Foodborne Disease Outbreak Detection:

Disease Detectives Wanted

Kara Cooper, Ph.D.

My Career Path

• Laboratory experience though high school and college

• B.S. in Microbiology from Kansas State University

• Ph.D. in Medical Microbiology and Immunology

• Worked for Centers for Disease Control and Prevention for 6.5 years

– Foodborne Disease Surveillance

• Currently work for MRIGlobal in Kansas City

– Manage Bacteriology and Molecular Biology Group

– BSL-2 and BSL-3 laboratories

Microbiology • Microbiology is the study of

microrganisms, which can’t be seen with the naked eye – Bacteria - ~1-10 µm

– Viruses - ~20-400 nm

– Fungi

– Prions

• Scale – Centi – 0.01

– Milli – 0.001

– Micro – 0.000001

– Nano – 0.000000001

It’s a Dirty World

• Microorganisms are all around

• Symbiotic Relationship at times

• Non-pathogenic vs. Pathogenic (organism that cause disease)

Biosafety Levels • Microorganisms are categorized in Risk Groups (RG)

based on their relative risk.

– Pathogenicity of the organism

– Mode of transmission and host range

– Availability of effective preventive measures or treatment (e.g., vaccines or antibiotics)

– Infectious dose

– Other factors

• BSL Levels

– BSL-1 – Are not associated with disease in healthy adult humans or animals (Ex. non-infectious bacteria and laboratory adapted strains)

– BSL-2 – Are associated with disease which is rarely serious and for which preventative or therapeutics is often available (Ex. Salmonella, Staphyloccus)

– BSL-3 – Are associated with serious or lethal human disease for which preventative or therapeutics may be available (Ex. Bacillus anthracis, Rift Valley Fever Virus)

– BSL-4 – Are associated with lethal human disease for which preventative or therapeutics are not readily available (Ex. Ebola)

Foodborne Illness

• Consumption of contaminated food

• Each year:

– 76 million cases of foodborne illness

– 325,000 hospitalizations

– $7 billion is the annual cost of treating the top 4 foodborne pathogens

Foodborne Illness

Food Poisoning Foodborne Disease

Harmful chemicals or bacterial toxins

Illness caused directly by infection with organism

Don’t need to ingest organism to become ill

Bacteria must be eaten to cause disease

Generally short incubation period before symptom onset (4-12 hrs)

Longer incubation period (days to weeks)

Nausea, vomiting, diarrhea Nausea, vomiting, diarrhea, fever

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Routes of Contamination

Food can be contaminated at any point along the food production process. This

is described as from “Farm to fork”.

Globalization

• New global economy has created a food revolution

– 1950’s: stocked an average of 300 items

– 1990’s: stocked 25,000-50,000 different items

– Rapid transit of perishable foods

– Increased demand for fresh produce year round

– Industrialization

Surveillance Systems • Surveillance is an epidemiological practice by which

the spread of disease is monitored in order to establish patterns of progression. The main role of disease surveillance is to predict, observe, and minimize the harm caused by outbreak,, as well as increase our knowledge as to what factors might contribute to such circumstances.

• Agencies involved in National Surveillance – Centers for Disease Control and Prevention (CDC)

– Food and Drug Administration (FDA)

– U. S. Department of Agriculture (USDA) Local and Public health departments

A large outbreak in one place may be obvious

A dispersed outbreak in many places may be difficult to detect, unless

• Test the bacteria from all the cases, and • Find they are infected with the same bacterial strain

Disease Reporting Pyramid

What is PulseNet USA?

• Established in 1996, The National Molecular Subtyping Network for Foodborne Disease Surveillance

• A national network of >85 state and local public health/food regulatory agency laboratories (USDA, FDA) coordinated by CDC and APHL

• Perform standardized DNA “fingerprinting” of foodborne disease-causing bacteria

– Pulsed-field gel electrophoresis (PFGE)

• Dynamic databases of DNA “fingerprints” at CDC

• Early identification of common source outbreaks

Deoxyribonucleic acid (DNA) • Building blocks of living things

• Unique for all individuals – Makes us what we are

• Used to distinguish between relatives of bacteria

• Useful in Outbreak identification – Molecular Epidemiology

The Three Basic Elements of PulseNet

3.Data exchange

1.Data acquisition 2.Data analysis

PulseNet Laboratory Network

Local

Databases

PulseNet National

Databases (CDC) Participating Labs PFGE Patterns

Philadelphia

West Mountain South Central North Central Midwest Mid-Atlantic Southeast Northeast

