Neurocysticercosis in California: Clinical Characteristics and Associated Comorbidities Across the University of California Health System

Introduction: Neurocysticercosis (NCC) is an infection of the central nervous system caused by the tapeworm Taenia solium. Despite documented increases of NCC in California, large-scale studies characterizing affected populations remain limited. The spectrum of NCC associated neuropsychiatric comorbidities has not been well defined in U.S. populations. This study aimed to estimate the prevalence of NCC within the University of California (UC) Health System, characterize the population demographic and clinical features, and identify factors associated with epilepsy among individuals with NCC. Methodology/Principal Findings: We conducted a cross-sectional analysis of electronic health records from 2012 through March 2026 using the UC Health Data Warehouse, which integrates data from six UC Health systems. Among individuals aged [≥] 1 year, there were 713 individuals with a diagnosis of NCC corresponding to a prevalence of 6.17 per 100,000. A comparison group was randomly selected at a 1:10 ratio. Relative to the comparison group, NCC patients were significantly older, more likely to identify as Hispanic or Latino, more likely to speak Spanish as a primary language, and more likely to have Medicaid insurance. NCC was strongly associated with epilepsy (OR = 19.20, 95% CI: 15.74-23.46), as well as migraines, cognitive impairment, mood disorders, Parkinsons disease, substance use, stroke, and sleep disorders. After adjusting for age, gender, and ethnicity, male NCC patients had 26% higher odds of epilepsy compared to female patients. Conclusion/Significance: In addition to epilepsy, NCC was associated with a broad range of neuropsychiatric comorbidities and occurred disproportionately among patients more likely to face socioeconomic and structural barriers to care, including limited insurance coverage, language barriers, and immigration-related challenges. These findings highlight the importance of recognizing NCC in non-endemic settings, where this often underrecognized disease contributes substantially to neurologic morbidity in a vulnerable population.