Eosinophilic Meningitis

Paratenic hosts of Angiostrongylus cantonensis and their relation to human neuroangiostrongyliasis globally

The nematode parasite Angiostrongylus cantonensis (rat lungworm) has a complex life cycle involving rats (definitive hosts) and gastropods (intermediate hosts), as well as various paratenic hosts. Humans become infected and develop rat lungworm disease (neuroangiostrongyliasis) when they consume intermediate or paratenic hosts containing the infective parasite larvae. This study synthesizes knowledge of paratenic hosts of A. cantonensis and investigates their role in causing human neuroangiostrongyliasis worldwide. A literature review was conducted by searching PubMed, JSTOR and Scopus, pooling additional information from sources accumulated over many years by RHC, and snowball searching. The review identified 138 relevant articles published between 1962 and 2022. Freshwater prawns/shrimp, crayfish, crabs, flatworms, fish, sea snakes, frogs, toads, newts, lizards, centipedes, cattle, pigs and snails were reported to act as paratenic hosts in various regions including South and Southeast Asia, Pacific islands, the USA and the Caribbean, as well as experimentally. Human cases of neuroangiostrongyliasis have been reported from the 1960s onwards, linked, sometimes speculatively, to consumption of freshwater prawns/shrimp, crabs, flatworms, fish, frogs, toads, lizards and centipedes. The potential of paratenic hosts to cause neuroangiostrongyliasis depends on whether they are eaten, how frequently they are consumed, the preparation method, including whether eaten raw or undercooked, and whether they are consumed intentionally or accidentally. It also depends on infection prevalence in the host populations and probably on how high the parasite load is in the consumed hosts. To prevent human infections, it is crucial to interrupt the transmission of rat lungworm to humans, from both intermediate hosts and frequently consumed paratenic hosts, by adhering to safe food preparation protocols. Educating the general public and the medical community about this largely neglected tropical/subtropical disease is key.

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Neuroangiostrongyliasis, an emerging parasitic disease of humans and wildlife.

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Caused by the nematode Angiostrongylus cantonensis (rat lungworm).

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Infection primarily via ingestion of stage 3 larvae of the parasite.

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People eat raw intermediate or paratenic hosts infected with stage 3 larvae.

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Comprehensive review of paratenic hosts’ role in neuroangiostrongyliasis globally.

Angiostrongylus spp. (Nematoda; Metastrongyloidea) of global public health importance

Human angiostrongyliasis is an important foodborne zoonosis, caused by the infection with Angiostrongylus costaricensis and Angiostrongylus cantonensis. These two species have a significant public health impact in different areas of the world. Angiostrongyliasis is re-emerging and expanding to urban settings rising significant concerns regarding the control of these infections. This review focuses on aspects such as life cycle, epidemiology, clinical manifestations, diagnostics, food safety and control of illness caused especially by A. cantonensis.

Occurrence of Angiostrongylus cantonensis in rodents from the rice granary of the Philippines and associated risk factors for zoonotic transmission

Rattus tanezumi and Rattus norvegicus are the most common rodent species in the Philippines, with the former mainly inhabiting agricultural land and the latter in urban areas. Generating information on the Angiostrongylus cantonensis harbored by these rodents would be useful for public health. A total of 600 rodents were collected from traps placed each month from July to December 2012 in selected villages of Muñoz, Nueva Ecija; the rice granary of the Philippines. The prevalence of A. cantonensis in R. tanezumi and R. norvegicus was, 100%; all the rodents from the five villages were infected. The study shows that regardless of stages, body weight and length, rodents are vulnerable to infection by Angiostrongylus cantonensis present in the environment. However in terms of sex, results revelead that the male and female in R. tanezumi has no statistically significance while R. norvegicus revealed that male and female has statistically significance. This study also show that, rodents that were caught in the agricultural area has higher mean intensity compared to rodents that were trapped in the residential areas but found to be insignificant. Also through survey interviews the various risk factors with zoonotic implication of A. cantonensis in the area was also discussed.

