Agricultural Fair, British Columbia

During August and September of 1998 the British Columbia Center for Disease Control sent all E. coli O157:H7 isolates to an outside laboratory for molecular sub-typing (BC Center for Disease Control, March, 1999).  On September 17 it was reported that nine of the 69 referred isolates had a common genotype.  Three individuals were hospitalized, though none developed hemolytic-uremic syndrome (HUS).  Seven of the nine had onset of illness within ten days of visiting a large agricultural fair.  Despite in-depth interviews, no common source of infection could be identified.  No environmental investigation of the fair could be carried out; because by the time laboratory results were available the fair had closed.