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A Review of Foodborne Illness & an Outbreak Investigation that Lead to a Product Recall: 

A Review of Foodborne Illness & an Outbreak Investigation that Lead to a Product Recall Rashid A. Chotani, MD, MPH Assistant Professor & Director Global Infectious Disease Surveillance & Alert System (GIDSAS) Center for International Emergence, Disaster & Refugee Studies Johns Hopkins Schools od Medicine & Public Health Phone: 410-614-8330 E-mail: rchotani@jhsph.edu

Significance: 

Significance Foodborne illness is one of the largest preventable public health problem in the world In the US it causes an estimated 9,000 deaths/yr (CDC) 6.5 to 81 mil cases of diarrheal disease/yr Most of the infections go undiagnosed & unreported

Sequelae: 

Sequelae Guillain-Barre Syndrome (C. jejuni) Renal Disease (E. coli O157:H7 and other Shiga-like toxin producing bacteria)

Contributing Factors: 

Contributing Factors Poor foodhandler hygiene (inadequate handwashing, open wounds, etc.) Inadequate cooking of raw products or holding temperatures Cross contamination (equipment/work surface/hands) Improper cooking Food obtained from an unsafe source Inadequate washing of fresh produce Others

Events and potential contamination sources during produce processing : 

Events and potential contamination sources during produce processing Event Contamination sources Production and harvest Growing, picking, bundling Irrigation water, manure, lack of field sanitation Initial processing Washing, waxing, sorting, boxing Wash water, handling Distribution Trucking Ice, dirty trucks Final processing Slicing, squeezing, shredding, peeling Wash water, handling, cross-contamination

Enteric Host Defense: 

Enteric Host Defense Saliva Gastric Acid Intestinal motility Enteric flora Shedding & replication of epithelium Mucus layer Immune system Proteolytic enzymes

Changing Patterns of Foodborne Diseases: 

Changing Patterns of Foodborne Diseases Newly identified pathogens, routes & vehicles (e.g. increasing frequency of outbreaks associated with consumption of raw fruits and vegetables) Increasing complexity of of foodborne disease outbreaks Old Outbreak Scenario New Outbreak Scenario acute: local diffuse: multi-state & inter dose & attack rate: high dose & attack rate : low detected : by groups detected : by lab-based surveillance

Factors in the Emergence of Foodborne Diseases: 

Factors in the Emergence of Foodborne Diseases Changes in agricultural practices New methods of food processing, especially mass production Globalization of food industry Changes in consumer behavior Changes in consumer susceptibility Epidemiology & laboratory

FoodNet: 

FoodNet

The Foodborne Disease Activity Surveillance Network: 

The Foodborne Disease Activity Surveillance Network Established in 1995 in 5 states - Minnesota, Oregon, Georgia, California, and Connecticut; MD & NY joined the program in 1997 Foodborne disease component of Emerging Infections Program (EIP) Collaborative project CDC EIP states USDA FDA Active surveillance system

FoodNet Goal: 

FoodNet Goal Determine & monitor the burden of foodborne diseases Determine the proportion of foodborne diseases attributable to specific foods Develop a network to respond to new & emerging foodborne diseases

FoodNet Components: 

FoodNet Components Active lab-based surveillance Surveys of clinical labs Survey of physicians Survey of the population Case-Control studies

Classification: 

Classification

Definition: 

Definition Poisoning: results from eating foods containing poisons (chemicals or toxins) Infections: result from eating food containing pathogenic microorganisms Toxin: a poison produced by a living organism Intoxication: disease caused by consumption of food containing toxins

Epidemiologic Triad: 

Epidemiologic Triad Agent Host Environment

Mechanisms of foodborne Agents: 

Mechanisms of foodborne Agents Preformed toxin in food = rapid onset of nausea, vomiting, and cramps e.g. S. aureus and Bacillus cereus emetic syndrome Direct tissue invasion = inflammatory diarrhea (often fever &/or bloody stool) e.g. Salmonella, Shigella, Campylobacter, Vibrio parahaemolyticus, Yersinia, and Entamoeba histolytica

Mechanisms of foodborne Agents: 

Mechanisms of foodborne Agents Enterotoxin producing in the gut = noninflammatory (watery) diarrhea e.g. Clostridium perfringens, Bacillus cereus diarrhea syndrome, Vibrio cholerae, and Enterotoxigenic E. coli Neurotoxin producing = e.g. Clostridium botulinum; mushroom, shellfish, ciguatera fish and puffer fish poisioning

Etiologic Agents of foodborne Disease: 

Etiologic Agents of foodborne Disease 1.Bacteria S. aureus, B. cereus, C. perfringens, C. botulinum, E. coli, Salmonella, Shigella, Streptococcus, Brucella, Listeria monocytogenes, Yersinia sp. Campylobacter sp. Vibrio sp., others 2. Parasites Protozoa Giardia, Cryptosporidium, Entameoba histolytica, Toxoplasma gondii, Cylospora, others Helminths Trichinella spiralis, Tapeworms (e.g. taenisis, cysticercosis), others.

