1. Good Agricultural Practices Fruit and Vegetable Microbial Safety Issues

2. Fruits and Vegetables
Promotional campaigns to increase produce consumption to at least 5 servings a day.
U.S. Dietary Guidelines
Healthy People 2010
National Cancer Institute
Produce for Better Health Foundation
Federal initiatives, including the U.S. Dietary Guidelines, the Food Guide Pyramid, Healthy People 2002, and the National Cancer Institute’s Five a Day Program, have highlighted the nutritional importance of eating fruits and vegetables. “Strive for Five” programs initiated by agricultural companies and food trade associations also have stressed the need to increase fruit and vegetable consumption.

3. Fruit and Vegetable Consumption
Between , the U.S. per capita consumption of fruits and vegetables increased 24 % !
577 lbs to 718 lbs per year
Consumers have listened to these messages and have altered their food choices. Between 1970 and 1997, the U.S. per capita consumption of fruits and vegetables increased 24%, from 577 to 718 pounds.
Growers have responded positively by growing and harvesting a wide variety of traditional and “new” fruits and vegetables. Global production and distribution, coupled with innovative packaging, and improved marketing and merchandising strategies, have provided consumers with an abundance of fruits and vegetables. The increase in global trade makes the world available to U.S. consumers and provides year-round availability of fresh produce.

4. Fruits and Vegetables
Significant increases in the number of produce associated foodborne disease outbreaks in the U.S.
Produce associated outbreaks per year more than doubled from and
As produce consumption has increased, scientists at the CDC noticed another important trend. From 1973 through 1998, a significant increase in the number of foodborne outbreaks associated with fresh produce.

5. U.S. Fruit and Vegetable Outbreaks: 1973 - 19985 10 15 20 25 30
Number of Outbreaks
Year
‘74 76 78 80 82 84 86 88 90 92 94 96 98
Source: CDC Foodborne outbreak surveillance system

6. Number of Produce Associated Outbreaks by Decade, 1973 - 1997
Outbreaks / year
Since 1973, there has been a continuous increase in the number of fresh produce associated outbreaks. This and the next few slides show data collected via CDC’s foodborne diseases outbreak surveillance system, a passive reporting system in which State Health Departments send CDC reports of investigated foodborne disease outbreaks. Since this is a passive reporting system these data are not all inclusive. Since our database contains information from , 1980 through 89 and 1990 through 97 for the rest of this talk I will refer to these time periods as the 70’s 80’s and 90’s. This graph shows the number of fresh-produce associated outbreaks per year by decade. The number of outbreaks per year increased from 3.7 in the 70’s to 10.5 in the 90’s
Decade

7. Produce Related Outbreaks & Cases per Outbreak, 1973 - 1997
Mean # ill / outbreak
Outbreaks / yr 2 4 6 8 10 12 20 30 40 50
This graph shows the number of outbreaks per year in the orange bars, but it also shows the the size of the outbreaks in the yellow bars. The yellow bars show that the median number ill per outbreak increased from 4 in the 70’s to 40 in the 90’s. This suggests that the increase in the number of outbreaks associated with fresh produce is not just a reflection of better reporting but is truly a real increase.
70's
80's
90's

8. Selected Produce-Associated Outbreaks, 1990 - 1997
# of
Year Pathogen Vehicle Cases States Source
1990 S. chester Cantaloupe Central America (CA)
1990 S. javiana Tomatoes US
Hep. A Strawberries 18 2 US
S. poona Cantaloupe > US/CA
1993 O157:H7 Apple cider 23 1 US
1993 S. montevideo Tomatoes 84 3 US
The information contained in these next three slides provides a chronology of selected produce associated outbreaks in the U.S. What should be noticed is the organisms that caused the outbreaks, the type of produce involved, the number of people made ill and the source of the produce.

9. Selected Produce-Associated Outbreaks, 1990-1997
# of
Year Pathogen Vehicle Cases States Source
1994 Shigella flexneri Scallions 72 2 CA
1995 S. stanley Alfalfa sprouts ?
1995 S. hartford Orange juice US
O157:H7 Leaf lettuce 70 1 US
1995/6 S. newport Alfalfa sprouts >100 7 ?
1996 O157:H7 Leaf lettuce 49 2 US
You may note the E. coli O157:H7 outbreak that occurred in lettuce in A case study will be presented on this outbreak later in this presentation.

