LONDON — The World Health Organization said Monday it is too soon to say whether there could be an outbreak of a SARS-like killer respiratory disease after health officials in Britain announced they detected a related virus in a severely ill patient from the Middle East.

British officials alerted WHO on Saturday of the new virus in a man transferred from Qatar for treatment in London. He had recently travelled to Saudi Arabia, where another man died of a similar illness earlier this year.

The man in the new case was sickened by a coronavirus, from a family of viruses which causes most common colds but also includes the virus that causes SARS, or severe acute respiratory syndrome. In 2003, SARS killed some 800 people, mostly in Asia, in a short-lived epidemic.