The investigation into an E.coli bacterial outbreak that sickened about 60 children at Monett Elementary School and some residents of Monett, Missouri, has not produced a common link that can explain the illnesses, according to The Joplin Globe.

Robert Neizgoda, an epidemiologist with the Missouri Department of Health and Senior Services, said the focus of the investigation has been the school and the foods that were served there, but that investigators have had additional contacts about illnesses from people who were not associated with the school. The school has an enrollment of about 700 pupils.

Water samples taken this week in Monett showed no signs of bacterial contamination. Additional sampling and water tests are planned at the school.

Public-health nurses are making home visits to interview the families of children affected by the illness. At present, only 50 percent of those needing to be interviewed have been questioned.