Foodborne Illnesses Wong 2007 July

Community Physician’s Role in Foodborne Illness Investigations

Chicago Medical Society

Chicago Department of Public Health

Preparedness and Emerging Infections Training Program 2007

Chicago Medical Society Chicago Department of Public Health

Overview

• Public health impact of foodborne illnesses and goals for investigations

• Physician role in foodborne illness investigations– Patient symptoms– Clusters of illness– Report to public health– Appropriate testing– Educate patients

• Resources for more information


Foodborne Illness – United States

• Each year– Estimated 76 million illnesses (18% known cause)– Estimated 5,000 deaths (30% known cause)

• Bacteria, viruses, parasites, toxins

• Primarily affects– Very young– Very old– Immunocompromised

Burden of Disease Pyramid – Foodborne Illnesses

Person exposed to foodborne pathogen

Person becomes ill

Person seeks medical care

Specimen obtained

Lab test(s) done

Test confirms case

CaseReported

Estimated76 million annually

in U.S.


Serious Consequences of Foodborne Illnesses

• Chronic diarrhea (certain parasites)

• Miscarriage (Listeria)

• Hemolytic uremic syndrome (HUS) (Shiga toxin producing E. coli)

• Reactive arthritis (Campylobacter)

• Guillain-Barré syndrome (Campylobacter)


Foodborne Disease Outbreaks:Public Health Priorities

• Get the facts– Identify the scope and severity of the outbreak

• Stop disease transmission– Implement control measures to stop spread

• Prevent future occurrences– Correct the food safety problem and educate


Clinician’s Role

• Recognize suspicious symptoms in patients

• Recognize suspicious clusters of illness• Obtain appropriate testing• Report cases of foodborne illness to

public health authorities• Talk with patients about ways to prevent

foodborne illnesses


Clinician’s Role


• Recognize suspicious clusters of illness• Report cases of foodborne illness to

public health authorities• Obtain appropriate testing• Talk with patients about ways to prevent

foodborne illnesses


Recognizing Suspicious Symptoms

• Every outbreak begins with an index patient who may or may not be severely ill

• Important clues to determining the etiology– Incubation period– Duration of the resultant illness– Predominant clinical symptoms– Types of food consumed





Hours Days 2 6 10 14 18 22 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46

Hepatitis A

Yersinia

E. coli O157:H7Campylobacter

Shigella spp.

Cyclospora cayetanensis

Clostridium botulinum toxin

Enterotoxigenic E. coli

Norovirus

Clostridium perfringens toxin

Vibrio parahemolyticus

Bacillus cereus toxin

Staph aureus toxin

Salmonella spp.

Invasive disease

Usual Incubation Periods for Selected Foodborne Pathogens

ListeriaGI disease

24h / 1day





Duration of Illness of Common Foodborne Pathogens

Bacterial pre-formed toxins

(Bacillus, C. perfringens, Staph)

24 – 48 hrs

Viruses

Norovirus

Rotavirus and others

12 hrs – 5 days

2 – 9 days

Bacteria

Campylobacter

E. coli

Salmonella / Shigella

2 – 10 days

5 – 10 days

4 – 7 days

Parasites

Crypto, Giardia, Cyclospora,

Entamoeba

Weeks to months (may remit and relapse)





Diagnosis of Foodborne Illness by Clinical Presentation

Prominent Clinical Presentation

Additional Signs or Symptoms

Potential Food-Related Agent

Vomiting Acute onset

(within minutes to hours)

•Chemical agent (heavy metals, ammonia)•Bacterial toxins (S. aureus, B. cereus, C. perfringens)

Fever and/or diarrhea

•Norovirus•Rotavirus•Bacterial toxins (S. aureus, B. cereus, C. perfringens)

Diagnosis by clinical presentation, continued




Diarrhea Acute, watery, non-bloody

(noninflammatory)

Nearly all enterics, but especially:•Enteric viruses (norovirus, rotavirus, astrovirus)

Prolonged, non-bloody

•Enterotoxigenic E. coli (ETEC)•Parasites: Cryptosporidium, Cyclospora, Giardia

Bloody

(inflammatory)

Fever also more likely to be present with inflammatory process

•Shigella •Salmonella (nontyphoidal)•Campylobacter •E. coli (enteroinvasive, enterohemorrhagic)•Shiga toxin producing E. coli (STEC), including E. coli 0157:H7•Yersinia•Entamoeba



