Daybreak's Health Editor Dr Hilary Jones has told viewers that Norovirus is "very bad news".
He said: "Although it's not hugely a life-threatening it is the most common form of gastroenteritis in adults in the UK."
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Some 66 people have been killed after the plane they were travelling on crashed in southern Iran.
The letter calls for an end to harassment, abuse, and impunity in a world "ripe for change".
Police say that anyone who sees Whitehouse should not approach him, but instead call them on 999 and quote incident 23 of 18 February.