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Updated: Aug 15, 2026

An Allelotyping PCR for Identifying Salmonella enterica serovars Enteritidis, Hadar, Heidelberg, and Typhimurium
Published on: July 22, 2011
Emergence of Salmonella serotype Enteritidis phage type 4 in Hawaii traced to locally-produced eggs
Roger Burr1, Paul Effler, Rebecca Kanenaka
1Epidemic Intelligence Service, State Branch, Division of Applied Public Health Training, Epidemiology Program Office, Centers for Disease Control and Prevention, Atlanta, GA, USA. mailto:rkmaktub@yahoo.com
Objectives:
In August 1998, the Hawaii Department of Health observed a nine-fold increase in human Salmonella Enteritidis (SE) infections. Isolates were phage type 4 (PT4). An investigation was initiated to determine the source of the outbreak.
Methods:
A matched case-control study enrolled 38 cases. Cases were Hawaii residents with diarrhea and a stool culture yielding SE.
Results:
Eating eggs was associated with SE illness; 28 cases (74%) ate eggs in the three days before illness compared to 34 (45%) of 76 controls (MOR=3.0, 95% CI=1.4-7.4). Eighteen (47%) of 38 case patients ate eggs from Farm A compared to 11 (14%) of 76 controls (MOR=12.0, 95% CI=3.1-78.0); the eggs were not properly handled or refrigerated. Cultures from Farm A yielded SE. Human illness subsided following selective flock depopulation.
Conclusions:
This outbreak highlights the importance of proper handling and refrigeration of eggs. The egg industry must implement quality assurance programs to prevent the spread of SE PT4 and human SE illness.
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