Preliminary expression profile of cytokines in brain tissue of BALB/c mice with Angiostrongylus cantonensis infection

Background

Angiostrongylus cantonensis (A. cantonensis) infection can result in increased risk of eosinophilic meningitis. Accumulation of eosinophils and inflammation can result in the A. cantonensis infection playing an important role in brain tissue injury during this pathological process. However, underlying mechanisms regarding the transcriptomic responses during brain tissue injury caused by A. cantonensis infection are yet to be elucidated. This study is aimed at identifying some genomic and transcriptomic factors influencing the accumulation of eosinophils and inflammation in the mouse brain infected with A. cantonensis.

Methods

An infected mouse model was prepared based on our laboratory experimental process, and then the mouse brain RNA Libraries were constructed for deep Sequencing with Illumina Genome Analyzer. The raw data was processed with a bioinformatics’ pipeline including Refseq genes expression analysis using cufflinks, annotation and classification of RNAs, lncRNA prediction as well as analysis of co-expression network. The analysis of Refseq data provides the measure of the presence and prevalence of transcripts from known and previously unknown genes.

Results

This study showed that Cys-Cys (CC) type chemokines such as CCL2, CCL8, CCL1, CCL24, CCL11, CCL7, CCL12 and CCL5 were elevated significantly at the late phase of infection. The up-regulation of CCL2 indicated that the worm of A. cantonensis had migrated into the mouse brain at an early infection phase. CCL2 could be induced in the brain injury during migration and CCL2 might play a major role in the neuropathic pain caused by A. cantonensis infection. The up-regulated expression of IL-4, IL-5, IL-10, and IL-13 showed Th2 cell predominance in immunopathological reactions at late infection phase in response to infection by A. cantonensis. These different cytokines can modulate and inhibit each other and function as a network with the specific potential to drive brain eosinophilic inflammation. The increase of ATF-3 expression at 21 dpi suggested the injury of neuronal cells at late phase of infection. 1217 new potential lncRNA were candidates of interest for further research.

Conclusions

These cytokine networks play an important role in the development of central nervous system inflammation caused by A. cantonensis infection.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-015-0939-6) contains supplementary material, which is available to authorized users.

Corticosteroids for parasitic eosinophilic meningitis

BACKGROUND

Angiostrongylus cantonensis (A. cantonensis) is the major cause of infectious eosinophilic meningitis. Dead larvae of this parasite cause inflammation and exacerbate symptoms of meningitis. Corticosteroids are drugs used to reduce the inflammation caused by this parasite.

OBJECTIVES

To assess the efficacy and safety of corticosteroids for the treatment of eosinophilic meningitis.

SEARCH METHODS

We searched CENTRAL (2014, Issue 11), MEDLINE (1950 to November Week 3, 2014), EMBASE (1974 to December 2014), Scopus (1960 to December 2014), Web of Science (1955 to December 2014), LILACS (1982 to December 2014) and CINAHL (1981 to December 2014).

SELECTION CRITERIA

Randomised controlled trials (RCTs) of corticosteroids versus placebo for eosinophilic meningitis.

DATA COLLECTION AND ANALYSIS

Two review authors (SiT, SaT) independently collected and extracted study data. We graded the methodological quality of the RCTs. We identified and analysed outcomes and adverse effects.

MAIN RESULTS

We did not identifiy any new trials for inclusion or exclusion in this 2014 update. One study involving 110 participants (55 participants in each group) met our inclusion criteria. The corticosteroid (prednisolone) showed a benefit in shortening the median time to resolution of headaches (five days in the treatment group versus 13 days in the control group, P value < 0.0001). Corticosteroids were also associated with smaller numbers of participants who still had headaches after a two-week course of treatment (9.1% versus 45.5%, P value < 0.0001). The number of patients who needed repeat lumbar puncture was also smaller in the treatment group (12.7% versus 40%, P value = 0.002). There was a reduction in the median time of analgesic use in participants receiving corticosteroids (10.5 versus 25.0, P value = 0.038). There were no reported adverse effects from prednisolone in the treatment group.

AUTHORS' CONCLUSIONS

Corticosteroids significantly help relieve headache in patients with eosinophilic meningitis, who have a pain score of four or more on a visual analogue scale. However, there is only one RCT supporting this benefit and this trial did not clearly mention allocation concealment and stratification. Therefore, we agreed to grade our included study as a moderate quality trial. Future well-designed RCTs are necessary.

