A chain casual dining restaurant located in the Bellevue Marketplace has been implicated in four consecutive outbreaks of salmonellosis since the beginning of the year.  Cases were traced back to the establishment in mid-April, early May and late June.

Although the serotype has not been disclosed, ProMED reported that a common serotype was involved in all cases.  After each episode, the restaurant was decontaminated before reopening.

The serial nature of outbreaks could be attributed to:

• A chronic carrier in the food preparation or wait-staff who should be identified by consecutive fecal samples.

• The presence of the causal Salmonella in a storage or kitchen location that has not been decontaminated.

• A food item from a contaminated source introduced into menu items at regular intervals.  If S. Enteritidis is involved, eggs could be responsible.  It is unlikely that eggs were involved as the vehicle of infection. Given the competence of the King County Department of Health, the presence of S. Enteritidis would have been investigated and the source flock identified.  Given that the restaurant was part of a chain, it is presumed that eggs were purchased from a food service supplier who would have been sourcing eggs from a number of farms or packers compliant with the FDA Final Rule on Salmonella.

Obviously investigations are in progress to determine the origin of the infection given that whole genome sequencing of recent isolates from the establishment and patients were homologous.