MEDizzy - A 28-year-old man is brought to the emergency department by

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Infection causing diseases 2

A 28-year-old man is brought to the emergency department by his wife for altered mental status, fevers, vomiting, and headache. He developed a bilateral headache that began about a day ago that has progressively worsened. He hand his wife returned from a trip to Thailand and Vietnam where they spent a lot of time in rural settings eating local mollusks, seafood, and vegetables. His physical examination is notable for fever, nuchal rigidity, confusion, and lethargy. Lumbar puncture reveals elevated opening pressure, elevated protein, normal glucose, and WBC count of 200/μL with 50% eosinophils, 25% neutrophils, and 25% lymphocytes. Which of the following is the most likely etiology of his meningitis?

ExplanationA. Angiostrongylus cantonensis The clinical presentation of this patient, with symptoms of altered mental status, fever, vomiting, and headache, along with the findings of nuchal rigidity and eosinophilic pleocytosis in the cerebrospinal fluid, is highly suggestive of eosinophilic meningitis. Eosinophilic meningitis is often associated with parasitic infections. Among the options provided, the most likely etiology of eosinophilic meningitis in this case is Angiostrongylus cantonensis, a parasitic nematode commonly known as rat lungworm. This parasite is primarily found in Southeast Asia and is commonly transmitted to humans through the consumption of raw or undercooked mollusks, such as snails or slugs, which serve as intermediate hosts. The larvae migrate to the central nervous system, causing meningitis. Gnathostoma spinigerum, another parasitic nematode, can also cause eosinophilic meningitis, but it is less common in the areas mentioned (Thailand and Vietnam) compared to Angiostrongylus cantonensis. Trichinella murrelli and Trichinella nativa are species of Trichinella that primarily cause trichinellosis, which is characterized by muscle involvement rather than meningitis. Toxocara canis is a parasitic roundworm that can cause visceral larva migrans but is not commonly associated with eosinophilic meningitis. Therefore, based on the travel history and clinical findings, Angiostrongylus cantonensis is the most likely etiology of this patient's eosinophilic meningitis.