Public health officials are investigating three cases in which people contracted Listeria infections after eating deli sandwiches at a Toronto hospital.

Toronto Public Health says the individuals were diagnosed with the infection after eating deli meats from the Druxy's restaurant in Princess Margaret Cancer Centre.

Officials say the restaurant is currently closed and the owner is co-operating with the agency to make sure there is no further risk to the public.

They're asking anyone who ate meat from the restaurant between Jan. 1 and March 12 of this year to seek medical attention if they develop symptoms of Listeria, which include fever, diarrhea, vomiting, nausea and cramps.

Listeria can progress to cause headaches, stiff neck, confusion, loss of balance and convulsions, and people with weakened immune systems are more vulnerable.