progress and challenges in decreasing foodborne illnesses in the united states
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Progress and challenges in decreasing foodborne illnesses in the United States. Patricia M. Griffin, M.D. Chief, Enteric Diseases Epidemiology Branch Division of Foodborne, Bacterial and Mycotic Diseases National Center for Zoonotic, Vectorborne and Enteric Diseases - PowerPoint PPT PresentationTRANSCRIPT
Progress and challenges in decreasing foodborne illnesses
in the United States
Patricia M. Griffin, M.D.Chief, Enteric Diseases Epidemiology BranchDivision of Foodborne, Bacterial and Mycotic Diseases National Center for Zoonotic, Vectorborne and Enteric DiseasesApril 12, 2008 Who’s Minding the Store? Seattle, Washington
Foodborne illnesses United States
Estimates for 1997• 76 million ill• 300,000 hospitalized• 5,000 deaths
Healthy People 2010 targets: 50% reduction (from 1997 to 2010) in• E. coli O157 • Campylobacter• Salmonella• Listeria
Mead et al., EID 5:707-25, 1999
Major known foodborne pathogens, 2008 Bacteria
• Bacillus cereus• Brucella• Campylobacter• Clostridium botulinum• Clostridium perfringens• E. coli O157• E. coli, non-O157 Shiga toxin-producing• E. coli, other diarrheagenic• Listeria monocytogenes• Mycobacterium bovis• Salmonella Typhi• Salmonella non-typhoidal• Shigella• Staphylococcus• Streptococcus• Vibrio cholerae, toxigenic• Vibrio vulnificus
Bacteria (continued)• Vibrio, other• Yersinia enterocolitica• Yersinia pseudotuberculosis
Parasites• Cryptosporidium• Cyclospora• Giardia• Toxoplasma• Trichinella• Trypanosoma cruzii
Virus• Caliciviruses• Rotavirus• Astrovirus• Hepatitis A• Hepatitis E
• Prions Fungus
• Aflatoxin-producing
Major known foodborne pathogens, 2008 Bacteria
• Bacillus cereus• Brucella• Campylobacter• Clostridium botulinum• Clostridium perfringens• E. coli O157• E. coli, non-O157 Shiga toxin-producing• E. coli, other diarrheagenic• Listeria monocytogenes• Mycobacterium bovis• Salmonella Typhi• Salmonella non-typhoidal• Shigella• Staphylococcus• Streptococcus• Vibrio cholerae, toxigenic• Vibrio vulnificus
Bacteria (continued)• Vibrio, other• Yersinia enterocolitica• Yersinia pseudotuberculosis
Parasites• Cryptosporidium• Cyclospora• Giardia• Toxoplasma• Trichinella• Trypanosoma cruzii
Virus• Caliciviruses• Rotavirus• Astrovirus• Hepatitis A• Hepatitis E
• Prions Fungus
• Aflatoxin-producing
* Green = recognized as foodborne in past 30 years
Major identified foodborne pathogens, 2008 Bacteria
• Bacillus cereus• Brucella• Campylobacter*• Clostridium botulinum• Clostridium perfringens• E. coli O157*• E. coli, non-O157 Shiga toxin-producing*• E. coli, other diarrheagenic*• Listeria monocytogenes*• Mycobacterium bovis• Salmonella Typhi• Salmonella non-typhoidal• Shigella• Staphylococcus• Streptococcus• Vibrio cholerae, toxigenic*• Vibrio vulnificus*
Bacteria (continued)• Vibrio, other*• Yersinia enterocolitica*• Yersinia pseudotuberculosis*
Parasites• Cryptosporidium*• Cyclospora*• Giardia*• Toxoplasma*• Trichinella• Trypanosoma cruzii*
Virus• Caliciviruses*• Rotavirus*• Astrovirus*• Hepatitis A• Hepatitis E*
• Prions* Fungus
• Aflatoxin*
Yellow = “Home” of organism is the animal kingdom
Topics National networks
• National surveillance• FoodNet
• Overview• E. coli O157• Campylobacter• Salmonella
• PulseNet• OutbreakNet
• Overview• Some recent outbreaks• Example: Salmonella outbreak
Attribution project Progress and challenges
Topics National networks
• National surveillance• FoodNet
• Overview• E. coli O157• Campylobacter• Salmonella
• PulseNet• OutbreakNet
• Overview• Some recent outbreaks• Example: Salmonella outbreak
Attribution project Progress and challenges
FoodNet Sites, 2008Population 45.5 million (15% of U.S. population)
FoodNet
Although all 50 states conduct surveillance for foodborne pathogens,• methods and data quality vary
Need accurate counts of illnesses to measure trends FoodNet sites have extra resources
• to get reports from clinical labs when ill people submit a specimen (usually stool) for testing, and
• to submit those reports to CDC FoodNet measures trends in common foodborne pathogens
• Issues an annual “report card” (MMWR April 11, 2008)
Pyramid of Surveillance
Population exposed
Person becomes ill
Person seeks care
Specimen obtained
Lab tests for pathogen
Pathogen isolated
Reported to health department
Pyramid of Surveillance
Population exposed
Person becomes ill
Person seeks care
