Washington state health officials are investigating a possible gastrointestinal illness outbreak among attendees of a cheerleading competition on February 4.
Kate Lynch, a spokeswoman for the Washington State Department of Health, said thousands of people attended the competition at Everett's Comcast Arena, and the onset of symptoms, which include vomiting and diarrhea, began Feb. 5 and 6.
Lynch said the cause and the source of the illness is still unknown, and the department does not yet know exactly how many people have been sickened.
The investigation is still in its infancy, and the department is sending a questionnaire to participants and collecting samples, which will be tested at the state Public Health Laboratories, Lynch said.
The Washington Interscholastic Activities Association hosted the event.
"Our immediate concerns are for those who have been affected by this illness, and our thoughts are with them," said Mike Colbrese, the association's executive director. "The WIAA appreciates the cooperation of Comcast Arena and of state and local health partners for addressing the entire scope of this situation."