Tests confirmed the norovirus -- which causes stomach cramping, diarrhea and vomiting -- was present in food catered by the restaurant at 1040 Leonard St. NW.
Health Department spokeswoman Amy Morris said the establishment has been given a clean bill of health and was cleared to reopen after it hired a professional cleaning crew to sanitize the interior.
"I would go there for lunch today -- it's probably one of the cleanest restaurants in Grand Rapids," Morris said. "Even our communicable disease and epidemiology staff would eat there, and they know all about these kinds of things."
Some customers, however, were cautious after learning the news.
Grand Rapids resident Abby Young said she still planned to eat her ham and cheese sub.
"It seems like that could happen to any restaurant," said Young, a bank employee on a lunch break. "I'm kind of leery of eating it, but then again, if they did clean and sanitize then it's probably OK."
The Health Department began investigating earlier this month when up to 80 people became sick after the restaurant catered a luncheon at School Specialty Publishing Co. in Walker. About a dozen teachers at Sibley Elementary in Grand Rapids also became sick after a teachers' appreciation luncheon catered by the restaurant.
Morris said the norovirus is second in occurrence to the common cold, and is considered the leading cause of food-borne illnesses. The highly-contagious virus is spread through contact with contaminated surfaces or objects. It is prevented by washing hands and disinfecting contaminated surfaces.
Morris said because the virus can be active for nine to 14 days after symptoms subside, the employee did not realize he or she still was contagious.
"It could happen to anybody," she said.
Owner Joe Hohbach reopened the restaurant this week after he voluntarily closing it during the Health Department investigation.
Morris said Hohbach was "very cooperative from beginning to end."
Hohbach referred all comment to Blimpie International corporate offices.
In a statement, Blimpie International President and CEO Jeff Endervelt said: "Everyone in the Blimpie system is greatly saddened that a number of customers in the Grand Rapids area have fallen ill, and we express our sympathies."
"We have a rigorous process in place to ensure the safety of all our food products," he said. "This was an isolated incident."