Specimen obtained
Lab tests for pathogen
Pathogen isolated
Reported to health department
} Population survey
Active surveillance
Clinical lab survey
Topics National networks
• National surveillance• FoodNet
• Overview• E. coli O157• Campylobacter• Salmonella
• PulseNet• OutbreakNet
• Overview• Some recent outbreaks• Example: Salmonella outbreak
Attribution project Progress and challenges
Sequence of events in E. coli O157 infection
E. coli O157 ingested
3 - 4 days
non-bloody diarrhea, abdominal cramps
5 - 6 daysresolution
92% 8%
HUS
bloody diarrhea
1 - 2 days80%
Mead. Lancet 1998
Hemolytic uremic syndrome (HUS)
Kidney failure, anemia, blood clotting problems
Affects persons of all ages• most common in <5 years old and elderly
~5% die
E. coli O157 infections, incidence by year, FoodNet, 1996-2007
0
0.5
1
1.5
2
2.5
3
1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
Year
Inci
denc
e pe
r 10
0,00
0 p
opul
atio
n
National objective
1.20
0.90
Healthy People 2010 Objective: 1.0 illness/100,000 persons
00.10.20.30.40.50.60.70.80.9
1
2000 2001 2002 2003 2004 2005 2006 2007
Percent of USDA ground beef samples that yielded E. coli O157:H7, 2000-2007
% positiveOutbreak investigation resulted in recall of18 million pounds ground beef
Source: www.fsis.usda.gov
E. coli O157 infections, incidence by year, FoodNet, 1996-2007
0
0.5
1
1.5
2
2.5
3
1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
Year
Inci
denc
e pe
r 10
0,00
0 p
opul
atio
n
National objective
1.20
0.90
Healthy People 2010 Objective: 1.0 illness/100,000 persons
Topics National networks
• National surveillance• FoodNet
• Overview• E. coli O157• Campylobacter• Salmonella
• PulseNet• OutbreakNet
• Overview• Some recent outbreaks• Example: Salmonella outbreak
Attribution project Progress and challenges
Campylobacter
Common cause of foodborne illness• diarrhea• paralysis is rare complication
Most illnesses from chicken• that is undercooked, or• that contaminates other foods
Campylobacter infections, incidence by year, FoodNet, 1996-2007
0
5
10
15
20
25
30
1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
Year
Inci
denc
e pe
r 10
0,00
0 p
opul
atio
n
National objective
12.78
Healthy People 2010 Objective: 12.30 illnesses/100,000 persons
Topics National networks
• National surveillance• FoodNet
• Overview• E. coli O157• Campylobacter• Salmonella
• PulseNet• OutbreakNet
• Overview• Some recent outbreaks• Example: Salmonella outbreak
Attribution project Progress and challenges
Salmonella
Common cause of foodborne illness
• diarrhea
• severe illness in vulnerable populations Carried by all food animals Foodborne illness mainly from
• foods of animal origin
• vegetables contaminated with fecal matter from animals
Salmonella infections, incidence by year , FoodNet, 1996-2007
0
2
4
6
8
10
12
14
16
18
1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
Year
Inci
denc
e pe
r 10
0,00
0 p
opul
atio
n
National objective
14.92
Healthy People 2010 Objective: 6.8 illnesses/100,000 persons
Percent change in the incidence of bacterial infections in 2007compared with the previous 3 years (2004-2006), FoodNet
No change
Increase
Decrease
Pe
rce
nt
ch
an
ge
Percent change estimate
95% confidence interval
Graph Interpretation
No significant change = The 95% confidence interval is both above and below the “no change” line
Significant increase = The estimate and the entire 95% confidence interval are ABOVE the “no change” line
Significant decrease = The estimate and the entire 95% confidence interval are BELOW the “no change” line
-100
-80
-60
-40
-20
0
20
40
60
80
100
Campylobacter Listeria Salmonella Shigella STEC*O157 Vibrio Yersinia
Topics National networks
• National surveillance• FoodNet
• Overview• E. coli O157• Campylobacter• Salmonella
• PulseNet• OutbreakNet
• Overview• Some recent outbreaks• Example: Salmonella outbreak
Attribution project Progress and challenges
PulseNet USA
National network of >75 public health and regulatory laboratories Perform molecular typing of foodborne disease-causing bacteria
• current method is pulsed-field gel electrophoresis (PFGE)• create DNA “fingerprints”
Share DNA “fingerprints” electronically DNA “fingerprints” are sent to database at CDC
• Reviewed daily at CDC
• available on-demand to participants
PulseNet searches for clusters
Cluster of indistinguishable patterns
•State health departments submit patterns electronically•CDC and State labs search for similar patterns in past 2-4 months•compare patterns visually