A rare case of Ibuprofen-induced eosinophilic meningitis in a 13-year-old girl

Eosinophilic meningoencephalitis is based on clinical manifestations and microscopic identification of eosinophils present in cerebrospinal fluid (CSF). It is caused by a variety of helminthic infections with most common being angiostrongyliasis, gnathostomiasis, toxocariasis, cysticercosis, schistosomiasis, baylisascariasis, and paragonimiasis. Many case reports are there in which parasites have been found responsible, but there are rare reports of CSF eosinophilia associated with the use of drugs. We report a case of drug-induced (ibuprofen) eosinophilic meningitis in a healthy female who presented to us with severe headache and improved dramatically after drug withdrawal.

Endemic angiostrongyliasis in the Brazilian Amazon: natural parasitism of Angiostrongylus cantonensis in Rattus rattus and R. norvegicus, and sympatric giant African land snails, Achatina fulica

Angiostrongylus cantonensis, the rat lungworm, is one etiological agent of eosinophilic meningoencephalitis in humans. This zoonosis is frequently found in Asia and, more recently, in North America, Caribbean Island and northeastern of South America. Until now, research of A. cantonensis in southern, southeastern and northeastern regions of Brazil has been found natural infections only terrestrial and freshwater intermediate snail hosts (Achatina fulica, Sarasinula marginata, Subulina octona, Bradybaena similaris and Pomacea lineate). In this study, we examined the occurrence of helminthes in the synantropic rodents Rattus rattus and Rattus norvegicus in northern Brazil, focusing on the role of these species as vertebrate hosts of A. cantonensis and A. fulica as intermediate host have found natural. Thirty specimens of R. rattus and twelve of R. norvegicus were collected in the Guamá and Jurunas neighborhoods of the city of Belém, in the Brazilian state of Pará, of which almost 10% harbored adult worms in their pulmonary arteries. Sympatric A. fulica were found to be infected by L(3) larvae, which experimental infection confirmed to be A. cantonensis. Natural infection of snails and rodents with A. cantonensis was confirmed through morphological and morphometrical analyses of adults and larvae using light microscopy, scanning electron microscopy and molecular sequences of partial Cytochrome Oxidase subunit I. Phylogenetic analyses showed that A. cantonensis isolated from Pará, Brazil is similar to Japan isolate; once these specimens produced a single haplotype with high bootstrap support with Rio de Janeiro isolate. This study confirms that A. cantonensis is now endemic in northern Brazil, and that R. rattus and R. norvegicus act as natural definitive hosts, and A. fulica as the intermediate host of the parasite in this region.

Corticosteroids for parasitic eosinophilic meningitis

BACKGROUND

Angiostrongylus cantonensis (A. cantonensis) is the major cause of infectious eosinophilic meningitis. Dead larvae of this parasite cause inflammation and exacerbate symptoms of meningitis. Corticosteroids are drugs used to reduce inflammation caused by this parasite.

OBJECTIVES

To examine the effects and adverse events of corticosteroids in patients with eosinophilic meningitis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 6), MEDLINE (1950 to July Week 4, 2012), EMBASE (1974 to July 2012), Scopus (1960 to July 2012), Web of Science (1955 to July 2012), LILACS (1982 to July 2012), and CINAHL (1981 to July 2012).

SELECTION CRITERIA

Randomised controlled trials (RCTs) of corticosteroids versus placebo for eosinophilic meningitis.

DATA COLLECTION AND ANALYSIS

Two review authors (SiT, SaT) independently collected and extracted study data. We graded the methodological quality of the RCTs. We identified and analyzed outcomes and adverse effects.

MAIN RESULTS

One study involving 110 participants (55 participants in each group) met our inclusion criteria. The corticosteroid (prednisolone) showed a benefit in shortening the median time to resolution of headaches (five days in the treatment group versus 13 days in the control group, P < 0.0001). Corticosteroids were also associated with smaller numbers of participants who still had headaches after a two-week course of treatment (9.1% versus 45.5%, P < 0.0001). There was a reduction in median time of analgesics use in participants receiving corticosteroids (10.5 versus 25.0, P = 0.038). There were no reported adverse effects from prednisolone in the treatment group.

AUTHORS' CONCLUSIONS

Corticosteroids significantly help relieve headache in patients with eosinophilic meningitis. However, there is only one RCT supporting this benefit and this trial did not clearly mention allocation concealment and stratification. Future well-designed RCTs may be necessary.

