Looking for tips to find icebergs--surveillance of haemolytic uraemic syndrome to detect outbreaks of Shiga toxin-producing E. coli infection.

We agree with the authors that active surveillance of haemolytic uraemic syndrome (HUS) patients allows the detection of outbreaks of virulent STEC strains and that underascertainement of verocytotoxin-producing E. coli (VTEC) is explained by the non-routine practice of culturing stools, by the under-use of sorbitol-MacConkey (SMAC) agar, and by the fact that most clinical laboratories do not test for these micro-organisms in routine gastroenteritis samples.