Gastroenteritis Case Study

1. GASTROENTERITIS
OUTBREAK REPORT AT THE
UNIVERSITY OF TEXAS AT
AUSTIN
Yves Amougou
NURS700
Maryville University

2. COVER PAGE
 Report Date: April 3rd, 1998
 Release Date: May 12th, 1998
 To: University of Texas at Austin Board of Directors, Austin Director of Health Department
 From: Yves Amougou, DNP, FNP-BC, University of Texas at Austin
 Report Co-authors: John Doe, MD, CDC Austin Chief Epidemiology
 Peer Reviewers: Patrick Doe, PHD, Austin Food Hygiene Inspector, Patrick Doe III, MD, Austin Texas
Health Department. Epidemiology Specialist.
 Reported by: Unnamed student at a university in south-central Texas
 Persons contacted: Cafeteria staff, Students Diagnosed with Gastroenteritis

3. INTRODUCTION
 On March 11th, a staff at Texas Department of Health (THD) at Austin received
a telephone call from an unamend student at a university in south-central
Texas. The student reported that he and his roommate, a fraternity brother,
were suffering from nausea, vomiting, and diarrhea. Both had become ill
during the night. A report was taken.
 A call to the emergency room at a local hospital (Hospital A) revealed that 23
university students had been seen for acute gastroenteritis in the last 24
hours.
 The physician from the University Student Health Center returned the call
from TDH and reported that 20 students with vomiting and diarrhea had been
seen the previous day.

4. INTRODUCTION CONTINUED
 Who: by March 13, 125 persons with vomiting or diarrhea had been reported
to TDH.
 Where: University cafeteria.
 When: March 5th and March 10th.
 What: They were diagnosed with Gastroenteritis within days of eating at the
cafeteria.
 Why: Suspected infection from food and beverage contamination at the
cafeteria deli.

5. EPIDEMIOLOGY
 By March 12, seventy-five persons with new onset of vomiting or diarrhea had
been reported to TDH. All were students who lived on the university campus.
 No cases were identified among university faculty or staff or from the local
community.
 Except for one case, the dates of illness onset were March 9-12. (Figure 1)
 The median age of patients was 19 years (range: 18-22 years), 69% were
freshman, and 62% were female.

6. Figure 1. Onset of gastroenteritis among
students, University X, Texas, March
1998. (N=72) (Date of onset was not
known for three ill students.) (Graph provided by hospital
A data).

7. EARLY INVESTIGATION
 On March 11th, the preliminary stool collected at the ER did not identify any
bacteria as infective agent.
 Additional stool test collected at the university from students and cafeteria
staff yield similar results.
 Initial findings were suggestive of viral infection.
 Because most cases were among college students, and no incident involving
contamination at the community level.
 The goal of the initial investigation was to identify the causative agent and
the mode of transmission.
 Leading Hypothesis: a viral gastroenteritis outbreak that originated at the
school cafeteria, due to contaminated food and/or beverage.

8. GASTROENTERITIS FACT
 Acute gastroenteritis (AGE) is a condition marked with symptoms such as
diarrhea, vomiting, abdominal pain (Graves, 2013).
 The Centers for Disease Control and Prevention (CDC, 2012) estimate there
are more than 48 million cases of acute gastroenteritis in the United States
annually, with more that 3000 deaths.
 Most times AGE is viral in origin. Norovirus is the most common cause.
 Infectious agents include bacteria, viruses, parasites and toxins.
 Infectious agent may enter the food chain at any stage from the garden to
the plate.
 In many cases AGEs are self-limited.
 Dehydration is the most common complication

9. GASTROENTERITIS (picture from
www.emedihealth.com)

10. INITIAL STUDY DESIGN
 The investigators administered the study questionnaire by telephone from
March 15-23
 Case Control Study
 Case: Students who ate at the deli during critical period and became sick.
Patients should have at least 3 episodes of diarrhea over 1 day along with
nausea/vomiting.
 Control: Dormitory mates who ate at the deli during the critical period and
who did not get sick.
 A diary of what participants ate was recorded to identify commonalities.

11. INITIAL FINDINGS AND LIMITATIONS
 Most cases were among student who are ate the deli during March 5th to
March 10th.
 No bacteria were identified as infective agent.
 Initial findings were suggestive of viral gastroenteritis associated with food
and/or beverage contamination at the deli.
 Investigators reported to the cafeteria to observe cafeteria routine.
 Food and beverage samples were collected
 Sample from food preparation area were collected.
 Limitations from initial selection bias from paired samples.

