SECTION 8 FOODBORNE ILLNESS BUREAU OF ENVIRONMENTAL EPIDEMIOLOGY Outbreak Definitions 1997 Overview Summary of Selected Foodborne Outbreaks Interstate Food Recalls Source: Bureau of Environmental Epidemiology Foodborne Illness Surveillance and Investigation. Annual Report, Florida, 1997. 102 FLORIDA MORBIDITY STATISTICS 1997 OUTBREAK DEFINITIONS FOODBORNE ILLNESS OUTBREAK of a food item or a meal with illness. A thorough investigation is documented by diligent case find- An outbreak is an incident in which two or ing, interviewing ill and well individuals, collecting more persons have the same disease, have similar clinical and food lab samples where appropriate symptoms, or excrete the same pathogens and there and available, confirmation of lab samples where is a time, place, and/or person association between possible, field investigation of the establishment(s) these persons. A foodborne disease outbreak is one concerned, and statistical analysis of the informa- in which a common food has been ingested by such tion collected during the investigation. The summa- persons. Nevertheless, a single case of suspected ry report of all of the information collected in an botulism, mushroom poisoning, ciguatera (paralytic investigation in a confirmed outbreak will indicate shellfish poisoning), or other rare disease, or a case a strong association with a particular food and/or of a disease that can be definitely related to inges- etiologic agent and a group of two or more people, tion of a food, can be considered an incident of or single incidents as described above. foodborne illness and warrants further investiga- tion. Suspected Outbreak Confirmed Outbreak A suspected foodborne outbreak is one for which the sum of the epidemiological evidence is A confirmed foodborne outbreak is an outbreak not strong enough to consider it a confirmed out- that has been thoroughly investigated and the break. results include strong epidemiological association SECTION 8 – FOODBORNE ILLNESS 103 1997 OVERVIEW In 1997, 439 outbreaks with 2,744 cases were the outbreaks (Figure 8.4). April was the month in reported, compared to 305 outbreaks and 2,777 which the largest percentage of outbreaks was cases for 1996 (Table 8.1, Figures 8.1, 8.2). Investiga- reported (12.6%). January was the month in which tors were able to laboratory confirm 55 of the out- the largest number of cases was reported (14.0%) breaks (including 6 V. vulnificus outbreaks) associat- (Figure 8.5). ed with 840 cases. Staphylococcus was identified in the largest per- Restaurants were the source site in 75.8% of the centage of the total reported outbreaks (12.1%). outbreaks reported and in 55.9% of the cases (Fig- Norwalk virus was identified in the largest percent- ure 8.3). Beef (11.2% of outbreaks) and shellfish age outbreaks (30.7%) (Figure 8.6). (11.2% of outbreaks) were commonly indicated in Table 8.1. Summary of Foodborne/Waterborne Illness Outbreaks Reported, Florida, 1994–1997. Number of Outbreaks Number of Cases Year Confirmed Suspect Total Confirmed Suspect Total 1994 57 201 258 807 719 1,526 1995 80 216 296 2,125 783 2,908 1996 79 226 305 2,018 759 2,777 1997 82 357 439 1,327 1,417 2,744 500 3,500 450 3,000 400 Number of Cases 350 Number of Cases 2,500 300 250 2,000 200 1,500 150 100 1,000 50 0 500 1994 1995 1996 1997 0 Conf Susp Year 1994 1995 1996 1997 Conf Susp Year Figure 8.1. Foodborne/Waterborne Illnesses – Number of Sus- pected and Confirmed Outbreaks by Year, Florida, 1994–1997. Figure 8.2. Foodborne/Waterborne Illnesses – Number of Cases for Suspected and Confirmed Outbreaks by Year, Florida, 1994–1997. 104 FLORIDA MORBIDITY STATISTICS 1997 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec % Cases % Outbreaks Month % Cases Figure 8.5. Foodborne/Waterborne Illnesses – Percent of Total % Outbreaks Site Outbreaks and Cases by Month, Florida, 1997. Figure 8.3. Foodborne/Waterborne Illnesses – Percent of Total Outbreaks and Cases by Site, Florida, 1997. B. cereus C. botulinum C. perfringens Campylobacter Chemical Ciguatera % Outbreaks Cyclospora % Cases E. coli 0157:H7 Giardia Listeria Norwalk Other Salmonella Scombroid Shigella Staphylococcus V. parahaemolyticus V. vulnificus Viral 0% 5% 10% 15% 20% 25% 30% 35% % Cases Figure 8.6. Foodborne/Waterborne Illnesses – Percent of Total % Outbreaks Vehicle Outbreaks and Cases by Etiologic Agent, Florida, 1997. Figure 8.4. Foodborne/Waterborne