Summary about Disease
Baylisascaris infection, also known as neural larva migrans, is a parasitic infection caused by the roundworm Baylisascaris procyonis, commonly found in raccoons. Humans, particularly young children, can become infected by accidentally ingesting eggs of the parasite from contaminated soil, surfaces, or objects. While raccoons are the definitive host, other animals, including dogs, can also be infected and shed eggs. In humans, the larvae migrate through the body, causing severe neurological damage as they invade the brain and spinal cord. The infection is often severe and can be fatal.
Symptoms
Symptoms vary depending on the number of larvae ingested and the organs they invade. Neurological symptoms are the most common and severe. These can include:
Nausea
Lethargy
Irritability
Ataxia (loss of coordination)
Altered mental status
Coma
Blindness
Muscle weakness
Seizures Other symptoms might involve internal organs.
Causes
The primary cause is the ingestion of Baylisascaris procyonis eggs. These eggs are typically found in raccoon feces. Infection occurs when humans, especially young children, accidentally ingest soil, objects, or surfaces contaminated with raccoon feces containing the eggs. The eggs hatch in the human intestine, and the larvae migrate throughout the body.
Medicine Used
Treatment is challenging and not always effective, especially once neurological symptoms have developed. Medications used may include:
Albendazole: An anti-parasitic medication that may kill the larvae. It's most effective when administered early in the infection, before extensive larval migration.
Corticosteroids: To reduce inflammation caused by the migrating larvae in the brain and other organs. Supportive care is also crucial to manage symptoms and complications.
Is Communicable
Baylisascaris infection is not directly communicable from person to person. It is acquired through contact with contaminated environments (raccoon feces containing the eggs).
Precautions
Avoid contact with raccoons and their feces.
Teach children about the importance of handwashing, especially after playing outdoors or handling soil.
Supervise children closely in areas where raccoons may be present.
Prevent children from putting soil, dirt, or other potentially contaminated objects in their mouths.
Control raccoon populations around homes and communities by removing food sources (pet food, garbage).
Wear gloves and wash hands thoroughly after gardening or working with soil.
Clean and disinfect surfaces that may have been contaminated with raccoon feces.
Consult a pest control professional for safe and effective raccoon removal.
How long does an outbreak last?
There are no "outbreaks" in the traditional sense of a rapidly spreading contagious disease. Baylisascaris infection is acquired individually through contact with contaminated environments. The presence of viable eggs in the environment can persist for years, meaning that the risk of infection exists continually in contaminated areas. A specific case's duration is measured by the duration of the illness in the infected individual.
How is it diagnosed?
Diagnosis can be difficult, especially early in the infection. It typically involves a combination of factors:
Clinical suspicion: Based on symptoms and a history of potential exposure to raccoons or their feces.
Laboratory tests:
Blood tests: May show elevated eosinophil levels (a type of white blood cell often elevated in parasitic infections). Antibody testing is available but might not be readily accessible.
Cerebrospinal fluid (CSF) analysis: Examination of CSF obtained through a spinal tap may show inflammation or the presence of parasitic larvae (though this is rare).
Imaging studies:
MRI: Can reveal lesions in the brain caused by migrating larvae.
Microscopic identification: In rare cases, larvae may be identified in tissue samples obtained through biopsy.
Timeline of Symptoms
The incubation period (time between ingestion of eggs and the onset of symptoms) can vary, but it is typically 1-4 weeks.
Early Symptoms (1-4 weeks post-ingestion): Vague symptoms like fatigue, nausea, and irritability may appear. Eosinophilia might be present in blood tests.
Neurological Symptoms (Later stages): As larvae migrate to the brain, neurological symptoms develop. The specific timeline and severity of these symptoms depend on the number of larvae and the areas of the brain affected. These symptoms can worsen progressively over weeks to months.
Progression: Without effective treatment, neurological damage can become permanent, leading to severe disability or even death.
Important Considerations
Early diagnosis and treatment are crucial to improve the chances of a favorable outcome.
Prevention is the most effective strategy to avoid Baylisascaris infection.
Public awareness campaigns are important to educate people about the risks and preventive measures.
Veterinarians play a role in controlling the spread of the parasite in animal populations (e.g., by deworming dogs).
This is a rare but serious infection, and healthcare providers should consider it in patients with unexplained neurological symptoms, especially if there is a history of potential exposure to raccoons.