Most of the 100-plus people infected with norovirus last month had eaten at a local Subway franchise.

The Star Press reports an investigation by the Blackford County Health Department (that’s in Indiana) was unable to determine whether a customer or an employee spread the virus, also known as a stomach bug and food poisoning.

"We don’t know how it bounced in there," said Linda Briles, an environmental health specialist at the department. "We may never know. I use the term ‘bounced in there,’ either www.barfblog.com/blog/152553/12/01/14/eat-fresh-90-sick-norovirus-linked-indiana-subwaywith an employee or a customer, I don’t know. But it bounced in and went from there."

She said the virus could have been spread by a customer who failed to properly wash his or her hands after using the restroom. "A customer could have left it on a door knob," Briles said. "It (transmission) is fecal-oral. Or an employee could have caused it by poor hand washing."

An outbreak investigation report from the state department of health won’t be completed for several months, spokeswoman Amanda Turney said. A state epidemiologist will conduct a "hot wash" meeting today with the county health department staff to identify lessons learned from the outbreak.

"I want to do a final hot wash before I release my report (of the investigation to the public)," Briles said. "It should be available after I get down to the state health department and have it checked by the media (relations office)."

Briles said tests showed that more than one Subway employee was infected with the norovirus. "They were sick the same time everyone else was," Briles said. To her knowledge, the infected employees were not sick before the outbreak.

There has been an Indiana administrative code regulating food workers with diagnosed illnesses since 2000, but it wasn’t being enforced in Indiana until 2008.

Under the code, any food employee who is diagnosed with one of the following illnesses must be excluded from the food establishment: salmonella, shiga toxin-producing E. coli, shigella, hepatitis A or norovirus.

From company headquarters in Milford, Conn., Subway public relations manager Kevin Kane said, "Upon learning of the norovirus investigation by the Blackford County Health Department, the franchisee in Hartford City voluntarily closed the restaurant and had an independent company come in to thoroughly clean and sanitize the restaurant. This was in addition to the stringent cleaning and sanitizing procedures practiced here on a daily basis.

Despite hiring an independent contractor to sanitize the restaurant, Subway was cited by Briles for mold, dirty floors and other violations after re-opening.