Cloning and characterization of a novel cathepsin B-like cysteine proteinase from Angiostrongylus cantonensis

Cysteine protease plays a key role in host-parasite interactions. In this study, we identified a novel gene encoding a cathepsin B-like cysteine protease (AcCBL1) from the cDNA library of Angiostrongysus cantonensis fourth-stage larvae (L4) and characterized its biological role in the parasite. Sequence and phylogeny analysis showed that AcCBL1 is related to other cathepsin B family members with the conserved catalytic triad (Cys, His, Asn) and diagnostic occluding loop. In addition, the sequence contains a specific "hemoglobinase motif" and might have a hemoglobinase (Hb)-degrading function. The recombinant AcCBL1 (rAcCBL1) exhibited the protease activity by gelation SDS/PAGE assay; rAcCBL1 can cleave the fluorogenic substrate Z-Arg-Arg-AMC, and the optimum pH was 5.5. The enzyme can hydrolyse several host proteins including Hb and human IgG in acidic pH, but low levels of hydrolysis were observed in neutral pH. Reverse transcription polymerase chain reaction revealed that AcCBL1 expression was detected throughout various developmental stages, L3, L4, adult male and female worms. Western blotting analysis indicated that AcCBL1 was an excretory/secretory product of L4 in mature form of protease. Immunolocalization demonstrated that AcCBL1 was mainly localized in the intestine of L4. These results suggest that rAcCBL1 may play an important role in the parasite nutrition uptake.

Eosinophilic meningitis attributable to Angiostrongylus cantonensis infection in Hawaii: clinical characteristics and potential exposures

The most common infectious cause of eosinophilic meningitis is Angiostrongylus cantonensis, which is transmitted largely by consumption of snails/slugs. We previously identified cases of angiostrongyliasis that occurred in Hawaii from 2001 to 2005; the highest incidence was on the island of Hawaii. We now report symptoms, laboratory parameters, and exposures. Eighteen patients were evaluated; 94% had headache, and 65% had sensory symptoms (paresthesia, hyperesthesia, and/or numbness). These symptoms lasted a median of 17 and 55 days, respectively. Three persons recalled finding a slug in their food/drink. Case-patients on the island of Hawaii were more likely than case-patients on other islands to consume raw homegrown produce in a typical week (89% versus 0%, P < 0.001) and to see snails/slugs on produce (56% versus 0%, P = 0.03). Residents and travelers should be aware of the potential risks of eating uncooked produce in Hawaii, especially if it is from the island of Hawaii and locally grown.

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

Background

Eosinophilic 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.

Methods

Thirteen 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.

Results

The 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.

Conclusion

Intrathecal 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.

Distribution of eosinophilic meningitis cases attributable to Angiostrongylus cantonensis, Hawaii

During November 2004-January 2005, 5 cases of eosinophilic meningitis (EM) attributable to Angiostrongylus cantonensis infection were reported in Hawaii. To determine if this temporal clustering reflected an increased incidence, we ascertained EM and A. cantonensis cases by systematic review of statewide laboratory and medical records for January 2001-February 2005 and generalized the data to population estimates. We identified 83 EM cases; 24 (29%) were attributed to A. cantonensis infection, which was included in the discharge diagnoses for only 2 cases. Comparison of A. cantonensis infection incidence rates (per 100,000 person-years) for the baseline (January 2001-October 2004) and cluster (November 2004-February 2005) periods showed statistically significant increases for the state as a whole (0.3 vs. 2.1), the Big Island of Hawaii (1.1 vs. 7.4), and Maui County (0.4 vs. 4.3). These findings underscore the need to consider the diagnosis of A. cantonensis infection, especially in the state of Hawaii.

Eosinophilic meningitis in a returned traveler from Santo Domingo: case report and review

We describe one case of eosinophilic meningitis (EM) in a traveler returning from Santo Domingo, presumably caused by Angiostrongylus cantonensis. Treatment with mebendazole and steroids was effective. The presence of persistent headache, fever, and eosinophilia in travelers who return from developing countries should alert clinicians to the possibility of EM.

