Incidence of paragonimiasis in Chongqing China: a 6-year retrospective case review.

Paragonimiasis is an important infectious disease in Chongqing, China. However, no epidemiological surveys of paragonimiasis have been carried out in Chongqing since it became a municipality in 1997. We conducted a retrospective case review of 683 patients who were referred to our laboratory and diagnosed as having paragonimiasis during 2010-2015. Patients were diagnosed with paragonimiasis based on immunodiagnostic tests in addition to clinical and laboratory findings. Patient data extracted from the epidemiologic form were analysed. The majority of patients were distributed on the east side of the Wujiang River, which belongs to the Three Gorges Reservoir region. Consumption of raw or undercooked freshwater crab or crayfish in the family Cambaridae was the main reason for infection. Notably, more than 50·0% of patients were diagnosed between March and July, indicating that serious clinical symptoms only appear approximately 6 months post-infection. Paragonimiasis remains a public health issue in Chongqing, and an epidemiological study of Paragonimus in the Three Gorges region is strongly recommended.