Objective To analyze the epidemiological and clinical characteristics of paragonimiasis cases in Sichuan Province, and to provide an evidence for the prevention, diagnosis and treatment of paragonimiasis in medical institutions.

Methods Data were collected from case reports submitted by cities (prefectures) from 2020 to 2023, including demographic information, epidemiological features, clinical symptoms, laboratory testing indicators, and awareness of paragonimiasis. Epidemiological descriptions and statistical analyses were performed on these variables.

Results A total of 125 paragonimiasis cases were reported in Sichuan Province from 2020 to 2023, including 53 thoracic/pulmonary cases and 72 extrapulmonary cases. Geographically, cases were distributed in Dazhou City (63 cases, 50.40%), Yibin City (61 cases, 48.80%), and Deyang City(1 case, 0.80%). The male-to-female ratio was 1.66∶1, with 77.60% (97 cases) aged 0‒18 years. Students accounted for the majority of cases (67 cases, 53.60%). Among the patients, 67 cases (53.60%) had a history of consuming raw or undercooked crabs, and 94 cases (75.20%) reported drinking untreated water. The predominant symptoms included migratory subcutaneous nodules (26.40%), cough (24.80%), and abdominal pain/diarrhea (21.60%). Younger patients exhibited a higher proportion of migratory subcutaneous nodules, while older patients more frequently presented with cough and chest pain (χ²=4.060, P=0.044; χ²=9.235, P=0.002). Elevated eosinophil percentages and absolute counts were observed in 99.20% (124 cases) and 93.60% (117 cases) of patients, respectively. Peripheral white blood cell counts were higher in thoracic/pulmonary cases than that in extrapulmonary cases (Z=2.398, P=0.016), but no statistically significant differences were found in eosinophil absolute counts or percentages between the two types (Z=0.609, P=0.542; Z=0.732, P=0.464). In terms of treatment courses, 28 cases had 1 course, 31 cases had 2 courses, 43 cases had 3 courses, 11 cases had 4 courses, and 10 cases had 5 courses or more. Extrapulmonary cases required significantly longer treatment durations than thoracic/pulmonary cases (t=2.299, P=0.023). Only 12.80% (16 cases) of patients were aware of paragonimiasis.

Conclusion Paragonimiasis in Sichuan Province occurred sporadically, and the patients were mainly children and adolescents. The clinical manifestations of the patients lacked specificity, making it easy to lead to misdiagnosis. During the diagnosis, epidemiological history, migratory subcutaneous nodules and other main symptoms should be fully considered. An increase of the absolute count and proportion of eosinophils served as significant warning indicators for paragonimiasis infection.