The paper analyses the frequency and clinical course of diarrhea caused by enterohemorrhagic E.coli. Material and methods:735 children with diarrhea, 81 of them with sanguineous diarrhea were hospitalized in the Department of Pediatrics, Pediatric Gastroenterology and Oncology of the Gdansk Medical University during 1999-2001. Results: analysed group consisted of eight girls and four boys, aged 3 months to 14 years (8 infants) with diagnosis of enterohemorrhagic E.coli O157, based on stool bacteriology culture (sorbitol -Mc Conkey agar medium).The illness was sporadic in all cases, mono-etiological, it occurred mainly during autumn-winter period. Diarrhea was rarely accompanied by general manifestations, like: vomiting, fever, abdominal pain. Additional tests showed: leukocytosis in 7 children, thrombocytosis in 3; coagu-lation disturbances and elevated renal insufficiency parameters were absent in all cases. Conclusions: Incidence if diarrhea caused by entero-hemorrhagic strain of E.coli O157 in the analyzed population of children was similar to that observed in other countries. Clinical course of infection caused by enterohemorrhagic strain of E.coli O157 in the analyzed group of children was mild with tendency to protraction in some cases. No serious complications were observed. Epidemiology of diarrhea caused by enterohemorrhagic strain of E.coli O157 in Poland needs further studies.

Keywords: Enterohemorrhagic Escherichia coli, diarrhea, children