PORTLAND, Ore. -- Eighteen Oregon middle school students on a trip to Mexico were back home early and have been asked to stay home until Thursday.

Officials at the Oregon Episcopal School in Portland said the students were not facing a state-mandated quarantine; rather, the home stay was a precaution.

The eighth grade students, along with three staff members, left for Oaxaca, Mexico last Thursday for a 10-day Spanish immersion trip.

The entourage had been on the ground less than 48 hours when school officials heard about the swine flu outbreak and canceled the trip early.

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“The instant thought on Friday evening when we heard the news was, we’ve got to get our kids home quickly and safely, immediately,” said Matthew Hanly, head of the school. “Our director of safety was on the phone with Alaska Airlines and they couldn’t have been more accommodating getting our kids home on Saturday.”

Washington County health officials advised Hanly that the students and staff members stay home for 96 hours -- double the incubation period for a typical flu strain. 

Hanly said he has fielded concern from parents, but most are taking this in stride.

“Obviously they’re disappointed, they’re having a hard time containing their kids because their kids are healthy. None of the students have symptoms, we check in with them daily; they’re just finding it hard to keep their kids away from group things like church, school, malls and movie theaters,” Hanley said.  

The students and staff were expected to be back on campus Thursday. Health officials said there was no need for them to be administered flu tests.