Robert E. Brackett, Ph.D. Senior Vice President and Chief Science and Regulatory Affairs Officer

The impact of pre-harvest practices on the microbial safety of produce—

the US experienceIAFP Latin America Symposium on Food Safety

Campinas, SP, BrazilMay 26, 2008

Robert E. Brackett, Ph.D.Senior Vice President and

Chief Science and Regulatory Affairs OfficerGrocery Manufacturer’s Association

Outbreaks of foodborne illness associated with fresh produce are becoming more apparent.

Outbreaks

• Seen an increase in the number of reported outbreaks of foodborne illnesses from fresh produce– E. coli O157:H7 outbreaks

• From spinach – 204 cases in 26 States• From lettuce at Taco John’s – 81 cases in 3 States• From lettuce at Taco Bell – 71 cases in 5 States

Outbreaks

• Seen an increase in the number of reported outbreaks of foodborne illnesses from fresh produce– E. coli O157:H7 outbreaks– Salmonella Typhimurium outbreak from

tomatoes• 186 cases in 21 States

Outbreaks

• Seen an increase in the number of reported outbreaks of foodborne illnesses from fresh produce– E. coli O157:H7 outbreaks– Salmonella Typhimurium outbreak from

tomatoes– Salmonella Newport from tomatoes

• 98 cases 19 States

Recent Outbreaks

• Seen an increase in the number of reported outbreaks of foodborne illnesses from fresh produce

• There are several possible explanations for the apparent increase– Better and more rapid detection of outbreaks– Increase in sale of fresh-cut produce– Globalization of the produce supply– Increase in the numbers of consumers at high risk

for foodborne illnesses

Increase in Outbreaks

• Data reported to CDC indicate that between 1973 and 1997 reported outbreaks associated with fresh produce increased.– From 0.7% in the 1970s to 6% of all outbreaks

in the 1990s.

Average annual number of produce-associated outbreaks by decade, USA,1973-2002*

3.76.5

10.5

49.8

0

10

20

30

40

50

60

1973-79 1980-89 1990-97 1998-2002

Decade

Outbreaks/year

* Preliminary data

*

Increase in Outbreaks

• Data reported to CDC indicate that between 1973 and 1997 reported outbreaks associated with fresh produce increased.

• Unpublished data compiled by FDA indicate that from 1996 to 2006 there were approximately 71 reported outbreaks associated with fresh produce.

Vehicle Categories 1996 - 2006

Category Outbreaks Illnesses

Processed Foods 53 3,219

Produce 71 8,734Sprouts 27 1,633

Seafood 99 2,822

Eggs 207 6,558

Opportunities for Contamination

Before and During Harvest

Contamination Opportunities

• Animal Management Issues

Animal Management

• Wild animals in the field

• Domestic animals in the field

• Animal manure in the field



• Processing/Packing Operations

Processing and Packing Operations

• Unsanitary conditions• Produce not cleaned• Packing in the field• Vermin




• Worker Health/Hygiene

Work Health and Hygiene

• Inadequate handwashing

• Inadequate hygiene training

• Unsanitary worker facilities

• Unexplained worker absences

• Community illnesses





• Harvest Tools/Equipment

• Bare hand or unknown glove use

• Cross contamination issues

• Non-sanitized tools

• Non-cleanable tools

Harvest Tools and Equipment





• Harvest Tools/Equipment

• Water Issues

Water Issues

• Inadequate chlorination

• Hydrocooler Issues

• Storage tank issues

• Ice issues

• Cross connection issues

E. coli O157:H7 Outbreak Associated with Pre-Packaged

Spinach Findings

Findings Related to Growing

• E. coli O157:H7 found in environmental samples collected near the fields that provided the spinach– River water– Cattle feces– Wild pig feces

Investigation Findings Related to Growing

• E. coli O157:H7 found in environmental samples collected near the fields that provided the spinach

• Ready-to-eat crops are being grown in close proximity to livestock or livestock waste




• Evidence of wildlife activity in proximity to fields where ready-to-eat crops are grown – Riparian habitats




• Evidence of wildlife activity in proximity to fields where ready-to-eat crops are grown

• Irrigation wells used for ready-to-eat produce exposed to feces from cattle and wildlife via surface waterways

Other Investigation Findings

• E. coli O157:H7 was not found in the samples taken from the processor.

Other Investigation Findings

• E. coli O157:H7 was not found in the samples taken from the processor.

