Four people were tested positive for the A/H1N1 influenza virus in Hong Kong on Tuesday, bringing the number of confirmed cases of the disease in the city to 45, local health authorities announced here.

A spokesman for the Department of Health said the department was investigating four newly confirmed cases of A/H1N1 influenza. All of the 45 cases in Hong Kong so far are imported cases.

The first case involved a 27-year-old woman who traveled with a friend to the United States and Canada from May 28 to June 6. They returned to Hong Kong in the evening of June 7 by taking Air Canada flight no. AC007, code share TG5867. She sat in row 54.

She developed a runny nose and cough on the morning of June 8. She took a taxi to Alice Ho Miu Ling Nethersole Hospital and was admitted for isolation. Her family contact is asymptomatic.

The second case is a 33-year-old man who went to Phuket with a friend from June 4 to 8. They returned to Hong Kong by taking a Dragonair flight no. KA213 on June 8. He sat in row 26.

The man developed a cough on June 7. He declared symptoms in the health declaration form and did not pass temperature screening. He was taken to Princess Margaret Hospital by ambulance for isolation.

The third case involved a 39-year-old man living in Melbourne. He traveled with his family to Hong Kong on June 8 by taking Cathay Pacific flight no. CX134. He sat in row 54.

He developed a fever during the journey and did not pass temperature screening. He was taken to Princess Margaret Hospital by ambulance for isolation. His family members are asymptomatic.

The fourth case involved a 15-year-old girl studying in San Francisco. She returned to Hong Kong with an elder sister and a younger brother by taking Cathay Pacific flight no. CX873 on June 7. She sat in row 59.

As her brother was confirmed to have the A/H1N1 influenza upon arriving in Hong Kong on June 7, the girl had been put under directly observed chemoprophylaxis and had taken tamiflu at Lei Yue Mun Park and Holiday Village on the same day.

She was detected to have a fever on June 8 and was sent to Queen Elizabeth Hospital by ambulance for isolation. Her family contacts are currently asymptomatic.

The Department of Health is now tracing passengers sitting in rows 51-57 of CA007 which arrived in Hong Kong on June 7, those sitting in rows 23-29 of KA213 which arrived in Hong Kong on June 8, and those sitting in rows 54-57 of CX134 which arrived in Hong Kong on June 8, and crew members of the flights who served the affected sections of the cabins concerned as well as other close contacts of the four patients.

Editor: 欧阳妍