Eosinophilic Meningoencephalitis Research Articles

Mannose-binding lectin deficiency with eosinophilic meningoencephalitis due to Angiostrongylus cantonensis in children: a case series

IntroductionEosinophilic meningitis, a potentially fatal disease caused by Angiostrongylus cantonensis, is considered an emerging infectious disease.Case presentationThree Caucasian boys (aged five-years-old, 10-years-old and six-years-old) with a diagnosis of eosinophilic meningoencephalitis caused by Angiostrongylus cantonensis were studied. Serum immunoglobulin A (IgA), IgM, IgG, and complements C3c and C4 levels were quantified by using an immunodiffusion technique. Immunoglobulin E in serum was quantified by nephelometry and mannose-binding lectin by time-resolved fluorometry. Mannose-binding lectin deficiency was observed in the three patients. The first patient showed a reduction in the levels of IgA and IgM and an increase in the values of IgE and C4. The second patient showed a reduction in mannose-binding lectin level with increased IgG, C4 and IgE levels, and the third patient showed a decrease in mannose-binding lectin level and increased levels of IgM and complement C3c as well as a low level of C4.ConclusionsTo the best of our knowledge, this is the first report of mannose-binding lectin deficiency associated with Angiostrongylus cantonensis meningoencephalitis in children, and it may contribute to the understanding of the participation of this component of the lectin pathway in the development of the disease.

Endemic Angiostrongyliasis, Rio de Janeiro, Brazil

Endemic Angiostrongyliasis, Rio de Janeiro, Brazil

Spinal cord involvement in a child with raccoon roundworm (Baylisascaris procyonis) meningoencephalitis

A 14-month-old previously healthy boy developed progressively worsening neurological symptoms secondary to eosinophilic meningoencephalitis with myelitis caused by raccoon roundworm (Baylisascaris procyonis) infection. MRI demonstrated T2 hyperintensity and enhancement of the cerebral white matter, cerebellum and spinal cord. Prior case reports have described signal abnormality within the brains of patients with raccoon roundworm neural larva migrans (NLM). This is a unique case in which spinal cord involvement was established by imaging. Knowledge of this combination of imaging findings expands the known imaging phenotype of this noteworthy infection.

Fatal equine meningoencephalitis in the United Kingdom caused by the panagrolaimid nematodeHalicephalobus gingivalis: Case report and review of the literature

A fatal case of eosinophilic and granulomatous meningoencephalitis caused by the free-living panagrolaimid nematode Halicephalobus gingivalis is reported in a 10-year-old Welsh gelding in the United Kingdom. Clinical examination first revealed behavioural abnormalities which rapidly progressed to severe ataxia, reduced mentation status and cranial nerve signs. Despite symptomatic treatment no amelioration of neurological signs was achieved and the horse was subjected to euthanasia. A complete post mortem examination revealed eosinophilic and granulomatous meningoencephalitis mainly affecting the cerebellum and brain stem with intralesional adult nematodes, larvae and eggs. There was also eosinophilic meningitis of the cervical spinal cord. The intralesional nematodes were morphologically consistent with the panagrolaimid nematode H. gingivalis. Although infection by this facultative neurotropic parasite is extremely rare, it needs to be considered in the differential diagnosis of central nervous signs in horses and, in particular, other equine helminthic infection of the central nervous system. This fatal case is unusual since lesions were locally very extensive and the nematodes did not colonise haematogenously to other organs as seen often in equine halicephalobosis. As the taxonomy of H. gingivalis has changed and some recent reports in the literature still refer to this species as Micronema deletrix or Halicephalobus deletrix, we here provide a short update of the species and some insights on the order Tylenchida, which contains free-living nematodes with parasitic tendencies.

