Cause Of Eosinophilic Meningitis Research Articles

A Scoping Review of Angiostrongyliasis and Other Diseases Associated with Terrestrial Mollusks, Including Lissachatina fulica: An Overview of Case Reports and Series.

Terrestrial mollusks, including the invasive giant African snail (Lissachatina fulica), pose significant public health risks due to their role as carriers of various pathogens, such as Angiostrongylus cantonensis and Angiostrongylus costaricensis. This scoping review aims to provide a comprehensive evaluation of diseases associated with Lissachatina fulica and other terrestrial mollusks, with a particular focus on the prevention, diagnosis, and treatment of these conditions. Following the Joanna Briggs Institute guidelines and the PRISMA-ScR framework, we conducted a systematic search and filtered results, identifying 27 relevant case reports and series for analysis. Our findings reveal that ingesting raw or undercooked snails is the most hazardous exposure route, with a 75% mortality rate in affected adults, particularly in regions where snail consumption is culturally significant, such as France. A. cantonensis is the primary cause of eosinophilic meningitis, while A. costaricensis leads to abdominal angiostrongyliasis. The review also highlights the widespread impact of L. fulica in countries like France, the United States, Brazil, and Colombia, emphasizing the global nature of the threat. Children show consistent vulnerability across all exposure types, underscoring the need for targeted preventive strategies. This review underscores the urgent need for public health interventions, particularly educational campaigns to inform communities about the dangers of L. fulica. Additionally, it highlights the importance of enhancing diagnostic methods and expanding surveillance to better manage the risks associated with these invasive snails. The findings provide valuable insights for the scientific community and recommend a multidisciplinary approach to effectively mitigate the public health risks posed by L. fulica across diverse regions.

Reaching new lands: Updating the distribution of Angiostrongylus cantonensis in South America with the first record in Argentina.

Angiostrongylus cantonensis, commonly known as the rat lungworm, is a metastrongyloid nematode found primarily not only in tropical and subtropical regions but also in temperate areas and considered the leading cause of eosinophilic meningitis in humans. Synanthropic rodents such as Rattus norvegicus and Rattus rattus are the most frequent definitive hosts of this parasite. The presence of this parasite was detected in the pulmonary arteries of three specimens of R. norvegicus in the city of Buenos Aires representing the species' southernmost known record in natural hosts. Species confirmation was achieved through partial sequences of 18S and COI genes. By comparing the COI gene sequences with those available in GenBank through the construction of a haplotype network, we obtained that the analysed specimen presents high similarity with those reported in Japan and Southeast Asia. All infected rats were captured in an area surrounding a port with significant import and export activity, suggesting that A. cantonensis may have been introduced through commercial ships. Specifically, the parasite was detected in a neighbourhood with vulnerable socio-economic conditions and in a nature reserve, which exhibit biotic and abiotic characteristics conducive to sustaining high-density rat populations, scattered waste, areas of spontaneous vegetation, debris accumulation and flooded areas or lagoons offering suitable habitats for intermediate hosts such as snails. Thus, the close proximity of the port to these sites creates a favourable ecological context for the establishment of A. cantonensis. This study shows the need to conduct research to detect A. cantonensis in non-endemic areas but with the characteristics that promote its arrival and development of its life cycle in order to implement control measures to prevent expansion of this parasite and its transmission to humans and other animals.

Efficacy of X-Ray Phytosanitary Irradiation on the Infectivity and Reproduction of Angiostrongylus cantonensis in Experimentally Infected Rats.

