Connecticut's Response to the Management of Pathogenic Vibrio parahaemolyticus

Vibrio parahaemolyticus is a naturally occurring marine bacterium in the same family as those that cause cholera <http://www.cdc.gov/cholera/index.html> and Vibrio vulnificus <http://www.cdc.gov/vibrio/vibriov.html>.  Since 2012, the Northeast region of the U.S. has experienced a sharp increase in the number of illnesses linked to Vibrio parahaemolyticus.  During 2013 the State of Connecticut shellfish control authority closed shellfish harvest areas after an outbreak of illness was linked to oysters harvested from growing areas in Norwalk and Westport.  Beginning in 2014, Connecticut's Vibrio parahaemolyticus control program managers have worked with industry to incorporate more stringent time to temperature requirements in order to minimize the proliferation of this virulent strain of bacteria, and reduce the risk of consumer illness associated with molluscan shellfish.  Post-harvest time and temperature controls as required by Connecticut's Vibrio parahaemolyticus Control Plans are evaluated by using continuous temperature data loggers to determine the effectiveness of post-harvest temperature controls, and correlated to impacts on Vibrio levels in shellfish and the associated risk of consumer illness.  

In order to gain a better understanding of Vibrio parahaemolyticus levels in Connecticut shellfish, the State's monitoring plan includes the collection of environmental parameters such as water temperature, air temperature, salinity and depth that may correlate to levels of Vibrio bacteria in shellfish.  Program managers are working with UCONN researchers to analyze this  expanded dataset of environmental variables and Vibrio parahaemolyticus concentrations in shellfish tissue, to determine the Long Island Sound-specific Vibrio parahaemolyticus vs. temperature relationship following methods in the FDA pre-harvest risk model.  This information is combined with output from a high-resolution hydrodynamic model of LIS to make daily forecasts of Vibrio parahaemolyticus levels available to industry and managers.