12. Table 3. Food items eaten by students who ate at
deli bar during implicated meals, unmatched case-
control study, University X , Texas, March 9-10,
1998.* (table provided by case study).
Exposure Ill exposed/ Total ill
(%)
Well exposed/ Total well
(%)
Odds Ratio 95% Confidence Interval p-value
American cheese 13/28 (46) 4/20 (20) 3.4 0.80-17.5 0.06
Swiss cheese 8/28 (29) 8/20 (40) 0.61 0.15-2.4 0.30
Ham 11/28 (39) 6/20 (30) 1.5 0.38-6.3 0.36
Turkey 15/28 (54) 11/20 (55) 0.95 0.26-3.5 0.57
Shredded lettuce 13/28 (46) 10/20 (50) 0.87 0.24-3.2 0.52
Tomato 7/28 (25) 6/20 (30) 0.78 0.18-3.5 0.50
Pickles 7/28 (25) 7/20 (35) 0.63 0.15-2.6 0.63
Mayonnaise 20/28 (71) 9/20 (45) 3.1 0.78-12.4 0.06
Mustard 10/28 (36) 9/20 (45) 0.68 0.18-2.6 0.52

13. ADDITIONAL INVESTIGATION
• The staff member who initially refused to be interviewed worked primarily
at the deli bar. When she finally agreed to be interviewed on March 23,
she reported slicing ham on March 9, for use at the deli bar during lunch
and dinner that day, and lunch the following day.
• The staff reported that she was wearing gloves, but she did not practice
good hand washing.
• The staff also revealed that she was caring for an infant who was
diagnosed with gastroenteritis prior to the food outbreak.

14. NEW CONTROL STUDY
 A new case control study was done with unmatched pair,
in order to eliminate the initial sample bias.
 CDC staff suggested submission of fresh stool specimens
from ill students for viral studies including reverse
transcriptase-polymerase chain reaction.
 The study design was done with face to face interview
along with phone interview.

15. INTERPRETATION
 It appears that for the critical period for this table,
people who ate American cheese were 3.4 time more
likely to get sick than the control (p value 0.06).
 For people who ate Ham were 1.5 more likely than the
control to get sick (p value 0.36).
 People who ate Mayonnaise were 3.1 time likely than the
control to get sick (p value 0.06).
 In all the above cases, p value was greater than 0.05. This
implies that chance alone cannot be excluded to be the
cause of illness

16. STUDY FINDINGS
 A viral gastroenteritis outbreak occurred at the deli.
 There is a strong suspicion that a foodhandler may have
been the one spreading the germs at the cafeteria with
her poor hand hygiene.
 PCR sequences between the stools samples of the ill
infant were identical to those products from the ill
students and the deli ham is strongly suggestive of
causality

17. RECOMMENDATIONS
 Deep cleaning of cafeteria prior to re-opening.
 Discard all leftover food and beverage prior to re-opening.
 Food handling in-service for all cafeteria staff, with
frequent
 Fridge temperature logs
 All cafeteria staff should submit a new stool sample and
they should certify absence of recent AGE.
 Random inspection of cafeteria by county food inspectors.
 Food inspection score should be displayed at the dining
room to restore trust.

18. CONCLUSION
 AGE outbreak occurred at the cafeteria deli.
 It appears that the son of one staff member was the primary source of
infection.
 The staff member became a vehicle of the infection due to her role as
caretaker/parent.
 While working at the deli, the staff unintentionally contaminated food due to
her reluctance to wash her hand.
 PCR sequences between the stools samples of the ill infant were identical to
those products from the ill students and the deli ham is strongly suggestive of
causality
 While observing staff routine, other deficiencies were identified.
 Recommendations were given to all stakeholders in order to prevent future
foodborne illnesses.

19. References
CDC Division of News and Electronic Media (2012). Deaths from gastroenteritis
double. Available at: www.cdc.gov. Accessed August 14, 2022 from
https://www.cdc.gov/media/releases/2012/p0314_gastroenteritis.html
Emedihealth. (2022). Gastroenteritis: cases, symptoms and treatment. Image
obtained from https://www.emedihealth.com/digestive-health/health-
conditions/treat-gastroenteritis
Graves, N. S. (2013). Acute gastroenteritis. Primary care: clinics in office
practice, 40(3), 727-741.