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Clinical Microbiology Reviews Jun 2020neurocysticercosis (NCC) is endemic in most of the world and contributes significantly to the burden of epilepsy and other neurological morbidity. Also present in... (Review)
Review
neurocysticercosis (NCC) is endemic in most of the world and contributes significantly to the burden of epilepsy and other neurological morbidity. Also present in developed countries because of immigration and travel, NCC is one of few diseases targeted for eradication. This paper reviews all aspects of its life cycle (taeniasis, porcine cysticercosis, human cysticercosis), with a focus on recent advances in its diagnosis, management, and control. Diagnosis of taeniasis is limited by poor availability of immunological or molecular assays. Diagnosis of NCC rests on neuroimaging findings, supported by serological assays. The treatment of NCC should be approached in the context of the particular type of infection (intra- or extraparenchymal; number, location, and stage of lesions) and has evolved toward combined symptomatic and antiparasitic management, with particular attention to modulating inflammation. Research on NCC and particularly the use of recently available genome data and animal models of infection should help to elucidate mechanisms of brain inflammation, damage, and epileptogenesis.
Topics: Animals; Antiparasitic Agents; Cysticercosis; Humans; Neurocysticercosis; Swine; Swine Diseases; Taenia solium; Taeniasis
PubMed: 32461308
DOI: 10.1128/CMR.00085-19 -
The Lancet. Neurology Dec 2014The infection of the nervous system by the cystic larvae of Taenia solium (neurocysticercosis) is a frequent cause of seizure disorders. Neurocysticercosis is endemic or... (Review)
Review
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.
Topics: Animals; Humans; Magnetic Resonance Imaging; Neurocysticercosis; Seizures; Swine; Taenia solium; Tomography, X-Ray Computed; Treatment Outcome
PubMed: 25453460
DOI: 10.1016/S1474-4422(14)70094-8 -
The New England Journal of Medicine Jan 2017
Topics: Animals; Humans; Male; Middle Aged; Taenia solium; Taeniasis
PubMed: 28121503
DOI: 10.1056/NEJMicm1606747 -
Continuum (Minneapolis, Minn.) Dec 2012Neurocysticercosis occurs when humans become intermediate hosts in the life cycle of Taenia solium by ingesting its eggs directly from a taenia carrier or, less often,... (Review)
Review
PURPOSE OF REVIEW
Neurocysticercosis occurs when humans become intermediate hosts in the life cycle of Taenia solium by ingesting its eggs directly from a taenia carrier or, less often, by contaminated food. Within the nervous system, cysticerci may lodge in the brain parenchyma, subarachnoid space, ventricular system, or spinal cord, causing a number of pathologic changes that are responsible for the pleomorphism of neurocysticercosis. This article discusses the clinical manifestations, diagnosis, and treatment of neurocysticercosis.
RECENT FINDINGS
Formerly endemic in the developing world, mass immigration of people from disease-endemic to nonendemic areas has caused a recent increase in the prevalence of neurocysticercosis in developed countries, where this condition should no longer be considered exotic. Recent advances in neuroimaging and immune diagnostic methods, and the introduction of a set of diagnostic criteria, have enhanced the diagnostic accuracy for neurocysticercosis. Likewise, introduction of potent cysticidal drugs has radically changed its prognosis.
SUMMARY
Neurocysticercosis is the most common helminthic infection of the CNS and a major cause of acquired epilepsy worldwide. Diagnosis of neurocysticercosis is possible after interpretation of clinical data together with findings of neuroimaging studies and results of immunologic tests in a proper epidemiologic context. The use of cysticidal drugs reduces the burden of infection in the brain and improves the clinical course of most patients. Further efforts must be directed to eradicate the disease through the implementation of control programs against all interrelated steps in the life cycle of T. solium, including human carriers of the adult tapeworm, infected pigs, and eggs in the environment.
