An Outbreak of Escherichia coli O157 Infection Following Exposure to a Contaminated Building

• Published in: JAMA : the journal of the American Medical Association 2003-11, Vol.290 (20), p.2709-2712
• Main Authors: Varma, Jay K, Greene, Katherine D, Reller, Megan E, DeLong, Stephanie M, Trottier, Janine, Nowicki, Scott F, DiOrio, Mary, Koch, Elizabeth M, Bannerman, Tammy L, York, Steven T, Lambert-Fair, Mary-Ann, Wells, Joy G, Mead, Paul S
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Air Pollution, Indoor - adverse effects; Air Pollution, Indoor - analysis; Bacterial diseases; Bacterial diseases of the digestive system and abdomen; Biological and medical sciences; Case-Control Studies; Child; Child, Preschool; Contamination; Diarrhea - epidemiology; Diarrhea - microbiology; Disease; Disease Outbreaks; Environmental Exposure - adverse effects; Environmental Exposure - analysis; Epidemics; Escherichia coli; Escherichia coli Infections - epidemiology; Escherichia coli Infections - etiology; Escherichia coli O157 - isolation & purification; Female; Hemolytic-Uremic Syndrome - epidemiology; Hemolytic-Uremic Syndrome - etiology; Human bacterial diseases; Humans; Infant; Infectious diseases; Male; Medical sciences; Middle Aged; Ohio - epidemiology; Pathology; Risk Factors
• ISSN: 0098-7484; 1538-3598
• DOI: 10.1001/jama.290.20.2709

CONTEXT Infection with Escherichia coli O157 causes an estimated 70 000 diarrheal illnesses per year in the United States and can result in hemolytic-uremic syndrome and death. Environmental contamination with E coli O157 may be a public health problem. OBJECTIVES To determine risk factors for E coli O157 infection during an outbreak investigation at a county fair and to evaluate environmental contamination as a possible cause of the outbreak. DESIGN, SETTING, AND PARTICIPANTS Case-control study of 23 patients (median age, 15 years) and 53 age-matched controls who had attended the Lorain County, Ohio, fair between August 20 and August 26, 2001. Case-patients had laboratory-confirmed E coli O157 infection, hemolytic-uremic syndrome, or bloody diarrhea within 7 days of attending the fair; controls attended the fair and did not have diarrhea. MAIN OUTCOME MEASURES Risk factors for infection and isolates of E coli O157 from environmental specimens. RESULTS Six (26%) case-patients were hospitalized and 2 (9%) developed hemolytic-uremic syndrome. Case-patients were more likely than controls to have visited building A (a multipurpose community facility on the fairgrounds; matched odds ratio [MOR], 21.4 [95% confidence interval {CI}, 2.7-170.7]). Among visitors to building A, illness was independently associated with attending a dance in the building (MOR, 7.5; 95% CI, 1.4-41.2), handling sawdust from the floor (MOR, 4.6; 95% CI, 1.1-20.0), or eating and/or drinking in the building (MOR, 4.5; 95% CI, 1.2-16.6). Twenty-four (44%) of 54 specimens collected from building A 6 weeks after the fair grew Shiga toxin–producing E coli O157. Isolates from sawdust, the rafters, and other surfaces were identical by molecular fingerprinting to patient isolates. Sawdust specimens collected 42 weeks after the fair also grew the same E coli O157 strain. CONCLUSIONS Absence of evidence implicating specific food or beverage sources and the recovery of E coli O157 from the rafters suggest that airborne dispersion of bacteria contributed to the contamination. Because E coli O157 can survive in the environment for more than 10 months, humans may be at risk of infection long after an environment is initially contaminated.