In November 1996, over 400 fell ill and 21 were killed in Scotland by E. coli O157:H7 found in deli meats produced by family butchers John Barr & Son. The Butcher of Scotland, who had been in business for 28 years and was previously awarded the title of Scottish Butcher of the Year, was using the same knives to handle raw and cooked meat.

Locking et al report in Emerging Infectious Disease that to determine the proportion of Escherichia coli O157 cases in Scotland attributable to secondary spread, we analyzed data obtained through entire-population enhanced surveillance. We identified 11% of cases as secondary. Secondary cases in single households were younger than secondary cases in outbreaks affecting >1 household and had similar risk for hemolytic uremic syndrome.

The full paper is available at http://www.cdc.gov/eid/content/17/3/524.htm.