Albendazole therapy for eosinophilic meningitis caused by Angiostrongylus cantonensis

Eosinophilic meningitis in humans is commonly caused by the nematode Angiostrongylus cantonensis. A severe headache is the most common presenting symptom. A prospective, randomized, double-blind, placebo, controlled study was conducted to determine if albendazole was efficacious in relieving such headaches. Seventy-one patients (36 and 35 in the treatment and control groups) were enrolled in the study. Five patients (two and three in the treatment and control groups) were excluded from the study because of being lost to follow-up, and the clinical data were incomplete. Therefore, 34 and 32 patients in the treatment and control groups were studied, respectively. Albendazole was administered at 15 mg/kg/day or identical placebo for 2 weeks. The number of patients with persistent headaches after 2 weeks was 7 and 13 in the albendazole and placebo groups (p = 0.08), respectively. The mean duration of a headache was 8.9 and 16.2 days in the albendazole and placebo groups, respectively (p = 0.05). No serious drug events were observed. A 2-week course of albendazole appeared to reduce the duration of headache in eosinophilic meningitis.

sICAM-1 in meningoencephalitis due to Angiostrongylus cantonensis

INTRODUCTION: Angiostrongylus cantonensis meningoencephalitis is an emergent disease in the Americas. METHOD: Twelve children suffering from eosinophilic meningoencephalitis due to this parasite aged between 6-10 years were studied. Cerebrospinal fluid (CSF) and serum samples were taken simultaneously in the first diagnostic puncture at admission. RESULTS: All cases showed typical findings on the routine CSF and serum analysis: increased CSF total protein, increased Q (CSF/serum) albumin accompanied by eosinophilia in CSF. No intrathecal synthesis of immunoglobulins was found. Mean serum and CSF sICAM-1 values were 337.4 and 3.97 ng/mL. Qalbumin and QsICAM-1 mean values were 4.1 and 6.2 respectively. In 50% of the patients an increased brain-derived fraction of sICAM-1 was found. CONCLUSION: It may be suggested that a dynamic of the sICAM-1 brain derived fraction is perhaps associated to the immune response in the evolution of the disease.sICAM-1 may be an agent in negative feedback for eosinophils passage through the blood-CSF barrier into the inflammatory brain response.

IgG1,IgG2 and IgE intrathecal synthesis in Angiostrongylus cantonensis meningoencephalitis

INTRODUCTION

Angiostrongylus cantonensis meningoencephalitis is an emergent zoonotic disease in the Caribbean basin, characterized by the presence of eosinophils and third stage larva of the helmint.

OBJECTIVE

To analyze the IgG subclasses and IgE intrathecal synthesis patterns obtained by reibergrams in pediatric patients suffering from eosinophilic meningoencephalitis due to A. cantonensis.

PATIENTS AND METHODS

20 pediatric patients with the disease were studied. During the first diagnostic lumbar puncture an eosinophilic pleocytosis was found. Simultaneously a serum sample was taken. Eight days later, a second lumbar and venous puncture was performed. IgA, IgM, IgG, albumin in serum and cerebrospinal fluid samples were quantified by immunodiffusion in addition to a differential cell count in cerebrospinal fluid. IgG subclasses were quantified in 10 patients by immunodiffusion and IgE in four patients by nephelometry.

RESULTS

During the first diagnostic lumbar puncture, all the cases had a blood-cerebrospinal fluid barrier dysfunction with absence of immunoglobulins intrathecal synthesis, a mean of 450 cells/mul and an average of 48% of eosinophils. In the second lumbar puncture 40% of the patients had a dysfunction of the blood-cerebrospinal fluid barrier and an intrathecal synthesis pattern of IgA+IgM+IgG in 50% of the patients. Eight patients had an intrathecal IgA+IgG class response. The synthesis pattern of IgG subclasses was IgG1+IgG2 in six patients, IgG1+IgG2+IgG3 in one patient, IgG1+IgG2+IgG4 in one more patient. Two patients from the second lumbar puncture remained without intrathecal synthesis. IgE intrathecal synthesis was observed in the four analyzed patients in the first diagnostic lumbar puncture.

CONCLUSIONS

The IgG1+IgG2 and IgE intrathecal synthesis pattern demonstrated the complexity of the antigenic mosaic of the helmint and it can contribute to diagnosis of eosinophilic meningoencephalitis due to A. cantonensis.