Angiostrongylus cantonensis is a globally distributed nematode and the leading cause of eosinophilic meningitis in humans. As a global hotspot for this disease, Hawaii's agricultural exports may be contributing to the spread of A. cantonensis. Phytosanitary irradiation doses of 150 or 400 Gy provide quarantine security against multiple insect pests. We evaluated the invitro and invivo effects of phytosanitary irradiation on infectious, third-stage, A. cantonensis larvae. In vitro experiments directly exposed larvae to irradiation doses ranging from 200 to 1,000 Gy. Results showed low mortality and no dose response across all treatments 27 days post-irradiation. In vivo studies isolated larvae from wild-caught Parmarion martensi after exposure to x-ray irradiation at doses of 0, 150, and 400 Gy and infected them into laboratory rats. Fourteen rats were assigned to each treatment and infected with 50 larvae from their assigned irradiation dose. Results at 3 and 6 weeks post-infection demonstrated a significant negative dose response in regard to the number of larvae that migrated to the brain and adults found in the pulmonary artery. No irradiated larvae that grew into adults were able to produce eggs. These findings indicate that x-ray irradiation does not result in the direct mortality of A. cantonensis larvae; however, it does affect the infectivity and reproduction of A. cantonensis within its definitive host, the rat. Phytosanitary irradiation at doses ≥150 Gy appears to be an effective means of preventing the establishment of viable populations of A. cantonensis, thus reducing the potential for global spread due to agricultural exports from Hawaii.

Amyloid-\u03b2 related angiitis presenting as eosinophilic meningitis: a case report

BackgroundEosinophilic meningitis is uncommon and often attributed to infectious causes.Case presentationWe describe a case of a 72-year-old man who presented with subacute onset eosinophilic meningitis, vasculitis, and intracranial hypertension with progressive and severe neurologic symptoms. Brain MRI demonstrated multifocal strokes and co-localized right temporo-parieto-occipital vasogenic edema, cortical superficial siderosis, and diffuse leptomeningeal enhancement. He ultimately underwent brain biopsy with immunohistochemical stains for amyloid-β and Congo red that were extensively positive in the blood vessel walls and in numerous diffuse and neuritic parenchymal confirming a diagnosis of amyloid-β related angiitis. He was treated with immunosuppression with clinical stabilization.ConclusionsAmyloid-β related angiitis is an underrecognized cause of eosinophilic meningitis that can present fulminantly and is typically responsive to immunosuppression. The presence of eosinophils may provide additional clues to the underlying pathophysiology of amyloid-β related angiitis.

Ultrastructural Aspects of The Intestinal Cells Surface of Angiostrongylus Cantonensis By Using of Transmission Electron Microscopy.

SummaryThe rat lungworm Angiostrongylus cantonensis is a zoonotic parasite and the main cause of eosinophilic meningitis in the world. Its main source of nutrients originates from the degradation of host hemoglobin in blood-feeding helminths, such as A. cantonensis. The purpose of this study was to analyze the ultrastructure of the intestinal cells by using of transmission electron microscopy (TEM). A. cantonensis worms obtained from Rattus norvegicus (norway rats) from endemic area were used for TEM. The ultrastructural analysis was performed using fragments cut from the middle part of the worms, and the TEM study revealed the cells with microvilli and nuclei containing areas of loose and condensed chromatin and the presence of macrovesicles and microvesicles of digestion and it was observed in this study that intestinal epithelium is look like a syncytium. The ultrastructural aspects of the intestinal cells surface of A. Cantonensis the indicate that the intestinal epithelium is a multinucleate mosaic or syncytium.

Infectious Causes of Eosinophilic Meningitis in Korean Patients: A Single-Institution Retrospective Chart Review from 2004 to 2018.

Eosinophilic meningitis is defined as the presence of more than 10 eosinophils per μl in the cerebrospinal fluid (CSF), or eosinophils accounting for more than 10% of CSF leukocytes in patients with acute meningitis. Parasites are the most common cause of eosinophilic meningitis worldwide, but there is limited research on patients in Korea. Patients diagnosed with eosinophilic meningitis between January 2004 and June 2018 at a tertiary hospital in Seoul, Korea were retrospectively reviewed. The etiology and clinical characteristics of each patient were identified. Of the 22 patients included in the study, 11 (50%) had parasitic causes, of whom 8 (36%) were diagnosed as neurocysticercosis and 3 (14%) as Toxocara meningitis. Four (18%) patients were diagnosed with fungal meningitis, and underlying immunodeficiency was found in 2 of these patients. The etiology of another 4 (18%) patients was suspected to be tuberculosis, which is endemic in Korea. Viral and bacterial meningitis were relatively rare causes of eosinophilic meningitis, accounting for 2 (9%) and 1 (5%) patients, respectively. One patient with neurocysticercosis and 1 patient with fungal meningitis died, and 5 (23%) had neurologic sequelae. Parasite infections, especially neurocysticercosis and toxocariasis, were the most common cause of eosinophilic meningitis in Korean patients. Fungal meningitis, while relatively rare, is often aggressive and must be considered when searching for the cause of eosinophilic meningitis.