Signs or Symptoms Potential Food-Related Agent

Neurological Descending paralysis, blurred vision, constipation

•Clostridium botulinum (preformed toxin)

Numbness and tingling of lips and mouth, weakness, vomiting and diarrhea

•Ciguatera toxin•Shellfish toxins

Flushing, rash, hives, burning sensation of skin and mouth, dizziness

•Scombroid (histamine)





Systemic•Malaise

•Fever

•Chills

•Muscle aches

Nausea, diarrhea •Listeria monocytogenes

Diarrhea, dark urine, jaundice

•Hepatitis A

Abdominal pain, constipation may be an early feature, diarrhea later, minimal vomiting

•Salmonella Typhi

(typhoid fever)






**Disclaimer**

Because new vehicles are constantly being identified for various pathogens, it is important not to exclude the possibility of an organism contaminating almost any food.


Some Food-Pathogen Associations

Unpasteurized Milk and Cheese

Listeria monocytogenes

Brucella spp.

Fresh Produce

Berries, Melon, Juice, Sprouts, Lettuce, Spinach, Tomatoes

Cyclospora, E. coli, Salmonella

Ground Beef E. coli (especially O157:H7)


Pork Trichinella spiralis, Yersinia spp.

Chicken Campylobacter, Salmonella

Fried Rice Bacillus cereus

Tuna

Marlin Scombroid (histamine)

Mahi Mahi

Oysters Vibrio parahaemolyticus

Eggs Salmonella spp.


Deli Meats Listeria monocytogenes

Hot Dogs

Home-canned fruits and vegetables Botulinum toxin

Ice Cream Salmonella spp.


Patient’s Hypothesis

“I’m sick… It must have been the _________.”

(Fill in the blank with the last food eaten before becoming ill)


Clinician’s Role




foodborne illnesses


Foodborne Disease Outbreak

Definition: An incident in which two or more individuals

from separate households experience a similar illness resulting from the ingestion of a common food or visiting a common food establishment


Could This Be an Outbreak?

• Yes, No, Maybe?“The only thing that these ill people had in

common was the meal/food named in the complaint.”

If yes, definitely investigate further. If no, still may need to investigate. Examine all

aspects of situation before deciding. If maybe, need to ask complainant more

questions.


• When in doubt, call your local health department


Reported Foodborne Outbreaks

• Illinois– 60-92 foodborne outbreaks reported annually– Outbreak etiologies (1999-2005)

• 29% Confirmed• 71% Suspect or Unknown

• Chicago– 9–18 foodborne outbreaks reported annually– 14 in 2006

Chicago Foodborne Outbreaks: Etiologic Agents1997-2006 (N=116)

7

3

4

4

16

18

64

0 10 20 30 40 50 60 70

All Other

Shigella

Histamine

C. perfringens

Salmonella

Norovirus

Suspect or Unknown

No. of Outbreaks

(60%)(17%)

(15%)

S. aureus, A. cantonensis, B. cereus, Ciguatoxin, E. coli O157, raphides

Chicago Foodborne Outbreaks: Detection Methods 1997-2006 (N=116)

1

2

3

7

12

91

0 20 40 60 80 100

Media

CD* Investigation

Lab Surveillance

FSE* Self Report

Clinician Report

Citizen Complaint

No. of Outbreaks

*FSE = Food Service Establishment, CD = Communicable Disease


Could This Be Intentional?

• Unusual agent or pathogen in a common food– Example: Arsenic-laced curry served at a festival in

Japan, 1998; 4 of 67 patients died

• Common agent or pathogen affecting an usually large number of people– Example: Religious commune contaminated salad bars

with Salmonella at multiple restaurants in an Oregon town, 1984; 751 persons ill

• Common agent or pathogen that is uncommonly seen in clinical practice– Example: pesticide poisoning


Clinician’s Role




foodborne illnesses


• Medical providers and laboratories are required by law to report certain infectious diseases and syndromes

Foodborne Surveillance

Hospital

Doctor’s office

Citizens

Private Laboratory

Public Health Laboratory

Local Health Department

Media CDC


Reportable Foodborne Illnesses in Illinois

• Amebiasis• Botulism• Campylobacteriosis• Cholera• Cryptosporidiosis• Cyclosporiasis• Enteric E. coli

infections• Giardiasis• HUS• Hepatitis A

• Listeriosis• Salmonellosis• Shigellosis• Trichinosis• Typhoid fever• Yersiniosis• Foodborne or

waterborne illness• Any unusual

case/cluster that may indicate a public health hazard


What Happens When I Call the Health Department? (It’s not at all like the TV shows…)

• You will speak with an epidemiologist or physician• You will be asked questions about the situation:

who, how many, when, what, etc.

