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

1. 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

2. 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 Rashid A. Chotani, MD, MPH GIDSAS-JHU

3. Sequelae • Guillain-Barre Syndrome (C. jejuni) • Renal Disease (E. coli O157:H7 and other Shiga-like toxin producing bacteria) Rashid A. Chotani, MD, MPH GIDSAS-JHU

4. 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 Rashid A. Chotani, MD, MPH GIDSAS-JHU

5. Events and potential contamination sources during produce processing Event Contamination sources Production and harvest Growing, picking, bundling Irrigation water, manure, lack offield 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

6. Enteric Host Defense • Saliva • Gastric Acid • Intestinal motility • Enteric flora • Shedding & replication of epithelium • Mucus layer • Immune system • Proteolytic enzymes Rashid A. Chotani, MD, MPH GIDSAS-JHU

7. 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 ScenarioNew Outbreak Scenario acute: local diffuse: multi-state & inter dose & attack rate: high dose & attack rate : low detected : by groups detected : by lab-basedsurveillance Rashid A. Chotani, MD, MPH GIDSAS-JHU

8. 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 Rashid A. Chotani, MD, MPH GIDSAS-JHU

9. FoodNet Rashid A. Chotani, MD, MPH GIDSAS-JHU

10. 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 Rashid A. Chotani, MD, MPH GIDSAS-JHU

11. 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 Rashid A. Chotani, MD, MPH GIDSAS-JHU

12. FoodNet Components • Active lab-based surveillance • Surveys of clinical labs • Survey of physicians • Survey of the population • Case-Control studies Rashid A. Chotani, MD, MPH GIDSAS-JHU

16. Classification

17. 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 Rashid A. Chotani, MD, MPH GIDSAS-JHU

18. Epidemiologic Triad Agent Host Environment Rashid A. Chotani, MD, MPH GIDSAS-JHU

19. 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, andEntamoeba histolytica Rashid A. Chotani, MD, MPH GIDSAS-JHU

20. 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 Rashid A. Chotani, MD, MPH GIDSAS-JHU

21. 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. Rashid A. Chotani, MD, MPH GIDSAS-JHU

22. 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 Rashid A. Chotani, MD, MPH GIDSAS-JHU

23. 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 Rashid A. Chotani, MD, MPH GIDSAS-JHU

24. 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) Rashid A. Chotani, MD, MPH GIDSAS-JHU

25. Viruses • Obliterate intracellular organisms • Require host cell to multiply • Do not produce toxins or multiply in food • Reservoirs are humans Rashid A. Chotani, MD, MPH GIDSAS-JHU

26. 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 Rashid A. Chotani, MD, MPH GIDSAS-JHU

27. Source • Public • Laboratory reports • Healthcare providers • Health departments • Other state departments Rashid A. Chotani, MD, MPH GIDSAS-JHU

28. Goal • Prevent transmission • Early detection • Understanding outbreak disease epidemiology • Evaluate food safety programs • Identify high risk food & processes Rashid A. Chotani, MD, MPH GIDSAS-JHU

29. Information • Timing is ESSENCE • Designate team leader • Assign responsibilities • Obtain maximum information on first contact • Use standardized form Rashid A. Chotani, MD, MPH GIDSAS-JHU

30. 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 Rashid A. Chotani, MD, MPH GIDSAS-JHU

31. 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 Rashid A. Chotani, MD, MPH GIDSAS-JHU

32. 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) Rashid A. Chotani, MD, MPH GIDSAS-JHU

33. Point Source Outbreak 10 8 6 Catered event # of Cases 4 2 0 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 Rashid A. Chotani, MD, MPH GIDSAS-JHU

34. Intermittent Source Outbreak 10 8 6 # of Cases 4 2 0 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 Rashid A. Chotani, MD, MPH GIDSAS-JHU

35. Continuous Source Outbreak 10 8 6 # of Cases 4 2 0 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 Rashid A. Chotani, MD, MPH GIDSAS-JHU

36. Propagated Source Outbreak 10 8 6 # of Cases 4 2 0 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 Rashid A. Chotani, MD, MPH GIDSAS-JHU

37. 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 Rashid A. Chotani, MD, MPH GIDSAS-JHU

38. 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 Rashid A. Chotani, MD, MPH GIDSAS-JHU

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

40. Hospital • 940 bed hospital with 4 cafeterias. • Cafeteria A, located in the OPD, serves approximately 600 visitors and employees daily. Rashid A. Chotani, MD, MPH GIDSAS-JHU

41. Events • On 12/9/97 individuals who ate at Cafeteria A reported nausea and projectile vomiting after eating a noon meal. Rashid A. Chotani, MD, MPH GIDSAS-JHU

42. 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. Rashid A. Chotani, MD, MPH GIDSAS-JHU

43. 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. Rashid A. Chotani, MD, MPH GIDSAS-JHU

44. 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. Rashid A. Chotani, MD, MPH GIDSAS-JHU

45. 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 Rashid A. Chotani, MD, MPH GIDSAS-JHU

46. 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 Rashid A. Chotani, MD, MPH GIDSAS-JHU

47. Results • N = 75 (ill = 40; non-ill = 35) • Mean age: 39 years (range 25-56) • Sex: 85% female Rashid A. Chotani, MD, MPH GIDSAS-JHU

48. Incubation period: JHH employees (n=40)

49. Symptoms

50. Results: outcomes • Duration of illness: mean--24 hr. (range <24 - 72 hr.) • Bedridden 62.5% • Sought medical care 27.5% • Hospitalized 2.5% Rashid A. Chotani, MD, MPH GIDSAS-JHU