Certain parasitic infections can lead to meningitis, an inflammation of the membranes surrounding the brain and spinal cord. Specifically, some parasites are known to cause a type of meningitis called Eosinophilic Meningitis (EM). This condition is characterized by an increase in eosinophils (a type of white blood cell) in the cerebrospinal fluid (CSF).
The three main parasites responsible for causing Eosinophilic Meningitis in infected individuals are:
Key Parasites Causing Eosinophilic Meningitis
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Angiostrongylus cantonensis (Neurologic Angiostrongyliasis)
- Often referred to as the "rat lungworm," Angiostrongylus cantonensis is a common cause of eosinophilic meningitis, particularly in tropical and subtropical regions.
- Humans typically become infected by consuming raw or undercooked snails, slugs, or contaminated produce that contains the parasite's larvae.
- Once ingested, the larvae migrate to the brain, causing inflammation and neurological symptoms.
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Baylisascaris procyonis (Baylisascariasis; Neural Larva Migrans)
- This parasite, commonly known as the "raccoon roundworm," primarily affects raccoons, but humans can become accidental hosts.
- Infection occurs when individuals ingest eggs from contaminated soil or objects.
- The larvae hatch in the intestines and then migrate to various organs, including the brain and central nervous system, leading to severe neurological damage and eosinophilic meningitis, often termed neural larva migrans due to the migrating larvae.
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Gnathostoma spinigerum (Neurognathostomiasis)
- Gnathostoma spinigerum is a nematode found in parts of Asia and Central America.
- People get infected by eating raw or undercooked fish, poultry, reptiles, or amphibians that harbor the parasite's larvae.
- After ingestion, the larvae migrate through tissues, including the central nervous system, causing inflammation and various neurological symptoms, including eosinophilic meningitis (neurognathostomiasis).
These parasites are significant causes of parasitic meningitis, especially in regions where their life cycles overlap with human activities and dietary practices. Recognizing the specific parasite is crucial for appropriate diagnosis and management.
Summary of Parasites and Associated Conditions
| Parasite Name | Common Name / Associated Disease | Primary Mode of Transmission | Geographic Prevalence |
|---|---|---|---|
| Angiostrongylus cantonensis | Neurologic Angiostrongyliasis | Ingestion of raw/undercooked snails, slugs, or contaminated produce | Tropical/subtropical regions (e.g., Southeast Asia, Pacific Islands, Caribbean) |
| Baylisascaris procyonis | Baylisascariasis; Neural Larva Migrans | Ingestion of eggs from raccoon feces-contaminated soil/objects | North America (especially areas with high raccoon populations) |
| Gnathostoma spinigerum | Neurognathostomiasis | Ingestion of raw/undercooked fish, poultry, reptiles, amphibians | Asia (e.g., Thailand, Japan), Central America |