•When cluster identified, PulseNet contacts epidemiologists
Topics National networks
• National surveillance• FoodNet
• Overview• E. coli O157• Campylobacter• Salmonella
• PulseNet• OutbreakNet
• Overview• Some recent outbreaks• Example: Salmonella outbreak
Attribution project Progress and challenges
CDC OutbreakNet Team
Supports a national network of epidemiologists and other public health officials who investigate outbreaks of foodborne, waterborne, and other enteric illnesses in the United States
Mission • Ensure rapid, coordinated detection & response to multi-
state enteric disease outbreaks• Promotes comprehensive outbreak surveillance
CDC OutbreakNet Team (continued)
Works in partnership with PulseNet
Involves collaborations between CDC and• State and local health departments
• U.S. Department of Agriculture (USDA) Food Safety and Inspection Service (FSIS)
• U.S. Food and Drug Administration (FDA)
Outbreaks
Outbreaks that we find and solve are the “tip of the iceberg”
We investigate outbreaks
• To take immediate action to protect people
• To learn how to prevent similar occurrences
Topics National networks
• National surveillance• FoodNet
• Overview• E. coli O157• Campylobacter• Salmonella
• PulseNet• OutbreakNet
• Overview• Some recent outbreaks• Example: Salmonella outbreak
Attribution project Progress and challenges
Lettuce at Mexican-style fast food chain
Snack food with vegetable coating
Topics National networks
• National surveillance• FoodNet
• Overview• E. coli O157• Campylobacter• Salmonella
• PulseNet• OutbreakNet
• Overview• Some recent outbreaks• Example: Salmonella outbreak
Attribution project Progress and challenges
Increase in Salmonella Tennessee illnesses
August to December 2006• gradual increase in ill persons over expected
number December 2006
• epidemiologists interviewed some ill persons• found no common exposures
States where patients with the outbreak strain of Salmonella Tennessee lived (as of December 1, 2006)
PulseNet found more than the expected number of this strain of Salmonella
States where patients with the outbreak strain of Salmonella Tennessee lived (as of December 1, 2006)
PulseNet found more than the expected number of this strain of Salmonella
Most states had only 1-2 ill persons
Illnesses continued to increase
January 2007• interviewed 31 ill persons with long questionnaire
• consumed peanut butter and turkey more often than general population• Interviewed 6 people with open-ended questions
• suspected a brand of peanut butter February 2007
• designed questionnaire focusing on peanut butter (brand, quantity)
• interviewed ill and well persons• peanut butter statistically linked to illness
– only Brands A and B
Actions
February 13, 2007 • notified Food and Drug Administration (FDA) • found that brands A and B produced at same plant• distributed to 50 states and ~70 countries
Next day• plant ceased all production
Voluntary recall of all products
35 jars (opened and unopened) yielded outbreak strain
Peanut butter testing after recall
Investigation of plant
Two environmental samples yielded outbreak strain
Leaky roof and faulty sprinkler in summer • timing coincided with start of outbreak• moisture in processing plants favors growth of
Salmonella
0
5
10
15
20
25
30
35
40
7 /2 3
Week illness began
Nu
mb
er o
f C
ases
Product Recall: February 14, 2007
Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul2006 2007
Contaminated jars produced July 2006 – January 2007
Persons with Salmonella Tennessee infection, by onset week, August 2006 – July 2007 (N=532)
None 10 – 191 – 9 ≥ 20
Persons with Salmonella Tennessee infection, by state, August 2006 – July 2007
(N=714 persons ill)
Summary of peanut butter outbreak Diffuse national outbreak
• Detected by routine Salmonella surveillance, enhanced by PulseNet subtyping
Required intensive multi-state investigation First U.S. outbreak linked to peanut butter Product recall based on epidemiologic findings Contamination at plant over many months
Points out the importance of controlling contamination in processed ready-to-eat foods
Topics National networks
• National surveillance• FoodNet
• Overview• E. coli O157• Campylobacter• Salmonella
• PulseNet• OutbreakNet
• Overview• Some recent outbreaks• Example: Salmonella outbreak
Attribution project Progress and challenges
Attribution project
How much foodborne illness is from each food commodity, e.g., beef, eggs, vegetables?
