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Food Safety: FDA Needs to Reassess Its Approach to Reducing an Illness Caused by Eating Raw Oysters

GAO-11-607 Published: Sep 08, 2011. Publicly Released: Oct 11, 2011.
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Highlights

Vibrio vulnificus (V. vulnificus) is a bacterium that occurs naturally in the Gulf of Mexico. On average, since 2000, about 32 individuals a year in the United States have become ill from eating raw or undercooked oysters containing V. vulnificus, and about half have died. The Food and Drug Administration (FDA) is responsible for ensuring oyster safety and works with the Interstate Shellfish Sanitation Conference (ISSC), which includes representatives from FDA, states, and the shellfish industry to establish guidelines for sanitary control of the shellfish industry. GAO was asked to determine the extent to which FDA and the ISSC agree on the V. vulnificus illness reduction goal, use a credible approach to measure progress toward the illness rate reduction goal, have evaluated the effectiveness of their actions in reducing V. vulnificus illnesses, and whether the Gulf Coast oyster industry has adequate capacity to postharvest process oysters harvested April through October. GAO reviewed data and documents and interviewed officials in FDA, the ISSC, Florida, Louisiana, and Texas.

FDA and the ISSC do not agree on a common V. vulnificus illness reduction goal. In October 2009, FDA announced its intention to change its approach to V. vulnificus illnesses from reducing them to largely eliminating them. To do so, FDA would require states to use postharvest processing methods, which include a mild heat treatment known as low temperature pasteurization. FDA's announced approach was a change from the 60 percent illness rate reduction goal established by the ISSC in 2001, with FDA concurrence. In a November 2009 letter to FDA, the ISSC expressed disappointment that FDA had not followed a 1984 memorandum of understanding that calls for FDA and the ISSC to consult on such matters. If FDA and the ISSC are not in agreement on the illness reduction goal and strategies to achieve it, it will be difficult for the Gulf Coast states to move forward to significantly reduce the number of consumption-related V. vulnificus illnesses. The approach FDA and the ISSC have been using to measure progress toward the previously agreed upon V. vulnificus illness rate reduction goal established in 2001 has limitations that undermine its credibility. For example, the ISSC continues to include California's results in its illness rate reduction calculation along with Florida, Louisiana, and Texas. Doing so overstates the effectiveness of consumer education and time and temperature controls--FDA's and the ISSC's primary strategies for reducing V. vulnificus illnesses--because California, unlike these other states, requires that all raw Gulf Coast oysters harvested during the summer and sold in the state be processed to reduce V. vulnificus to nondetectable levels, which has reduced V. vulnificus illnesses to nearly zero. FDA and the ISSC have taken few steps to evaluate the effectiveness of their consumer education efforts since 2004. Likewise, they have not directly evaluated the effectiveness of the time and temperature controls implemented in 2010, which call for harvesters to ensure that oysters are cooled to specific temperatures within certain times to reduce V. vulnificus growth. Although data are not available, our discussions with state and oyster industry officials suggest 100 percent compliance with the controls is highly unlikely. Moreover, our analysis shows--even assuming 80 percent compliance in the summer months-- it is unlikely that these controls will lead to the level of illness reduction estimated by a model developed by FDA. The Gulf Coast oyster industry does not have sufficient capacity to process all of its oysters intended for raw consumption that are harvested from April through October to reduce V. vulnificus to nondetectable levels, according to an FDA-commissioned report. The report concluded that it will take a minimum of 2 to 3 years to develop the infrastructure needed to process these oysters. However, the report has some limitations that call into question the completeness of its cost and timeline estimates. For example, the report's cost estimates did not include some construction costs and costs associated with purchasing land needed to expand existing processing facilities or build new ones. Without this information, the full cost of developing sufficient processing capacity will not be known. GAO recommends that FDA work with the ISSC to agree on an illness reduction goal, improve its approach to measuring progress in reducing V. vulnificus illnesses, regularly evaluate its illness reduction strategies, and address the limitations in the FDA-commissioned report. FDA and the ISSC generally agreed with our recommendations.

Recommendations

Recommendations for Executive Action

Agency Affected Recommendation Status
Department of Health and Human Services To better ensure the safety of oysters from the Gulf of Mexico that are sold for raw consumption, the Secretary of Health and Human Services (HHS) should direct the Commissioner of FDA to work with the ISSC to agree on a nationwide goal for reducing the number of V. vulnificus illnesses caused by the consumption of Gulf Coast raw oysters and develop strategies to achieve that goal, recognizing that consumer education and time and temperature controls have not resulted in achievement of the 60 percent V. vulnificus illness rate reduction goal and that the capacity to use postharvest processing on Gulf Coast oysters harvested from April through October that are intended for raw consumption does not currently exist.
Closed – Not Implemented
As of August 30, 2017, FDA had not acted on this recommendation so we are closing it as unimplemented.
Department of Health and Human Services To better ensure the safety of oysters from the Gulf of Mexico that are sold for raw consumption, the Secretary of Health and Human Services (HHS) should direct the Commissioner of FDA to work with the ISSC to correct the limitations in the current approach to measuring progress toward the 60 percent V. vulnificus illness rate reduction goal or design and implement a new approach without these limitations.
Closed – Not Implemented
As of August 30, 2017, FDA had not acted on this recommendation, so we are closing it as unimplemented.
Department of Health and Human Services To better ensure the safety of oysters from the Gulf of Mexico that are sold for raw consumption, the Secretary of Health and Human Services (HHS) should direct the Commissioner of FDA to work with the ISSC to regularly evaluate the effectiveness of V. vulnificus illness reduction strategies, such as consumer education and time and temperature controls, to determine whether they are successful and should be continued or are ineffective and should be stopped.
Closed – Not Implemented
As of August 30, 2017, FDA had not acted on this recommendation, so we are closing it as unimplemented.
Department of Health and Human Services To better ensure the safety of oysters from the Gulf of Mexico that are sold for raw consumption, the Secretary of Health and Human Services (HHS) should direct the Commissioner of FDA to work with the ISSC to conduct further study of the six issues of concern we identified regarding the FDA-commissioned Research Triangle Institute International (RTI) report's economic analysis to ensure a more accurate assessment of the feasibility of developing adequate capacity and before FDA and the ISSC move forward with revising the National Shellfish Sanitation Program's shellfish safety guidelines to provide postharvest processing for oysters harvested from Gulf Coast waters during warmer months and intended for raw consumption.
Closed – Implemented
In our September 2011 report entitled Food Safety: FDA Needs to Reassess Its Approach to Reducing an Illness Caused by Eating Raw Oysters, we identified six issues of concern regarding the economic analysis in an FDA-commissioned report. The issues we identified called into question the completeness of the cost and timeline estimates used to determine the feasibility of requiring additional shellfish safety guidelines for oysters harvested from Gulf Coast waters and intended for raw consumption. To help ensure a more accurate assessment of the feasibility of requiring the safety guidelines, we recommended that the Secretary of Health and Human Services direct the Commissioner of FDA to work with the Interstate Shellfish Sanitation Conference to conduct further study of the six issues of concern before moving forward with revising the safety guidelines. To address the issues raised in our report, FDA contracted with the Research Triangle Institute to perform additional analysis. In response to the concerns raised in our report and at the request of FDA, in March 2012, the Research Triangle Institute published an addendum to its original report stating that it had revised some of its original estimates. FDA shared the results with the Interstate Shellfish Sanitation Conference.

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