:e2908. [PMID: 24875312 PMCID: PMC4038481 DOI: 10.1371/journal.pntd.0002908] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 04/16/2014] [Indexed: 11/21/2022] Open
Abstract
Background Epilepsy is common in developing countries, and it is often associated with parasitic infections. We investigated the relationship between exposure to parasitic infections, particularly multiple infections and active convulsive epilepsy (ACE), in five sites across sub-Saharan Africa. Methods and Findings A case-control design that matched on age and location was used. Blood samples were collected from 986 prevalent cases and 1,313 age-matched community controls and tested for presence of antibodies to Onchocerca volvulus, Toxocara canis, Toxoplasma gondii, Plasmodium falciparum, Taenia solium and HIV. Exposure (seropositivity) to Onchocerca volvulus (OR = 1.98; 95%CI: 1.52–2.58, p<0.001), Toxocara canis (OR = 1.52; 95%CI: 1.23–1.87, p<0.001), Toxoplasma gondii (OR = 1.28; 95%CI: 1.04–1.56, p = 0.018) and higher antibody levels (top tertile) to Toxocara canis (OR = 1.70; 95%CI: 1.30–2.24, p<0.001) were associated with an increased prevalence of ACE. Exposure to multiple infections was common (73.8% of cases and 65.5% of controls had been exposed to two or more infections), and for T. gondii and O. volvulus co-infection, their combined effect on the prevalence of ACE, as determined by the relative excess risk due to interaction (RERI), was more than additive (T. gondii and O. volvulus, RERI = 1.19). The prevalence of T. solium antibodies was low (2.8% of cases and 2.2% of controls) and was not associated with ACE in the study areas. Conclusion This study investigates how the degree of exposure to parasites and multiple parasitic infections are associated with ACE and may explain conflicting results obtained when only seropositivity is considered. The findings from this study should be further validated. The prevalence of epilepsy is greater in developing countries compared to developed countries, and parasitic infestations are thought to contribute to this increased burden. We conducted a case-control study across five sites in sub-Saharan Africa to investigate the relationship between epilepsy and exposure to parasitic infections, and the association between epilepsy and multiple co-incidental infections. Exposure to Onchocerca volvulus, Toxocara canis and Toxoplasma gondii as well as high antibody levels (top tertile) to Toxocara canis was positively associated with the prevalence of active convulsive epilepsy (ACE). Multiple co-incidental parasitic infections were common, and the combined effect of T. gondii and O. volvulus co-infection on ACE was greater than the sum of the individual effects. The contribution of each of these parasitic infections on the burden of epilepsy in sub-Saharan Africa should be explored.
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Affiliation(s)
- Gathoni Kamuyu
- KEMRI/Wellcome Trust Research Programme, The Centre of Geographical Medicine Research – Coast, Kilifi, Kenya
- Studies of the Epidemiology of Epilepsy in Demographic Surveillance Systems (SEEDS)-INDEPTH Network, Accra, Ghana
- * E-mail:
| | - Christian Bottomley
- Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
- MRC Tropical Epidemiology Group, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - James Mageto
- KEMRI/Wellcome Trust Research Programme, The Centre of Geographical Medicine Research – Coast, Kilifi, Kenya
- Egerton University, Nakuru, Kenya
| | - Brett Lowe
- KEMRI/Wellcome Trust Research Programme, The Centre of Geographical Medicine Research – Coast, Kilifi, Kenya
- Studies of the Epidemiology of Epilepsy in Demographic Surveillance Systems (SEEDS)-INDEPTH Network, Accra, Ghana
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Patricia P. Wilkins
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention (CDC), Atlanta, Georgia, United States of America
| | - John C. Noh
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention (CDC), Atlanta, Georgia, United States of America
| | - Thomas B. Nutman
- Laboratory of Parasitic Diseases. National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Anthony K. Ngugi
- KEMRI/Wellcome Trust Research Programme, The Centre of Geographical Medicine Research – Coast, Kilifi, Kenya
- Studies of the Epidemiology of Epilepsy in Demographic Surveillance Systems (SEEDS)-INDEPTH Network, Accra, Ghana
- Research Support Unit, Faculty of Health Sciences, Aga Khan University (East Africa), Nairobi, Kenya
| | - Rachael Odhiambo
- KEMRI/Wellcome Trust Research Programme, The Centre of Geographical Medicine Research – Coast, Kilifi, Kenya
| | - Ryan G. Wagner