10. Selected Produce-Associated Outbreaks, 1990-1997
# of
Year Pathogen Vehicle Cases States Source
1996 S. montevideo Alfalfa sprouts >600 1 US
1996 Cyclospora Raspberries CA
1996 O157:H7 Apple Juice 71 3 US
1997 Hepatitis A Strawberries CA
1997 Cyclospora Raspberries > CA
1997 S. infantis/ Sprouts 81 4 US
anatum
Produce associated outbreaks have been caused by bacteria, viruses and parasites. Bacteria like Salmonella, E. coli O157:H7, Shigella and Bacillus cereus are of significant concern. Parasites like Cyclospora and Cryptosporidium, and viruses such as Hepatitis A and Norwalk also have been the causative agents in a number of produce associated outbreaks. Lettuce, salad mix, green onions, tomatoes, sprouts, cantaloupe, carrots, raspberries, frozen strawberries,basil and basil-containing products, unpastuerized apple cider,and unpastuerized orange juice have been associated with these disease causing microorganisms and have caused illnesses an deaths in children and adults throughout the U.S.

11. Fruit & Vegetable Outbreaks by Specific Agent, 1973 - 1998
Bacterial 24 57
Parasitic 1 8
Viral 4 7
Unknown 35 (55%) 41 (37%)
Total Outbreaks
Outbreaks/year
Source: CDC Foodborne outbreak surveillance system
Bacterial agents have caused the largest number of outbreaks where a specific agent has been identified. It is thought that the unknown agents are probably viruses.

12. Fruit and Vegetable Bacterial Outbreaks: 1988 - 1998
Of the produce associated outbreaks caused by bacterial agents reported between 1988 and 1998, Salmonella was responsible for 26 of those outbreaks, while E. Coli was responsible for 22, Shigella, 3, Campylobacter for 2 and several other organisms responsible for a few outbreaks.

13. Fruit and Vegetable Parasitic Outbreaks: 1973 - 1998y c l o s p 5 T t O u b e k
Source: CDC Foodborne outbreak surveillance system

14. Sources of Produce Outbreak Agents
Animal
Cryptosporidium (cider and onions)
non-typhoidal Salmonella (sprouts)
E. coli 0157:H7 (lettuce and sprouts)
Human
Shigella (parsley)
Hepatitis A (green onions/strawberries)
S. typhi (mamey)
C. cayetanensis (raspberries)
ETEC (carrots)
Produce outbreak agents include both animal and human sources.

15. US Produce Outbreaks: 1990 - 1998

16. Fruit and Vegetable Outbreaks by Origin of Produce: 1990 - 1998
Although many people think that imported produce causes most of the outbreaks, when the outbreaks that were reported between 1990 and 1998 were analyzed for origin, 75.3% of the outbreaks were related to produce grown domestically. About 7.5% of the produce items incriminated in outbreaks during this time period were imported. In many cases it was difficult to determine where the produce was grown, due to packing and repacking and the mixing of lots.
Source: CDC Foodborne outbreak surveillance system

17. Frequency of Pathogens on Produce
Vegetables (from literature):
Salmonella 1- 8%
L. monocytogenes %
Shigella 1%
FDA Produce Surveillance Program
Imports - 4% positive rate (Salmonella & Shigella)
Domestic - currently being conducted

18. E. coli O157:H7 Lettuce Outbreak
A multistate Outbreak of Escherichia coli O157:H7 Infections Associated with Consumption of Mesclun Lettuce
By Elizabeth D. Hilborn, et.al.
Archives of Internal Medicine,Vol. 159, August 9/23, 1999.
This multistate outbreak of E. coli O157:H7 infections associated with the consumption of mesclun lettuce has been published in the Archives of Internal Medicine, Volume 159, August, 1999.

19. E. coli O157:H7 Lettuce Outbreak
Occurred during May & June, 1996
49 Cases
Two separate outbreaks reported in:
Connecticut - mesclun mix
Illinois - red leaf lettuce
Patients had similar demographics
This multistate outbreak of E. coli O157:H7 infections associated with the consumption of mesclun lettuce has been published in the Archives of Internal Medicine, Volume 159, August, 1999.

20. E. coli O157:H7 Lettuce Outbreak
Were these two outbreaks related?
Case-control studies conducted.
Molecular subtyping by pulsed field gel electrophoresis (PFGE) showed they were indistinguishable.

21. E. coli O157:H7 Lettuce Outbreak
49 Cases of Infection
Connecticut 21
Illinois 28
21 Patients (49%) were hospitalized
3 Patients (7%) developed HUS
Patients age from years

22. E. coli O157:H7 Lettuce Outbreak
Results of the Investigation
Lettuce traced back to one California grower.
Lettuce grown near beef cattle ranch.
A dirt track separated the two operations.
Free range chickens had access to cattle and lettuce fields.

23. E. coli O157:H7 Lettuce Outbreak
Unchlorinated well water used for cattle husbandry, lettuce culture and processing.
The processing shed was open to the environment; there was no mechanism to exclude dust, insects, birds or rodents.
No handwashing facilities were available.

