Human Salmonella Isolates, 2012 No. 12, December

·    This month, ERL confirmed  a further 6 cases of S. Montevideo (compared to 0 cases this time last year).
·    Interviews with cases using hypothesis generating questionnaires established that 12/13 cases, confirmed since 1st of November 2012, had eaten Middle Eastern food prior to becoming ill.
·    Salmonella Montevideo, S. Maastricht and S. Mbandaka were isolated from unopened tubs of tahini (sesame seed paste) sourced from the warehouse of the Auckland distributor.
·    Since the 1st of November 2012, one case of S. Maastricht and 3 cases of S. Mbandaka were confirmed from the Auckland DHB.
·    The implicated product has been traced forward to trade (cafes, takeaway restaurants), wholesale and retail providers. A trade withdrawal was initiated prior to confirmation of Salmonella contamination; a consumer-level recall commenced on 18/12/2012. All remaining product is on hold. Food Act Officers are following up the trade withdrawal to ensure product has been removed from sale.
·    Recall information: http://www.foodsmart.govt.nz/elibrary/consumer/gesas-tahini-recall.htm
·    Molecular typing was performed on some of the S. Montevideo isolates and the “outbreak” PFGE profile was distinguishable from the bovine and poultry isolates that had been previously identified in NZ. This “outbreak” PFGE profile was sent to CDC for comparison. CDC had previously seen this PFGE profile which had been associated with a recent outbreak in September 2012 and for which no epidemiological  link was found.
·    Of the 3 S. Mbandaka cases reported from Auckland DHB in November, one human case from Auckland had a PFGE profile indistinguishable from the S. Mbandaka isolated from tahini.
·    The PFGE profile of the S. Mbandaka isolated from tahini was distinguishable to bovine and poultry PFGE profiles that had been previously identified in NZ.