Imported Pediatric Paragonimiasis in China: Two Cases From Zhaotong to Hangzhou

BACKGROUND Paragonimiasis, a food-borne parasitic zoonosis mainly caused by Paragonimus westermani and Paragonimus skrjabini in China, is rarely reported in Hangzhou, Zhejiang Province, a low-incidence urban setting. Paragonimiasis is often misdiagnosed due to its long incubation period, atypical manifestations, and low clinician awareness in non-endemic regions. Pleural effusion is common in thoracopulmonary paragonimiasis. We describe 2 imported, family-clustered pediatric cases (cousins) from endemic Zhaotong, Yunnan Province, both of whom presented with pleural effusion detected by chest computed tomography (CT); our report highlights clustered imported paragonimiasis in a low-incidence city. CASE REPORT Case 1: A 4-year-old boy was admitted with an 8-day history of fever and cough and was initially misdiagnosed with bacterial pneumonia (elevated leukocyte count, C-reactive protein levels, and loculated pleural effusion). Paragonimiasis was suspected based on eosinophilia and epidemiological exposure; it was confirmed by positive Paragonimus IgG test results. The patient recovered after treatment with oral praziquantel (PZQ). Case 2: The 9-year-old cousin of the patient in Case 1 displayed a persistent cough 1 month after the first case, with eosinophilia, right-sided pneumonia, and pleural effusion. Recognition of family clustering facilitated prompt diagnosis and successful treatment with PZQ. CONCLUSIONS This report highlights imported, family-clustered pediatric paragonimiasis in Hangzhou, a low-incidence city, providing greater diagnostic and epidemiological value than sporadic cases. Family clustering serves as a key clue for reducing misdiagnosis in non-endemic regions. Clinicians should consider paragonimiasis in children with relevant epidemiological exposure, unexplained pleural effusion, or eosinophilia, particularly when family clustering is present.