Discussions on Vibrio in seafood have revealed a number of developments in recent years, according to a report.

Raw shellfish such as oysters and clams are the most common foodborne source of vibriosis.

The Food and Agriculture Organization of the United Nations (FAO) and World Health Organization (WHO) published a review of risk assessment tools for Vibrio in 2020.

The latest report covers an expert meeting held at the Centre for Environment Fisheries and Aquaculture Science (Cefas) in the United Kingdom in May 2019. This event updated advice on risk assessment for Vibrio parahaemolyticus and Vibrio vulnificus in seafood.

Contributors included Erin Stokes, of the U.S. Centers for Disease Control and Prevention; Rachel Hartnell from Cefas; Enrico Buenaventura at Health Canada, and Dominique Hervio-Heath from Ifremer in France.

Range of developments
Experts reviewed draft outputs from a 2010 meeting on the topic and agreed with the basic information on pathogenicity including virulence markers and factors relevant to the fate of Vibrio parahaemolyticus and Vibrio vulnificus, such as water temperature and salinity, had not changed substantially.

However, several new models and methods were now available. Other developments were the emergence of highly pathogenic strains of Vibrio parahaemolyticus and the spread of associated infections which posed challenges to the seafood industry, risk managers, clinicians, and public health.

Topics, where new information had emerged in the past decade, included epidemiological data, approaches on remote sensing-based risk assessment models, improvements to detection and molecular methods, best practices for reducing risk, and new information on climate change with the increase and geographical spread of seafood-associated infections.

Cases have been recorded in traditionally non-endemic areas such as the northeast U.S., Spain, and South America. In a warming marine environment, there are likely to be more vibrio-associated infections. A bigger at-risk population increased population densities in coastal regions and improvements in the diagnosis of infections may also have played a role in seeing more reported cases.

Mitigation measures and next steps
Best practice approaches were high-pressure treatment, harvesting curfews, depuration or purification, and temperature control. New methods included the use of genomics and satellite imagery.

Remote-sensing-based tools have helped understand the conditions that can drive outbreaks and potentially offer the capability to predict future outbreak conditions in near real-time.

Data gaps were approaches to further characterize strains, virulence testing, and the lack of high-quality data from geographically diverse regions.

Experts recommended creating systems for epidemiological data collection at the regional, national, and international levels and an assessment of laboratory methods used to study the bacteria.

They also proposed a review of the efficacy of post-harvest processing treatments and pre and post-harvest interventions in risk mitigation including a cost/benefit analysis.

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