First report of Angiostrongylus cantonensis (Nematoda: Metastrongylidae) in Achatina fulica (Mollusca: Gastropoda) from Southeast and South Brazil

The rat lungworm Angiostrongylus cantonensis is a worldwide-distributed zoonotic nematode that can cause human eosinophilic meningoencephalitis. Here, for the first time, we report the isolation of A. cantonensis from Achatina fulica from two Brazilian states: Rio de Janeiro (specifically the municipalities of Barra do Piraí, situated at the Paraiba River Valley region and São Gonçalo, situated at the edge of Guanabara Bay) and Santa Catarina (in municipality of Joinville). The lungworms were identified by comparing morphological and morphometrical data obtained from adult worms to values obtained from experimental infections of A. cantonensis from Pernambuco, Brazil, and Akita, Japan. Only a few minor morphological differences that were determined to represent intra-specific variation were observed. This report of A. cantonensis in South and Southeast Brazil, together with the recent report of the zoonosis and parasite-infected molluscs in Northeast Brazil, provide evidence of the wide distribution of A. cantonensis in the country. The need for efforts to better understand the role of A. fulica in the transmission of meningoencephalitis in Brazil and the surveillance of molluscs and rodents, particularly in ports, is emphasized.

Molecular differentiation of Angiostrongylus taxa (Nematoda: Angiostrongylidae) by cytochrome c oxidase subunit I (COI) gene sequences

Nematodes of the genus Angiostrongylus are parasites of rodents and carnivores. They reside in the pulmonary or mesenteric arteries of their hosts. Two species are pathogenic in humans – Angiostrongylus cantonensis causes eosinophilic meningitis or meningoencephalitis, and Angiostrongylus costaricensis produces abdominal angiostrongyliasis. In addition Angiostrongylus malaysiensis may have the potential of being pathogenic in humans. The mitochondrial gene cytochrome c oxidase subunit I (COI) of these Angiostrongylus species and three geographical isolates (China, Hawaii and Thailand) of A. cantonensis were studied by polymerase chain reaction amplification and DNA sequencing. COI sequences of A. cantonensis, A. costaricensis and Angiostrongylus vasorum in the GenBank were included for comparison. Phylogenetic analysis by maximum-likelihood (ML), maximum-parsimony (MP), neighbour-joining (NJ) and Bayesian inference (BI) produced similar tree topology except variation in the bootstrap support values. There were two major clades – (1) A. cantonensis and A. malaysiensis, and (2) A. costaricensis and A. vasorum. The three geographical isolates of A. cantonensis formed a clade with low to high bootstrap values, and consisted of two subclades: (a) China and Hawaii isolates, and (b) monophyletic Thailand isolate. The individuals of each isolate formed a distinct cluster. In the second major clade, the Europe isolates of A. vasorum were distinctly different from the Brazil isolates. For A. costaricensis, the Costa Rica isolate was distinct from the Brazil isolate with an uncorrected ( p) distance of 11.39%, indicating the possible occurrence of cryptic species. The present results indicate that COI sequences might be a useful marker for differentiating geographical isolates of A. cantonensis and in uncovering cryptic species. Efforts are being made to carry out an extensive collaborative study to cover a wide range of Angiostrongylus species and geographical isolates.

Alterations of myelin proteins in inflammatory demyelination of BALB/c mice caused by Angiostrongylus cantonensis

Angiostrongylus cantonensis causes eosinophilic meningitis or meningoencephalitis, yet little is known about demyelination caused by this parasite. To define the course of demyelination caused by A. cantonensis, we analyzed the expression of myelin proteins including myelin-associated glycoprotein (MAG), myelin basic protein (MBP), myelin-associated oligodendrocytic basic protein (MOBP), and proteolipid protein (PLP) in brain and cerebrospinal fluid (CSF)-like fluid of infected and uninfected BALB/c mice. In A. cantonensis-infected mice, the expression of MAG, MBP, MOBP, and PLP mRNAs in brain tissue was decreased, while expression of the corresponding proteins was significantly increased in CSF-like fluid. Light microscopy revealed perivascular infiltrates in the brain during meningoencephalitis, suggesting that the cause of demyelination in angiostrongyliasis was immune system attack on the oligodendrocytic myelin sheath and subsequent release of myelin proteins into the CSF. Thus, intracerebral myelin breakdown in angiostrongyliasis may be a response to inflammatory mediators and the cause of increased myelin proteins in the CSF-like fluid.

Recently reemerging helminthic infections causing eosinophilic meningoencephalitis: neuroangiostrongyliasis, baylisascariasis, and gnathostomiasis.