A Peculiar Distribution of the Emerging Nematode Angiostrongylus cantonensis in the Canary Islands (Spain): Recent Introduction or Isolation Effect?

Simple SummaryAngiostrongylus cantonensis, commonly known as the rat lungworm, is considered the leading cause of eosinophilic meningitis in humans. It is an emerging zoonotic parasite, endemic to the temperate and tropical zones of the Far East, Southeast Asia and the Pacific Islands, that has expanded to all continents with the exception of Antarctica. Considering the recent finding of this parasite in rats from the Canary Islands, the aim of this study was to determine its current distribution in these islands in order to highlight the risk sources for angiostrongyliasis in the archipelago. We also analyzed the environmental conditions that could determine distribution. A. cantonensis was detected in only one of the eight islands that constitute this archipelago, i.e., in the north part of the island, which presents better environmental conditions than the south for the parasite to establish itself. This limited distribution could indicate a recent introduction of the parasite in the Canaries or an isolation effect that has not allowed the expansion to the other islands. The presence of A. cantonensis implies risks for humans and other animals that justify the need of control measures to prevent the expansion to other similar areas of the archipelago.Angiostrongylus cantonensis is an emerging zoonotic nematode recognized as the leading cause of eosinophilic meningitis in the word. After its discovery in China, it was recorded in 30 countries worldwide. Recently, it has expanded to new areas such as South America and it has been recently found in the Atlantic island of Tenerife (Canary Islands). In order to characterize the distribution of A. cantonensis in the Canary Islands, the lungs of 1462 rodents were sampled in eight islands of the archipelago over 13 years and were then analyzed for A. cantonensis. Remarkably, the parasite was detected only in Tenerife, in Rattus rattus (19.7%) and Rattus norvegicus (7.14%). They were concretely in the northern part of the island, which had a warmer and more humid climate than the south and main cities. The absence of this nematode in other islands with similar environmental conditions could be explained by an isolation effect or by a recent introduction of the parasite in the islands. Besides, the presence in Tenerife of the most invasive lineage of A. cantonensis reinforced the hypothesis of a recent introduction on this island. This study highlights the need to implement control measures to prevent the expansion to other areas in order to avoid the transmission to humans and other animals.

348. Etiology of Eosinophilic Meningitis in Korea

BackgroundEosinophilic meningitis is defined as the presence of more than 10 eosinophils per mm3 in the cerebrospinal fluid (CSF), or eosinophils accounting for more than 10 percent of CSF leukocytes in a patient with symptoms or signs suggestive of acute meningitis. Parasites are known to be the most common cause of eosinophilic meningitis worldwide, but there is limited research on patients in South Korea.MethodsWe retrospectively reviewed patients with eosinophilic meningitis at a tertiary hospital in Seoul, South Korea, from 2004 to 2018. Patients who were suspected of having a non-infectious cause were excluded. Etiology and clinical characteristics such as age, sex, risk factors, symptoms and signs, laboratory and radiologic findings, treatment, and prognosis were identified.ResultsOf the 35 patients included in this study, 11 (31.4%) had parasitic causes, with 8 (22.9%) diagnosed as neurocysticercosis, and 3 (8.6%) as toxocara meningitis. Four (11.4%) were diagnosed with fungal meningitis, and underlying immunodeficiency was found in 2 of these patients. Tuberculous meningitis was suspected in 4 (11.4%), while viral and bacterial meningitis were rare causes of eosinophilic meningitis, with 2 (5.7%) and 1 (2.9%) patients, respectively. One patient with neurocysticercosis and one patient with fungal meningitis died, while 8 (22.9%) had remaining neurologic sequelae. The etiology was unknown in 13 patients (37.1%). Four of these patients received empirical anti-tuberculosis therapy, while 5 were treated empirically with acyclovir. ConclusionParasite infections, especially neurocysticercosis and toxocariasis, were the most common cause of eosinophilic meningitis in South Korean patients. Fungal meningitis, while relatively rare, is often aggressive and should always be considered when searching for the cause of eosinophilic meningitis.Disclosures All Authors: No reported disclosures

