What are the treatment and management options for a patient, particularly a child or immunocompromised individual, who has ingested raccoon feces and is at risk for Baylisascaris procyonis infection?

Management of Raccoon Feces Ingestion

For any patient who has ingested raccoon feces, immediately initiate prophylactic albendazole treatment without waiting for confirmatory testing, as Baylisascaris procyonis infection can cause devastating and irreversible neurologic damage or death if treatment is delayed. 1, 2, 3, 4

Immediate Actions

Decontamination and Initial Assessment

• Wash hands thoroughly with soap and running water for at least 20 seconds, scrubbing backs of hands, between fingers, and under nails, as this is the single most important intervention to prevent further pathogen transmission 1
• Remove and clean any contaminated clothing, shoes, or objects that contacted the feces 5
• Do not allow the patient to eat, drink, or place anything in mouth until hands are thoroughly washed 1, 5

Immediate Prophylactic Treatment

• Start albendazole immediately upon recognition of exposure, before environmental testing confirms B. procyonis contamination 1, 2, 4
• The Infectious Diseases Society of America recommends albendazole plus diethylcarbamazine (C-III) for confirmed Baylisascaris infection 1
• Treatment efficacy is excellent if given promptly after infection but poor once clinical disease develops 6, 4
• A 2025 case series demonstrated that delays in diagnosis and treatment resulted in severe neurologic sequelae, while prompt treatment allowed return to baseline neurologic status 3

Corticosteroid Consideration

• The Infectious Diseases Society of America recommends corticosteroids (B-III) for Baylisascaris infection to reduce inflammatory damage from dying larvae 1
• Both patients in the 2025 Los Angeles County cases received albendazole plus corticosteroids 3

Risk Stratification

High-Risk Populations Requiring Heightened Vigilance

• Children aged <5 years are at particularly high risk for serious infection and severe disease 1, 4
• Patients with developmental disabilities or pica have increased exposure risk through geophagia and hand-to-mouth behaviors 3, 4, 7
• Immunocompromised individuals (HIV/AIDS, asplenia, immunosuppressive therapy) are at increased risk for serious infection 1
• Male sex and age <4 years are documented risk factors for B. procyonis infection 4

Disease Severity Factors

• The severity of CNS disease depends on the number of eggs ingested, extent and location of larval migration, and severity of inflammation and necrosis 4
• Symptoms range from mild CNS dysfunction to severe deficits, coma, and death based on inoculum size 1
• Without prompt treatment, B. procyonis can cause devastating encephalitis with permanent neurologic sequelae or death 3, 6, 4

Diagnostic Evaluation

Clinical Presentation to Monitor

• Neurologic symptoms: behavioral changes, lethargy, gait instability, seizures, hemiparesis, cranial nerve abnormalities, extrapyramidal signs 1, 3, 4
• Laboratory findings: peripheral blood eosinophilia (>1,000 eosinophils/mL) and cerebrospinal fluid eosinophilia 1, 3, 4
• Imaging: MRI reveals deep white matter lesions characteristic of larval migration 1, 4

Confirmatory Testing

• Serum and CSF antibodies against B. procyonis assist in documenting infection, with serologic conversion confirming exposure 4, 7
• Identification of larvae in tissue is diagnostic but rarely practical 1
• Environmental testing of raccoon feces for B. procyonis eggs can confirm exposure source but should not delay treatment 2, 7

Monitoring During Albendazole Treatment

Required Laboratory Surveillance

• The FDA mandates monitoring blood counts at the beginning of each 28-day cycle and every 2 weeks during therapy, as albendazole can cause bone marrow suppression, aplastic anemia, and agranulocytosis 8
• Monitor liver enzymes (transaminases) before each treatment cycle and at least every 2 weeks, as albendazole causes mild-to-moderate elevations in approximately 16% of patients 8
• Discontinue albendazole if clinically significant decreases in blood cell counts occur or if hepatic enzymes exceed twice the upper limit of normal 8

Special Considerations for Females of Reproductive Potential

• Obtain pregnancy test prior to initiating albendazole, as the drug causes embryotoxicity and skeletal malformations in animal studies 8
• Advise use of effective contraception during treatment and for 3 days after the final dose 8

Prevention of Future Exposures

Environmental Control Measures

• Raccoons defecate in communal latrines that contain enormous numbers of parasite eggs and play a vital role in transmission 6, 7
• The 2025 Los Angeles County investigation identified a rooftop raccoon latrine as the exposure source, with one case having no identifiable source 3
• A 2000 field investigation demonstrated raccoon populations far exceeding previous reports, with abundant B. procyonis eggs at numerous defecation sites around the patient's residence 7
• Prevent raccoon activity around properties and safely remove raccoon latrines to reduce exposure risk 3

Hand Hygiene and Supervision

• Closely supervise children to prevent hand-to-mouth activities including nail-biting, thumb-sucking, and touching contaminated surfaces 5
• Do not allow children to sit or play on ground in areas where raccoons defecate 5
• Assist young children with proper hand washing technique 1, 5

Critical Pitfalls to Avoid

• Never delay treatment waiting for confirmatory testing—albendazole must be started immediately upon recognition of exposure, as treatment efficacy is poor once clinical disease develops 2, 4
• Do not underestimate exposure risk in urban and suburban settings—raccoons have become well adapted to living alongside people, with high prevalence of B. procyonis infection 6, 7
• Do not rely on hand sanitizer alone when hands are visibly soiled—soap and water are essential for removing parasite eggs 1, 5
• Do not overlook developmental disabilities or pica as major risk factors requiring immediate prophylaxis 3, 4
• Do not assume brief or minimal exposure is safe—the infectious dose of B. procyonis is relatively low, and eggs can survive in the environment for extended periods 6