Salmonella Illness & Attribution

Arthur P. Liang, M.D., M.P.H. Senior Advisor for Food Safety

Division of Foodborne Waterborne & Environmental Diseases Centers for Disease Control & Prevention

CHEROKEE CASINO & HOTEL

WEST SILOAM SPRINGS, OKLAHOMA

Salmonella Illness & Attribution

The Poultry Federation

SALMONELLA SUMMIT MARCH 26, 2013

 1,027,561 foodborne illnesses and 378 deaths annually1  Since 1997, incidence of Salmonella

infections have remained unchanged.

 Many different sources based on outbreaks2  Eggs  Meat  Poultry  Produce  Animal contact

Executive Summary

Salmonella & Attribution

Scanning electron micrograph, Salmonella

enterica

1. Scallan E, Hoekstra RM, Angulo FJ, et al. Foodborne illness acquired in the United States--major pathogens. Emerging infectious diseases 2011;17:7-15. 2. Centers for Disease C, Prevention. Surveillance for foodborne disease outbreaks--United States, 2008. Morbidity & mortality weekly report 2011;60:1197-202.

 Chicken identified as a risk factor for sporadic Salmonella &

Campylobacter infection

 Attribution “models” based on outbreaks identifies poultry as a

frequent source of Salmonella & Campylobacter illness

 Preliminary results of a “Danish” model prevalence estimates of Salmonella contamination on food at processing suggests

poultry most common source

Some Context

 The vast majority of meals are safe  Lean meats, poultry, fish, fruits and

vegetables are among the essential parts of a healthy diet

0 200 400 600 800 1000 1900 1920 1940 1960 1980 Year Mortality Rat e per 100,000

Armstrong et al, JAMA 1999

Foodborne Disease: 1900 vs. 2000

– Amoebiasis – Botulism – Brucellosis – Cholera – Diphtheria – Hepatitis – Polio – Salmonellosis – Scarlet fever

– Septic sore throat

– (Strep zooepidemicus)

– Staph food poisoning – Tapeworms – Trichinosis – Tuberculosis, bovine – Typhoid fever 1. Norovirus 2. Salmonella 3. Clostridium perfringens 4. Campylobacter 5. Staphylococcus 6. Shigella 7. STEC non-O157 8. Yersinia enterocolitica 9. Toxoplasma gondii 10. Giardia * Scallan et al, 2011 1900-39 2011*

0 10 20 30 40 50 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 Years In c id e n c e p e r 1 0 0 ,0 0 0 p o p u la ti o n Typhoid Fever

Reported Salmonella Typhi infections

USA, 1920-2010

0 10 20 30 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 Years In c id e n c e p e r 1 0 0 ,0 0 0 p o p u la ti o n Non-typhoid salmonellosis

The rise of reported other Salmonella infections

USA, 1920-2011

9

CDC provides the vital link between illness in people & the food

safety systems of

government agencies & food producers.

Roles in Food Safety

 Not regulatory

 Disease surveillance  Outbreak detection,

investigation & response

 Analysis of burden, trends &

attribution of illnesses to sources

 Education & training

CDC

_{FDA, USDA, Industry}

 Regulatory  Inspection &

enforcement

 Product traceback &

recall

 Investigation of farm &

processing facilities

 Risk assessment &

management

Roles in Food Safety

State & local public health

 CDC depends on state & local public health

 Reportable conditions reported by law to local or state officials

 State officials notify CDC voluntarily through longstanding agreements

 States invite CDC investigators for assistance

 State & local investigators constitute the “front line”

 State & local public health depend on CDC

 Serve as the national resource for expertise & reference laboratory work, training, & funding

 Coordinate & lead multi-jurisdictional investigations

Major Foodborne Illness Surveillance Systems

Main Categories

I.

National surveillance

• PulseNet

• Foodborne outbreak surveillance

II.

Sentinel site surveillance

III.