AcanR3990 qPCR: A Novel, Highly Sensitive, Bioinformatically-Informed Assay to Detect Angiostrongylus cantonensis Infections.

Angiostrongylus cantonensis (Ac), or the rat lungworm, is a major cause of eosinophilic meningitis. Humans are infected by ingesting the 3rd stage larvae from primary hosts, snails, and slugs, or paratenic hosts. The currently used molecular test is a qPCR assay targeting the ITS1 rDNA region (ITS1) of Ac. In silico design of a more sensitive qPCR assay was performed based on tandem repeats predicted to be the most abundant by the RepeatExplorer algorithm. Genomic DNA (gDNA) of Ac were used to determine the analytical sensitivity and specificity of the best primer/probe combination. This assay was then applied to clinical and environmental samples. The limit of detection of the best performing assay, AcanR3990, was 1 fg (the DNA equivalent of 1/100 000 dilution of a single 3rd stage larvae). Out of 127 CDC archived CSF samples from varied geographic locations, the AcanR3990 qPCR detected the presence of Ac in 49/49 ITS1 confirmed angiostrongyliasis patients, along with 15/73 samples previously negative by ITS1 qPCR despite strong clinical suspicion for angiostrongyliasis. Intermediate hosts (gastropods) and an accidental host, a symptomatic horse, were also tested with similar improvement in detection observed. AcanR3990 qPCR did not cross-react in 5 CSF from patients with proven neurocysticercosis, toxocariasis, gnathostomiasis, and baylisascariasis. AcanR3990 qPCR failed to amplify genomic DNA from the other related Angiostrongylus species tested except for Angiostrongylus mackerrasae (Am), a neurotropic species limited to Australia that would be expected to present with a clinical syndrome indistinguishable from Ac. These results suggest AcanR3990 qPCR assay is highly sensitive and specific with potential wide applicability as a One Health detection method for Ac and Am.

MicroRNA miR-155-5p knockdown attenuates Angiostrongylus cantonensis-induced eosinophilic meningitis by downregulating MMP9 and TSLP proteins

Angiostrongylus cantonensis infection is a major cause of eosinophilic meningitis (EM). Severe cases or cases that involve infants and children present poor prognoses. MicroRNAs (miRNAs), which are important regulators of gene expression in many biological processes, were recently found to be regulators of the host response to infection by parasites; however, their roles in brain inflammation caused by A. cantonensis are still unclear. The current study confirmed that miR-155-5p peaked at 21 days after A. cantonensis infection, and its expression was positively correlated with the concentration of excretory and secretory products (ESPs). We found that miR-155-5p knockdown lentivirus successfully ameliorated brain injury and downregulated the expression of major basic protein (MBP) in vivo, and the number of eosinophils in CSF (and the percentage of eosinophils in peripheral blood were also decreased in the miR-155-5p knockdown group. Moreover, the expression of several eosinophilic inflammation cytokines such as CCL6/C10, ICAM-1, and MMP9, declined after the miR-155-5p knockdown. SOCS1 protein, which is an important negative regulator of inflammation activation, was identified as a direct miR-155-5p target. We further detected the effect of miR-155-5p knockdown on phosphorylated-STAT3 and phosphorylated-p65 proteins, which were found to be negatively regulated by SOCS1 and play an important role in regulating the inflammatory response. We found that miR-155-5p knockdown decreased the activity of p-STAT3 and p-p65, thereby leading to lower expression of MMP9 and TSLP proteins, which were closely related to the chemotaxis and infiltration of eosinophils. Interestingly, the inhibition of p-STAT3 or p-p65 was found to induce the downregulation of miR-155-5p in an opposite manner. These observations suggest that a positive feedback loop was formed between miR-155-5p, STAT3, and NF-κB in A. cantonensis infection and that miR-155-5p inhibition might provide a novel strategy to attenuate eosinophilic meningitis.