Using outbreak data to make estimates Preliminary data indicates that more illnesses due to
known pathogens are acquired by consuming vegetables than any other commodity• leafy greens an important concern
Outbreaks caused by leafy greens,1973–2006
(N=219)
Lettuce 66%
Cabbage 22%
Fresh herbs 8%
Broccoli 1%Spinach 3%
Herman, Lynch, CDC, unpublished
0%
2%
4%
6%
8%
10%
1981-1985 1986-1990 1991-1995 1996-2000 2001-2005
Year
Proportion of outbreaks due to consumpton of leafy greens, 1981–2005
Source: USDA/Economic Research Service. Data last updated Feb. 15, 2007.http://www.ers.usda.gov/Data/FoodConsumption/FoodAvailSpreadsheets.htm
Denominator is outbreaks with known food vehicle
% of outbreaks
Topics National networks
• National surveillance• FoodNet
• Overview• E. coli O157• Campylobacter• Salmonella
• PulseNet• OutbreakNet
• Overview• Some recent outbreaks• Example: Salmonella outbreak
Attribution project Progress and challenges
Progress in the past 10 years
Much better systems for detecting and investigating foodborne illnesses• FoodNet• PulseNet• OutbreakNet
Declines in incidence of several pathogens, e.g.,• E. coli o157• Campylobacter
Progress in the past 10 years (continued)
Improved safety of some foods, e.g.,• ground beef less contaminated• fewer outbreaks from shell eggs• fewer outbreaks from juice• increased attention to ready-to-eat foods, e.g.,
peanut butter Developing methods to attribute foodborne
illnesses to food commodities
Some of the challenges
Salmonella infections have not decreased• widespread in food animals
Campylobacter from live chickens contaminates retail chicken
Complex ecologies in farming areas link food animals with vegetable fields• food animal manure contaminates
vegetables consumed raw
Foodborne diseases in the 21st century
Attention to ecologies of foodborne agents Many foodborne agents live in animals’ intestines Many foodborne agents can survive in outdoor environments
and processing plants Food safety needs to be an integral part of farming practice
Food concerns, e.g., Produce consumed raw Processed foods, e.g., peanut butter, pot pies, snacks New food products and processes every year
pic
Foodborne diseases in the 21st century (continued) More diffuse, multi-state and multi-national outbreaksStrong public health capacity for surveillance and response
needed to identify problems assure that knowledge of safety gaps from outbreak
investigations are applied throughout industry
The fall and rise of Salmonella infections, United States, 1920-2004
0
510
15
2025
30
35
4045
50
1920 1930 1940 1950 1960 1970 1980 1990 2000
Years
Inci
den
ce p
er 1
00,0
00 p
op
ula
tion
Typhoid fever Non-typhoid salmonellosis
CDC, National Notifiable Diseases Surveillance data
Prevented contamination of food and water with human sewage
Increasing contamination of food and water with animal manure
Challenge: provide safe feed and water to food animals and plants
?
Acknowledgments
State and Local Health Departments & Public Health LaboratoriesAlabama Louisiana North DakotaAlaska Maine OhioArizona Maryland OklahomaArkansas Massachusetts OregonCalifornia Michigan PennsylvaniaColorado Minnesota Rhode IslandConnecticut Mississippi South CarolinaDelaware Missouri South DakotaFlorida Montana TennesseeGeorgia Nebraska TexasIdaho Nevada VirginiaIllinois New Hampshire VermontIndiana New Jersey WashingtonIowa New Mexico WisconsinKansas New York West VirginiaKentucky North Carolina Wyoming
The findings and conclusions in this presentation are those of the author(s) and do not necessarily represent the views of the Centers for Disease Control and Prevention.
Other major CDC contributors Fred Angulo Christopher Braden Patricia M. Griffin Karen Herman John Painter Anandi Sheth Robert V. Tauxe Ian Williams
The conclusions and opinions expressed herein are those of the presenter and do not necessarily represent the views or policies of CDC or DHHS
Acknowledgments (continued)
Major CDC contributors to peanut butter investigation Tracy Ayers Cheryl Bopp Gwen Ewald Peter Gerner-Smidt Olga Henao Mike Hoekstra Mike Lynch Manoj Menon Laura Moyer Thai-An Nguyen Katherine Niksich Nehal Patel Nancy Puhr Anandi Sheth Samir Sodha Kathleen Wannemuehler
FDAUSDA
FoodNet:http://www.cdc.gov/foodnet
PulseNet:http://www.cdc.gov/pulsenet
Foodborne outbreak surveillance:http://www.cdc.gov/foodborneoutbreaks
CDC Safe Water System:http://www.cdc.gov/safewater
General Information About Diseases:http://www.cdc.gov/health
Our websites
Thank you
The findings and conclusions in this presentation are those of the author and do not necessarily represent the views of the Centers for Disease Control and Prevention