China has its first domestic swine-flu infection - in a Guangzhou woman who caught it from a customer recently arrived from the United States. The man arrived in Guangzhou on Sunday on Asiana Airlines flight 369 after transiting in South Korea. A 28-year-old American Chinese who works at a hospital in New York, he travelled to Guangdong to attend a friend's wedding. He showed flu-like symptoms on Wednesday and went to a hospital. Despite his illness, the following day he visited a wedding photo studio, where the woman works as a makeup artist, for a photo shoot. His infection was confirmed yesterday. The makeup artist developed a sore throat and headache on Wednesday morning. She developed a fever in the afternoon and was taken to hospital. Provincial health officials said the woman's infection would not trigger a community outbreak since she had had only limited contact with other people before being quarantined. The World Health Organisation said there was no cause for panic. 'The situation is evolving. We must be mindful as we still do not understand how this will unfold,' Hans Troedsson, the organisation's representative in China, said. 'At the moment, most of the confirmed cases in China are linked to travel. We don't have any evidence of sustained community transmission.' The man travelled with 15 others by coach to Nanhai district for the photo shoot. 'The coach ride took about 40 minutes and it was an enclosed environment. It is easy to be infected in this kind of environment,' said He Jianfeng , head of research at the Guangdong Centre for Disease Control and Prevention. Four people who were on the coach had fever, but all tested negative for swine flu, Mr He said. He attributed their symptoms to the fact it was flu season in Guangzhou. Guangdong authorities are still looking for three taxi drivers who may have had contact with the American Chinese man from New York. Yang Zhicong , deputy director of Guangzhou's Centre for Disease Control and Prevention, declined to estimate how many people might have had contact with the patient. He urged them to contact the health authorities. Four other people on the mainland - two in Shenzhen and two in Shanghai -were confirmed yesterday to have swine flu. All were 'imported' cases. The cases took the number of swine flu cases on the mainland to 21. The WHO raised its global tally of swine flu infections to 15,510 yesterday, an increase of more than 2,000 cases in two days. The death toll stood at 99, the global body said.