Reducing Rat Lungworm Disease in Hawai'i Through a Collaborative Partnership With K-12 School Garden and Agriculture Projects.

A recent increase in serious cases of rat lungworm disease impacts Hawai'i's agriculture and human health. Slugs and snails, agricultural pests, are intermediate hosts of Angiostrongylus cantonensis the rat lungworm. Infection by this parasitic nematode is the leading cause of eosinophilic meningitis globally. Infection can result from ingestion of infected produce and has caused chronic neurological problems, disability, coma, and death. There are over 200 K-12 school and youth garden, and agriculture projects throughout the Hawaiian Islands. This existing network provides an avenue for teacher and student involvement in community health education and host control programs. We collaborated with five Hawai'i Island schools connected with the Hawai'i Island School Garden Network to develop an integrated pest management plan for the control of invasive, intermediate hosts of A. cantonensis. Curricula relating to rat lungworm for grades 5–8 that support student academic achievement with a focus on science, technology, engineering, art, and math were developed. The management plan trialed the use of five different materials for shelters, which provided refuge for and easy removal of unwanted slugs and snails. Over 4,000 invasive slugs and snails were removed. Students learned how to safely dispatch pests and they collected data on species found, numbers of species removed, and shelter-type capture rates. Using the arts, students shared information at school and within their family and community. A written management plan, eleven lesson plans, and auxiliary materials are now available online. A concerted effort is needed to reduce parasite hosts if we are to reduce human cases of disease and restore public faith in local agriculture. Use of the established school garden network is an ideal avenue through which to educate the public and develop solutions for this public health problem.

Geographic distribution of Angiostrongylus cantonensis in wild rats (Rattus rattus) and terrestrial snails in Florida, USA

The parasitic nematode Angiostrongylus cantonensis is a major cause of eosinophilic meningitis in humans, and has been documented in other incidental hosts such as birds, horses, dogs and non-human primates. It is endemic in Hawaii, and there have been sporadic reports in the southern continental United States. This parasite uses rats as definitive hosts and snails as intermediate hosts. In this study, we collected potential definitive and intermediate hosts throughout Florida to ascertain the geographic distribution in the state: Rats, environmental rat fecal samples, and snails were collected from 18 counties throughout the state. Classical diagnostics and morphological identification, along with molecular techniques were used to identify nematode species and confirm the presence of A. cantonensis.Of the 171 Rattus rattus collected, 39 (22.8%) were positive for A. cantonensis, and 6 of the 37 (16.2%) environmental rat fecal samples collected in three of the surveyed counties were also positive for this parasite by real time PCR. We examined 1,437 gastropods, which represented 32 species; 27 (1.9%) were positive for A. cantonensis from multiple sites across Florida. Three non-native gastropod species, Bradybaena similaris, Zachrysia provisoria, and Paropeas achatinaceum, and three native gastropod species, Succinea floridana, Ventridens demissus, and Zonitoides arboreus, which are newly recorded intermediate hosts for the parasite, were positive for A. cantonensis. This study indicates that A. cantonensis is established in Florida through the finding of adult and larval stages in definitive and intermediate hosts, respectively, throughout the state. The ability for this historically subtropical nematode to thrive in a more temperate climate is alarming, however as the climate changes and average temperatures rise, gastropod distributions will probably expand, leading to the spread of this parasite in more temperate areas. Through greater awareness of host species and prevalence of A. cantonensis in the United States, potential accidental infections may be avoided.

Real-Time Polymerase Chain Reaction Detection of Angiostrongylus cantonensis DNA in Cerebrospinal Fluid from Patients with Eosinophilic Meningitis.

