Where most health departments would have publicly done little – it takes work – the Southern Nevada Health District has already issued its second interim report on the Salmonella outbreak linked to Firefly restaurant in Las Vegas.

Excepts below:

On April 26, 2013, the SNHD performed investigative inspections and closed Firefly and Dragonfly restaurants to minimize ongoing risk of illness. The SNHD OOE, Environmental Health (EH) and Southern Nevada Public Health Laboratory (SNPHL) have been collaborating on the investigation and response to this outbreak. The Centers for Disease Control and Prevention (CDC) and the Nevada State Health Division were also notified of the outbreak investigation.

A total of 33 Firefly employees were interviewed on April 26, 2013. Three employees were identified as having been recently ill with gastrointestinal symptoms after having eaten at Firefly within the previous 7 days of their illness; these workers submitted stool specimens. The OOE staff identified an additional ill staff member at a later interview, but stool testing was not offered to this employee. The timing of their illness onset dates suggests that none of these 4 restaurant workers was the source of the illness. The restaurant has a sick employee policy and employees may call-in sick when necessary.

Thus far, surveillance for additional cases revealed 200 people who became ill after eating at Firefly during April 21-26, 2013. The Epi-X posting resulted in reports of salmonellosis from five public health agencies outside of NV. From various surveillance data sources, we have received reports of illness from restaurant patrons who normally reside in twenty states (AZ, CA, CO, HI, IL, MA, MN, MS, NC, NE, NV, NY, OH, OK, OR, PA, SC, TX, UT, WA) and two foreign countries (Canada, United Kingdom) who ate at Firefly during their visits to Las Vegas.

No single menu item appeared to be the likely source for the outbreak. Additionally, no common factors or ingredients were identified among the statistically significant menu items. We also looked for associations between illness and several common ingredients such as parsley, aioli, and grated hard cheeses (parmesan and manchego). Of these, only the grated hard cheeses showed a statistical association with illness.

However, many of the statistically significant menu items contained none of that cheese.