- MRC/Wits Rural Public Health & Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Epidemiology and Public Health, Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden
| | - Angelina Kakooza-Mwesige
- Studies of the Epidemiology of Epilepsy in Demographic Surveillance Systems (SEEDS)-INDEPTH Network, Accra, Ghana
- Iganga-Mayuge Health and Demographic Surveillance System, Iganga, Uganda
- Department of Paediatrics and Child Health, Makerere University College of Health Sciences, Kampala, Uganda
| | | | | | | | - Faith H. A. Osier
- KEMRI/Wellcome Trust Research Programme, The Centre of Geographical Medicine Research – Coast, Kilifi, Kenya
| | - Peter Odermatt
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- Unversity of Basel, Basel, Switzerland
| | - Charles R. Newton
- KEMRI/Wellcome Trust Research Programme, The Centre of Geographical Medicine Research – Coast, Kilifi, Kenya
- Studies of the Epidemiology of Epilepsy in Demographic Surveillance Systems (SEEDS)-INDEPTH Network, Accra, Ghana
- Neurosciences Unit, UCL Institute of Child Health, London, United Kingdom
- Clinical Research Unit, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Department of Psychiatry, University of Oxford, Oxford, United Kingdom
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Abstract
Published reviews vary on the question of whether geohelminth infections affect cognitive development: some claim that the scarcity of evidence means that it is unlikely that they do; others present modest evidence for an effect; and others raise the possibility that the damage is considerable but largely unresearched. This chapter reviews the characteristics of the geohelminths themselves and the pathways by which they could affect the development of children in endemic areas. It describes the progress made in the last decade in conceptualizing children's brains as complex adaptive systems, with the suggestion that infections at different stages in brain development might have different neurobehavioral consequences. An examination of research reports and review articles highlights the difficulties inherent in assessing the effects of geohelminth infections: other serious obstacles to healthy development in the same population may mask the effects of the geohelminths, and consequently the intensity and pathogenicity of the infection is probably an important issue. Selecting cognitive measures suitable for assessing development in very young children is no simple matter, and careful statistical analysis is required to tease out the primary and secondary factors at work. The insights gained from a broad range of relevant research reports have placed us in a better position to conduct more telling research into the effects of these widespread, but neglected, tropical diseases.
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Abstract
Parasites infect the central nervous system of children, particularly in resource-poor areas and tropical countries. However, these infections are increasingly seen in the West with the increase in children travelling to these areas and immigrant populations. These conditions are important in the differential diagnosis of common neurological syndromes. Falciparum malaria is a common cause of seizures and coma in endemic areas. Neurocysticercosis is a common cause of acquired epilepsy in some areas. Schistosomiasis is an important cause of spinal cord disease. Toxocara is ubiquitous and may cause encephalitis and retinal changes, and may be associated with epilepsy. Other parasitic conditions tend to be localized to specific regions of the world. Parasitic diseases are often associated with eosinophilia, and some cause an eosinophilic meningoencephalitis, although there are many nonparasitic causes of this syndrome. Most parasitic conditions can be treated, but in some diseases it is unclear whether the treatment influences outcome.
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22
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Wagner RG, Ngugi AK, Twine R, Bottomley C, Kamuyu G, Gómez-Olivé FX, Connor MD, Collinson MA, Kahn K, Tollman S, Newton CR. Prevalence and risk factors for active convulsive epilepsy in rural northeast South Africa. Epilepsy Res 2014; 108:782-91. [PMID: 24582322 PMCID: PMC4000269 DOI: 10.1016/j.eplepsyres.2014.01.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2013] [Revised: 11/21/2013] [Accepted: 01/14/2014] [Indexed: 11/21/2022]
Abstract
Epilepsy is prevalent in rural South Africa, but less than other parts of Africa. Most epilepsy starts in childhood. Poor obstetric history and snoring were associated with active convulsive epilepsy. HIV and parasitic infection were not associated with active convulsive epilepsy.