Angiostrongylus cantonensis is the most common infectious cause of eosinophilic meningitis. Timely diagnosis of these infections is difficult, partly because reliable laboratory diagnostic methods are unavailable. The aim of this study was to evaluate the usefulness of a real-time polymerase chain reaction (PCR) assay for the detection of A. cantonensis DNA in human cerebrospinal fluid (CSF) specimens. A total of 49 CSF specimens from 33 patients with eosinophilic meningitis were included: A. cantonensis DNA was detected in 32 CSF specimens, from 22 patients. Four patients had intermittently positive and negative real-time PCR results on subsequent samples, indicating that the level of A. cantonensis DNA present in CSF may fluctuate during the course of the illness. Immunodiagnosis and/or supplemental PCR testing supported the real-time PCR findings for 30 patients. On the basis of these observations, this real-time PCR assay can be useful to detect A. cantonensis in the CSF from patients with eosinophilic meningitis.

The mitochondrial genome of Angiostrongylus mackerrasae as a basis for molecular, epidemiological and population genetic studies.

BackgroundAngiostrongylus mackerrasae is a metastrongyloid nematode endemic to Australia, where it infects the native bush rat, Rattus fuscipes. This lungworm has an identical life cycle to that of Angiostrongylus cantonensis, a leading cause of eosinophilic meningitis in humans. The ability of A. mackerrasae to infect non-rodent hosts, specifically the black flying fox, raises concerns as to its zoonotic potential. To date, data on the taxonomy, epidemiology and population genetics of A. mackerrasae are unknown. Here, we describe the mitochondrial (mt) genome of A. mackerrasae with the aim of starting to address these knowledge gaps.MethodsThe complete mitochondrial (mt) genome of A. mackerrasae was amplified from a single morphologically identified adult worm, by long-PCR in two overlapping amplicons (8 kb and 10 kb). The amplicons were sequenced using the MiSeq Illumina platform and annotated using an in-house pipeline. Amino acid sequences inferred from individual protein coding genes of the mt genomes were concatenated and then subjected to phylogenetic analysis using Bayesian inference.ResultsThe mt genome of A. mackerrasae is 13,640 bp in size and contains 12 protein coding genes (cox1-3, nad1-6, nad4L, atp6 and cob), and two ribosomal RNA (rRNA) and 22 transfer RNA (tRNA) genes.ConclusionsThe mt genome of A. mackerrasae has similar characteristics to those of other Angiostrongylus species. Sequence comparisons reveal that A. mackerrasae is closely related to A. cantonensis and the two sibling species may have recently diverged compared with all other species in the genus with a highly specific host selection. This mt genome will provide a source of genetic markers for explorations of the epidemiology, biology and population genetics of A. mackerrasae.

Spread of the Rat Lungworm (Angiostrongylus cantonensis) in Giant African Land Snails (Lissachatina fulica) in Florida, USA.

The rat lungworm (Angiostrongylus cantonensis) is a parasitic nematode that causes rat lungworm disease. It is the leading cause of eosinophilic meningitis and is a zoonotic health risk. We confirmed the presence of A. cantonensis using species-specific, quantitative PCR in 18 of 50 (36%) giant African land snails (Lissachatina fulica) collected from Miami, Florida, US in May 2013. These snails were collected from seven of 21 core areas that the Florida Department of Agriculture and Consumer Services monitor weekly. Rat lungworms have not previously been identified in these areas. Duplicate DNA extractions of foot muscle tissue from each snail were tested. Of the seven core areas we examined, six were positive for A. cantonensis and prevalence of infection ranged from 27% to 100%. Of the 18 positive snails, only five were positive in both extractions. Our results confirm an increase in the range and prevalence of rat lungworm infection in Miami. We also emphasize the importance of extracting sufficient host tissue to minimize false negatives.

Eosinophilia à deux: a brain nagging souvenir from the Philippines

Angiostrongylus cantonensis is the most common cause of eosinophilic meningitis. Although a rare condition among travelers, increased travel and global transportation of food products may result in more cases across non-endemic, developed countries in the future. We here describe two men with headache and painful skin after visiting the Philippines as presenting symptoms. Subsequently, confusion and focal neurologic symptoms developed. Both had increased serum eosinophils; however, CSF eosinophilia was only demonstrated after repeated lumbar puncture. In the CSF of both, Angiostrongylus spp. DNA was detected. Both were treated with albendazole combined with corticosteroids, after which symptoms improved.