Illnesses – Percent of Total Outbreaks by Vehicle, Florida, 1997. SECTION 8 – FOODBORNE ILLNESS 105 SUMMARY OF SELECTED FOODBORNE OUTBREAKS Interstate Oyster Outbreak: Norwalk Virus tiple waterways contaminated by raw sewage from from Louisiana Oysters, January, 1997 one or more harvesters. In addition, individual shellfish were dissected and the oysters’ digestive On Friday afternoon, January 3, 1997, the tracts were processed to recover viruses. A total of Bureau of Environmental Epidemiology received a three shellfish were positive for SRSVs, each from a phone call from the Escambia County Health different sample. In addition, the samples were test- Department (Pensacola) describing unusual num- ed for the toxins associated with red tide but were bers of gastroenteritis following the ingestion of found to be negative. raw oysters (12/25, 8 cases; 12/28, 7 cases). On Sat- urday, January 4, the Jackson County Health Norwalk-like viruses, the leading cause of non- Department (Marianna) also reported 14 persons ill. bacterial gastroenteritis in the U.S., are a group of All had attended a New Year’s Eve party and had closely related RNA viruses also known as SRSVs. eaten Louisiana oysters. The onset time varied from They cause diarrhea and vomiting, with occasional 12 to 48 hours, and the duration was 10 to 40 hours. low-grade fever, which lasts one to two days. Trans- The attack rate appeared to be fairly high. In Jack- mission is by person-to-person contact; by fecal son County, of 23 persons who attended the party; contamination of food, recreational and drinking 7 did not eat oysters and did not become ill, 2 ate water, and ice; and possibly via aerosolized vomit oysters and did not become ill, and 14 ate oysters and contact with soiled linen and other articles. and became ill. Anecdotal evidence indicates simi- lar attack rates in the other counties. All of the Person-to-person transmission usually accom- implicated oysters came from Louisiana. All cases panies foodborne outbreaks. Although the illness is had eaten raw oysters within 3 days of their illness. usually self-limiting, the associated dehydration can A case was defined as a person with vomiting or be life threatening in the elderly or the debilitated. diarrhea for over 24 hours who had consumed Louisiana oysters harvested between December 15, Three similar outbreaks have been associated 1996, and January 3, 1997. with Louisiana oysters since the 1970s: 1982 (over 400 cases), November 1993 (45 cases), and February Florida eventually identified 279 cases of illness 1996 (23 cases). Similar outbreaks associated with associated with ingestion of raw Louisiana oysters. Florida oysters occurred in 1980 (13 cases), 1993 (45 Louisiana had 179 persons that met the case defini- cases), and 1995 immediately following New Year’s tion, Georgia had 7 persons, Alabama had 12, and (139 cases). Mississippi had 14. A total of 17 Florida counties (Alachua, Brevard, Citrus, Columbia, Duval, This investigation demonstrated several limita- Escambia, Flagler, Hillsborough, Jackson, Leon, tions in both the current sewage disposal mecha- Marion, Orange, Pinellas, Santa Rosa, Sarasota, nism for oyster harvest vessels and the oyster tag- Seminole, and Suwannee) reported cases of illness ging system designed to reduce the number and from ingestion of raw Louisiana oysters. Escambia magnitude of oyster-associated gastroenteritis out- County reported the most cases (193). breaks. Oyster-related outbreaks of viral gastroen- teritis will likely continue to occur unless seafood The Centers for Disease Control and Preven- regulators and the oyster industry develop and tion, using electron microscopy, found small round- enforce control measures to prevent overboard dis- structured viruses (SRSVs) which include both Nor- charge of sewage from oyster-harvesting boats. This walk and Norwalk-like viruses in 8 of 11 ill persons. investigation highlights the need to further explore The laboratory findings suggest that at least three the interaction between harvesting practices, envi- strains of SRSVs caused this outbreak and support ronmental conditions, oysters, and Norwalk virus.1 the hypothesis that the source may have been mul- 106 FLORIDA MORBIDITY STATISTICS 1997 SRSV AT A RELIGIOUS CELEBRATION, toms of nausea (90%), fatigue (93%), diarrhea (84%), BROWARD COUNTY, JANUARY 1997 cramps (74%), vomiting (50%), or fever (17%). On January 6, 1997, the Broward County Health Food-specific attack rates were determined for Department was notified of a potential foodborne all menu items served at both catered events of Jan- outbreak involving 120 individuals attending a uary 4, 1997. Exposure to whitefish salad doubled catered religious celebration on January 4, 1997. The the risk of illness. No other food-specific attack celebration consisted of two catered events serviced rates were statistically significant. Information by two different caterers. The interview process regarding menu items and exposure at the Chinese revealed that a third dinner party attended by dinner was not gathered, and its possible signifi- approximately 24 guests was held at a Chinese cance was not apparent until well into the investi- restaurant on Friday, January 3, 1997. gation. Preliminary laboratory reports were indica- tive of non-bacterial pathogens and, given the time The owner/operators of the catering companies lapse, an extended investigation into the Chinese were interviewed to review menu items served, dinner menu was not undertaken and probably along with preparation procedures. The Depart- would not have provided any clearer insight into ment of Business and Professional Regulation and the mode of transmission, as all three events are the Broward County Health Department were each implicated as possible source(s) of exposure. The responsible for one of the catering facilities. Accord- epidemic curve of the illness as shown in Figure 8.7 ing to both operators, they were not aware of any clearly indicates a common source outbreak illness among their respective employees. The find- occurred on January 5. ings at the time of the environmental investigation did not reveal any temperature abuse of foods or Eleven stool sample results were negative for deficiencies in food-handling procedures. bacterial pathogens. Three food items were submit- ted for testing, and all were negative for bacterial A questionnaire was developed and adminis- pathogens. On January 28, the Centers for Disease tered to 77 guests and 5 staff members. A case was Control and Prevention confirmed the presence of defined as any attendee who, within three days of SRSVs in four of six stool specimens examined by the event, became ill with nausea, diarrhea, or vom- electron microscopy. No hospitalizations or deaths iting and at least one of the following symptoms: were associated with the outbreak. cramps, fatigue, or fever. The hosts and the atten- dees were queried regarding their state of health The symptomatology, incubation, and duration prior to the attendance at this event, any other of illness are consistent with a Norwalk-like viral events that they attended in common with other gastroenteritis. Cases of January 8 and 9 were most attendees, what foods they ate, if they were ill, the likely secondary cases. Exposure at the Friday night symptoms they experienced, date of onset, dura- dinner and illness manifestation on January 5 still tion, and if they were associated with anyone that falls within the incubation range of the agent. had experienced similar symptoms. Seventy-seven (64%) of the 120 listed guests were interviewed, as well as 5 catering employees. 25 22 Of the guests interviewed, 31 (40%) met the case Number of Cases 20 definition of the outbreak (37 reported being ill). 15 None of the interviewed employees met the case definition, although one of the positive SRSV stools 10 was from an employee. Among the cases, the mean 5 5 incubation period was 24 hours (range 24 to 96 1 1 1 1 0 0 hours); and the duration of illness was 24 to 48 1/4/97 1/5/97 1/6/97 1/7/97 1/8/97 1/9/97 1/10/97 hours (range of 24 to 96 hours). The mean age Date of Onset among the cases was 46 years. Gender distribution among the cases was 14 females and 17 males. Thir- Figure 8.7. SRSV at a Religious Celebration – Epidemic Curve ty-one (40%) of respondents were ill with symp- of Viral Gastroenteritis, Broward County, January 1997. SECTION 8 – FOODBORNE ILLNESS 107 Attendance at the 1:30 p.m. ceremony on January 4, people who were a part of two separate groups. was strongly associated with illness with 31 of 55 The groups experienced gastrointestinal illness fol- attendees who became ill. Four of the 31 cases lowing consuming food at the same restaurant. The attended only the cocktail and dinner event. The March 14 group was comprised