• Number of other conditions observed that may provide opportunities for spread of pathogens, if pathogens arrived on incoming products.– Harvesting– Cooling– Processing

E. coli O157:H7 in the Salinas Valley Watershed Study*

January 2005 – August 2006

*Robert E. Mandrell, Ph.D.*Robert E. Mandrell, Ph.D.Research Leader, Produce Safety and MicrobiologyResearch Leader, Produce Safety and Microbiology Research UnitResearch UnitUSDA, Agricultural Research Service, Western Regional Research CenterUSDA, Agricultural Research Service, Western Regional Research Center

Salinas Valley Watershed Study

• Prompted by identification of a farm that supplied leafy vegetables associated with 3 separate outbreaks



• “Farm” investigation: soil, water, plants, feces tested



• “Farm” investigation: soil, water, plants, feces tested

• E. coli O157:H7 isolated from samples obtained from 15 of 22 different Salinas Valley (California) watershed locations– Highest incidence occurred after heavy rainfall


• E. coli strains representing at least 203 different genetic fingerprint types (MLVA) were identified for all isolates tested

Salinas Valley Watershed Study• E. coli strains representing at least 203

different genetic fingerprint types (MLVA) were identified for all isolates tested

• Sets of strains with identical MLVA types were isolated from watershed samples up to eight months apart, and samples collected at, near, and up to 20 miles away from, a point source on same and different days

Salinas Valley Watershed Study• E. coli strains representing at least 203 different

genetic fingerprint types (MLVA) were identified for all isolates tested

• Sets of strains with identical MLVA types were isolated from watershed samples up to eight months apart, and samples collected at, near, and up to 20 miles away from, a point source on same and different days

• Strains with nearly identical MLVA types were isolated from 3 farm/ranches separated approximately 18 to 45 miles apart


• Results from the Salinas watershed study and the spinach outbreak investigation indicate that E. coli O157 was isolated more frequently from samples obtained near or on grazing land compared to other locations


• Results from the Salinas watershed study and the spinach outbreak investigation indicate that E. coli O157 was isolated more frequently from samples obtained near or on grazing land compared to other locations

• Results are consistent with the frequent incidence of E. coli O157 reported in numerous surveys of incidence in cattle in other locations of the country and incidence in water

Time for a More Holistic View

“Balancing Agriculture, Food Safety, and Environmental

Concerns”

Potential Conflict with Environmental and Wildlife Preservation Efforts

• Concern about the potential conflict between food safety, environmental and wildlife preservation efforts

Potential Effect of Food Safety Practices

• Concerns about the effects of food safety practices on water quality– Riparian buffers, grassed waterways, filter

strips and other forms of non-crop vegetation are critical conservation measures for reduction of sedimentation and filtering of other pollutants

Potential Effect of Food Safety Practices

• Concerns about the effects of food safety practices on habitats– Riparian vegetation provides important

substrates for aquatic invertebrates, cover for predator avoidance, and resting habitats

• Removal of non-crop vegetation may increase sedimentation and lead to habitat degradation

• Increased suspended solids from runoff have damaging physical and biological effects

Where Do We Go From Here?

“Working Together with the Agricultural and Environmental

Communities To Find Solutions”

We Are In This Together

• Must work TOGETHER to solve the problem instead of each of us solving our piece of the problem

Best Practices

• Need to better understand the dynamics of agriculture, food safety practices, and the environment

Best Practices

• Need to better understand the dynamics of agriculture, food safety practices, and the environment– We know cattle are a principal source of E.

coli because the organism lives in the intestines of healthy cattle

Best Practices

• Need to better understand the dynamics of agriculture, food safety practices, and the environment– We know cattle are a principal source of E. coli

because the organism lives in the intestines of healthy cattle

– We know cattle manure is an important source of E. coli infection and can contaminate the environment, including streams that flow through produce fields and are used for irrigation, pesticide application, or washing

Best Practices


• Need to identify and better understand the “stumbling blocks” so that we can work together to develop and implement solutions

Best Practices


• Need to identify and better understand the “stumbling blocks” so that we can work together to develop and implement solutions– Are vertebrate populations sources of E. coli

O157:H7 contamination of watersheds?

Best Practices


• Need to identify and better understand the “stumbling blocks” so that we can work together to develop and implement solutions– Are vertebrate populations sources of E. coli O157:H7

contamination of watersheds?– Do climate, landscape attributes and irrigation

management practices correlate with an increased risk of contamination?

Best Practices• Need to better understand the dynamics of

agriculture, food safety practices, and the environment

• Need to identify and better understand the “stumbling blocks” so that we can work together to develop and implement solutions– Are vertebrate populations sources of E. coli O157:H7

contamination of watersheds?– Do climate, landscape attributes and irrigation

management practices correlate with an increased risk of contamination?

– Is in-field contamination associated with management production practices and environmental risk factors?

Best Practices


• Need to identify and better understand the “stumbling blocks” so that we can work together to develop and implement solutions

• Use of guidance to identify the best practices and solutions

Next Steps

“Future Strategies and Activities for Produce Safety”

A closer examination of the measures and their effectiveness

and determination of what additional or different interventions might be

appropriate.