MicroRNA expressions associated with eosinophilic meningitis caused by Angiostrongylus cantonensis infection in a mouse model

Angiostrongylus cantonensis (A. cantonensis) infection is the major cause of eosinophilic meningitis (EM). Severe cases or infant and child cases have poor prognosis. MicroRNAs (miRNAs) play important roles in inflammation; however, little is known about the roles in brain inflammation caused by A. cantonensis. In this study, Illumina deep sequencing and bioinformatics were used to determine the abundance and differential expression of miRNAs in the brain tissues of a mouse model. A total of 648 conserved miRNAs were identified, 157 of which were significantly differentially expressed between infected mice and normal mice. The five most fold-changed miRNAs were miR-511-5p, miR-511-3p, miR-223-3p, miR-155-5p and miR-206-3p. These expressions of miR-511, miR-223, miR-155, miR-206, miR-142 and miR-21a were validated by quantitative reverse transcription polymerase chain reaction (RT-PCR). The analysis of these miRNAs showed that miR-511-3p was more abundant than the miR-511-5p strand, and increased to a peak in 21 days after A. cantonensis infection, miR-223 might be a potential indicator of disease severity and the upregulation of miR-155-5p after stimulation with the somatic antigen of phase IV A. cantonensis implied its involvement in the central nervous system (CNS) inflammation induced by A. cantonensis infection. These observations suggest that miRNAs may play important roles in the regulation of EM caused by A. cantonensis infection.

Cloning and characterization of a novel gene encoding 16 kDa protein (Ac16) from Angiostrongylus cantonensis

Angiostrongylus cantonensis is the most common infectious cause of eosinophilic meningitis or meningoencephalitis. A novel gene (AC16) was isolated from a cDNA library of A. cantonensis fourth-stage larvae. The putative 16-kDa protein has 149 amino acids and is homologous to an immunodominant hypodermal antigen (IHA16) from Ancylostoma caninum (identities = 57%). In this paper, we cloned the gene and purified the recombinant Ac16 (rAC16) protein. Real-time quantitative PCR revealed that Ac16 was expressed significantly higher in the fourth-stage larvae and adult worms derived from rats than that in the fourth-stage larvae derived from mice. Moreover, sera from rat (permissive host) infected with A. cantonensis detected Ac16 by Western blot, while sera from infected mouse (non-permissive host) could not. The results implied that Ac16 was related to the parasitic adaptation of A. cantonensis in different hosts and non-permissive host mouse had no circulating antibody to the antigen Ac16 from A. cantonensis and thus might contribute to understanding the mechanism of parasite immune evasion. Furthermore, we evaluated the ability of Ac16 antibody diagnosing A. cantonensis infection by an indirect enzyme-linked immunosorbent assay. The results showed that the Ac16 antibody had a 79.17% sensitivity to rAC16 and 83.33% to crude adult worm antigens (CA) (P > 0.05), while the specificity to rAC16 and to CA were 95.89% and 86.30% respectively (P < 0.05), thus implying that rAc16 may constitute a putative serodiagnostic antigen for Angiostrongyliasis cantonensis.

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.

A Case Report on Eosinophilic Meningitis Caused by Angiostrongylus cantonensis

Angiostrongylus cantonensis is the most common cause of eosinophilic meningitis in humans. It is usually caused by ingestion of raw or inadequately cooked intermediate hosts or food contaminated with infective third-stage larvae. We describe a case of eosinophilic meningitis caused by A. cantonensis in a male Chinese patient. The patient had a history of eating raw fish and snail. We describe the clinical features of the patient, the diagnostic process and treatments. We also provide a brief update for physicians on the characteristics, diagnosis and treatment of eosinophilic meningitis caused by A. cantonensis, with particular emphasis on the update of prevalence and treatment of the disease in China.