Outbreak investigation

PulseNet NARMS Listeria Initiative NNDSS-LEDS FoodNet FDOSS CaliciNet NVEAIS

 >650 clinical laboratories for laboratory-confirmed infections

 bacteria: Salmonella, Shigella, Campylobacter, E. coli O157 & non-O157, Listeria, Yersinia, Vibrio

 parasites: Cryptosporidium & Cyclospora

 with pediatric nephrologists for hemolytic uremic syndrome (HUS)

FoodNet

INTRAMURAL VS EXTRAMURAL

Foodborne Disease Active Surveillance Network

Population-based,

active surveillance at 10 sites: California

Colorado, Connecticut

Georgia, Maryland

Minnesota, New Mexico

New York, Oregon

 42,000 cases reported annually

 Estimate 1,027,561 illnesses & 378 deaths annually1 from food  4 different clinical manifestations:

 gastroenteritis

 bacteremia

 enteric fever

 asymptomatic carrier state

 Infectious Dose: 103 bacilli

Salmonella in the United States

1. Scallan E, Hoekstra RM, Angulo FJ, et al. Foodborne illness acquired in the United States--major pathogens. Emerging infectious diseases 2011;17:7-15.

Salmonellosis by age group

FoodNet 2011

67.55 20.31 12.07 11.65 16.31 0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 <5yo 5-9 10-19 20-64 65+ Age Group Inciden ce r at e per 10 0,00 0

Salmonellosis by age group

• Children < 5 years of age

highest incidence of Salmonella

• Adults ≥ 65 years old accounted for

– 11% of infections

– 35% of hospitalizations – 44% of deaths.

Pathogen rates per 100,000

FoodNet 1996-2011

0 5 10 15 20 25 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 Salmonella Campylobacter Shigella Cryptosporidium E.coli Listeria Yersinia Cyclospora _Vibrio Since 1996-1998

↓E. coli O157 42% ↓Campylobacter 22% ↓Listeria 35% ↓Shigella 65% ↓Yersinia 52% ±Salmonella ↑Vibrio 76%

Pathogen rates per 100,000

FoodNet 1996-2011

0 1 2 3 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 E.coli Listeria Yersinia Cyclospora Vibrio Since 1996-1998

↓E. coli O157 44% ↓Listeria 38% ↓Yersinia 52%

Poultry-Associated

Foodborne Outbreaks —

United States, 1998–2008*

FOR EXAMPLE

2007 – Salmonella & pot pies

2010 – Salmonella & Cheesy Chicken Rice Frozen Entrée 2011 – Salmonella & Kosher Chicken Livers

2011 – Salmonella & turkey burgers

2011 – Salmonella & ground turkey

Multistate Foodborne Disease Outbreaks by 5 year intervals, 1990-2009 N u m b er of outb reak s 0 10 20 30 40 50 60 70 80 1990-94 1995-99 2000-04 2005-09  ~1000 Outbreaks in USA each year  Multistate outbreaks

detected more frequently

 CDC tracks 15–40 clusters of human illnesses per week

 About 30 major

multistate investigations in 2011

Data from Foodborne Disease Outbreak Surveillance System

Detecting & Responding

to Multistate Outbreaks

In 1995, the Hubble Space Telescope found distant galaxies & star clusters never seen before.

 7,724 outbreaks reported an implicated food

 1,184 outbreaks (15%) with confirmed food (epidemiologic or

laboratory evidence)

 679 (57%) outbreaks with a simple food

 21,269 illnesses

 5,212 healthcare visits

 1,481 hospitalizations

 41 deaths

 229 (34%) outbreaks associated with poultry

 More than any other commodity & more than the second & third most frequently implicated commodities combined (fish, 129; beef, 97)

 35% of illnesses

 Median number of illnesses was 14 (range 2-741)

1998-2008 Results

0 2 4 7 9 10 14 Onset of symptoms Collect stool sample Case report to PH dept Stool culture result Submit isolate to PH lab Case interview Consume food

Hedberg, CW, et al. Timeliness of enteric disease surveillance in 6 US states. JEID 14(2), February, 2008.

Foods Associated with Outbreaks

Simple Commodity 24% Complex Commodity 34% No food reported 42%

Foodborne disease outbreaks by food vehicle reported,1998-2008 N=13,405

Confirmed etiologies of reported outbreaks

Norovirus 39% Salmonella enterica 25% E.coli, Shiga toxin-producing 6% Clostridium perfringens 5% Scrombroid toxin 5% Staphylococcus enterotoxin 3% Ciguatoxin 3% Campylobacter jejuni 2% Other etiology 12%

Percent of FBDOs of confirmed etiology, 1998-2008 N=5,059

Serotype Enteritidis was one third of all confirmed Salmonella outbreaks reported from 1998 – 2008.

