SCIENTIFIC INSTITUTE OF PUBLIC HEALTH

Epidemiology Unit

Case Control study among schoolchildren on the incident related to complaints following the consumption of Coca-Cola Company products, Belgium, 1999.

Stefaan Demarest
November 1999

Table of contents

PRELIMINARY 1
1. EXECUTIVE SUMMARY 2
2. INTRODUCTION 4
3. OBJECTIVES 5
4. HYPOTHESES 5
5. METHOD 6
5.1. Study design 6
5.2. Population 6
5.3. Definition of the cases and the controls 6
5.4. Sample size 6
5.5. Case finding 6
5.6. Data collection 6
5.7. Information from the physicians 7
5.8. Information on the scenario in schools 7
5.9. Analysis 7
6. TOXICOLOGICAL INFORMATION 9
7. ATTACK RATE AND EPIDEMIC CURVE 10
7.1. Attack rate and epidemic curve in Bornem 10
7.2. Attack rate and epidemic curve in the other schools 10
8. SYMPTOMS 13
8.1. Symptoms of the students of Bornem 13
8.2. Symptoms of the students of the other schools 14
9. RESULTS OF THE CASE-CONTROL STUDY 16
9.1. Odds of exposure to regular Coca-Cola consumption in Bornem 16
9.2. Odds of exposure to regular Coca-Cola consumption in the other schools 16
9.3. Odds of exclusive exposure to specific beverages in Bornem 16
9.4. Odds of exclusive exposure to specific beverages in the other schools 17
9.5. Odds of exposure to other risk factors in Bornem 17
9.6. Odds of exposure to other risk factors in the Other schools 19
9.7. Odds of exposure to regular Coca-Cola stratified by the mental health score (SF36) 19
9.8. Odds of experiencing a low mental health (SF36) stratified on the consumption of regular Coca-Cola 21
10. SCENARIO OF THE OUTBREAKS IN THE SCHOOLS 24
10.1. Scenario in Bornem 24
10.2. Scenario in Brugge 25
10.3. Scenario in Harelbeke 25
10.4. Scenario in Kortrijk 26
10.5. Scenario in Lochristi 26
11. BIOLOGICAL PARAMETERS AND OTHER EXAMINATIONS 28
11.1. Bornem 28
11.2. Other schools 28
12. DELAY BETWEEN THE TIME OF BEVERAGE AND THE ONSET OF THE DISEASE 29
12.1. Bornem 29
12.2. Other schools 30
13. TOXICOLOGICAL ANALYSIS ON BLOOD AND URINE SAMPLES 31
13.1. Bornem 31
13.2. Other schools 31
14. CUMULATIVE NUMBER OF CASES AMONG THE STUDENTS (CASES + CONTROLS) WHO HAVE CONSUMED BEVERAGES 32
15. CLUSTER IN CLASSROOMS 33
15.1. Bornem 33
15.2. Other schools 33
16. TOXICOLOGICAL, BACTERIOLOGICAL, VIROLOGICAL ANALYSIS OF THE BEVERAGES 34
16.1. Hydrogen sulphide (H2S) and carbonyl sulphide (COS) 34
16.2. P-chloro-m-cresol (PCMC) 34
16.3. Bacteriological and virological analysis 35
17. MEDIA INFORMATION 36
18. DISCUSSION 37
18.1. Bornem 37
18.2. Other schools 38
19. LIMITATIONS 40
20. CONCLUSION 41
21. RECOMMENDATIONS 42
21.1. Recommendation specific to the study 42
21.2. General recommendation on the management of such events 42
22. BIBLIOGRAPHY 43
23. ANNEX (questionnaires only in Dutch) (available on request)