Rationale Epilepsy is among the most common neurological disorders worldwide. However, there are few large, population-based studies of the prevalence and risk factors for epilepsy in southern Africa. Methods From August 2008 to February 2009, as part of a multi-site study, we undertook a three-stage, population-based study, embedded within the Agincourt health and socio-demographic surveillance system, to estimate the prevalence and identify risk factors of active convulsive epilepsy (ACE) in a rural South African population. Results The crude prevalence of ACE, after adjusting for non-response and the sensitivity of the screening method, was 7.0/1,000 individuals (95%CI 6.4–7.6) with significant geographic heterogeneity across the study area. Being male (OR = 2.3; 95%CI 1.6–3.2), family history of seizures (OR = 4.0; 95%CI 2.0–8.1), a sibling with seizures (OR = 7.0; 95%CI 1.6–31.7), problems after delivery (OR = 5.9; 95%CI 1.2–24.6), and history of snoring (OR = 6.5; 95%CI 4.5–9.5) were significantly associated with ACE. For children, their mother's exposure to some formal schooling was protective (OR = 0.30; 95%CI 0.11–0.84) after controlling for age and sex. Human immunodeficiency virus was not found to be associated with ACE. Conclusions ACE is less frequent in this part of rural South Africa than other parts of sub-Saharan Africa. Improving obstetric services could prevent epilepsy. The relationship between snoring and ACE requires further investigation, as does the relative contribution of genetic and environmental factors to examine the increased risk in those with a family history of epilepsy.
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Affiliation(s)
- Ryan G Wagner
- Studies of Epidemiology of Epilepsy in Demographic Surveillance Systems (SEEDS)-INDEPTH Network, Accra, Ghana; MRC/Wits Rural Public Health & Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Division of Epidemiology and Global Health, Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden.
| | - Anthony K Ngugi
- Studies of Epidemiology of Epilepsy in Demographic Surveillance Systems (SEEDS)-INDEPTH Network, Accra, Ghana; KEMRI/Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya; Research Support Unit, Faculty of Health Sciences, Aga Khan University- East Africa, Nairobi, Kenya
| | - Rhian Twine
- Studies of Epidemiology of Epilepsy in Demographic Surveillance Systems (SEEDS)-INDEPTH Network, Accra, Ghana
| | - Christian Bottomley
- Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom; MRC Tropical Epidemiology Group, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Gathoni Kamuyu
- KEMRI/Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya
| | - F Xavier Gómez-Olivé
- MRC/Wits Rural Public Health & Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Myles D Connor
- MRC/Wits Rural Public Health & Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Borders General Hospital, Melrose, United Kingdom
| | - Mark A Collinson
- MRC/Wits Rural Public Health & Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Division of Epidemiology and Global Health, Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden
| | - Kathleen Kahn
- Studies of Epidemiology of Epilepsy in Demographic Surveillance Systems (SEEDS)-INDEPTH Network, Accra, Ghana; MRC/Wits Rural Public Health & Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Division of Epidemiology and Global Health, Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden
| | - Stephen Tollman
- Studies of Epidemiology of Epilepsy in Demographic Surveillance Systems (SEEDS)-INDEPTH Network, Accra, Ghana; MRC/Wits Rural Public Health & Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Division of Epidemiology and Global Health, Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden
| | - Charles R Newton
- Studies of Epidemiology of Epilepsy in Demographic Surveillance Systems (SEEDS)-INDEPTH Network, Accra, Ghana; MRC/Wits Rural Public Health & Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; KEMRI/Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya; Neurosciences Unit, UCL Institute of Child Health, London, United Kingdom; Clinical Research Unit, London School of Hygiene and Tropical Medicine, London, United Kingdom; Department of Psychiatry, University of Oxford, Oxford, United Kingdom
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Abstract
Paragonimiasis is a zoonotic disease caused by lung flukes of the genus Paragonimus. Humans usually become infected by eating freshwater crabs or crayfish containing encysted metacercariae of these worms. However, an alternative route of infection exists: ingestion of raw meat from a mammalian paratenic host. Adult worms normally occur in pairs in cysts in the lungs from which they void their eggs via air passages. The pulmonary form is typical in cases of human infection due to P. westermani, P. heterotremus, and a few other species (Table 5.1). Worms may occupy other sites in the body, notably the brain, but lung flukes have made their presence felt in almost every organ. Ectopic paragonimiasis is particularly common when infection is due to members of the P. skrjabini complex (Table 5.1). Human paragonimiasis occurs primarily in the tropics and subtropics of Asia, Africa, and the Americas, with different species being responsible in different areas (Table 5.1).
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Affiliation(s)
- David Blair
- College of Science and Engineering, James Cook University, Townsville, QLD, Australia.
