British health authorities have alerted the UN of a new respiratory virus in a severely ill patient from Qatar. The man was sickened by a coronavirus, which causes most common colds but also causes Sars, or severe acute respiratory syndrome. In 2003, Sars killed hundreds of people, mostly in Asia, in a short-lived outbreak. Britain’s Health Protection Agency said in a statement late on Sunday that the 49-year-old patient had recently travelled to Saudi Arabia. The UN health agency says virus samples from the patient were almost identical to those of a 60-year-old Saudi national who died earlier this year. The World Health Organisation says it is trying to determine the public health implications of the two cases but isn’t currently recommending travel restrictions.