About half of the 20 Dedham Country Day School fifth-graders who came down with salmonella poisoning after a field trip to a New Hampshire camp have returned to class, with the rest expected back at school by Monday.
The students became ill following an annual trip to the Stone Environmental School of New England in Madison, N.H., last week.
All 30 students from the school's fifth-grade class went on the April 22-24 trip to the environmental camp. School spokeswoman Leslie Bowen said three boys became ill enough to be sent home on April 23.
The rest of the group came back as scheduled, but ultimately 20 students showed symptoms of salmonella poisoning. Those effects included gastrointestinal illness, diarrhea and fever, Bowen said.
"There were complications with a couple of them from dehydration, and they had to spend an overnight in the hospital," she said.
Dedham Country Day did not learn until this past Monday that the cause had been confirmed as salmonella poisoning, Bowen said.
The week before the Dedham trip, 70 of 98 students and staff from a different school group became ill after visiting the camp, according to the New Hampshire Department of Health and Human Services. Those students were from the Woodbury School, a middle school in Salem, N.H.
Bowen said the New Hampshire health department checked out the situation and initially thought that the Woodbury kids had brought the bacteria with them to the site.
"We thought it was safe for our kids to go. We wouldn't have sent them if we thought that there was salmonella there," Bowen said.
After the kids from Dedham and students from an elementary school in Wilton, N.H., became sick, the Stone school decided to temporarily suspend its operations at the Madison site, according to the health department. The site is owned and operated by Purity Spring Resort.
Late yesterday, the health department announced that its investigators have determined "that pudding served to the campers prepared by Purity Spring, which provides all the food to the environmental camp, was contaminated with salmonella."
The mixer used to make the pudding has been removed and is being tested further, the department added.
The camp has also been cleared to reopen.
"We are pleased that the source of the illness has been found," said the camp's director, David Freese. "Our first priority of course is the safety of our campers, and we will be looking forward to reopening as soon as possible."
After the salmonella diagnosis was confirmed Monday, the head of Dedham Country Day School, Nicholas Thacher, sent a letter to all parents on Tuesday explaining what had happened, Bowen said. The school nurse also issued a public health fact sheet on salmonella and met with parents Tuesday morning, Bowen added.
Some students are still at home recovering. Bowen said the school's consulting pediatrician has recommended that the fifth-graders be kept separate at lunchtime as a precautionary measure "when they do come back, although it's extremely unlikely that they might spread it."
Dedham Country Day, a private school on Sandy Valley Road, serves 246 students between pre-kindergarten and eighth grade. Bowen said the fifth-grade field trip, and other such excursions by middle schoolers to Mount Washington and the nation's capital, are a hands-on part of the school's curriculum.
"These outside-of-the-classroom experiences are just as important as learning in the classroom," she said.
Daily News staff writer Edward B. Colby can be reached at 781-433-8336 or ecolby@cnc.com.