25. E. coli O157:H7 Lettuce Outbreak
Gloves were not worn during processing.
Recirculated wash water was used.
The recirculating and filtration systems failed in May and the water was changed 3X a day.
Lettuce was crisped in reused plastic baskets.

26. E. coli O157:H7 Lettuce Outbreak
E coli O157:H7 was not isolated from the lettuce during the investigation.
But, E. coli bacteria were present on the finished lettuce and in the wash water.
This indicated the presence of fecal contamination from humans or animals.

29. Produce Associated Outbreaks
Conclusions:
Outbreaks have increased by nearly a factor of 3.
Number of cases per outbreak have increased x10.
A variety of produce involved.

30. Produce Associated Outbreaks
Conclusions:
Most due to bacteria, esp. Salmonella.
New agents detected, E. coli O157:H & Cyclospora.
Unknown agents may be due to Norwalk-like virus.
Domestic versus international.

31. Why are Foodborne Illnesses Increasing?
Complexities of the Food System
Aging of the Population
Chronic Illnesses / Compromised Immunity
Awareness of Hygiene & Risks Changing
Changing Microorganisms:
More Virulent Strains
Adapting to Stresses

32. The Cycle of Infection HOSTS MICROBES ENVIRONMENT
The cycle of infection is made up of microbes, human hosts and environmental factors. Lets examine them further. All of these factors are changing. The population is aging and people are living longer. As a result, there are many people with compromised immune systems, who are more susceptible to foodborne illnesses. The environment is also changing and new niches are evolving where microbes can survive, grow and contaminate foods. The microorganisms are changing, too. There are more virulent pathogens, where few cells will cause serious illness. Several bacteria can grow slowly at refrigerator temperatures, while others have become more resistant to antibiotics.

33. Foodborne illness outbreaks are a major cause of:
Why Should We Care?
Foodborne illness outbreaks are a major cause of:
Personal distress
Preventable death
Avoidable economic burden

34. Every year foodborne illnesses result in an estimated:
Why Should We Care?
Every year foodborne illnesses result in an estimated:
76 million cases of foodborne illness.
325,000 people hospitalized for foodborne illness.
5,200 needless deaths each year.
Economic losses between billion dollars.

35. Produce Associated Outbreaks Affect Business
Strawberry industry lost an estimated $50 million in 1996 after mistakenly being indicated as the source of pathogens in an outbreak.
Odwalla shareholder value dropped approximately 41% ($12.4 million) in six months after outbreak.
Work against produce promotions campaigns.
May result in unwanted legislation or regulation.

36. Produce Associated Outbreaks Affect Business
Food retailers interested in food safety & addressing the issue because of consumers.
Food retailers are requiring third party inspection of farms that supply produce and certification of Good Agricultural Practices.
Growers are having to absorb the costs of these inspections.

37. The Cost of Foodborne Illness
Loss of business and reputation
Lawsuits, attorney and court fees
Increased insurance premiums
Loss of employee morale
Embarrassment
Financial disaster!

38. Contamination With Microbial Pathogens: Where Can It Occur?
In fields or orchards
During harvesting and transport
During packing or processing
In distribution and marketing
In restaurants and food service facilities
In the home
FARM to FORK

39. Sources of Pathogens on Fresh Produce*
Contaminated irrigation water
Fresh or uncomposted manure/fecal material
Wild and domestic animals
Handling by infected workers
Beuchat, 1996

40. Sources of Pathogens on Fresh Produce*
Equipment
Transport vehicles
Contaminated flume, wash water, or ice
Contamination during processing
Beuchat, 1996

41. Sources of Pathogens on Fresh Produce*
Improper storage and packaging
Cross contamination
Improper handling after wholesale or retail purchase
Beuchat, 1996

42. PREVENTION is the Key to Reducing Microbial Contamination of Fresh Fruits and Vegetables
Studies have indicated that once contamination occurs, it is hard to remove the pathogens from the produce, so prevention really is the key to the problem.

43. What Can Growers and Packers Do?
Learn About the Risks
Develop a Food Safety Plan
Strengthen GAPs
Document Activities

44. Reduce Microbial Risks to Assure Food Safety.
Goal:
Reduce Microbial Risks to Assure Food Safety.
The goal is to apply good agricultural practices to your farming operation and reduce microbial risks to assure the safety of fruits and vegetables.

45. The End

46. Acknowledgements This presentation created by
Robert B. Gravani and Elizabeth A.Bihn.
Images provided by USDA (k8666), California Department of Health Services Food and Drug Branch, Robert B.Gravani, Elizabeth A. Bihn , Al B. Wagner and
Ed McLaughlin.