Today most emerging infectious diseases, such as sudden acute respiratory syndrome (SARS) and novel influenza A H1N1 (swine flu), arise in the natural environment as zoonoses and are distributed by international commerce and travel. The helminthic infections that can cause eosinophilic meningoencephalitis (EM), such as neu- roangiostrongyliasis, baylisascariasis, and gnathostomiasis, share these characteristics of emerging infectious diseases. Neuroangiostrongyliasis, a rodent zoonosis, is now endemic in the United States (US) following the introduction of giant African land snails as biological controls and exotic pets. Baylisascariasis, a raccoon zoonosis, has extended its US distribution range from the northern US to the southeast and west coast since the 1980s and was exported to Japan in the exotic pet trade. Gnathostomiasis, a zoonosis of wild carni- vores, has been recently recognized as an emerging cause of EM in returning travelers to the United Kingdom (UK). This review analyzes scientific articles selected by PubMed and Medline search engines, 1966-2009, in order to assess the evolving epidemiology of these three examples of recently reemerging helminthic infections causing EM worldwide in order to compare their epidemiology, clinical manifes- tations, diagnoses, and management outcomes and to alert clinicians to populations at increased risk of helminthic EM as a result of age, ethnicity, lifestyle, food choices, location of permanent residence, or recent international travel.

Parelaphostrongylus tenuis–Associated Meningoencephalitis in a Sika Deer (Cervus nippon)

An adult, female, free-ranging, sika deer (Cervus nippon yakushimae) from Wicomico County, Maryland, USA, was found circling and having no fear of humans. The animal was euthanized and submitted for a postmortem exam. There were no gross lesions and the deer was negative for rabies. Microscopic examination revealed lymphoplasmacytic, neutrophilic, and eosinophilic meningoencephalitis with intralesional adult nematodes, larvae, and eggs consistent with nematodes in the family Protostrongylidae. Parelaphostrongylus tenuis was identified by polymerase chain reaction and DNA sequencing. To our knowledge, this is the first report of P. tenuis-associated encephalitis in a sika deer.

Baylisascaris Procyonis Neural Larva Migrans in an Infant in New York City.

Neural larva migrans (NLM) with eosinophilic meningoencephalitis secondary to raccoon roundworm (Baylisascaris procyonis) infection has been reported in rural and suburban areas of North America and Europe with extant raccoon populations. Most cases have occurred in infants less than two years of age exposed to areas of raccoon fecal contamination. Here, we present a case of Baylisascaris-induced NLM from the densely populated borough of Brooklyn in New York City and alert urban pediatricians to consider this cause of clinical neurologic disease even in areas not typically thought to be associated with endemic risk factors. Infected raccoons also occur in urban settings, and urban children may be exposed to environmental areas or materials contaminated with their feces and the parasite's eggs.

Anti-CCR3 monoclonal antibody inhibits eosinophil infiltration in Angiostrongylus cantonensis-infected ICR mice

ICR mice were each infected with 35 Angiostrongylus cantonensis larvae. One group of mice received an intraperitoneal injection of anti-CCR3 monoclonal antibody (mAb) (50 microg) at 10 days post-infection (dpi), while another similarly-treated group also received a booster injection (25 microg) at 12 dpi. All the mice were sacrificed at 14 dpi for pathological examination, enzyme-linked immunosorbent assay analysis and RNA extraction. The infiltration of eosinophils and the severity of eosinophilic meningitis were reduced in both the mAb-treated groups, relative to infected but untreated animals. The levels of CCL11 (eotaxin) in the peripheral circulation and the expression of the Th2-type cytokine interleukin-5 in the brains were significantly reduced. A. cantonensis infection is the major cause of eosinophilic meningoencephalitis in Taiwan, and the results of this study could be useful for the development of strategies to reduce the neurological damage caused by this infection.

GLOBAL NEUROLOGIC DEFICITS WITH BAYLISASCARIS ENCEPHALITIS IN A PREVIOUSLY HEALTHY TEENAGER

We present a case of acute eosinophilic meningoencephalitis caused by Baylisascaris procyonis in a previously healthy teenager with a history of substance abuse. Treatment included methylprednisolone; no anthelmintic drugs were administered. This case identifies a new risk factor, altered behavior related to substance abuse, and a newly described outcome of cognitive deficits for B. procyonis disease in older children.