Note• HIPAA is not an issue

Patient information can be disclosed to public health authorities for public health investigations, surveillance, and interventions

• Don’t worry about duplicate reportingHealth department staff check for duplicate reports before launching an investigation


Prompt Case Report Revealed an OutbreakJanuary 2007

• 67 y.o. female presents to ED with 2 day h/o vomiting, bloody diarrhea, abdominal pain. She attended a baby shower 3 days ago.

• Patient found to have renal failure, ischemic colitis, thrombocytopenia, mild anemia

• ID physician consulted in ED. She notified the hospital infection control practitioner (ICP), who called the health department to report case of possible HUS.

• Subsequent investigation revealed 23 of 40 attendees of baby shower ill with GI symptoms. C. perfringens found in the leftover chili that was served at the baby shower.


The Foodborne Disease Outbreak Investigation Team

• Communicable disease: Epidemiologists and Physicians– Design questionnaires and conduct interviews– Manage data and perform statistical analysis– Follow patient’s clinical course and obtain lab results– Guide overall response, talk with media, write reports

• Food protection: Sanitarians– Perform inspections– Collect left over foods

• Public health laboratory: IDPH Laboratorians– Test patient specimens and food– Perform molecular analysis

http://www.elpasocitycountyhealth.com/environment/FoodInspection/FoodInspection.asp

Sanitarians at work…

“No, I’m not trying to sell you anything, sir. I’m investigating an outbreak and all I ask is two or three hours of your time to answer a few thousand questions.”

Epidemiologists at work…


Notify Public Health

• For cases that reside in Chicago, call311 (if dialing from a city area code) or

312-744-5000 (if dialing from a non-city area code) Ask for the ‘Communicable Disease physician on-call’(available 24/7)

• If case resides outside of Chicago, notify the appropriate local health department– Cook County Department of Public Health: 708-492-2000

• If unable to reach your local health department, call Illinois Department of Public Health duty officer217-782-7860 or 800-782-7860


Clinician’s Role




foodborne illnesses


When to Consider Testing

• Bloody diarrhea• Weight loss• Fever

• Diarrhea leading to dehydration

• Prolonged diarrhea (>3 days)• Neurological involvement• Severe abdominal pain


Collection of Stool Specimen

• Stool sample or rectal swab placed in stool culture transport vial– Cary-Blair or C&S

• Whole stool: Clean, dry, leak-proof container• Rectal swab: Pass swab beyond the anal

sphincter, carefully rotate, and withdraw • Regular bacterial transport is not acceptable, but

the swab may be used for stool collection (e.g., from a diaper) and then placed in a stool culture transport vial


What does ordering a “routine” stool culture get?

• LabCorp and ARUP: Campylobacter, Shigella, Salmonella, and detection of Shiga toxin by EIA

• Quest: Campylobacter, Shigella, Salmonella

• Hospital labs: varies; contact the microbiology section

• Therefore,

** Best to order the individual tests you want **


Bacterial Special Requests

• Require special media– E. coli O157:H7– Yersinia spp.– Vibrio spp.

• Require quantitative culture– C. perfringens

• Bacterial toxins– Only consider testing food and stool in

outbreak situations


Norovirus Diagnostic Methods

• Many different genome types, some of which can be distinguished by PCR

• Must obtain whole stool for analysis

• IDPH State Lab can perform PCR but only for outbreak related cases

• Private labs may perform testing – need to call


Barriers to Testing in Foodborne Disease Outbreaks

• Delays in collecting specimens from ill people• Lack of easy-to-use collection materials and

instructions• Inconvenience of storing and transporting

specimens to the laboratory

About 65% of foodborne outbreaks reported to CDC lack a confirmed etiology– In 2/3 of these outbreaks no stool specimen submitted for

testing


Facilitating Specimen Collection

Use of Stool Collection Kits Delivered to Patients Can Improve Confirmation of Etiology in Foodborne Disease OutbreaksJones TF, et al. Clin Infect Dis 2004;39:1454-9

