WEST LINN, Ore. – A preschool in West Linn, Ore., remains closed after three children were sickened byE. coliin September and October. Two children were hospitalized after being sickened by
E. coliO157:H7.

Public health officials with Clackamas County performed environment tests inside and outside Heart Centered Montessori School during September and October, but did not find the source of the bacteria. Meg O’Keeffe, founder and director of the school, voluntarily closed the facility pending the outcome of the investigation.

In a letter to parents of children attending the school, the health department said the investigation into the source of the infections is ongoing. Also, the health department made the decision to expand the investigation by testing all children at the Heart Centered Montessori School.

The letter advised parents to have their children tested for the pathogen. Two of the children tested positive forE. coliO157:H7, a virulent strain ofE. colithat can be fatal to very young children, the elderly and individuals with weakened immune systems. The health department also advised parents to keep their children out of schools, daycares, group activities and water activities. Additionally, parents were advised against allowing their children to prepare food for others or share food to prevent further spread of the infections.

"We recognize that keeping children at home during the testing period and if diagnosed with STEC can present challenges to parents," the letter stated. The Health Department feels strongly that these measures are necessary to protect your children."