Public health officials said Thursday that E. coli bacteria have been spreading person-to-person through inadequate hand washing in a Green County outbreak that has killed one and sickened 12 others since mid-July.

No original source of the outbreak has been isolated, and no information has been released about the first case, or the individual who died. Most of those sickened are children younger than 6, according to Green County Health Department Officer RoAnn Warden.

Two elementary school children from Monroe were hospitalized last week with E. coli O157: H7 infections that officials confirmed were the same bacteria strain responsible for the deadly outbreak in this south-central Wisconsin county from mid-July through the first week of September, Warden said Thursday.

The first case in the outbreak was reported in mid-July, followed three weeks later by a second case and a cluster of seven more within several weeks of each other. Two people were hospitalized.

Students infected

Then last week, three students in 4-year-old kindergarten and kindergarten at Lincoln Elementary School in Monroe were confirmed to have the bacterial infection. Two of the three were hospitalized, Warden said. An adult in the same household as one of the three sickened schoolchildren also was confirmed this week to have an E. coli infection, Warden said. The adult has not been hospitalized.

Anyone can become infected by having contact with fecal material from infected people or animals (especially cattle), or by eating contaminated food or water. Symptoms include diarrhea, which often is bloody, and severe abdominal cramps, which typically occur three to four days after exposure to the bacteria.

The investigation so far has not implicated contaminated food or water as the source of the bacterium, Warden said.

It appears that inadequate hand washing after use of the bathroom, or changing a diaper, has spread the bacterium from person to person, Warden said.