A newly published report by a UK-based outbreak team reveals how whole genome sequencing and food traceback investigations linked a multinational outbreak of Salmonella Enteritidis PT4b infection to an egg producer in Germany.
The UK outbreak occurred between May and September 2014 and included at least 287 cases linked to a hospital in central England and restaurants in the North West and South of the country. At the same time outbreaks of Salmonella Enteritidis PT14b infection were also reported in France and Austria. Isolates from these outbreaks were found to be the same as the UK isolates when tested for their multilocus variable-number tandem repeat analysis (MLVA) genetic profiles. Related cases were also later identified in Luxembourg and Germany.
The French outbreaks were linked to a German egg producer and further food traceback investigations in the supply chain suggested that the other outbreaks were also associated with this producer. This was confirmed by whole genome sequencing of isolates from UK and European cases, from implicated premises in the UK and from German eggs. The results showed that all the isolates were very similar and were all linked to the same egg producer in Germany.
The report is published in the journal Eurosurveillance and can be found in full here.