City and state health officials are trying to find out why 22 Reiche Elementary School students got sick an hour after eating lunch Tuesday.

Michael Russell, who oversees Portland’s health inspection program, said school officials alerted the city about the outbreak after 16 students began vomiting and six others complained about upset stomachs.

“It might not be anything to do with the food,” Russell said Friday. “The only question was the timing of it.”

One menu item in particular is under suspicion: a pickled beet salad.

Reiche was the only school to serve the beet salad Tuesday and there were no illnesses at other city schools.

“We focused on that,” Russell said. “The lab results are pending.”

No students required medical treatment and all but one returned to school the next day, according to the district, which declined to provide the ages of the students affected.

State and city health officials Wednesday inspected the school district’s central kitchen on Waldron Way and the kitchen at Reiche School.

The central kitchen, where all of the school lunches are prepared, passed the inspection with only two minor violations that were corrected on site, Russell said. However, the Reiche kitchen failed after inspectors observed four critical violations which can compromise food safety, he said.

The violations inspectors found included:

• The salad bar sneeze guard was too high for the students, who also were dropping tong and ladle handles into the food after using them.

• The self-serve salad bar was not being monitored.

• Cut salad greens and macaroni and cheese were left out without proper time and temperature control.

• The school was not sanitizing a key pad used by students to confirm they had picked up their lunches.

Reiche’s kitchen passed a routine city inspection in January with no violations. It also passed inspections in 2014 and 2010.

The Maine Center for Disease Control and Prevention is assisting in the investigation, spokesman John Martins said.

“There has been no determination that the onset was due to a food-borne concern and the investigation remains ongoing,” Martins said. “The onset of any illness can be attributed to a variety of different factors. It is often difficult to ascertain with 100 percent certainty the cause.”

BAFFLING SPEED

At least one expert was baffled by the speed with which the illness came and went.

Dr. Dora Anne Mills, a former state epidemiologist, said it typically takes six to 10 hours for a foodborne illness, including the Norovirus, to present symptoms. Chemicals or toxins can cause immediate illness, but Mills said those symptoms tend to last longer than a few hours.

Investigators should be able to trace the cause in this case because it was a school with a fixed population and limited amount of food served Tuesday, Mills said, adding that interviews with kids and staff could reveal common elements among those who got sick.

Russell commended school staff, who have been cooperating with the investigation.

The school district sent a letter home to parents Wednesday. School officials did not publicly acknowledge the illness until being contacted by a reporter Friday.

School officials Friday morning would not grant interviews about the outbreak, and required a reporter to submit a list of questions in writing. The district responded nearly three hours later with a statement that included a copy of the report from the January inspection the Reiche kitchen had passed. It did not distribute the failed report from Wednesday.

In the statement, Tina Veilleux, the school nurse coordinator for the Portland Public Schools, said that while gastrointestinal infections can circulate throughout the school, this case was unusual because of the sudden onset of symptoms and the number of students affected.

‘SHELL-SHOCKED’ CUSTODIANS

Leah Whalen, president of the Reiche Parent Teacher Organization, said her 7-year-old daughter, second-grader Sophie Kilbreth, was among the children who got sick.

Whalen said her daughter usually takes her own lunch to school, but was excited to try a new pickled salad of root vegetables, including beets, being offered Tuesday.

“She really enjoyed it up until the point it disagreed with her stomach an hour later,” Whalen said.

Her daughter felt better a few hours after getting sick and was able to eat dinner, she said.

Whalen said some Reiche parents are referring to the outbreak as “The Episode.” She hopes it doesn’t deter the school or students from trying new, healthier foods such as the beet salad.

“They’re really trying to encourage the kids to try new vegetables,” Whalen said. “I have no concerns about her eating there. I think it was an isolated incident.”

Whalen said school nurses and custodians, who were kept busy cleaning up after the kids, looked “shell-shocked” Tuesday when she picked up her daughter.

“I feel like I should bake some cookies for the custodial staff,” she said.