He reported his situation to the Jinan Centre for Disease Control and Prevention while on the train. The authorities immediately sent him to the Jinan Infectious Disease Hospital for isolation and treatment.

The Jinan CDC and the Shandong CDC conducted tests on the virus specimen of the patient on Tuesday, and the results showed he was 'suspected positive' for swine flu. The specimen will be sent to the national CDC for further testing before confirmation.

The ministry said the man had been isolated. It was not known last night how many people had been in close contact with him and whether the authorities could track them down. Health officials are still trying to account for 34 people who had close contact with the mainland's first confirmed case of swine flu.

The officials have ordered local departments to report suspected cases to the national disease-surveillance system within two hours of identifying them, as part of strengthened flu monitoring and prevention measures released yesterday.

The first flu patient, identified only by his surname Bao, had 'clearly turned better' and was in good spirits at the Chengdu Infectious Disease Hospital, according to the Ministry of Health yesterday. His body temperature was reported as normal. An earlier statement said his father, girlfriend and the taxi driver in Chengdu who took him to the hospital had shown no flu symptoms.

Mr Bao, a student from Sichuan , had flown from St Louis, Missouri, to Tokyo, and on to Beijing on Saturday aboard Northwest Airlines flight 29. After staying in a Shunyi district hotel for nine hours, he boarded Sichuan Airlines flight 8882 on Sunday. Mainland authorities have been trying since Sunday night to account for the passengers who took the same flights as Mr Bao.

Of the 233 passengers who were on the Northwest flight from Tokyo to Beijing, 201 have been put under medical observation in 21 provinces and cities, but some of the 32 remaining passengers may no longer be on the mainland. The Sichuan Airlines flight Mr Bao took to Chengdu had 150 passengers and 10 crew members, all Chinese. Authorities were still trying to track down the last two, while the rest have been isolated.

All 103 guests and staff at the Shunyi district hotel where Mr Bao stayed, including some foreigners, were placed under a week-long quarantine at the hotel.

Cases like Mr Bao's were of such concern to the Ministry of Health that it issued guidelines yesterday on tracking those who had close contact with infected people. It was not clear how Mr Bao contracted the virus, but he said his flatmate had been diagnosed with common flu.

Meanwhile, a group of about 40 tourists from Japan were quarantined in a Shenzhen resort after some were found to have fever while taking a ferry from Hong Kong International Airport to the Shekou ferry terminal in Shenzhen yesterday.

The group landed in the morning and took a Chu Kong Passenger Transport ferry to Shekou in the afternoon. A number of them were found to have fever on the boat.

They were taken to Shenzhen Donghu Hospital when the ferry reached Shekou, while the rest were sent to Shanhai Farm in Longgang district for quarantine.

Hong Kong's Department of Health said it was studying the case.

Additional reporting by Danny Mok

War chest

China is battling the swine flu, which has spread to more than 20 countries and regions

The central government has created a war chest to block the disease from taking hold on the mainland, setting aside, in yuan, 5b