of 5 people and the risk of becoming ill increased three-fold with atten- March 15 group included 4 people who ate togeth- dance at the 1:30 p.m. ceremony. Review of the er. The incubation period ranged from 20 to 33 menu items served at that time revealed that all hours with a mean of 26 hours. Predominant symp- food items were served cold and required no fur- tomatology reported included nausea (100.0%), ther preparation or heating before ingestion. diarrhea (75.0%), and vomiting (75.0%). Fever Among the foods served, the whitefish salad was (25.0%), dizziness (25.0%), muscle aches (12.5%), most notable. Those who consumed the whitefish fatigue (37.5%), and chills (37.5%) were other symp- salad doubled their risk of becoming ill. toms described. Duration of illness was reported to range from 12 to 120 hours with a mean of 24 Given the incubation range of Norwalk-like hours. viral gastroenteritis of 10 to 50 hours, and the out- break peak on January 5, the likely points of expo- A total of 18 (39.1%) of 46 employees working sure could have been as recent at the evening event at the implicated food service facility reported gas- of January 4 (particularly for the four cases that trointestinal illness with onsets from February 28 attended only the evening event) or as far back as through March 17, 1997. Gastrointestinal illness in 48 to 50 hours, which would be inclusive of expo- household contacts during this period was reported sure during the Chinese dinner. In conclusion, this by 8 (17.4%) of the employees. One employee, who outbreak was an SRSV-associated outbreak of viral reported illness on February 28, was the chef who gastroenteritis of undetermined source with the prepared all food for the wedding reception on mode of transmission most likely foodborne. March 1, 1997. Symptoms he experienced on Febru- ary 28 and March 1 were described as nausea and Norwalk Virus and Food Handlers in “did not feel well.” Symptoms reported by the Seminole County, March 1997 employees were nausea (70.6%), vomiting (64.7%), diarrhea (52.9%), fever (41.2%), abdominal cramps In March the Seminole County Health Depart- (29.4%), chills (23.5%), and cold/sweats (5.9%). The ment investigated two foodborne illness outbreaks mean temperature of the fever was reported as that occurred two weeks apart in the same food ser- 100.5°F. Duration of the illness for the employees vice facility. The first outbreak was associated with ranged from 2 to 48 hours with a mean of 31.1 a wedding event, while the second transpired over hours, median of 30 hours, and a mode of 48 hours. two evenings involving two groups of people. Ini- Figure 8.8 depicts the days of onset of the two tially, a total of 36 (62.1%) of 58 people became ill cohorts and the employees. following a wedding reception at the food service facility on March 1, 1997. Predominant symptoma- tology reported included nausea (92.3%), diarrhea 30 (82.1%), and vomiting (66.7%). Fever was reported 25 in 19 (48.7%) of the cases with a mean temperature 25 of 101.0°F. Duration of illness was reported to range Number of Cases 20 from 1 to 120 hours with a mean of 50.7 hours, median of 48 hours, and mode of 24 hours. The 15 reported incubation period ranged from 9.25 to 10 9 71.25 hours with a mean of 33.84 hours and a medi- 6 4 5 an of 33.25 hours. Physician care was sought by 5 2 2 2 2 1 1 1 1 1 (13.2%) of the cases, with 2 (5.3%) visiting emer- 0 2/28 3/1 3/2 3/3 3/4 3/5 3/6 3/7 3/8 3/9 3/10 3/11 3/12 3/13 3/14 3/15 3/16 3/17 3/18 gency rooms. The single fecal specimen collected Employee Cohort Date of Onset was negative for Salmonella, Shigella, Campylobacter, Wedding Cohort and Staphylococcus. March 14/15 Cohort Figure 8.8. Norwalk Virus and Food Handlers, Seminole Two weeks later on March 14 and March 15, the County – Number of Cases by Date of Onset, March 1997. second outbreak occurred and consisted of eight 108 FLORIDA MORBIDITY STATISTICS 1997 The incubation periods, high attack rates, dura- Cyclospora Outbreak and Mesclun Lettuce, tion of the illness, and described symptoms of low Leon County, 1997 grade fever, chills, lethargy, weakness, and headache in addition to the high prevalence of diar- On April 15, 1997, a private lab in Tallahassee rhea and vomiting are consistent with confirmed reported two cases of cyclospora. The Department outbreaks caused by the Norwalk-like virus. The of Health Bureau of Laboratories