Children on Grand Avenue, in Belgium, Wisconsin became ill due to E. coli O157:H7. The first illness developed in December. The second and third cases occurred in January. The two laboratory confirmed cases were siblings. The three children had close personal contact with one another so person-to-person transmission was a possible route of transmission. The exact means of transmission had not been confirmed as of January, 18, 2010. Another child in the neighborhood was confirmed to be infected with Cryptosporidium. The village water was tested and found to be safe.