Topics: Animals; Anthelmintics; Antibody Formation; Cognition Disorders; Epilepsy; Female; Humans; Immunologic Tests; Intracranial Hypertension; Life Cycle Stages; Magnetic Resonance Imaging; Male; Middle Aged; Neurocysticercosis; Taenia solium; Tomography, X-Ray Computed; Young Adult
PubMed: 23221847
DOI: 10.1212/01.CON.0000423853.47770.90 -
The Yale Journal of Biology and Medicine Jun 2021In this perspectives paper, we discuss fertilization strategies for and as well as heterogeneity in , the causative agent of human cysticercosis. Two different... (Review)
Review
In this perspectives paper, we discuss fertilization strategies for and as well as heterogeneity in , the causative agent of human cysticercosis. Two different genotypes of (Asian and Afro/American) were confirmed by mitochondrial DNA analysis approximately two decades ago. Since then, outcrossings of the two genotypes have been identified in Madagascar where the two genotypes are distributed sympatrically. Outcrossings were confirmed by the presence of discordance between mitochondrial and nuclear DNA. Since multiple tapeworm infections are common in endemic areas, outcrossing events likely occur quite frequently. Therefore, mitochondrial DNA from specimens collected from humans and pigs in endemic areas should be analyzed. If variations are found between specimens, nuclear DNA analysis should be performed to confirm the presence of discordance between mitochondrial and nuclear genes. Additional outcrossings likely add complexity to understanding the existing genetic diversity. Serological surveys are also recommended since serodiagnostic glycoprotein can also differentiate between the two genotypes. Viable eggs from different genotypes or from hybrids of two different genotypes should be used for experimental infection of pigs or dogs in order to observe any pathological heterogeneity in cysticercosis development. Although genetic diversity of is expected to result in clinical heterogeneity of cysticercosis in humans and pigs, there is currently no evidence showing that this occurs. There are also no comparative experimental studies on this topic. Therefore, studies evaluating the link between parasite heterogeneity and clinical outcome are warranted.
Topics: Animals; Cysticercosis; DNA, Mitochondrial; Dogs; Genetic Variation; Swine; Taenia saginata; Taenia solium
PubMed: 34211353
DOI: No ID Found -
TheScientificWorldJournal 2012Neuroysticercosis is the most common helminthic infection of the nervous system, and a leading cause of acquired epilepsy worldwide. The disease occurs when humans... (Review)
Review
Neuroysticercosis is the most common helminthic infection of the nervous system, and a leading cause of acquired epilepsy worldwide. The disease occurs when humans become intermediate hosts of Taenia solium by ingesting its eggs from contaminated food or, most often, directly from a taenia carrier by the fecal-to-oral route. Cysticerci may be located in brain parenchyma, subarachnoid space, ventricular system, or spinal cord, causing pathological changes that are responsible for the pleomorphism of neurocysticercosis. Seizures are the most common clinical manifestation, but many patients present with focal deficits, intracranial hypertension, or cognitive decline. Accurate diagnosis of neurocysticercosis is possible after interpretation of clinical data together with findings of neuroimaging studies and results of immunological tests. The introduction of cysticidal drugs have changed the prognosis of most patients with neurocysticercosis. These drugs have shown to reduce the burden of infection in the brain and to improve the clinical course of the disease in most patients. Further efforts should be directed to eradicate the disease through the implementation of control programs against all the interrelated steps in the life cycle of T. solium, including human carriers of the adult tapeworm, infected pigs, and eggs in the environment.
Topics: Animals; Anthelmintics; Anticonvulsants; Brain; Cognition Disorders; Humans; Hydrocephalus; Intracranial Hypertension; Life Cycle Stages; Neurocysticercosis; Neuroimaging; Prevalence; Prognosis; Seizures; Taenia solium
PubMed: 22312322
DOI: 10.1100/2012/159821 -
The American Journal of Tropical... May 2016Human taeniasis/cysticercosis caused by the pork tapeworm Taenia solium has been identified as a potentially eradicable disease by the International Task Force for... (Review)
Review
Human taeniasis/cysticercosis caused by the pork tapeworm Taenia solium has been identified as a potentially eradicable disease by the International Task Force for Disease Eradication of the World Health Organization. In southeast Asia, T. solium taeniasis/cysticercosis is considered one of the major neglected tropical diseases afflicting the region. In the last few decades, a considerable effort has been invested toward establishing the epidemiology and burden of disease in several southeast Asian countries. Moreover, further evidence is emerging as to understanding the dynamics of disease transmission and cultural, political, and socioeconomic factors influencing the success of control and eradication efforts within the region. However, despite major collaborations by several champion groups, advances have been slow and little remains known about the complete epidemiology of taeniasis/cysticercosis and the barriers to programmatic success. This review article aims to address the above issues with a further focus on the challenges to control and eradicate taeniasis/cysticercosis within the southeast Asia region.