Potential Interventions

• Identify risk factors for contamination of fresh produce associated with agricultural and manufacturing practices


• Identify risk factors for contamination of fresh produce associated with agricultural and manufacturing practices– Leafy Green Safety Initiative

Leafy Green Safety Initiative

• Collaborative effort, initiated in 2006, between U.S. Food and Drug Administration (FDA) and State of California’s Departments of Public Health and Food and Agriculture

http://www.usda.gov/oc/photo/02c0425.jpg


• Collaborative effort, initiated in 2006, between FDA and State of California’s Departments of Public Health and Food and Agriculture– Part of a risk-based strategy intended to

reduce public health risks by heightening the focus of preventative food safety efforts on specific products, practices, pathogens, and growing areas of concern


• Collaborative effort, initiated in 2006, between FDA and State of California’s Departments of Public Health and Food and Agriculture– Part of a risk-based strategy intended to reduce public health risks by

heightening the focus of preventative food safety efforts on specific products, practices, pathogens, and growing areas of concern

– In 2007, FDA, State of California Departments of Public Health and Food and Agriculture, with the cooperation of industry began visiting farms:

• to assess the prevalence of factors in and near the field environment which may contribute to potential contamination

Leafy Green Safety Initiative• Collaborative effort, initiated in 2006, between FDA and State of

California’s Departments of Public Health and Food and Agriculture– Part of a risk-based strategy intended to reduce public health risks by

heightening the focus of preventative food safety efforts on specific products, practices, pathogens, and growing areas of concern

– In 2007, FDA, State of California Departments of Public Health and Food and Agriculture, with the cooperation of industry began visiting farms:

• to assess the prevalence of factors in and near the field environment which may contribute to potential contamination

• to assess the extent to which Good Agricultural Practices (GAPs) and other preventative controls are being implemented


• Identify risk factors for contamination of fresh produce associated with agricultural and manufacturing practices– Leafy Green Safety Initiative– Tomato Safety Initiative

Tomato Safety Initiative

• Collaborative effort, initiated in 2007, between FDA and state health and agriculture departments in Virginia and Florida, in cooperation with several universities and members of the produce industry


• Collaborative effort, initiated in 2007, between FDA and state health and agriculture departments in Virginia and Florida, in cooperation with several universities and members of the produce industry

– Part of a risk-based strategy to reduce foodborne illness by focusing efforts on specific products, practices, and growing areas found to be problematic in the past


• Virginia based tomato farms and packing facilities were visited:– To assess food safety practices


• Virginia based tomato farms and packing facilities were visited:– To assess food safety practices– To assess what degree Good Agricultural

Practices (GAPs) and Good Manufacturing Practices (GMPs) are implemented




– To assess a variety of environmental factors including:





• Irrigation water

Tomato Safety Initiative• Virginia based tomato farms and packing

facilities were visited:– To assess food safety practices– To assess what degree Good Agricultural Practices

(GAPs) and Good Manufacturing Practices (GMPs) are implemented


• Irrigation water• Wells

Tomato Safety Initiative• Virginia based tomato farms and packing

facilities were visited:– To assess food safety practices– To assess what degree Good Agricultural Practices

(GAPs) and Good Manufacturing Practices (GMPs) are implemented


• Irrigation water• Wells• Procedures for mixing chemicals

Tomato Safety Initiative• Virginia based tomato farms and packing facilities were

visited:– To assess food safety practices– To assess what degree Good Agricultural Practices (GAPs) and

Good Manufacturing Practices (GMPs) are implemented


• Irrigation water• Wells• Procedures for mixing chemicals• Drought and flooding events

Tomato Safety Initiative• Virginia based tomato farms and packing facilities were visited:

– To assess food safety practices– To assess what degree Good Agricultural Practices (GAPs) and Good

Manufacturing Practices (GMPs) are implemented


• Irrigation water• Wells• Procedures for mixing chemicals• Drought and flooding events• Animal proximity to growing fields



• Identify possible measures to improve safety



• Identify possible measures to improve safety

• Develop additional guidance– Refine Good Agricultural Practices– Commodity and/or Region Specific

Summary

• Fruit and vegetables are major components of a healthy diet, but eating fresh uncooked produce is not risk free.

Summary


• Greater application and implementation of good agricultural practices and good manufacturing practices are key to minimizing the microbial hazards and associated risks.

Summary



• Solutions must balance agricultural, food safety, and environmental needs.

Summary




• Increasing scientific knowledge and understanding of the risk factors are key to development and implementation of effective risk management strategies.

Summary




• Increasing scientific knowledge and understanding of the risk factors are key to development and implementation of effective risk management strategies.

• Success in improving the safety of fresh produce requires collaboration and cooperation.

Documents

Robert E. Brackett, Ph.D. Senior Vice President and Chief Science and Regulatory Affairs Officer