Exposure to animals at Denver’s National Western Stock Show was the likely cause of an E. coli outbreak that occurred in the Denver area in January and February, the Colorado Department of Public Health and Environment said today.
Specifically, contact with animals in the “Feed the Animals” exhibit on the third floor children’s area of the exposition center was probably where the outbreak originated, according to the extensive 15-page report.
A total of 30 cases were identified.
Pat Grant, president and CEO of the stock show, said the stock show continues to work closely with the health department.
“We have been open, transparent and cooperative,” said Grant.
He said that until this incident, the stock show had never had an outbreak of this nature in its 104-year history.
“We did get the report and we obviously regret anyone becoming ill,” said Grant.
He said the stock show’s goal is not only to provide the public with an educational opportunity but also to provide education in an atmosphere that is healthy and safe.
As a result, said Grant, there will be new signs warning of potential risks that can be encountered at stock and agricultural shows and the need to wash hands and observe proper hygiene.
The report said children were disproportionately affected in the outbreak, suggesting a source that children would likely have more contact with than adults.
The report noted that the third floor children’s area of the expo center had a variety of exhibits geared towards children, including pony rides, a playground area, cages housing rabbits and poultry, educational exhibits, and hands-on activities.
In addition, food vendors were also located on the floor.
One of the exhibits was the “Feed the Animals” exhibit, where calves, goats, lambs, pigs and other farm animals were brought in from private owners located throughout the region.
Different animals were brought into the “Feed the Animals” over the course of the stock show.
The report noted that the “Feed the Animals” area was not a designated petting zoo area – the formal petting zoo area was located on the second floor of the expo center and was not associated with the risk of illness.
However, in the “Feed the Animals” area, the animals were housed in pen enclosures where visitors could have direct contact with the animals, including the ability to pet them.
In addition, there were opportunities throughout the day for the visitors to feed the animals.
While feeding the animals was not a risk for illness, touching them put the visitors at higher risk of developing E. coli infection.
“We were not successful in pinpointing the exact animal that may have caused the outbreak,” said the report. “We hypothesize that an animal (or animals) in the ‘Feed the Animals’ area was likely shedding E. coli 0157:H7 in its feces and contaminated the pen enclosure, pen bedding materials, floor and/or other environmental surfaces.”
The contamination was likely to have been spread over a wide area given the number of spectators who walked through the area – the contamination having been spread by shoe bottoms or strollers.
The investigators said that while hand sanitizer dispensers were readily available in the “Feed the Animals” area, and there were numerous signs instructing visitors to practice hand hygiene, the use of the sanitizers “was not protective against the illness.”
In addition, handwashing facilities with running water, soap and paper towels were not readily available in the area.
There were no signs that warned that animals could cause disease or any that specifically cautioned against sipping from cups or eating or drinking in the animal contact areas as well as the use of strollers in that area.
The investigators suggested that such signs be posted in the future.
The report noted that given the low infection dose of E. coli 0157:H7 required to cause illness, it is possible that the hands of those who became ill were contaminated with the bacteria and the process of eating and drinking introduced bacteria into the mouth.
The report noted that although the stock show has visitors from across Colorado and many states, all the cases that were identified resided in urban Denver counties and none had brought animals to the show or participated in events such as rodeos.
The state health department noted how the outbreak also highlighted the risks of secondary transmission of E. coli 0157:h7, especially in child care settings. Children must not attend child care when experiencing diarrhea, said the report.
The recommendations made by investigators included focusing prevention efforts on areas geared toward children, especially areas where contact with children and animals is encouraged. In addition, the state said the stock show should provide additional handwashing stations with running hot water, soap, and disposable paper towels. Also the stock show should increase efforts to educate patrons about animal disease risks and handwashing.
Of the 30 cases, children and women were disproportionately affected.
The median age was five years and 23 of the cases involved females. People involved lived in Adams, Arapahoe, Boulder, Broomfield, Denver, Douglas, and Jefferson counties.
Nearly all the cases had diarrhea. Nine were hospitalized. No one died.
Howard Pankratz: 303-954-1939 or hpankratz@denverpost.com