in Jacksonville reported similar illness among household members later confirmed the cases. A preliminary investiga- is also characteristic of this virus. The absence of tion indicated both cases had eaten at the same enteric pathogenic bacteria in the fecal sample indi- restaurant in Tallahassee. Due to the emerging cates a viral etiology. nature of this pathogen, the Bureau of Environmen- tal Epidemiology requested epidemiologic assis- Epidemiological data did not indicate a statisti- tance from the Centers for Disease Control and Pre- cally significant association with a single food item vention on April 20, 1997. as a vehicle of transmission in either outbreak. This could be due to the limited choice of food items, On March 19, the day implicated by the initial sampling technique, or a statistically small cohort. questionnaire, the restaurant served approximately There is also a strong possibility that multiple food 243 persons, 142 of whom had charged their meals. items were involved in transmitting the causative Of the 142 persons in the charge-card group, 89 agent in all three outbreak clusters. The preparation (62.7%) were interviewed. A retrospective cohort of all food items for the wedding reception was per- study using charge card receipts was initiated. The formed by a single person who exhibited symptoms case definition was as follows: of illness similar to those involved in the outbreak. It is therefore possible that multiple food items laboratory-confirmed case: laboratory confir- which were highly handled and not subsequently mation plus 1 gastrointestinal symptom; heated were inoculated with an infectious dose. An probable case: diarrhea (3 or more loose infectious dose of the Norwalk-like virus is thought stools in a 24-hour period) for 3 or more to be less than 10 organisms. There is strong evi- days; and dence showing that the Norwalk-like virus can be possible case: 5 or more symptoms including shed up to 72 hours following onset of symptoms at least 1 gastrointestinal symptom. and growing evidence that this virus can be shed 24 hours prior to expression of symptoms. Seventy-five persons were in the cohort. The cohort had a median age of 44 years and 62.7% The high attack rate of nearly identical gastroin- were female. Twenty-nine persons met the case def- testinal illness among the employees of the food inition. The onset of illness occurred a median of 8 service facility for a two-week period during the days after eating lunch at the restaurant (range 0 to last week of February and the first two weeks of 14 days). March indicates that the agent was present and cir- culating in the food service facility. The agent was Analytical epidemiology indicated consump- most likely introduced to an employee or employ- tion of mesclun greens correlated with cyclosporia- ees of the restaurant via a community-acquired case sis. The relative risk associated with consumption of of illness and was transmitted among the employ- mesclun was 8.5 with a confidence interval of 2.8, ees. The presence of ill or asymptomatic employees 25.7 and a P value of < 0.001. The traceback indicat- either by itself or in conjunction with a breach in ed that the mesclun originated from either a domes- personal hygiene practices probably caused the tic farm or one of 2 farms in Peru. The local whole- agent to be transmitted to the single or multiple saler was not able to conclusively state the source of food items. While it appears that the gastrointesti- the mesclun greens consumed at the local restau- nal illness among the food workers at this establish- rant on the day of the outbreak.2 ment had significantly decreased prior to the sec- ond cluster of gastrointestinal illness, there still is a high degree of probability that the organism trans- mitted during the previous outbreak was still pre- sent in the kitchen population. SECTION 8 – FOODBORNE ILLNESS 109 Staphylococcus aureus and Chicken Fajitas, The investigation and tracebacks of the hog Lee County, May 1997 snapper revealed that two retail outlets were involved. Both retail outlets bought hog snapper In Lee County, 7 people sought medical treat- from the same local wholesaler. The lots of fish ment after consuming chicken fajitas from a mobile implicated in the poisoning were from a lot pur- food vendor on May 20, 1997. The Lee County chased on May 21, 1997, consisting of 707 pounds Health Department