Central nervous system infection by Angiostrongylus cantonensis in children: experience from Guangdong, China

Abstract Background Angiostrongylus cantonensis (A. cantonensis)–induced central nervous system (CNS) infection is a rare parasitic disease. Although global incidence is rising, pediatric cases remain underrecognized. This study aimed to characterize clinical features and evaluate the diagnostic utility of metagenomic next-generation sequencing (mNGS) in children. Methods We retrospectively analyzed pediatric CNS angiostrongyliasis cases admitted to a national neurology center in Guangdong, China, between 2017 and 2024. Results A total of 22 pediatric patients were enrolled (median age 1.8 years; male: female = 14:8). Most cases (68.2%) began between June and October; 45.5% had confirmed or probable exposure. Fever was the most common symptom (77.2%), followed by somnolence or lethargy (63.6%) and vomiting (59.1%). No patients reported neck stiffness or hyperesthesia. All patients showed peripheral eosinophilia (median peak 24.0%, IQR 16.0%–36.0%) and cerebrospinal fluid (CSF) pleocytosis. The initial CSF eosinophil percentage exceeded 10% in 10/22 patients (45.5%), and this increased in 7/22 patients (31.8%) during follow-up. Median peak CSF eosinophil percentage was 17.2% at day 18. Among 10 patients tested for CSF cytokines, 90.0% had elevations, with IL-6 being the most common and associated with higher CSF eosinophil percentages. Serum and CSF IgG against A. cantonensis were positive in 44.4% and 46.7%, respectively. Metagenomic next-generation sequencing (mNGS) of cerebrospinal fluid was performed in 18 of the 22 patients, and A. cantonensis was identified in all tested cases (18/18, 100%), including four who were seronegative. The median mNGS read counts of A. cantonensis were 2,453 (IQR 353.5–28,641.75), which were not significantly correlated with CSF eosinophil percentages, white blood count, or protein levels. Brain magnetic resonance imaging abnormalities (81.8%) included leptomeningeal enhancement (45.5%), ventricular enlargement (40.9%), and cortical lesions (31.8%). Electroencephalogram was abnormal in 54.5%, mainly showing slowing (50.0%) or epileptiform activity 9.1%. Albendazole was used alone in 13.6% of patients, while 86.4% received combined therapy with corticosteroids. Of the 20 patients with follow-up (median 2.5 months), all recovered clinically and radiologically without relapse or sequelae. Conclusion Pediatric CNS angiostrongyliasis in Guangdong primarily affects rural children during summer–autumn. Clinical signs may be nonspecific. mNGS outperformed serology, especially in early or seronegative cases. Most patients had favorable short-term outcomes.