Transmission of shiga toxin-producing Escherichia coli O104:H4 at a family party possibly due to contamination by a food handler, Germany 2011.

We investigated a cluster of shiga toxin-producing Escherichia coli (STEC) O104:H4 infections after a family party during a large STEC O104:H4 outbreak in Germany. To identify the vehicle we conducted a retrospective cohort study. Stool samples of party guests, and food and environmental samples from the catering company were tested for STEC. We defined cases as party guests with gastrointestinal symptoms and laboratory-confirmed STEC infection. We found 23 cases among 71 guests. By multivariable analysis consumption of salmon [odds ratio (OR) 15, 95% confidence interval (CI) 2.3-97], herb cream (OR 6.5, 95% CI 1.3-33) and bean salad (OR 6.1, 95% CI 1.4-26) were associated with STEC infection. STEC O104:H4 was detected in samples of bell pepper and salmon. The food handler developed STEC infection. Our results point towards transmission via several food items contaminated by a food handler. We recommend regular education of food handlers emphasizing their role in transmitting infectious diseases.

Secondary transmissions during the outbreak of Shiga toxin-producing Escherichia coli O104 in Hesse, Germany, 2011.

During the recent outbreak of Shiga toxin-producing Escherichia coli (STEC) O104:H4 in Germany most cases notified in the State of Hesse (6 million inhabitants) were linked to satellite clusters or had travelled to the outbreak area in northern Germany. Intensified surveillance was introduced to rapidly identify cases not linked to known clusters or cases and thus to obtain timely information on possible further contaminated vehicles distributed in Hesse, as well to describe the risk of secondary transmission among known cases. As of 2 August 2011* [corrected], 56 cases of haemolytic uraemic syndrome (HUS) including two fatal cases, and 124 cases of STEC gastroenteritis meeting the national case definitions have been reported in Hesse. Among the 55 HUS and 81 STEC gastroenteritis cases thatmet the outbreak case definition, one HUS case and eight STEC gastroenteritis cases may have acquired their infection through secondary transmission. They include six possible transmissions within the family, two possible nosocomial and one possible laboratory transmission. Our results do not suggest an increased transmissibility of the outbreak strain compared to what is already known about E. coli O157 and other STEC serotypes.