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 Illness caused directly by toxins infection with organism Don’t need to ingest organism Bacteria must be eaten to to become ill cause disease Generally short incubation Longer incubation period (days period before symptom onset to weeks) (4-12 hrs) Nausea, vomiting, diarrhea Nausea, vomiting, diarrhea, fever
E. Coli O157:H7 Campylobacter Listeria Salmonella
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 2.Data analysis 1.Data acquisition 3.Data exchange
PulseNet Laboratory Network PulseNet National Participating Labs PFGE Patterns Databases (CDC) Local Databases
The National Molecular Subtyping Network for Foodborne Disease Surveillance NEW HAMPSHIRE Milwaukee MAINE FDA-ORA VERMONT WASHINGTON MINNESOTA MONTANA NORTH DAKOTA MASSACHUSETTS Philadelphia OREGON WISCONSIN RHODE ISLAND NEW YORK MICHIGAN CONNECTICUT IDAHO SOUTH DAKOTA FDA-ORA WYOMING New York City IOWA NEW JERSEY FDA-CVM NEBRASKA OHIO NEVADA DELAWARE ILLINOIS FDA-CFSAN UTAH FDA-ORA MARYLAND FDA-ORA Washington D.C. COLORADO VIRGINIA Las KANSAS Vegas KENTUCKY Santa Clara CALIFORNIA MISSOURI County USDA-AMS TENNESSEE ARKANSAS SOUTH OKLAHOMA FDA-ORA ARIZONA CAROLINA NEW MEXICO Los Angeles County USDA- FDA-ORA ARS/FSIS ALABAMA Area Orange County GEORGIA FDA-ORA Laboratories San Diego TEXAS LOUISIANA County PulseNet Central Florida Ag Lab County/City Tarrant County Laboratories ALASKA Houston USDA Tampa Laboratories PUERTO FDA Laboratories RICO HAWAII West Mountain South Central North Central Midwest Mid-Atlantic Southeast Northeast
PulseNet Activity, 1996-2010
PulseNet in the Numbers
What is a Cluster Search? • Patterns submitted electronically • 60- or 120-day cluster search performed • Visually compare indistinguishable patterns with 1 st enzyme, then 2 nd • Patterns and clusters are named by CDC Cluster of indistinguishable patterns by primary enzyme
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.......
1993 Western States E. coli O157 Outbreak 70 60 outbreak detected 1993 726 ill, 4 deaths 50 Number of Cases 40 30 39 d 20 10 0 1 8 15 22 29 36 43 50 57 64 71 Day of Outbreak 2002 Colorado E. coli O157 Outbreak 70 60 Number of Cases 50 outbreak detected 2002 44 ill, no deaths 40 30 20 18 d 10 0 1 8 15 22 29 36 43 50 57 64 71 Day of 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 ( Xba I)
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 Preliminary data outbreak
States reporting cases in 0609mlEXH-2 (as of October 6, 2006) NEW HAMPSHIRE MAINE VERMONT WASHINGTON MINNESOTA MONTANA NORTH DAKOTA MASSACHUSETTS OREGON WISCONSIN RHODE ISLAND NEW YORK MICHIGAN CONNECTICUT IDAHO SOUTH DAKOTA WYOMING New York City IOWA NEW JERSEY NEBRASKA OHIO NEVADA DELAWARE ILLINOIS UTAH MARYLAND COLORADO VIRGINIA KANSAS KENTUCKY CALIFORNIA MISSOURI TENNESSEE ARKANSAS SOUTH OKLAHOMA ARIZONA CAROLINA NEW MEXICO ALABAMA States reporting GEORGIA cases TEXAS LOUISIANA ALASKA PUERTO HAWAII RICO Preliminary data
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/21/7hO5WZ 0oshw
Questions????
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