Chinese health departments said on Thursday more people were put under quarantine while the two citizens who were confirmed to have contracted A(H1N1) this week were recovering swiftly.

Health authorities in east China's Shandong Province put 30 people under home or hospital quarantine as of 2:00 PM on Thursday to check for symptoms of A(H1N1) influenza, said the provincial health department at a news briefing held on Thursday.

A patient surnamed Lv (seen on TV), the second confirmed case to test positive for A(H1N1) flu, talks with his father on the phone in an isolation ward in the Jinan Hospital of Infectious Diseases in Jinan, east China's Shandong Province, May 14, 2009. [CFP]

The 30 people, consisting of 27 passengers and three train service workers, were in close contact in a Beijing-Jinan train with a male resident of Shandong who health officials said on Wednesday had tested positive for A(H1N1) flu. They didn't show any symptoms of the disease.

The provincial health authorities are seeking the remainder 13 other passengers who were in the same car of train D41, from Beijing to the provincial capital of Jinan, Monday night.

After the man who was only identified by his family name as Lv was diagnosed, Shandong Province declared China's first A(H1N1) flu health emergency at about 6:00 PM on Wednesday.

Wang Suilian, vice governor of the eastern province, said Shandong declared the second-level health emergency, which will involve many departments coordinating to contain the disease and keep the public informed.

A health official surnamed Zhang said that the second-degree emergency declaration was the highest-level response available to provincial governments. A first-degree emergency declaration would be up to the central government.

Shandong's flu case, the second known case on the Chinese mainland, involved a 19-year-old student surnamed Lv who arrived in Beijing from Canada May 8 in a flight labeled AC029 and traveled to Jinan three days later.

Lv was hospitalized Monday. Apart from a sore throat, Lv was recovering with a normal body temperature, and showed no other symptoms of discomfort such as headache, coughing or a runny nose Thursday, said Li Zhongjun, spokesman for Shandong Provincial Health Department.

Lv is in an isolation ward in the Jinan Hospital of Infectious Diseases.