Detection of STEC and epidemiological investigations in surrounding of a HUS patient.

After occurrence of a case of HUS infection in a 2-year-old infant from a dairy farmer's family living near Oldenburg, investigations were performed in the infant's surrounding in order to elucidate the route of infection. Since hospitalization took place at a late stage, it was not possible to isolate EHEC from the patient's stool samples. However, E. coli O157 antibody determinations in serum were positive. Since STEC of serogroup O157 were found in faeces from the 34 dairy cows of the farm, stool samples were taken from 6 members of the child's family and examined. Non-O157 STEC could be isolated from the stools of 2 family members. Determination of other virulence factors and other characteristics such as serotype, biotype and phage type showed identity of the agent for 3 isolates (2 from animals, 1 from humans). By means of pulsed-field gel electrophoresis of the restricted DNA of the isolates and by means of RAPD-PCR it was not possible to establish any differences in the band patterns. It can be assumed, therefore, that the organisms had been transmitted from animals to humans.