Stool collection kits delivered to and from patients by courier or mail during 2-year period

Etiologic agent confirmed in 71% (37/52) of outbreaks in which ≥ 1 kit was received at lab– 28 (76%) attributable to norovirus– 9 (24%) attributable to bacterial pathogens


Clinician’s Role




foodborne illnesses


Physicians as Food-Safety Educators: A Practices and Perceptions Survey

Wong S, et al. Clin Infect Dis 2004:38 (Suppl 3) pp. S212-S218.

• Survey of 1110 physicians in U.S. (OB/gyn, neph, onc, ID)

• 70% agreed that ‘many of my patients are at risk for foodborne diseases’

• Only 30% worked in practices that provide food-safety information to patients

• Of the 769 physicians who worked in practices that did not provide food-safety information, 524 (68%) reported that they would like to provide such information to their patients


Risk Awareness vs. Risk Perception

• Persons can be aware of risks but choose to continue such behaviors if they believe they or others can control the risk“The government inspects raw meat and poultry, don’t

they?”

“The food will smell bad if it’s contaminated, right?”

• Persons may believe that negative events are relatively unlikely to harm them personally“Food contamination is more likely to occur at

manufacturing plants or at restaurants—not in my own kitchen.”


Advice for Patients for the Prevention of Foodborne Illness

COOK meat, poultry, and eggs thoroughly. Use a thermometer to measure the internal temperature of large cuts of meat.

SEPARATE: Don’t cross-contaminate cooked or ready-to-eat foods with raw meat, poultry, or eggs.

CHILL: Refrigerate leftovers promptly. Divide large volumes of food into several containers for quicker cooling.

CLEAN: Wash hands with soap and water before preparing food and after touching raw meat, poultry, or eggs. Wash produce with running water.


Additional Precautions for Patients at Higher Risk

Should avoid:• Soft cheeses, pâté• Uncooked hot dogs and deli meats• Raw (unpasteurized) milk or cheeses• Raw or partially cooked eggs• Foods containing raw eggs• Raw or undercooked meat and poultry• Unpasteurized juices• Raw sprouts • Raw or undercooked fish or shellfish

Pregnant women / Elderly / Immunocompromised


Additional Precautions for Patients at Higher Risk

• Any leftover formula, milk, or juice in bottles should be discarded after infant has finished feeding and not kept longer than 1-2 hours after bottle prepared

• Honey should not be fed to infants < 1 year old (risk of botulism)

Infants


Eating Out?

• Choose which restaurants to patronize– Chicago restaurant inspections:

http://webapps.cityofchicago.org/health/inspection.jsp

• Ask for meats to be prepared well done—especially ground meats– Don’t hesitate to send back if still pink in middle

• Ask if sauces or dressings contain raw eggs

• Refrigerate leftovers promptly


Making Food Safer

• Food irradiation– Already approved in the U.S. for most perishable foods– Doesn’t impair nutritional value or make food unsafe– Endorsed by WHO, CDC, FDA, USDA, AMA

• Reduce antibiotics in animal feed– Antibiotics fed to animals for growth promotion

increase pressure for bacteria to become resistant– World Health Organization (WHO) has recommended

that antibiotics not be used for this purpose

• Eat locally– Smaller scale food production, less transport lower

risk of contamination?


When Seeing Patients With Acute Diarrhea

• Ask about the patient’s occupation– Food handler– Health care worker– Child care worker

• Consider a lower threshold for sending cultures on patients in sensitive occupations


Food Safety Web Sites

• CDChttp://www.cdc.gov/foodsafety

• FDA Center for Food Safety and Applied Nutrition (CFSAN)http://www.cfsan.fda.gov/

– “Bad Bug Book”

• USDA Food Safety and Inspection Service (FSIS): for meat, poultry, eggshttp://www.fsis.usda.gov/

• National Food Safety Initiative– http://www.foodsafety.gov


Diagnosis and management of foodborne illnesses: A primer for physicians and

other health care professionals (2nd Ed. 2004)

Available at:

http://www.ama-assn.org/ama/pub/category/3629.html

Print copies gone, but can get PDF version online

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