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Abstract
Rhizobiales (formerly named Rickettsiales) cause in rare instances meningitis and meningovasculitis, respectively. In case of history of exposure, infection by Rhizobiales needs to be considered since both diagnosis and therapy may be extremely difficult and pathogen-specific. The same applies to protozoa; in this chapter, Babesia species, free-living amoebae and Entamoeba histolytica infection, including severe meningitis and brain abscess, infection by Trypanosoma species (South American and African trypanosomiasis) are discussed with respect to history, epidemiology, clinical signs, and symptoms as well as differential diagnosis and therapy. Parasitic flatworms and roundworms, potentially able to invade the central nervous system, trematodes (flukes), cestodes (in particular, Cysticercus cellulosae), but also nematodes (in particular, Strongyloides spp. in the immunocompromised) are of worldwide importance. In contrast, filarial worms, Toxocara spp., Trichinella spp., Gnathostoma and Angiostrongylus spp. are seen only in certain geographically confined areas. Even more regionally confined are infestations of the central nervous system by metazoa, in particular, tongue worms (=arthropods) or larvae of flies (=maggots). The aim of this chapter is (1) to alert the neurologist to these infections, and (2) to enable the attending emergency neurologist to take a knowledgeable history, with an emphasis on epidemiology, clinical signs, and symptoms as well as therapeutic management possibilities.
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Affiliation(s)
- Erich Schmutzhard
- Department of Neurology, Medical University Hospital Innsbruck, Innsbruck, Austria.
| | - Raimund Helbok
- Department of Neurology, Medical University Hospital Innsbruck, Innsbruck, Austria
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25
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Ngugi AK, Bottomley C, Kleinschmidt I, Wagner RG, Kakooza-Mwesige A, Ae-Ngibise K, Owusu-Agyei S, Masanja H, Kamuyu G, Odhiambo R, Chengo E, Sander JW, Newton CR. Prevalence of active convulsive epilepsy in sub-Saharan Africa and associated risk factors: cross-sectional and case-control studies. Lancet Neurol 2013; 12:253-63. [PMID: 23375964 PMCID: PMC3581814 DOI: 10.1016/s1474-4422(13)70003-6] [Citation(s) in RCA: 218] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND The prevalence of epilepsy in sub-Saharan Africa seems to be higher than in other parts of the world, but estimates vary substantially for unknown reasons. We assessed the prevalence and risk factors of active convulsive epilepsy across five centres in this region. METHODS We did large population-based cross-sectional and case-control studies in five Health and Demographic Surveillance System centres: Kilifi, Kenya (Dec 3, 2007-July 31, 2008); Agincourt, South Africa (Aug 4, 2008-Feb 27, 2009); Iganga-Mayuge, Uganda (Feb 2, 2009-Oct 30, 2009); Ifakara, Tanzania (May 4, 2009-Dec 31, 2009); and Kintampo, Ghana (Aug 2, 2010-April 29, 2011). We used a three-stage screening process to identify people with active convulsive epilepsy. Prevalence was estimated as the ratio of confirmed cases to the population screened and was adjusted for sensitivity and attrition between stages. For each case, an age-matched control individual was randomly selected from the relevant centre's census database. Fieldworkers masked to the status of the person they were interviewing administered questionnaires to individuals with active convulsive epilepsy and control individuals to assess sociodemographic variables and historical risk factors (perinatal events, head injuries, and diet). Blood samples were taken from a randomly selected subgroup of 300 participants with epilepsy and 300 control individuals from each centre and were screened for antibodies to Toxocara canis, Toxoplasma gondii, Onchocerca volvulus, Plasmodium falciparum, Taenia solium, and HIV. We estimated odds ratios (ORs) with logistic regression, adjusted for age, sex, education, employment, and marital status. RESULTS 586,607 residents in the study areas were screened in stage one, of whom 1711 were diagnosed as having active convulsive epilepsy. Prevalence adjusted for attrition and sensitivity varied between sites: 7·8 per 1000 people (95% CI 7·5-8·2) in Kilifi, 7·0 (6·2-7·4) in Agincourt, 10·3 (9·5-11·1) in Iganga-Mayuge, 14·8 (13·8-15·4) in Ifakara, and 10·1 (9·5-10·7) in Kintampo. The 1711 individuals with the disorder and 2032 control individuals were given questionnaires. In children (aged <18 years), the greatest relative increases in prevalence were associated with difficulties feeding, crying, or breathing after birth (OR 10·23, 95% CI 5·85-17·88; p<0·0001); abnormal antenatal periods (2·15, 1·53-3·02; p<0·0001); and head injury (1·97, 1·28-3·03; p=0·002). In adults (aged ≥18 years), the disorder was significantly associated with admission to hospital with malaria or fever (2·28, 1·06-4·92; p=0·036), exposure to T canis (1·74, 1·27-2·40; p=0·0006), exposure to T gondii (1·39, 1·05-1·84; p=0·021), and exposure to O volvulus (2·23, 1·56-3·19; p<0·0001). Hypertension (2·13, 1·08-4·20; p=0·029) and exposure to T solium (7·03, 2·06-24·00; p=0·002) were risk factors for adult-onset disease. INTERPRETATION The prevalence of active convulsive epilepsy varies in sub-Saharan Africa and that the variation is probably a result of differences in risk factors. Programmes to control parasitic diseases and interventions to improve antenatal and perinatal care could substantially reduce the prevalence of epilepsy in this region.