interviewed approximately 15 of hog snapper, and a second lot, consisting of 999 people who had consumed food from the mobile pounds of hog snapper, purchased on June 9, 1997. truck, and only those that ate the chicken fajitas Both lots were bought by a local wholesaler from a became ill. Signs and symptoms (i.e., nausea, vom- single source, a fisherman who fishes the Dry Tor- iting, abdominal pain, diarrhea, sweating, chills, tugas Bank off the southwestern tip of the Florida and prostration) were consistent with Staphylococcus Keys. In all, there was a cluster of 7 cases, including aureus. Onset of symptoms ranged from 30 minutes the abovementioned 4 cases, 2 anecdotal reports to 2.5 hours (median 2 hours) and lasted about 48 from the traceback investigation in Broward Coun- hours. A clinical sample (vomitus) and a portion of ty, and 1 additional report to the FDA Boca Raton fajita tested positive for Staphylococcus aureus field office involving a Palm Beach County resident. enterotoxin type A. Contributing factors to the out- All had food history of eating hog snapper, with break include food obtained from an unapproved symptoms developing within the time frame sug- source and poor personal hygiene. The chicken faji- gestive of ciguatera poisoning. There was not tas were prepared in a private home, where a por- enough information available to investigate all the tion was consumed, and the next day were placed reported cases. Despite an extensive traceback on a “California” truck with an open steam table. effort, no fish from the implicated lots were found The fajitas were assembled on the back of the truck. for testing. There was no ability to wash hands as no sinks were provided on the vehicle. Although the exact Staphylococcal Intoxication in St. Johns cause of contamination is unknown, other con- County, September 1997 tributing factors to this outbreak could include time/temperature abuse, improper cooling, inade- In September 1997, 18 persons experienced quate reheating, unclean equipment, and cross con- staphylococcal food poisoning after attending a tamination. The catering company and their mobile retirement party. Seven of these persons sought food vehicles were closed until all Department of medical treatment for their illness and two were Agriculture and Consumer Services and Depart- hospitalized overnight. Ill persons reported nausea, ment of Business and Professional Regulation vomiting, diarrhea, weakness, sweats, and chills as requirements were met. their primary symptoms. Onset of illness occurred at a mean of 3.4 hours after eating (range 1 to 7 Ciguatera Cases in Broward County, June hours), and symptoms lasted a median of 24 hours 1997 (range 2 to 72 hours). Illness was strongly associat- ed with eating ham (risk ratio = 26.8; 95% confi- In June 1997, the Broward County Health dence interval = 3.8–189.6). Leftover ham was ana- Department received two medical reports of diag- lyzed and found positive for staphylococcal entero- nosed cases of ciguatera poisoning in two patients toxin type A. Investigation of the outbreak found with symptoms consistent with ciguatera poisoning that the 16-pound precooked, packaged ham had and a recent food history of eating hog snapper. been baked, sliced while hot and stored in one Additionally, two contemporaneous suspected small container the day prior to the party. The food cases were reported by two individuals calling in a preparer denied having any cuts, sores, or infected foodborne complaint with food history of hog snap- wounds. Cleaning methods of the slicer were inade- per and symptoms consistent with ciguatera poi- quate and it was not properly sanitized. The storage soning. The four individuals experienced symp- of 16 pounds of hot, sliced ham in one small con- toms including abdominal cramping, diarrhea, nau- tainer prevented rapid cooling of the ham and facil- sea, dizziness, muscle aches, chills, sensitivity to itated sufficient microbial growth and enterotoxin cold, and headache within a median incubation production to result in this outbreak of foodborne period of 5 hours (range 2 to 8 hours). illness.3 110 FLORIDA MORBIDITY STATISTICS 1997 Staphylococcus aureus in a Prep School, Palm veillance efforts expanded the cohort to 38 people. Beach County, November 1997 Eight people had laboratory-confirmed positive stools for cyclospora. A total of 12 of the 38 people On November 