Quantitative risk assessment of the effect of Vibrio parahaemolyticus in retail seafood on the health of residents in Hangzhou city: based on monitoring data

Objective To estimate the risk of Vibrio parahaemolyticus-caused illness associated with the consumption of seafood in Hangzhou, and identify the key points for risk control, thereby providing evidence for adopting effective risk management measures.

Methods The surveillance data of V. parahaemolyticus concentration in seafood in Hangzhou from 2011 to 2022 and Hangzhou residents′ seafood consumption data in 2015 were extracted. According to the growth model of V. parahaemolyticus and related parameters from scientific literature, the Monte Carlo simulation method was employed to analyze the change of V. parahaemolyticus concentration in seafood from market to table and quantify the exposure of V. parahaemolyticus in the residents by consuming seafood in Hangzhou. Finally, a dose-response model was adopted to assess the risk of gastroenteritis caused by V. parahaemolyticus.

Results The positive rate of V. parahaemolyticus in retail seafood in Hangzhou was 31.78% (90%CI: 28.38%–35.42%), with an initial contamination level of –0.20 (90%CI: –0.82 to 2.04) lg CFU/g. The average daily incidence risk of gastroenteritis caused by V. parahaemolyticus in seafood among residents was 1.93 × 10^–5 in Hangzhou. The number of people infected with V. parahaemolyticus per million residents per year due to seafood consumption was 7 044. The sensitivity analysis showed that the risk was mainly and positively correlated with the initial contamination level of V. parahaemolyticus in seafood and the transportation and storage temperature and time of seafood.

Conclusions There is certain health risk due to the consumption of seafood in Hangzhou. The risk could be effectively reduced by controlling the contamination level of V. parahaemolyticus in retail seafood and strictly controlling the storage and transportation temperature and time of seafood.