A significant number of prior E. coli O157:H7 outbreaks have been previously linked to county fairs, dairy farms, and petting zoos. Some of those outbreaks occurring in the United States between 2000 and 2012 are identified below:

The Snohomish Health District, Communicable Disease Department (June, 2000) reported five cases of bacterial diarrhea caused by E. coli O157:H7 in children in Snohomish County in May 2000. Three of the children visited a petting zoo several days before they became sick.

Crump et al (2002) discussed an outbreak of E. coli O157:H7 among visitors to a dairy farm in Pennsylvania in September, 2000. The total number of confirmed or suspected E. coli O157:H7 cases was 51.

An article published by WebMD Medical News on April 23, 2001 (Bloomquist, 2001), reported an outbreak of E. coli O157:H7 among visitors to the Merrymead Farm petting zoo in Worcester, Pennsylvania. In all, 16 children who had visited the zoo contracted E .coli, and it was suspected that another 45 people became ill from the bacteria.

The Ozaukee County Public Health Department and Wisconsin Department of Health and Family Services (2001) investigated an outbreak of E. coli O157:H7 associated with animals at the Ozaukee County Fair in August, 2001. A total of 59 E. coli O157:H7 cases were identified in this outbreak, with 25 laboratory confirmed cases (25 “primary cases” and 34 probable cases).

The Oregon Department of Human Services (Oregon, 2002) initially documented a patient with bloody diarrhea, who attended the Lane County Fair held during August, 2002. Epidemiologists identified 82 ill persons, 22 who were hospitalized, and 12 with HUS.  Although not confirmed, health officials postulated that possible exposures leading to the outbreak occurred at animal enclosures.

In 2003, 25 people (fair visitors and animal exhibitors) became ill with hemolytic uremic syndrome and one case of a related disease, thrombotic thrombocytopenic purpura. All seven laboratory-confirmed cases had an indistinguishable PFGE pattern which matched 10 isolates obtained from environmental samples taken from animal housing areas.

In late October 2004 the North Carolina Department of Health and Human Services (NCDHHS) conducted an E. coli O157:H7 outbreak investigation among attendees at the 2004 State Fair. 108 cases were identified with 15 who experienced HUS. The majority of cases occurred in children. Illness was associated with animal contact and hand-to-mouth activities.

The AgVenture Farms E. coli O157:H7 outbreak was first recognized after two separate HUS case reports were reported to the Florida Department of Health in mid-March.  The two cases (a 5-yr-old girl and a 7-yr-old boy) both reported having visited a fair with a petting zoo (AgVenture) a few days prior to becoming ill. The two children visited the same fair and did not have any other common risk factors.

At least six children were infected with E. coli O157:H7 – one gravely – visiting the petting zoo at the 2005 Big Fresno Fair.

In May and June 2007, seven Florida children were infected with E. coli O157:H7.  Six of the children had visited a Day Camp petting zoo, and the seventh was a sibling.  Two of the children were hospitalized, all seven recovered.  The petting zoo was closed on the recommendation of the health department.

In January 2009, the Communicable Disease and Consumer Protection Divisions of the Colorado Department of Public Health noticed an increase is in the number of laboratory confirmed cases of E. coli O157.  Thirty cases were identified—including nine hospitalizations and 2 cases of HUS.  All the children had visited the National Western Stock Show in Denver, Colorado.  A case-control study found the risk of E. coli infection was associated with touching animals in the “Kids Zone”…

At least 6 people who visited the Forest Park Petting Zoo in Everett, Washington, in June 2011 became ill with E. coli O157:H7 infections.  The Snohomish County Health Department investigated the E. coli outbreak and determined that there was a “clear association between disease and being in the open animal interaction area of the forest Park Animal Farm.”

North Carolina public health officials investigated an E. coli O157:H7 outbreak associated with attendance at the Cleveland County Fair, which ran from September 27 to October 7, 2012.  At least 106 people became ill with E. coli infections after either visiting the fair of coming into direct contact with a person who had attended the fair.

In October of 2012, Cowlitz County Health and Services announced that 4 children had become ill with E. coli O157:H7 infections after visiting the Willow Grove Gardens Pumpkin Patch and petting zoo.  One of the children was hospitalized for several days.  The suspected source of the E. coli outbreak was the petting zoo at the pumpkin patch.