Garfield County Public Health officials are working to pinpoint the cause of a disease outbreak after receiving dozens of calls from people with gastrointestinal complaints who attended the Rifle Rodeo on Monday.

The department asks anybody who attended the privately-organized event at the Garfield County Fairgrounds to call 970-625-5200, extension 8128, even if they are not ill.

“It appears that people became ill approximately six hours following the end of the rodeo event Monday night,” Billy Harkins, environmental health specialist with the Garfield County Consumer Protection Program, said in a news release Thursday.

“We are still investigating the cause of the outbreak, and are taking all possible factors into consideration,” Harkins said. “The total number of individuals who became ill and the duration of their illness has not been confirmed.”

Garfield County officials are working with the Colorado Department of Public Health and Environment to determine the cause of the illness.

The department began receiving calls Tuesday from residents with gastrointestinal complaints. Symptoms included nausea, cramping and diarrhea.

Although county officials declined to say whether they believe the illness to be foodborne, three people contacted the Post Independent saying they or family members became ill after eating at the event and two said they ate pulled pork sandwiches.

On Friday the county reported that the illnesses did not develop from a waterborne issue, an airborne issue, e-coli, salmonella, Hepatitis A, or anything transferred person to person.

“Due to the quick reporting by event attendees, Public Health was able to respond in an immediate and comprehensive manner to contain further outbreak,” the press release states. “Samples have and are being sent to a state lab for testing. Public Health staff hopes to receive data next week, but this depends on the number of investigations of both ill and well people that staff is still in the process of conducting.”

The county asks that people who attended the event leave a phone message at the number above with their phone contact information. A public health representative will return the call and ask the attendee to complete a brief questionnaire that will help to track down the source of the outbreak.