Topics: Animals; Asia, Southeastern; Cysticercosis; Humans; Taenia solium; Taeniasis; Zoonoses
PubMed: 26834197
DOI: 10.4269/ajtmh.15-0684 -
PLoS Neglected Tropical Diseases Apr 2020Taenia solium cysticercosis and taeniasis (TSCT), caused by the tapeworm T. solium, is a foodborne and zoonotic disease classified since 2010 by WHO as a neglected... (Review)
Review
Taenia solium cysticercosis and taeniasis (TSCT), caused by the tapeworm T. solium, is a foodborne and zoonotic disease classified since 2010 by WHO as a neglected tropical isease. It causes considerable impact on health and economy and is one of the leading causes of acquired epilepsy in most endemic countries of Latin America, Sub-Saharan Africa, and Asia. There is some evidence that the prevalence of TSCT in high-income countries has recently increased, mainly due to immigration from endemic areas. In regions endemic for TSCT, human cysticercosis can manifest clinically as neurocysticercosis (NCC), resulting in epileptic seizures and severe progressive headaches, amongst other neurological signs and/or symptoms. The development of these symptoms results from a complex interplay between anatomical cyst localization, environmental factors, parasite's infective potential, host genetics, and, especially, host immune responses. Treatment of individuals with active NCC (presence of viable cerebral cysts) with anthelmintic drugs together with steroids is usually effective and, in the majority, reduces the number and/or size of cerebral lesions as well as the neurological symptoms. However, in some cases, treatment may profoundly enhance anthelmintic inflammatory responses with ensuing symptoms, which, otherwise, would have remained silent as long as the cysts are viable. This intriguing silencing process is not yet fully understood but may involve active modulation of host responses by cyst-derived immunomodulatory components released directly into the surrounding brain tissue or by the induction of regulatory networks including regulatory T cells (Treg) or regulatory B cells (Breg). These processes might be disturbed once the cysts undergo treatment-induced apoptosis and necrosis or in a coinfection setting such as HIV. Herein, we review the current literature regarding the immunology and pathogenesis of NCC with a highlight on the mobilization of immune cells during human NCC and their interaction with viable and degenerating cysticerci. Moreover, the immunological parameters associated with NCC in people living with HIV/AIDS and treatments are discussed. Eventually, we propose open questions to understand the role of the immune system and its impact in this intriguing host-parasite crosstalk.
Topics: Animals; Anthelmintics; Anti-Inflammatory Agents; Host-Parasite Interactions; Humans; Immunity, Cellular; Neurocysticercosis; Taenia solium
PubMed: 32298263
DOI: 10.1371/journal.pntd.0008005 -
Parasite Immunology Aug 2014The life cycle of Taenia solium, the pork tapeworm, is continuously closed in many rural settings in developing countries when free roaming pigs ingest human stools... (Review)
Review
The life cycle of Taenia solium, the pork tapeworm, is continuously closed in many rural settings in developing countries when free roaming pigs ingest human stools containing T. solium eggs and develop cysticercosis, and humans ingest pork infected with cystic larvae and develop intestinal taeniasis, or may also accidentally acquire cysticercosis by faecal-oral contamination. Cysticercosis of the human nervous system, neurocysticercosis, is a major cause of seizures and other neurological morbidity in most of the world. The dynamics of exposure, infection and disease as well as the location of parasites result in a complex interaction which involves immune evasion mechanisms and involutive or progressive disease along time. Moreover, existing data are limited by the relative lack of animal models. This manuscript revises the available information on the immunology of human taeniasis and cysticercosis.
Topics: Animals; Cysticercosis; Host-Parasite Interactions; Humans; Life Cycle Stages; Meat; Swine; Swine Diseases; Taenia solium; Taeniasis
PubMed: 24962350
DOI: 10.1111/pim.12126 -
Acta Tropica Feb 2017Neurocysticercosis (NCC) is the most common parasitic disease of the human central nervous system (CNS), a pleomorphic disease with a diverse array of clinical... (Review)
Review
Neurocysticercosis (NCC) is the most common parasitic disease of the human central nervous system (CNS), a pleomorphic disease with a diverse array of clinical manifestations. The infection is pleomorphic and dependent on a complex range of interconnecting factors, including number and size of the cysticerci, their stage of development and localisation within the brain with resulting difficulties in accurate diagnosis and staging of the disease. This review examines the factors that contribute to the accurate assessment of NCC distribution and transmission that are critical to achieving robust disease burden calculations. Control and prevention of T. solium transmission should be a key priority in global health as intervention can reduce the substantial healthcare and economic burdens inflicted by both NCC and taeniasis. Surveillance systems need to be better established, including implementing obligatory notification of cases. In the absence of reliable estimates of its global burden, NCC will remain-along with other endemic zoonoses, of low priority in the eyes of funding agencies-a truly neglected disease.
Topics: Animals; Anticestodal Agents; Anticonvulsants; Central Nervous System; Cysticercus; Glucocorticoids; Humans; Neglected Diseases; Neurocysticercosis; Taenia solium
PubMed: 27880878
DOI: 10.1016/j.actatropica.2016.11.015