Differences of proteolytic enzymes and pathological changes in permissive and nonpermissive animal hosts for Angiostrongylus cantonensis infection

In this study, mice (nonpermissive hosts) infected with Angiostrongylus cantonensis showed significant worm degeneration and eosinophil degranulation, whereas infected rats (permissive hosts) showed lower worm degeneration and eosinophil degranulation. Pathophysiological changes developed to a lesser extent in rat than in the mouse strains. Neurological evaluation of A. cantonensis-infected mice showed mechanical damage caused by worms migrating to the brain. A significant correlation between the proteolytic enzymes, plasminogen activator (PA) and matrix metalloproteinase-9 (MMP-9), and pathological changes was found in hosts with eosinophilic meningitis or meningoencephalitis. Also, the ratio of cerebrospinal fluid (CSF) to serum albumin was consistently increased in hosts with angiostrongyliasis as compared with control. These data clearly indicate that PA and MMP-9 proteolytic enzymes as well as pathological changes are different in permissive and nonpermissive hosts.

Abdominal angiostrongyliasis caused by Angiostrongylus cantonensis: A possible cause of eosinophilic infiltration in human digestive tract

We report the pathological findings of a serologically proven case of Angiostrongylus cantonensis presenting with localized peritonitis followed by eosinophilic meningoencephalitis. The neurological involvement developed 3 days after the occurrence of gastrointestinal symptoms. Similarly to the life cycle in rats, it takes about 2 or 3 days for the larvae to reach the nervous system. The pathological section of the sigmoid colon showed focal eosinophilic infiltration with serosal vessel invasion. In the case reported here, we describe a new possible cause of eosinophilic infiltration in the human digestive tract.

Update on Eosinophilic Meningoencephalitis and Its Clinical Relevance

Eosinophilic meningoencephalitis is caused by a variety of helminthic infections. These worm-specific infections are named after the causative worm genera, the most common being angiostrongyliasis, gnathostomiasis, toxocariasis, cysticercosis, schistosomiasis, baylisascariasis, and paragonimiasis. Worm parasites enter an organism through ingestion of contaminated water or an intermediate host and can eventually affect the central nervous system (CNS). These infections are potentially serious events leading to sequelae or death, and diagnosis depends on currently limited molecular methods. Identification of parasites in fluids and tissues is rarely possible, while images and clinical examinations do not lead to a definitive diagnosis. Treatment usually requires the concomitant administration of corticoids and anthelminthic drugs, yet new compounds and their extensive and detailed clinical evaluation are much needed. Eosinophilia in fluids may be detected in other infectious and noninfectious conditions, such as neoplastic disease, drug use, and prosthesis reactions. Thus, distinctive identification of eosinophils in fluids is a necessary component in the etiologic diagnosis of CNS infections.

Activación y biosíntesis intratecal de C3c en niños con meningoencefalitis eosinofílica por Angiostrongylus cantonensis

Eosinophilic meningoencephalitis due to Angiostrongylus cantonensis is an emergent infectious disease in our area. The objective of the present paper is to determine if the activation of the complement system was taken placed with the C3c production in cerebrospinal fluid. 14 patients with an average age 4.5 years were studied. In such patients a lumbar punction was performed. C3c was quantified in serum and cerebrospinal fluid by radial immunodiffusion. Median cell number was 396 x 10(-6)/L with an average of 8.8% of eosinophils. Main symptoms were headache, vomiting and fever. Meningeal signs were present in 50% of the patients. C3c intrathecal synthesis occurred in 13 patients (92.8%). It was demonstrated the participation of complement system in third-stage larvae destruction in cerebrospinal fluid.

