A sixth person in B.C. is believed to be infected with the coronavirus, and the case is raising new questions about how the disease is spreading, health officials announced Thursday.

The latest patient is a woman in her 30s who lives in the Fraser Health region, according to provincial health officer Dr. Bonnie Henry. She had recently returned from a trip to Iran and is now recovering at home.

Henry said officials were surprised when they learned the woman had only visited Iran, and not China or neighbouring countries that have seen the bulk of COVID-19 cases.

"That could be an indicator that there's more widespread transmission. This is what we call an indicator or sentinel event," Henry told a news conference.

'We shouldn't panic,' says Dr. Richard Schabas, noting the virus appears to spread slowly and there are ways to defend against it. 0:38

"I expect there'll be an international investigation to try to understand where the exposure occurred."

She added that Iran has recently announced five cases of the virus and two deaths.

Henry described the woman's infection as relatively mild, and said she tested positive for the virus after visiting the hospital with what she thought were symptoms of the flu.

The patient has had contact with others since her return from Iran last week. Close family members are currently in isolation and being monitored by public health officials.

She said health officials are looking into when the patient's symptoms started to help determine if they need to notify those who travelled with her on the same aircraft. Her diagnosis is considered presumptive until confirmed by the National Microbiology Lab in Winnipeg.

Henry said the diagnosis shows B.C. has a robust system for identifying people who have the virus. All cases so far have been relatively mild, according to health officials.

The update comes one day after Henry revealed that B.C.'s first confirmed coronavirus patient has fully recovered, and that four others are symptom free.

The fifth, a woman in her 30s who returned from Shanghai, China, is in isolation at her home in B.C.'s Interior.

Henry said over 500 people have been tested for the virus in B.C. and many of those tested positive for the flu. Three cases of the virus have also been confirmed in Ontario.

Health Minister Adrian Dix said the province is currently testing a "very significant number" of patients for the virus, and he expects to provide another update on Friday.

New numbers from China

China, where an outbreak has caused more than 2,200 deaths, has reported another drop in new virus cases to 889 as COVID-19 spreads elsewhere.

China's latest figures released Friday for the previous 24 hours brought the total number of cases to 75,465. The 118 newly reported deaths raised the total to 2,236.

More than 1,000 cases and 11 deaths have been confirmed outside the mainland.

Iran announced three more infections Thursday, a day after it reported its first two deaths, and South Korea reported its first fatality. Japan said two former passengers of the Diamond Princess cruise ship had died of the illness.