Cleaners in protective gears disinfect Heng Tai House public estate at Tai Po in Hong Kong on March 15, 2020, a day into evacuation of several residents after three residents were confirmed to have contracted the new coronavirus. (PARKER ZHENG / CHINA DAILY)

HONG KONG - Health authorities in Hong Kong on Monday warned about a second round of coronavirus outbreak, after seven cases of infection, and two preliminarily positive cases were reported on Monday - all linked to overseas travel, pushing up the tally to 155. 

Head of the Communicable Disease Branch of the Centre for Health Protection of the Department of Health, Chuang Shuk-kwan, said at a press briefing that the increasing imported cases recently have raised the risk of community outbreak. 

Chuang Shuk-kwan acknowledged that the existing health declaration policy has its limit in identifying virus carriers, as some people developed symptoms after they entered Hong Kong

She acknowledged that the existing health declaration policy has its limit in identifying virus carriers, as some people developed symptoms after they entered Hong Kong. 

Among the seven newly-confirmed cases, three of the patients developed symptoms before or on the day of their arrivals. On Sunday, five of the seven patients confirmed to have been infected likewise evaded health check although they too had developed symptoms. 

Six of the seven new cases recorded on Monday involved overseas travel to Europe, Africa and Japan, while the other one is the driver of a patient with travel history. 

Meanwhile, one patient is a 73-year-old man who went on a group tour with some 20 people to Egypt from March 5 to 13. He had a headache on returning to Hong Kong and developed a cough and fever on Saturday.

Some patients went on skiing trips in Austria and Hokkaido in Japan. 

The two preliminarily positive cases involved two friends who went on a skiing trip together in Vancouver, Canada. 

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Three more patients have been discharged, taking the number of total recoveries to 87.

Among the seven new cases on Monday, one involved a 26-year-old woman, who’s the girlfriend of a 35-year-old patient. They went skiing together in Hokkaido, Japan from Feb 16 to March 11. 

The 58-year-old driver of the man, with no travel history, was also infected after picking the couple up at the Hong Kong airport.

Another case involved a French-speaking 30-year-old man of foreign nationality. He travelled to Dubai from western Africa between Feb 15 and March 10, and flew on EK380 to Hong Kong where he stayed in the Whole Sunshine International Hotel in Tsim Sha Tsui. 

He started coughing on March 8, and his conditions became worse on Sunday. On March 13, he went to Jamia Mosque to pray. 

READ MORE: Virus: HK sees 4 new infections, all linked to overseas travel

The other two cases involved a 42-year-old woman and a 59-year-old man. They both went to some European countries, and skied in Austria in early March separately. They developed symptoms of infection before they arrived in Hong Kong late last week. 

Another new case involved a 37-year-old man, who was on a business trip to attend an exhibition in the Netherlands from Feb 28 to Sunday. He developed a fever on March 13 before returning to Hong Kong on flight CX270 on Sunday and stayed at Hotel Icon in Tsim Sha Tsui.