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

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.

We retrospectively analyzed pediatric CNS angiostrongyliasis cases admitted to a national neurology center in Guangdong, China, between 2017 and 2024.

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.

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.