circle of latitude are unlike circle of longitude which are all great circle with the centre of the earth in the middle as the circle of latitude get get the smaller as the distance from the equator increase the 60th parallel parallel North or South is half as long as the equator so the latitude of a circle but longitude are only half circle
The disease has infected a few people, spread out over a large distance because Cholera can't suddenly spread, it infects few people and then spreads rapidly.
They are formed by subduction
