What is true for measles in Faeroes is true for any familiar acute infectious disease anywhere in the world. To survive, they need a large enough population and density so that by the time the disease should have started weakening, a new group of vulnerable children will be available. So measles and the like are also known as diseases of the crowd. Don’t tell me what to do cat poster. Obviously, the disease of the crowd cannot exist in hunter-gatherer tribes and farming populations in the guise of forest for cultivation.