13, 1997, the Palm Beach County had reported illness compatible with cyclospora. Health Department was notified of a foodborne ill- The cohort was comprised of four distinct groups of ness outbreak at the Boca Raton Preparatory School people. Group one consisted of 20 people from in Boca Raton, Florida. Four persons (3 students New York and Pennsylvania, with 8 reported ill. and 1 teacher) were admitted to the West Boca Group two had 2 ill people in a group of 9 from Medical Center and 3 others were seen at the emer- New York and North Carolina. The third group, gency room and released following the lunch meal from New York, had 1 person ill out of 5. The served on November 12. Two students and one fourth group, from New Hampshire and Massachu- adult admitted to the hospital submitted stool sam- setts, consisted of 4 people, with 1 reported ill. ples that were positive for Staphylococcus aureus. None of the people from any of the four groups Symptoms included abdominal cramping, fatigue, knew each other or had any other epidemiological headache, nausea, vomiting, dizziness, diarrhea, associations. and chills. The epidemiological investigation initiat- ed by the Division of Epidemiology and Disease The epidemiological investigation of these 38 Control of the Palm Beach County Health Depart- people shows that 100% consumed food at a dinner ment discovered 94 of 303 students (31%) were ill show held at a convention center in central Florida and 4 of 43 adults (9.3%) were ill. The school was on December 3, 1997. This dinner show was a tem- only approved to use a licensed caterer. However, porary holiday event that served 400 to 700 people the suspected foods, macaroni with ground turkey twice each night. The show ran from December 1 sauce and macaroni with Alfredo sauce, were pre- through December 24, 1997. The meals were pre- pared at unapproved food service facilities by an pared in the convention center food service facility. uncertified food handler. A food sample of the mac- Food items served included a relish tray consisting aroni and ground turkey sauce sent to the Depart- of cauliflower, broccoli, carrots, and celery with ment of Health’s Bureau of Laboratories in Jack- white creamy dressing or an apple vinaigrette sonville tested positive for Staphylococcus aureus dressing. Dessert was a yule log (a thin cake and enterotoxin at >300,000/gram and positive for frosting roll) or a raspberry, strawberry, or melon Staphylococcus aureus enterotoxin type A. A sample fruit cup. The yule log was offered to everybody. of raw turkey meat from the same lot sent to the lab Apparently, fruit cups were offered to those who recovered no Staphylococcus aureus enterotoxin. Of requested something other than the yule log. The those ill, 81.6% ate macaroni with turkey sauce, type of fruit cup offered depended on the time of 39.8% of those ill ate macaroni with Alfredo sauce, the night. A leafy green salad was also served, and and 92.9% of those ill ate macaroni with turkey it consisted of Romaine lettuce broken into bite-size sauce and/or macaroni with Alfredo sauce (RR = pieces, baby lettuce greens (spring mix, also known 12.85 with 95% confidence limits of 6.14< RR< as mesclun lettuce), dried apricots, dried cherries, 26.92). and raisins, with cherry tomatoes on the side. Holiday Dinner Cyclospora, Orange County, Statistical analysis of all the food products dis- December, 1997 closed a significant association with the consump- tion of the leafy green salad and the cyclospora ill- During the last days of 1997 and the first ness (OR = undefined; Uncorrected Chi-square = months of 1998, the Florida Department of Health 15.20; p = 0.000096). An on-site investigation of the Orange County Health Department investigated a food service facility disclosed that the romaine let- multistate cyclospora outbreak associated with a tuce in the leafy green salad was not added until tourist attraction in central Florida. Initial informa- December 6, 1997, in order to boost the volume of tion disclosed 4 cases of presumed cyclospora infec- the salad. The dried fruit was consumed by only 2 tion among approximately 20 persons in a group of the ill people and was not considered to be sig- from New York and Pennsylvania who traveled to nificant. Since cyclospora outbreaks earlier in 1997 the Orlando area from November 27 to December had implicated mesclun lettuce as a vehicle, the 12. Several other people in this party were also spring mix, or baby lettuce greens, became the reported to be ill. Nationwide case finding and sur- focus of traceback activities. Preliminary informa- SECTION 8 – FOODBORNE ILLNESS 111 tion from the traceback disclosed a single distribu- NOTES tor who supplied the warehouse servicing the con- 1 See also: Déjà vu: Another New Year’s Oyster Outbreak, vention center. This distributor, located in north Florida Journal of Environmental Health, 158:30, June, Florida, was also a grower of spring mix lettuce. 