Sporadic STEC O157 infection: Secondary household transmission in Wales

We conducted a study to quantify and characterize household transmission of Shiga toxin (Vero cytotoxin)-producing Escherichia coli O157 (STEC O157) f ollowing sporadic infection in Wales. Through total population surveillance , we identified 83 index case-patients and their household contacts. We scr eened fecal samples submitted from household contacts for STEC O157 and cal culated the household transmission rate for sporadic STEC O157 infection to be 4% to 15%. Household contacts in groups at high risk (particularly chil dren under 5 years of age) present a risk of spreading the infection in the wider community.