It's the immigrants bringing them (back) in... and the first thing they get when they arrive is a car, quickly followed by a taxi licence, quickly followed by 2 or 3 grand from mytaxi... so they can spread all these new(ish) diseases far and wide.
BTW, Duzza won a Players Championship event at the weekend after finishing second to Chizzy in another last weekend... not a bad start in the PDC, a win and a second out of 4 events.