The National Molecular Subtyping Network for

Foodborne Disease Surveillance

COLORADO

OREGON

CALIFORNIA

NEVADA

IDAHO

UTAH

ARIZONA

MONTANA

WYOMING

WASHINGTON

NEW MEXICO

NORTH DAKOTA

SOUTH DAKOTA

NEBRASKA

KANSAS

OKLAHOMA

MINNESOTA

IOWA

MISSOURI

ARKANSAS

ILLINOIS

WISCONSIN

MICHIGAN

ALASKA

TEXAS

HAWAII

LOUISIANA

KENTUCKY

OHIO

VIRGINIA

TENNESSEE

NEW YORK

MAINE NEW HAMPSHIRE

ALABAMA

MASSACHUSETTS

RHODE ISLAND

CONNECTICUT

NEW JERSEY

DELAWARE

MARYLAND

GEORGIA

SOUTH

CAROLINA Los Angeles

County

San Diego

County

Santa Clara

County

Houston

New York City

Tarrant County

Tampa

USDA-AMS

USDA-

ARS/FSIS

Orange County

Washington D.C.

FDA-CFSAN

FDA-ORA

FDA-ORA

FDA-ORA

FDA-ORA

FDA-ORA

FDA-CVM

FDA-ORA

Milwaukee

Florida Ag Lab

Area

Laboratories

PulseNet Central

County/City

Laboratories

USDA

Laboratories

FDA Laboratories

FDA-ORA Las

Vegas

PUERTO

RICO

VERMONT

PulseNet Activity, 1996-2010

PulseNet in the Numbers

What is a Cluster Search?

Cluster of indistinguishable patterns by primary enzyme

•Patterns submitted electronically

•60- or 120-day cluster search performed

•Visually compare indistinguishable patterns with 1st enzyme, then 2nd

•Patterns and clusters are named by CDC

Recent Foodborne Outbreaks With PulseNet Involvement

• Salmonella Enteritidis - eggs

• E. coli O145 – lettuce

• Salmonella Montevideo – salami/pepper

• E. coli O157 – cookie dough

• Listeria monocytogenes – sprouts

• Salmonella Typhimurium – African dwarf frogs; peanut butter products

• Salmonella Saintpaul – Raw Produce

Just to name a few.......

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Day of Outbreak

Num

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outbreak detected 1993 726 ill, 4 deaths

1993 Western States E. coli O157 Outbreak

39 d

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Day of Outbreak

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outbreak detected 2002 44 ill, no deaths

18 d

2002 Colorado E. coli O157 Outbreak

PFGE Patterns Spinach-associated E. coli O157:H7

Outbreak

This TIFF was uploaded to PulseNet on 9/8/2006

Outbreak patterns are in lanes 3, 4, 6-9 (XbaI)

Outbreak Pattern: Comparison shows 100%

similarity among PFGE patterns from various states

Isolate Submissions with Spinach Outbreak Pattern to PulseNet, by month,

since 2002

Increase due to outbreak

Preliminary data

States reporting cases in 0609mlEXH-2 (as of October 6, 2006)

COLORADO

OREGON

CALIFORNIA

NEVADA

IDAHO

UTAH

ARIZONA

MONTANA

WYOMING

WASHINGTON

NEW MEXICO

NORTH DAKOTA

SOUTH DAKOTA

NEBRASKA

KANSAS

OKLAHOMA

MINNESOTA

IOWA

MISSOURI

ARKANSAS

ILLINOIS

WISCONSIN

MICHIGAN

ALASKA

TEXAS

HAWAII

LOUISIANA

KENTUCKY

OHIO

VIRGINIA

TENNESSEE

NEW YORK

MAINE NEW HAMPSHIRE

ALABAMA

MASSACHUSETTS

RHODE ISLAND

CONNECTICUT

NEW JERSEY

DELAWARE

MARYLAND

GEORGIA

SOUTH

CAROLINA

New York City

VERMONT

PUERTO

RICO

Preliminary data

States reporting

cases

PulseNet International

A Family of Networks • 6 Networks, 67 total participating

countries

Disease Detectives • Careers in public health

– Epidemiologist

– Laboratorian

– Public Health Law

– Public Health Communication

– Physician

• Disease Detectives Camp – a week-long day camp for rising high school juniors and seniors that

exposes students to epidemiology, the field of public health and the diverse career opportunities within the field of public health • Dates: June 18-21, and July 16-20, 2012

• Times: 8:45-4:00pm

• Location: CDC, 1600 Clifton Road, Atlanta, GA

– http://www.cdc.gov/museum/camp/detective/

– http://www.youtube.com/user/CDCStreamingHealth#p/u/21/7hO5WZ0oshw

Questions????