Epidemical study of third stage larvae of Anisakis spp. infection in marine fishes in China from 2016 to 2017

Background: Anisakis, a genus of parasitic nematodes, can infect fish and potentially cause diseases in human. Yet it has not drawn public attention in China. It is urgent to conduct the first epidemical study on third stage larvae of Anisakis spp. infection in marine fishes across most coastal regions of China from 2016 to 2017. Methods: In this study, 2422 samples of marine fishes were collected from eight coastal regions in China from 2016 to 2017. The third-stage larvae of Anisakis spp. were examined under a light microscope. The chi-square test, the Fisher's exact test and the logistic regression were applied in this study. Results: The infection rate was 28.70% (695/2422). Compared with live fish, the infection rate of fresh fish was higher at 31.88% (577/1810). Statistical analyses showed that there existed a significant difference in infection rate of different sampling months, which could be explained by fishing ban. Conclusions: The result showed that sampling region, fish status, fish species and sampling month were the main factors influencing infection rate. Regulations or guidelines are urgent in China for the control of Anisakis spp. infection in marine fish.