SECTION 8 FOODBORNE ILLNESS by qhq29331

VIEWS: 17 PAGES: 12

									                                         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.

								
To top