Toronto Public Health continues to investigate as the number of students who have fallen ill from an unspecified illness at Humber College’s north campus continues to grow.

Nearly 200 students have now reported falling ill at the campus, TPH said in an email to CP24 Saturday.

“Toronto Public Health is aware of 11 students going to emergency rooms overnight and this morning based on reports from Humber College,” Dr. Michael Finkelstein, the city’s associate medical officer of health, said in a statement.

That brings the total number of emergency room visits to 40. One student has been admitted to hospital, while the others have been discharged.

While food poisoning has been suspected, Finkelstein said the city is still working to determine what exactly is making the students sick.

“At this point, determining the organism causing this illness will help narrow down the reasons why or potential sources for this cluster,” he said in the statement.

In the meantime, TPH and the college are working to try and stop the spread of whatever is causing the illness.

“Toronto Public Health continues to work closely with Humber College to gather information from ill students,” Finkelstein said. “Humber has provided up-to-date student contact information, timely responses related to environmental cleaning, and has sought immediate guidance and support on enhancing infection prevention and control practices in common areas.”

While they work to determine the cause of the illness, TPH has advised those affected to stay hydrated if they feel ill and wash hands well before preparing food and after using the bathroom.

Even after health authorities determine the bug responsible for the illnesses, halting its spread in a campus environment can be difficult, Finkelstein said

“Once certain viruses are in environments such as student residences where individuals live close together, preventing the spread of easily transmitted seasonal viruses like norovirus becomes challenging,” he said.

The illness first emerged on campus on Thursday night, when dozens of students were taken to hospital with symptoms ranging from vomiting to abdominal pain.