[Health implications of the finding of Angiostrongylus cantonensis, the main cause of eosinophilic meningoencephalitis, in continental Europe (Valencia, Spain)]

The rat pulmonary artery nematode, Angiostrongylus cantonensis (discovered in rats from the province of Canton, southern China, in 1933 ) is the main cause in humans of what is known as eosinophilic meningoencephalitis (EEM), with around of 3,000 confirmed cases in various parts of the world.

The metagenomic next-generation sequencing in diagnosing central nervous system angiostrongyliasis: a case report

Backgrounds

The incidence of angiostrongyliasis is increasing in recent decades due to the expanding endemic areas all over the world. Clinicians face tremendous challenge of diagnosing angiostrongyliasis because of the lack of awareness of the disease and less effective definitive laboratory tests.

Case presentation

A 27-year-old man initially manifested skin itching, emesis, myalgia and quadriparesis. With progressive weakness of four limbs and elevated protein in the cerebrospinal fluid (CSF), he was diagnosed as Guillain-Barré syndrome and treated with intravenous methylprednisolone and immunoglobulin. However, the patient deteriorated with hyperpyrexia, headache and then persistent coma. The routine tests for Angiostrongylus cantonensis (A. cantonensis) with both the CSF and the serum were all negative. In contrast, the metagenomic next-generation sequencing (mNGS) was applied with the serum sample and the CSF sample in the middle phase. The central nervous system (CNS) angiostrongyliasis was diagnosed by mNGS with the mid-phase CSF, but not the mid-phase serum. At the same time, the CSF analysis revealed eosinophils ratio up to 67%. The discovery of A. cantonensis was confirmed by PCR with CSF later. Unfortunately, the patient died of severe angiostrongyliasis. During his hospitalization, mNGS was carried out repeatedly after definitive diagnosis and targeted treatment. The DNA strictly map reads number of A. cantonensis detected by mNGS was positively correlated with the CSF opening pressure and clinical manifestations.

Conclusions

The case of A. cantonensis infection highlights the benefit of mNGS as a target-free identification in disclosing the rare CNS angiostrongyliasis in the unusual season, while solid evidence from routine clinical testing was absent. The appropriate sample of mNGS should be chosen according to the life cycle of A. cantonensis. Besides, given the fact that the DNA reads number of A. cantonensis fluctuated with CSF opening pressure and clinical manifestations, whether mNGS could be applied as a marker of effectiveness of treatment is worth further exploration.

Rapid progression and brain atrophy in anti-AMPA receptor encephalitis

Anti-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor encephalitis is an anti-neuronal surface antigen autoimmune encephalitis that is rarely reported. Our study evaluated the first known patient who developed anti-AMPA receptor encephalitis during pregnancy. Initial brain MRI revealed bilateral limbic encephalitis. However, rapid brain atrophy on MRI with extensive hypometabolism of cerebral cortices, caudate nuclei and brain stem hypoperfusion on (18)F-FDG PET developed when clinically progressed. IgG index of serial CSF studies reflected the clinical improvements after plasmapheresis and plasma exchange. The clinical spectrum of anti-AMPA receptor encephalitis may be expanded from limited limbic involvement to extended central nervous system.

Clinical aspects of eosinophilic meningitis and meningoencephalitis caused by Angiostrongylus cantonensis, the rat lungworm

Angiostrongylus Eosinophilic Meningitis is caused by human infection with larvae of the rat lungworm, Angiostrongylus cantonensis. The clinical presentation includes a spectrum of disease, from meningitis through radiculitis, cranial nerve abnormalities, ataxia, encephalitis, coma, and rarely death. The condition is diagnosed by recognizing the triad of: the clinical syndrome, eosinophils in the cerebrospinal fluid or blood, and exposure history. A history of eating raw or poorly cooked snails is classic, but ingestion of other intermediate hosts or unwashed produce (such as lettuce) harboring hosts is not uncommon. Several serologic tests exist but none has yet been fully validated. There is good evidence that a 2 week course of high dose corticosteroids shortens the duration and severity of symptoms. There is somewhat weaker evidence that albendazole reduces symptoms. The combination of prednisolone and albendazole is being used more commonly for treatment. Some suggestions for future research are given.

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.