Ontario health officials have confirmed a fourth case of novel coronavirus in Canada.

Chief Medical Officer Dr. David Williams says that the patient is a female in her twenties from London, Ont., and has recently returned from Wuhan on January 23.

The patient is currently a student at Western University, although health officials say that she has not been on campus since she has returned from Wuhan.

New #coronavirus patient from London is UWO student but not been on campus since returning from China. Went to University Hospital. Officials won’t reveal her airline and flight numbers, noting she wore mask and was not contagious at the time. #onpoli

— Rob Ferguson (@robferguson1) January 31, 2020

She wore a surgical mask for the duration of her flight to Canada despite being asymptomatic at that time.

Williams said that this case is "a little different than the other ones."

Health officials immediately switched the patient's status from a negative to a positive coronavirus case as a "precautionary" measure, despite her viral levels being low.

New #coronavirus case originally tested negative but later decided at federal lab in Winnipeg thatviral load was high enough to qualify as a positive #on polo

— Rob Ferguson (@robferguson1) January 31, 2020

This was not the case with previous cases.

The patient is currently in isolation at home, although health officials say that she is "perfectly well" now.

She was treated at University Hospital in London.

Williams said that there is "no risk" to the other passengers on the patient's return flight since she was wearing a mask.

He added that Canadian labs "are really moving at a quick pace" and "comparing notes back and forth" between different locations to control — and prevent — coronavirus.

This is the fourth reported case of coronavirus in Canada, following a B.C. man's diagnosis on January 28.

The first coronavirus patient was released from Sunnybrook Hospital this morning as he no longer required in-patient care.

Williams reiterated that the risk to Ontario remains low.