Etiologic Agents of foodborne Disease: 

Etiologic Agents of foodborne Disease 3.Virus Hepatitis A, Norwalk virus & Norwalk like viruses, others 4. Intoxicants & Chemical Poisons a) Poisonous plant tissue (jimson weed, rhubarb leaves) b) Poisonous animal tissues (puffer fish, blow fish, moray eels) c) Mycotoxins and poisonous fungi (ergot alkaloids, trichothecenes, zearalenone, alfatoxins, poisonous mushrooms) d) Dinoflagellate toxins (ciguatera fish poisoning, shell fish poisoning f) Chemicals (pesticides, heavy metals, MSG, drugs, nitrates) g) Others

Bacteria: 

Bacteria Single cell organisms Multiply by single division; can multiply in foods Most common cause of foodborne outbreak Some can produce resistant strains Some may produce toxins in food or gut

Parasites: 

Parasites Live on another organism (host) Transmitted through food & water Do not multiply outside host Some require favourable environment to become infectious (e.g. Cyclospora)

Viruses: 

Viruses Obliterate intracellular organisms Require host cell to multiply Do not produce toxins or multiply in food Reservoirs are humans

Foodborne disease Case Investigation: 

Foodborne disease Case Investigation I. Sources of case report II. Goals of foodborne illness case investigation III. Information collection Demographics Illness information Exposure information Miscellaneous information IV. Interventions & public health actions

Source: 

Source Public Laboratory reports Healthcare providers Health departments Other state departments

Goal: 

Goal Prevent transmission Early detection Understanding outbreak disease epidemiology Evaluate food safety programs Identify high risk food & processes

Information: 

Information Timing is ESSENCE Designate team leader Assign responsibilities Obtain maximum information on first contact Use standardized form

Information: 

Information Demographic Name, address, phone no., age, occupation, gender Illness Symptoms, onset, duration, have they been to a physician Name, Dx, Lab tests, results, Tx Exposure 72 hour food history What was eaten, who else was there, when was the meal eaten, where was the meal eaten, was there anything unusual

Definition: 

Definition The occurrence of more cases of disease than expected in a given area or among a specific group of people over a particular period of time Single case is considered an outbreak (inclusive) Anthrax, botulism, brucellosis, cholera, diptheria, encephalitis, measles, plauge, polio, psisticosis, human rabies, rubella, trichinosis, typhoid fever, hepatitis A, H. influenza type b, or meningococcal disease

Interpretation of Outbreak Curves: 

Interpretation of Outbreak Curves Common source transmission: Occur via point, intermittent or a continuous source Propagated transmission: Person-to-person transmission Cases increase gradually and than decrease gradually (uncommon foodborne outbreak)

Point Source Outbreak: 

Point Source Outbreak 0 2 4 6 8 10 4/1/01 4/2/01 4/3/01 4/4/01 4/5/01 4/6/01 4/7/01 4/8/01 Days # of Cases Catered event

Intermittent Source Outbreak: 

Intermittent Source Outbreak 0 2 4 6 8 10 4/1/01 4/2/01 4/3/01 4/4/01 4/5/01 4/6/01 4/7/01 4/8/01 4/9/01 4/10/01 Days # of Cases

Continuous Source Outbreak: 

Continuous Source Outbreak 0 2 4 6 8 10 4/1/01 4/2/01 4/3/01 4/4/01 4/5/01 4/6/01 4/7/01 4/8/01 4/9/01 4/10/01 Days # of Cases

Propagated Source Outbreak: 

Propagated Source Outbreak 0 2 4 6 8 10 4/1/01 4/2/01 4/3/01 4/4/01 4/5/01 4/6/01 4/7/01 4/8/01 4/9/01 4/10/01 4/11/01 4/12/01 4/13/01 Days # of Cases

Analytical Epidemiology:Measures of association: Case-Control Study: 

Analytical Epidemiology: Measures of association: Case-Control Study Odds Ratio (OR) = odds of exposure in cases odds of exposure in controls ill well Ate suspected YES a b Food item? NO c d OR = ad/bc Done when you CANNOT interview everyone

Analytical Epidemiology:Measures of association: Cohort Study: 

Analytical Epidemiology: Measures of association: Cohort Study Relative Risk (RR) = attack rate in exposed attack rate in non-exposed ill well Ate suspected YES a b Food item? NO c d RR = [(a/a+b)x100] / [(c/c+d)x100] Done when you CAN interview everyone

Slide39: 

A Foodborne Outbreak of Gastroenteritis in a Teaching Hospital Reference: Chotani et al. SHEA Annual Meeting 1998

Hospital: 

Hospital 940 bed hospital with 4 cafeterias. Cafeteria A, located in the OPD, serves approximately 600 visitors and employees daily.

