[Surveillance of parasitic infections in market-sold aquatic products and knowledge and practice towards food-borne parasitic diseases among residents in Shanghai Municipality from 2020 to 2023].

Abstract

Objective: To investigate the prevalence of parasitic infections in market-sold aquatic products in Shanghai Municipality, and to understand the knowledge and practice towards food-borne parasitic diseases among residents, so as to provide insights into the surveillance and control of food-borne parasitic diseases.

Methods: Freshwater products, seawater products and pickled products were randomly obtained from agricultural trade markets, supermarkets, retail stores and restaurants in Huangpu, Putuo, Minhang and Qingpu districts of Shanghai Municipality from 2020 to 2023. Parasite metacercariae and larvae were detected in these aquatic products using pressing method, digestion method and the dissection method, and the detection of parasitic infection was compared in different types of aquatic products. In addition, the knowledge and practice towards food-borne parasitic diseases were investigated among residents aged 10-80 years old who randomly selected from agricultural trade markets, supermarkets, community streets and other population concentration areas in these four districts by questionnaire in 2023, and the awareness of food-borne parasitic diseases knowledge and percentage of healthy behaviors formation were analyzed.

Results: A total of 2 109 aquatic products sampled from Huangpu, Putuo, Minhang and Qingpu districts of Shanghai Municipality from 2020 to 2023 were detected, and there were 317 products detected with parasitic infections, with an overall detection rate of 15.03%. There were 8 products detected with parasitic infections in 1 221 freshwater products, with a detection rate of 0.66%, and Clonorchis sinensis was the predominant parasite, which was detected in Pseudorasbora parva, Rhodeus amarus and Carassius auratus. There were 82 products detected with parasitic infections in 501 seawater products, with a detection rate of 16.37%, and Anisakis was the predominant parasite, which was detected in Trichiurus lepturus, Larimichthys polyactis, Pneumatophorus japonicus, Collchthys lucidus, Mugil cephalus, Larimichthys crocea, Scomberomorus niphonius, Stromateoides argenteus and Cololabis saira. There were 227 products detected with parasitic infections in 387 pickled products, with a detection rate of 58.66%, and the prevalence rates of Echinostoma metacercariae were 76.27% (225/295) in Bullacta exarata and 11.11% (2/18) in crab pastes, respectively (χ² = 159.511, P < 0.05). No Paragonimus infection was found in freshwater shrimps, crabs and pickled products, and no Diphyllobothrium latum larvae infection was detected in freshwater and seawater fish. Questionnaire surveys showed that the awareness of food-borne parasitic diseases knowledge was 79.00% (222/281), and the percentages of washing hands before and after meals, not drinking filtered water or tap water directly, not eating raw or semi-raw food, being willing to change special dietary preferences or bad living habits for health, and being willing to learn more about food-borne parasitic diseases knowledge were 99.64% (280/281), 72.24% (203/281), 56.23% (158/281), 96.80% (272/281) and 97.51%(274/281) among residents living in Huangpu, Putuo, Minhang and Qingpu districts, respectively.

Conclusions: There are food-borne parasite contaminations in market-sold aquatic products in Shanghai Municipality. Although residents are aware of food-borne parasitic diseases knowledge, sustainable surveillance of food-borne parasitic diseases and improved health education are required to minimize the risk of human parasitic infections.