1997; Viral Gastroenteritis Associated with Eating Oysters This distributor/grower also obtained spring mixes – Louisiana – December 1996–January 1997, Morbidity and Mortality Weekly Report, 46(47):1109–1112. from two other distributors during the 10 days prior to the December 3 exposure period. 2 See also: Outbreaks of Cyclosporiasis – United States – 1997, Morbidity and Mortality Weekly Report, 46(23):521–523; Herwaldt, Barbara et al. An Outbreak in Vibrio vulnificus 1996 of Cyclosporiasis Associated With Imported Raspber- ries, The New England Journal of Medicine, May, 1997, A total of 17 Vibrio vulnificus cases were report- 336:1548-1556; Outbreak of Cyclosporiasis, Northern Vir- ginia – Washington, DC – Baltimore, Maryland, Metropoli- ed in Florida during 1997. Of these, 11 were wound tan Area, Morbidity and Mortality Weekly Report, August related. The other 6 cases were associated with con- 1, 1997, 46(30):689–691. sumption of raw oysters. Five deaths were reported 3 See also: Outbreak of Staphylococcal Food Poisoning Asso- from Vibrio vulnificus (2 wound related, 3 oyster ciated With Pre-cooked Ham – Florida – 1997, Morbidity related) (Figure 8.9). and Mortality Weekly Report, 46(50):1189–1191. 2 1 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month # Cases # Deaths Figure 8.9. Vibrio vulnificus – Cases and Deaths due to Shellfish Consumption by Month, Florida 1997. 112 FLORIDA MORBIDITY STATISTICS 1997 INTERSTATE FOOD RECALLS The state of Florida participated in two highly The Hudson hamburger patty recall caused publicized interstate recalls in 1997—sliced frozen even more public concern as Hudson’s patties were strawberries (March) and Hudson’s hamburger pat- delivered to Sam’s and Walmart stores around ties (August). Frozen sliced strawberries were Florida, as well as other states. This recall was implicated in an outbreak of hepatitis A in school prompted by a 16-person outbreak of E. coli children in Michigan. These strawberries were from 0157:H7 in Colorado. Initially, three lots were a packer/processor and were supposedly USDA recalled. This was ultimately increased to 25 million approved for the school lunch program. Strawber- pounds of hamburger. Several small clusters of ries from the same lot had been shipped to distribu- Florida residents reported illness and were investi- tors in five other states including Florida, though gated as being possibly related to the nationwide the north Florida distributor shipped strawberries recall. A coordinated effort between the Department only to a school district in Georgia. The FDA initiat- of Agriculture and Consumer Services, who collect- ed a recall, from various school districts around the ed and tested hamburger patties from implicated country, of frozen strawberries from the same time lots, and the Department of Health, who collected period and the same packer/processor. In Florida, stools from ill persons, found no individuals in the recall notice came through the Florida Depart- Florida with E. coli 0157:H7 related to the recall and ment of Agriculture and Consumer Services. The no hamburger patties positive for the pathogen. strawberries were eventually found to have origi- nated from Mexico and therefore not USDA Both recalls involved extensive interagency approved for school lunch programs. While this coordination and cooperation at the local, state, and recall generated a lot of public interest and concern, federal levels. In addition, the recalls involved an none of the implicated strawberries ever reached enormous effort of quick response, information schools in Florida.1 sharing, and public reassurance on the part of health officials. NOTES 1 See also: HAV-tainted Frozen Strawberries Top National News: Tale of the Outbreak, Hepatitis Control Report, 2(1):1–12, Spring 1997.
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