The Minnesota Department of Health is investigating why dozens of Farmington High School students fell ill during homecoming weekend.

About 60 students missed school on Monday, after many reported symptoms including vomiting and diarrhea over the weekend, said Farmington district spokesman Jim Skelly. By Wednesday, that figure had shrunk to about 30, he said.

The district's food service provider, Chartwells, notified the Health Department of the situation on Monday. The company asked state officials to inspect the school kitchen, which was done that day, said Doug Schultz, a health department spokesman. The school also sent an e-mail to parents.

It's unclear whether the illness was food borne or passed person-to-person, Schultz said. The state has asked the district to provide the high school's absentee rates for the past week or so and a list of recent menus, and investigators plan to interview students about what they ate before they got sick, he said.

"Typically, once we have the information it can take as much as a week" to complete an investigation, he said.

It's not uncommon for the health department to deal with one or two similar incidents each year, Schultz said. "If this is indeed an outbreak, it would not be considered a large one."

Health officials "really didn't find anything out of the ordinary or anything of concern" during Monday's inspection at Farmington High, Schultz said. "Without knowing more about whether there's an outbreak or what the situation might be, you often don't know what to look for," he added.

Inspectors did offer some advice about ways to prevent any further transmission of disease, he said. One change the school made on Monday, Skelly said: Cafeteria workers are dishing out food to students instead of allowing them to serve items such as pizza themselves.

Farmington High has nearly 1,800 students, so only a small percentage has gotten sick. Even so, Monday's absentee rate was perhaps twice as high as usual, Skelly said.

To his knowledge, no students have been hospitalized.

"For the kids that were sick and the families that were impacted by this, it's not a very pleasant experience," he said. "It's very important that all the procedures are followed to determine the cause and make sure it doesn't happen again, if it did come from the school."

Sarah Lemagie • 952-746-3284