Petting zoos as sources of Shiga toxin-producing Escherichia coli (STEC) infections.

Despite their general low incidence, Shiga toxin-producing Escherichia (E.) coli (STEC) infections are considered an important public health issue due to the severity of illness that can develop, particularly in young children. We report on two Austrian petting zoos, one in Tyrol (2015) and one in Vorarlberg (2016), which were identified as highly likely infection sources of STEC infections. The petting zoo related cases involved a case of hemolytic uremic syndrome (HUS) due to STEC O157:HNM in 2015 and an outbreak of STEC O157:H7 infections affecting five young children and two adults in 2016. The HUS case accounted for 2.8% of the 36 STEC O157:HNM/H7 infections notified in Austria in 2015 (5,9% of 17 HUS cases). The seven cases described for 2016 accounted for 4.0% of the 177 human STEC infections documented for Austria in 2016, and for 19.4% of the 36 STEC O157:HNM/H7 infections notified that year. The evaluation of the STEC infections described here clearly underlines the potential of sequence-based typing methods to offer suitable resolutions for public health applications. Furthermore, we give a state-of-the-art mini-review on the risks of petting zoos concerning exposure to the zoonotic hazard STEC and on proper measures of risk-prevention.

A 2010 Austrian Salmonella enteritidis PT4 outbreak associated with a laying hen holding previously involved in an S. enteritidis PT4 cluster: pitfalls of regulatory responses in risk management.

We report on an outbreak caused by Salmonella enteritidis phage type 4 (PT4) among 143 participants at a soccer camp in Austria in August 2010. The outbreak affected 34 persons, including 24 epidemiologically related cases and 10 laboratory-confirmed cases. Food-specific cohort analyses revealed spaetzle (homemade noodles) (relative risks (RR): 2.68; 95% CI: 1.13-6.45), hamburger (RR: 2.70; 95% CI: 1.13-6.45) and potato salad (RR: 2.91; 95% CI: 1.69-5.02) as the most biologically plausible infection sources. Eggs used as ingredients were considered to be the vehicle of infection for the outbreak strain. The sole egg producer supplying the hotel that housed the soccer camp participants with table eggs operated two flocks. One flock had been epidemiologically and microbiologically related to a previous S. enteritidis PT4 outbreak affecting the same Austrian province in the four months preceding the August outbreak. We hypothesize that eggs from this flock, already condemned for industrial use only, were falsely declared table eggs and sold among eggs from the non-banned flock causing the subsequent outbreak. In Austria, the illegal distribution of eggs designated for industrial use (i.e., false declaration of these eggs as table eggs) has been previously documented. Our findings underscore the potential of proper epidemiological outbreak investigation to identify the pitfalls of regulatory responses in risk management.