A Large Outbreak of Brainerd Diarrhea Associated with a Restaurant in the Red River Valley, Texas
Divisions of 1Bacterial and Mycotic Diseases, 2Parasitic Diseases, and 3Viral and Rickettsial Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia; and 4Texas Department of State Health Services, Austin
Background.
In June 1996, an outbreak of chronic diarrhea was reported to the Texas Department of Health (Austin).
Methods.
We initiated active case finding, performed 2 case‐control studies, and conducted an extensive laboratory and environmental investigation.
Results.
We identified 114 persons with diarrhea that lasted
4 weeks. Symptoms among 102 patients who were studied included urgency (87%), fatigue (86%), fecal incontinence (74%), and weight loss (73%); the median maximum 24‐h stool frequency was 15 stools. Diarrhea persisted for >6 months in 87% and for >1 year in 70% of patients who were observed. Fifty‐one (89%) of 57 ill persons had eaten at a particular restaurant within 4 weeks before onset, compared with 8 (14%) of 59 matched control subjects (matched odds ratio [OR], undefined; 95% confidence interval [CI], 11.2‐∞). At the restaurant, patients were more likely than their unaffected dining companions to have drunk tap water (OR, 2.8; 95% CI, 1.0–9.9) and to have eaten several specific food items, and they were less likely to have drunk iced tea made from boiled water and store‐bought ice (OR, 0.3; 95% CI, 0.05–1.0). A multivariable model that included consumption of tap water and salad bar tomatoes best fit the data. The restaurant had multiple sanitary and plumbing deficiencies. Extensive laboratory and environmental testing for bacterial, parasitic, mycotic, and viral agents did not identify an etiologic agent.
Conclusions.
The clinical, laboratory, and epidemiologic findings are consistent with those of previous outbreaks of Brainerd diarrhea. To our knowledge, this is the largest reported outbreak of Brainerd diarrhea associated with a restaurant.
Received 1 November 2005; accepted 12 January 2006; electronically published 26 May 2006.
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(See the brief report by Vugia et al. on pages 62–4)
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Presented in part: 46th Annual Epidemic Intelligence Service Conference, Centers for Disease Control and Prevention, Atlanta, Georgia, 14–18 April 1997; and 35th Annual Meeting, Infectious Diseases Society of America, San Francisco, California, 13–16 September 1997 (abstract 670).
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A.C.K. and S.K.G. were with the Centers for Disease Control and Prevention’s Epidemic Intelligence Service at the time of this investigation.



