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Foodhandler-Associated Salmonella Outbreak in a University Hospital Despite Routine Surveillance Cultures of Kitchen Employees

Published online by Cambridge University Press:  02 January 2015

Najwa A. Khuri-Bulos*
Affiliation:
Jordan University Hospital, Amman, Jordan
Mahmoud Abu Khalaf
Affiliation:
Jordan University Hospital, Amman, Jordan
Asem Shehabi
Affiliation:
Jordan University Hospital, Amman, Jordan
Khaled Shami
Affiliation:
Jordan University Hospital, Amman, Jordan
*
Department of Pediatrics, Jordan University Hospital, Amman, Jordan

Abstract

Objective:

To describe an outbreak of salmonella food poisoning that probably was due to contamination of mashed potatoes by a foodhandler, which occurred despite a policy for routine surveillance stool cultures of kitchen employees.

Design:

A case control study of 223 individuals who ate the lunch meal on September 23, 1989, at the Jordan University Hospital (JUH) cafeteria.

Setting:

Tertiary care university hospital in Amman, the capital of Jordan.

Patients:

Individuals who developed loose stool or vomiting 6 to 72 hours after eating the lunch meal of September 23, 1989, at the JUH cafeteria.

Results:

Of 619 individuals, 183 fit the case definition (attack rate, 19.6%); 150 were employees, 26 were inpatients, and seven were visitors. Twelve other employees became sick 4 to 6 days later and probably were infected secondarily. The incubation period ranged from 16 to 72 hours in 183 instances. Symptoms included diarrhea (88%), fever (71%), abdominal pain (74%), dehydration (34%), and bloody stool (5%). Eighty-four were hospitalized. Cultures of eight food items were negative, but stool culture on 90 of 180 patients and 11 of 61 kitchen employees yielded Salmonella enteritidis group D.

A cohort study of 223 individuals revealed a food-specific attack rate of 72% for the steak and potato meal and 18% for the rice and meat meal (RR, 4; CI95, 2.62 to 6.24; P<0.01). Stratified analysis of the steak and potato meal revealed that the potatoes were implicated most strongly (RR, 1.93; CI95, 1.42 to 2.64; p<0.01). Cultures were obtained from all kitchen employees, and 11 of 61 grew Salmonella enteritidis group D. One asymptomatic, culture-positive employee prepared the mashed potatoes on September 23. All of these employees had negative stool cultures 3 months earlier.

Conclusion:

This outbreak probably was caused by massive contamination of mashed potatoes by the contaminated hands of the foodhandler. Routine stool culture of foodhandlers is not cost-effective and should not be used as a substitute for health education and proper hygienic practices.

Type
Original Articles
Copyright
Copyright © The Society for Healthcare Epidemiology of America 1994

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References

1. Centers for Disease Control. Foodborne disease outbreaks, 5yearsummary, 1983-1987. CDC surveillancesummaries, March 1990. MMWR 1990:39(no. SS1):1557.Google Scholar
2. Communicable Disease Surveillance Centre. Food poisoning and salmonella surveillance in England and Wales, 1983. Br Med J 1985;291:394396.Google Scholar
3. Hedberg, CW, White, KE, Johnson, JA, et al. An outbreak of Salmonella enteritidis infection at a fast-food restaurant: implications for food handler-associated transmission. J Infect Dis 1991;164:11351140.CrossRefGoogle Scholar
4. Spika, JS, Waterman, SH, Soo Hoo, GW, et al. Chloraphenicol-resistant Salmonella newport traced through hamburger to dairy farms. N Engl J Med 1987;316:565570.CrossRefGoogle ScholarPubMed
5. Reilly, WJ. Forbes, GI, Sharp, JC, Oboegbulen, SI, Collier, PW, Paterson, GM. Poultry-borne salmonellosis in Scotland. Epidemiol Infect 1988;101:115122.Google Scholar
6. Roberts, D. Factors contributing to outbreaks of food poisoning in England and Wales. J Hyg 1982;89:491498.Google Scholar
7. Opal, SM, Mayer, KH, Roland, F, Brondum, J, Heelan, J, Lyhte, L. Investigation of a food-borne outbreak of salmonellosis among hospital employees. Am J Infect Control 1989;17:141147.Google Scholar
8. Al Lahham, AB, Abu-Saud, M, Shehabi, AA. Prevalence of salmonella, shigella, and intestinal parasites in food handlers in Irbid, Jordan. J Diarrhoeal Dis Res 1990;8:160162.Google Scholar
9. Mantel, N, Haenzel, W. Statistical aspects of the analysis of data from retrospective studies of disease. J Nutl Cancer Inst 1959;22:719748.Google Scholar
10. Villario, ME, Vugia, DJ, Bean, NH, Jarvis, WR, Hugh, JM. Foodbome disease prevention in health care facilities. In: Bennett, JV, Brachman, PS. eds. Hospital Infections. 3rd ed. Boston. MA: Little, Brown & Co; 1992:345358.Google Scholar
11. Blaser, MJ, Newman, LS. A review of human salmonellosis: I. Infective dose. Rev Infect Dis 1982;4:1091106.Google Scholar
12. Bush, MFH. The symptomless salmonella excretor working in the food industry. Community Med 1985;7:133135.Google Scholar
13. Williams, WW. Personnel restriction because of illnesses or special conditions. In: CDC Guideline for Infection Control in Hospital Personnel. Atlanta, GA Centers for Disease Control; 1983:1819.Google Scholar
14. Pether, JVS, Gilbert, RJ. The survival of salmonella on finger tips and transfer of the organisms to food. JHyg 1971;69:673681.Google Scholar
15. Blaser, MI. Rafuse, EM. Wells, TG. Pollard, RA. Feldman, RA. An outbreak ‘of salmonellosis involving multiple vehicles. Am J Epidemiol 1981;663670.Google Scholar
16. Pether, JVS, Scott, RJD. Salmonella carriers: are they dangerous? A study to identify finger contamination with salmonellae by convalescent carriers. J Infect 1982;5:8185.Google Scholar
17. Escartin, EF, Ayala, AC, Lozano, JS. Survival and growth of salmonella and shigella on sliced fresh fruits. J Food Protect 1989;52:471472.CrossRefGoogle Scholar
18. World Health Organization. Health Surveillance and Management Procedures for Foodhandling Personnel. Geneva, Switzerland: World Health Organization: 1989. WHO Technical Reoort Series, no. 785.Google Scholar
19. Tauxe, RV, Hassan, LF, Findeisen, KO, Sharrar, RG, Blake, PA Salmonellosis in nurses: lack of transmission to patients. J Infect Dis 1988;157:370373.Google Scholar