How do you think mrsa came to be? when did mrsa start?

MRSA: The resistant forms first appeared in the 1960s in healthcare settings, and are called healthcare-associated MRSA (ha-mrsa). Then, around 1990, a new strain of the bacteria, community-associated MRSA (or ca-mrsa), began to affect even healthy people. It is this last type that has been receiving the most attention recently, though healthcare organizations have been aggressively fighting the disease.