“Other” includes crustaceans, game, oils-sugars, fungi, root, sprout & vine-stalk Data are preliminary & may change.

Commodities Implicated in Foodborne Disease

Outbreaks, 1998–2010 (n=3,565)

Poultry 18% Fish 18% Beef 12% Pork 8% Leafy 8% Mollusk 6% Fruits-Nuts 6% Dairy 6% Grains-Beans 5% Eggs 4% Other 9%

Reported characteristics of foodborne outbreaks with

confirmed association with poultry, 1998-2008

Characteristic _Chicken (N=156) no./total no. reported (%) Turkey (N=72) no./total no. reported (%) All poultry (N=229)* no./total no. reported (%) Pathogen (confirmed & suspected) Salmonella enterica 36/113 (32) 18/57 (32) 54/171 (32) Clostridium perfringens 29/113 (26) 22/57 (39) 51/171 (30) Norovirus 15/113 (13) 7/57 (12) 23/171 (13) Staphylococcus aureus 9/113 (8) 1/57 (2) 10/171 (6) Campylobacter 7/113 (6) 2/57 (4) 9/171 (5) Bacillus cereus 6/113 (5) 2/57 (4) 8/171 (5) Listeria monocytogenes 1/113 (1) 4/57 (7) 5/171 (3) Other 10/113 (9) 1/57 (2) 11/171 (6)

Poultry-associated outbreaks by setting

FDOSS, 1998-2008 (n = 229)

Restaurant Caterer Home Other

Reported characteristics of foodborne outbreaks

with confirmed association with poultry, 1998-2008

Characteristic Chicken (N=156) no./total no. reported (%) Turkey (N=72) no./total no. reported (%) All poultry (N=229)* no./total no. reported (%) Contributing factors (not mutually

Exclusive) Improper storage / handling 75/111 (68) 30/49 (61) 105/161 (65)

Inadequate cooking 53/111 (48) 32/49 (65) 85/161 (53) Inherent contamination 26/111 (23) 21/49 (43) 47/161 (29) Contaminated equipment 31/111 (28) 10/49 (20) 41/161 (25) Infected food worker 27/111 (24) 10/49 (20 38/161 (24)

* Includes 1 additional restaurant-associated outbreak in the Midwest of Norovirus illnesses associated with duck

“sporadic” Case-control study

Salmonella Serogroups B and D, 1996

• Salmonella Enteritidis & eating chicken prepared outside

the home (MOR, 2.0; 95% CI, 1.1–3.6)

• Reptile contact was associated with infection

• Salmonella Heidelberg & eating eggs prepared outside the

home & (MOR, 6.0; 95% confidence interval [CI], 1.2–

•Salmonella Heidelberg* –Eggs outside home

•Salmonella Enteritidis & Salmonella Heidelberg* –Eating chicken outside home

•Campylobacter

*

Campylobacter Case-Control

Study, 1998

–Turkey or chicken cooked outside the home –Other meat cooked outside the home

*

FoodNet case-control studies

Attribution of foodborne illnesses, hospitalizations, & deaths to food commodities by using outbreak data, United States, 1998–2008

Painter JA, et al. Attribution of foodborne illnesses,

hospitalizations, and deaths to food commodities by using outbreak data, USA, 1998–2008. Emerg Infect Dis 2013 Mar http://dx.doi.org/10.3201/eid1903.111866

By

 Produce was the

dominant source for illnesses

driven by norovirus

 Poultry & Meat together

was the dominant source for deaths

Estimating the Number of Illnesses

Painter et al.

Recent work using

complex food attribution combined information from simple and

complex food outbreaks to estimate the number (and range) of illnesses attributable to each commodity

The top 10 pathogen-food combinations in terms of annual disease burden by combined rank

Batz MB, Hoffmann S, Morris JG Jr., Ranking the disease burden of 14 pathogens in food sources in the United States using attribution data from outbreak investigations and expert elicitation. J Food Prot. 2012

Adaptation of a Danish Attribution Model

With FSIS, adapted a Bayesian model used in Denmark & adapted to other countries • Combines consumption data, sporadic human illness data, & FSIS data

Trends in Chicken Consumption,

ERS Food Availability (Per Capita) Data System (Aug 2012)

Thank you

The findings & conclusions in this presentation are those of the author & do not necessarily represent the views of the Centers for Disease