How on earth was this person diagnosed with coronavirus?? Think of all the people coming back from the whole of the Middle East!!
Until today, they were not testing them, Either they are seriously ill and it made the medics think, ”hmmmm.. what if?? ”or there is a much higher level of surveillance going on.
BBC news says
"The new UK patient is understood to be a middle-aged man who was isolated at home, tested positive and was taken to St Thomas's Hospital in central London"
Which, if correct, doesn't sound like he was seriously ill before diagnosis. Obviously we don't know the full details - maybe they were in contact with someone in Singapore who had it and told health officials that. It doesn't really make sense for there to be a higher level of surveillance than we're aware of, because if you don't tell people then they won't present themselves for testing so what would be the point.