A 30-year-old man has become Hong Kong's first monkeypox patient.

Officials said on Tuesday that the SAR resident is being treated in isolation in Queen Mary Hospital.

He recently spent time in Canada, the United States and the Philippines before flying to Hong Kong on Monday on flight PR300.

The man was taken to hospital from his quarantine room at the Ramada Harbour View Hotel in Sai Ying Pun after feeling unwell, officials said, adding that he is in a stable condition.

The Centre for Health Protection (CHP) said the man reported developing a rash on August 30, swollen lymph nodes on September 2, and a sore throat on the day he arrived in Hong Kong.

Dr Chuang Shuk-kwan from the CHP said the man was likely exposed to the virus abroad.

"Based on the date of onset of symptoms, incubation period and the high-risk activity, we suspect that the patient might have acquired the infection during his stay in the United States," she said.

The World Health Organisation notes that patients who have come down with monkeypox in a recent outbreak in multiple countries have mainly, but not exclusively, been identified among men who have sex with men. However, it notes that the virus is spread via close contact with lesions, body fluids, respiratory droplets and contaminated materials such as bedding, and anyone who has close contact with infected people can catch the virus regardless of their sexual orientation.

The controller of the CHP, Edwin Tsui, said it is difficult to detect monkeypox cases among arrivals at the airport.

No close contacts of the patient have been identified, but officials urged people who were on the same flight to Hong Kong as the infected man to monitor their health.