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Affiliation(s)
- Anthony K Ngugi
- Studies of Epidemiology of Epilepsy in Demographic Surveillance Systems, International Network for the Demographic Evaluation of Populations and Their Health (INDEPTH), Accra, Ghana.
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Abstract
Central nervous system (CNS) infections are the main cause of seizures and acquired epilepsy in the developing world. Geographical variations determine the common causes in a particular region. Acute seizures are common in severe meningitis, viral encephalitis, malaria, and neurocysticercosis, and in most cases are associated with increased mortality and morbidity, including subsequent epilepsy. Neuronal excitability secondary to proinflammatory signals induced by CNS infections are an important common mechanism for the generation of seizures, in addition to various other specific mechanisms. Newer insights into the neurobiology of these infections and the associated epilepsy could help in developing neuroprotective interventions. Management issues include prompt treatment of acute seizures and the underlying CNS infection, correction of associated predisposing factors, and decisions regarding the appropriate choice and duration of antiepileptic therapy. Strategies for the prevention of epilepsy in CNS infections such as early anti-infective and anti-inflammatory therapy need scientific exploration. Prevention of CNS infections is the only definitive way forward to reduce the burden of epilepsy in developing countries.
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Affiliation(s)
- Pratibha Singhi
- Department of Paediatrics, Advanced Paediatrics Centre, Post Graduate Institute of Medical Sciences and Research, Chandigarh, India.
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28
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Ndimubanzi PC, Carabin H, Budke CM, Nguyen H, Qian YJ, Rainwater E, Dickey M, Reynolds S, Stoner JA. A systematic review of the frequency of neurocyticercosis with a focus on people with epilepsy. PLoS Negl Trop Dis 2010; 4:e870. [PMID: 21072231 PMCID: PMC2970544 DOI: 10.1371/journal.pntd.0000870] [Citation(s) in RCA: 284] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2010] [Accepted: 10/04/2010] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND The objective of this study is to conduct a systematic review of studies reporting the frequency of neurocysticercosis (NCC) worldwide. METHODS/PRINCIPAL FINDINGS PubMed, 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/SIGNIFICANCE Only 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.
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Affiliation(s)
- Patrick C. Ndimubanzi
- Department of Biostatistics and Epidemiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Hélène Carabin
- Department of Biostatistics and Epidemiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Christine M. Budke
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine, Texas A&M University, College Station, Texas, United States of America
| | - Hai Nguyen
- Department of Biostatistics and Epidemiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Ying-Jun Qian
- National Institute of Parasitic Diseases, Shangai, People's Republic of China
| | - Elizabeth Rainwater
- Department of Biostatistics and Epidemiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Mary Dickey
- Department of Biostatistics and Epidemiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Stephanie Reynolds
- Department of Biostatistics and Epidemiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Julie A. Stoner
- Department of Biostatistics and Epidemiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
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Brown M. Parasites as aetiological agents in chronic diseases. Epidemiological associations and potential mechanisms of pathogenesis. Parasite Immunol 2010; 31:653-5. [PMID: 19825104 DOI: 10.1111/j.1365-3024.2009.01153.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The aetiological role of parasitic infection has been well established, through epidemiological studies, for many chronic diseases prevalent in the tropics. Examples include Schistosoma mansoni infection leading to portal hypertension, Schistosoma haematobium infection leading to obstructive uropathy and squamous cell carcinoma of the bladder, Clonorchis sinensis leading to cholangiocarcinoma, and Taenia solium infection leading to epilepsy. Our understanding of the pathogenesis of these associations, however, continues to evolve, with new insights from many fertile avenues in chronic disease research. There are also tenuous associations such as schizophrenia with toxoplasmosis, and the findings from observational studies that link malignancy and epilepsy with a range of helminthic infections. Imprecise case definitions, and the lack of good animal models, are limitations to the evidence for a causal role of parasitic infection in these diseases.
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