Events: 

Events On 12/9/97 individuals who ate at Cafeteria A reported nausea and projectile vomiting after eating a noon meal.

Method: case definition: 

Method: case definition Any person who ate lunch prepared at cafeteria A on December 9, 1997 and developed sudden onset of vomiting or diarrhea or abdominal cramps and Any of the following symptoms including nausea, fever, body aches, headache, chills or fatigue.

Method: case finding: 

Method: case finding We identified all cases who identified individuals who ate with them. All non-Ill persons were used as controls. Additional cases were found when we contacted: Nurse managers Hospital managers Directors of nursing, functional unit directors, JHH vice-presidents Several employee groups were notified via e-mail and asked to identify cases.

Methods: questionnaires: 

Methods: questionnaires Standard questionnaires were used to obtain medical and food history from Food service workers Ill and non-ill employees Menu reviewed at Cafeteria A.

Control Measures and Interventions: Cafeteria A: 

Control Measures and Interventions: Cafeteria A Cafeteria: Kitchen was inspected Leftover foods recovered and cultured Food preparation, kitchen cleaning procedures reviewed Certain food items quarantined Employees were interviewed, inspected for sores, boils, cuts, IV tract marks and sent to occupational health services We obtained nares swabs 3 cafeteria staff members submitted stool samples or rectal swabs All staff (n=17) were questioned daily for symptoms

Laboratory: 

Laboratory Food was processed in standard fashion Blood agar plate R/O Bacillus CAN plate R/O Staphylococcus Plates for enteric pathogens R/O Salmonella, Shigella, Aeromonas, Campylobacter, Yersinia Samples sent to city, state, FDA, and commercial laboratory Sequencing preformed Heavy metal testing

Results: 

Results N = 75 (ill = 40; non-ill = 35) Mean age: 39 years (range 25-56) Sex: 85% female

Incubation period: JHH employees (n=40): 

Incubation period: JHH employees (n=40)

Symptoms: 

Symptoms

Results: outcomes: 

Results: outcomes Duration of illness: mean--24 hr. (range <24 - 72 hr.) Bedridden 62.5% Sought medical care 27.5% Hospitalized 2.5%

Results: univariate analysis: 

Results: univariate analysis Food item OR CI 95% p-value Green beans 36.4 6.93,341.60 <0.0001 Tortellini 5.50 1.03, 54.50 0.02 Corn soup 0.23 0.04, 1.10 0.03 Veg soup 0.23 0.04, 1.10 0.03 Not associated: bread, breadsticks, chicken salad, broccoli salad, cheese salad, caesar salad, havarti cheese, swiss cheese, beef stew, Thai beef, couscous, honey turkey, chicken fingers, cheese pizza, sausage pizza, chow mein noodles, marinated tomatoes, onions, mixed greens, cucumbers, dressing tomato-bacon/peppercorn, creamy, sunflower seeds, crackers, chips, cookies, yogurt, and fresh fruits

Results: multivariate analysis: 

Results: multivariate analysis Variable OR CI 95% p-value Green beans 1.84 1.49,2.27 <0.005 Tortellini 1.25 0.98,1.59 NS Corn soup 0.89 0.69,1.16 NS Veg soup 0.93 0.71,1.21 NS

Results: laboratory: 

Results: laboratory Bacillus sp. recovered from garlic mix (opened/unopened jars), Moroccan beef stew and vegetable soup. Bacillus subtilis was identified based on the library profiles. Heavy metals negative. Patient/employees culture negative.

Food preparation: 

Food preparation Frozen green beans steamed for 10 minutes. Seasoned with salt, pepper, olive oil and garlic mix. Baked in oven for 15 minutes at 375 OF. Stored in warmer at 180 degrees. Placed in pan and sent to serving line (140 degrees); maximum time 4 hours.

Summary: 

Summary 40 persons became ill after eating green beans. We under-estimated magnitude of problem because case ascertainment difficult. The symptoms pointed to a toxin mediated illness. The process of preparing green beans with garlic (in soy oil base) most likely led to the illness. Bacillus was isolated from opened/unopened jars.

Conclusions: 

Conclusions FDA Inspected the manufacturing facility Inspected food supplier Ordered recall of all garlic jars produced by company A Mandated new control protocols Aggressive control measures should be taken to prevent the spread of any outbreak particularly in a hospitals in order to protect not just the patients but the staff. Rarely bacillus subtilis has been associated in food poisoning.

Slide57: 

Thank you