Intrathecal synthesis of IgE in children with eosinophilic meningoencephalitis caused by Angiostrongylus cantonensis

BackgroundEosinophilic meningoencephalitis caused by the helminth Angiostrongylus cantonensis, is an emerging infectious disease in America. The objective of this paper was to determine if the intrathecal synthesis of immunoglobulin E is produced during the acute phase of the disease.MethodsThirteen patients, mean age 4.5 years were studied; a diagnostic lumbar puncture was performed and serum samples taken. Immunoglobulin E (IgE) in serum and in cerebrospinal fluid (CSF) was quantified by nephelometry. Control patients had other infections or other neurological diseases.ResultsThe mean cell count in the CSF was 500 × 10-6 cells/L and of these 23% were eosinophils. In blood the eosinophils were 13%. The chief symptoms of the patients were migraine, vomiting and fever and 50% presented some meningeal signs. IgE intrathecal synthesis analyzed by the corresponding quotient diagram (Reibergram) was observed in all patients. No intrathecal IgE synthesis was seen in control patients.ConclusionIntrathecal synthesis of IgE demonstrates the participation of this immunoglobulin in the destruction of the third stage larvae of the parasite in the CSF. The test should be considered in our environment as a tool to aid diagnosis.

A Severe Eosinophilic Meningoencephalitis Caused by Infection of Angiostrongylus cantonensis

This paper reports a severe case of eosinophilic meningoencephalitis after infection with Angiostrongylus cantonensis.

Eosinophilic Meningoencephalitis: Psychiatric Presentation and Treatment

Eosinophilic meningoencephalitis (EM) is usually a self-limited neurological illness commonly accompanied by a variety of neurological symptoms. The presence of acute psychotic symptoms in EM, however, has not previously been reported, and there is no literature to guide its treatment and management. In this case report, the onset of psychotic symptoms in a hypoactive delirium and their significant improvement following the administration of atypical antipsychotics are described in a boy with EM. This case report demonstrates the efficacy and safety of antipsychotic agents during the acute phase of meningoencephalitis.

Review of idiopathic eosinophilic meningitis in dogs and cats, with a detailed description of two recent cases in dogs : review and clinical communication

Eosinophilic meningoencephalitis (EME) has been described in various species of animals and in humans. In dogs it has been associated with protozoal infections, cuterebral myiasis and various other aetiologies. Ten cases of idiopathic eosinophilic meningoencephalitis have been reported in dogs and one in a cat where the origin was uncertain or unknown. The dogs were all males, of various breeds but with a predominance of Golden Retrievers and Rottweilers; they generally had a young age of onset. Two cases with no apparent underlying aetiology were diagnosed on post mortem examination. The 18-month-old, male Boerboel presented with sudden onset of cerebellar ataxia, as well as various asymmetrical cranial nerve deficits of 2 weeks' duration and without progression. Haematology revealed a peripheral eosinophilia. Necropsy showed extreme generalised congestion especially of the meninges and blood smear and histological sections of various tissues showed intravascular erythrocyte fragmentation with the formation of microcytes. Histopathology revealed severe diffuse cerebrocortical subarachnoidal meningitis and submeningeal encephalitis, the exudate containing variable numbers of eosinophils together with neutrophils and mononuclear cells. There was also deeper white matter and hippocampal multifocal perivascular mononuclear encephalitis and multifocal periventricular malacia, gliosis and phagocytosis of white matter. The cerebellum, brain stem and spinal c showed only mild multifocal oedema or scattered occasional axon and myelin degeneration respectively, with no inflammation. Immunohistochemical staining of central nervous tissue for Toxoplasma gondii failed to show any antigen in the central nervous tissue. Ultrastructure of a single submeningeal suspected parasitic cyst showed it to be chromatin clumping within a neuron nucleus indicating karyorrhexis. Gram stain provided no evidence of an aetiological agent. The 3-year-old Beagle bitch had a Caesarian section after developing a non-responsive inertia 8 days prior to presentation. This animal's clinical signs included status epilepticus seizures unrelated to hypocalcaemia and warranted induction of a barbiturate coma. She died 4 hours later. Post mortem and histopathological findings in the brain were almost identical to those of the Boerboel and she also showed histological evidence of recent active intravascular haemolysis with microcyte formation. Rabies, distemper and Neospora caninum immunohistochemical stains were negative in the brains of both dogs. Immunohistochemical staining of the cerebral and meningeal exudates of the Beagle for T- and B-lymphocyte (CD3 and CD79a) markers showed a predominance of T-lymphocytes with fewer scattered B lymphocytes. A possible allergic response to amoxicillin/clavulanate is considered, as this appeared to be the only feature common to the recent history of both animals. An overview of EME in humans, dogs and cats is given and the previously published cases of idiopathic EME in dogs and the single published cat case are briefly reviewed.