Did the Sponge Bob leafy greens cone of silence descend on Illinois health types as they concluded in a 69-page report published today that lettuce, tomatoes and olives were the possible culprits in a Subway salmonella outbreak that sickened almost 200 earlier this year?

Pantagraph.com reported today that officials with the Illinois Department of Public Health traced a salmonella outbreak at Subway restaurants to one Central Illinois food distributor, but in a final report on the incident issued Thursday, could not identify the exact source of the problem, which led to 109 confirmed cases and another 90-plus probable or suspect cases of the illness between late April and June.

In the 69-page report, investigators said the “most likely source” of the lettuce, tomatoes and olives linked to the illnesses was Lincoln-based Sysco Central Illinois Inc., which delivered produce to the affected restaurants.

Samples collected at the company’s distribution facility in June, after many of the victims had already contracted the illness, were tested and found negative for salmonella.

Areas that may have been the source of salmonella may have been washed down and produce that was affected may have been discarded.

The report, which will be forwarded to the federal Centers for Disease Control, shows that 299 Subway restaurants were forced to dispose of their produce during the event.

More than 480 workers at the stores had to be tested. A dozen of them were found to be positive for the strain of salmonella.