LATEST: Michael Flatley's sister fears the dancer is suffering from a virus he caught at his wedding last month (0OCT06), and that other members of his family are affected. Flatley has been fighting a serious immune virus in a private London hospital for the past two weeks. Despite carrying out tests on the 49-year-old, doctors are reportedly struggling to diagnose the illness. It is so serious the star has cancelled the entire European run of his new show CELTIC TIGER. Flatley's sister THOMASINA insist she caught a virus at her brother's wedding to leading lady NIAMH O BRIEN in Cork, Ireland. She says, "I was sick for three weeks after the wedding and my daughter is sick right now."