An Italian tourist suspected of having the A(H1N1) flu virus was quarantined along with 23 fellow travelers Tuesday, the day on which a man in Guangzhou suspected of having the disease was confirmed positive.
If also found positive, the 42-year-old Italian woman will be the fifth A(H1N1) flu patient on the Chinese mainland - and the first foreign patient.
The woman was "in stable condition" in hospital in Zham town in the Tibet autonomous region, bordering Nepal.
The foreigners in her group are being quarantined at a local hotel.
The woman flew to Nepal from Italy on May 12. Three days later, she developed a sore throat, blocked nose and sweating. She had a fever and body temperature of 38.5 C when she entered Tibet at Zham on Saturday, causing her to be sent to hospital.
Tibet's Center for Disease Control and Prevention (CDC) conducted laboratory tests on Monday and said the national CDC will double-check the result.
Earlier Tuesday, the health ministry confirmed a man in Guangdong province, who recently returned from the US and Canada and who was suspected of having the virus, had tested positive.
The man, surnamed Yang, flew to Hong Kong via the Republic of Korea before taking a train to Guangdong on Friday.
Eighteen people who had close contact with him in Guangdong province could not be traced because some had provided false contact information, the health department of Guangdong said Tuesday.
The deputy director of Guangdong health department, Huang Fei, said 93 people had close contact with the man and 75 of them had been found.
"Another 18 people are still missing," he said. Nine are believed to be foreign, one from Hong Kong and eight from the mainland. The foreign affairs office of Guangdong province is attempting to help locate the missing people.
He said the eight from the mainland put false information on their health declaration forms.
People dishonestly filling out the forms could face legal charges, Huang said.
With lessons learned from SARS, Guangdong province, which was at the heart of the outbreak, will spend more than 34 million yuan ($5 million) on medical materials, including medicine, masks and protective clothing.
"We are going to buy a large amount of Tamiflu," said Zhang Yonghui, the director of Guangdong CDC. "Which is enough to treat 200,000 patients."
Some 110 hospitals in Guangdong are designated to receive H1N1 patients.
"All hospitals are ready for it, if the virus breaks out in the province," Zhang said.
Two confirmed patients - from Chengdu, Sichuan province, and in Jinan, Shandong province - have been discharged from hospital following successful treatment.
An 18-year-old woman surnamed Liu in Beijing will likely be discharged this weekend.
Meanwhile, Japan confirmed dozens more cases bringing its tally to 176.