The MRSA bacterium was detected in 173 different outbreaks during a 12-month study across east England.
They included hospitals, in the community, GP surgeries, homes and places in between.
There are fears the bug, which is incredibly hard to treat and has been going unrecognised in communities by doctors, could claim more lives.
For the first time, researchers used genome sequencing to map MRSA transmission with unprecedented detail by identifying 1,465 patients.
Dr Julian Parkhill, of the Wellcome Trust Sanger Institute in Hinxton, Cambridgeshire, where the research was carried out, said: “Using whole genome sequencing we have been able to see the full picture of MRSA transmission within hospitals and the community for the first time.
“We found sequencing MRSA from all affected patients detected many more outbreaks than standard infection control approaches.
“This method could also exclude suspected outbreaks, allowing health authorities to rationalise resources.”
MRSA can invade the body’s bloodstream and release poisonous toxins – killing up to a fifth of infected patients.
Dr Jonathan Pearce, of the Medical Research Council, said the bug’s antibiotic resistance poses a “global challenge to healthcare”.
He added: “To tackle it we need to prevent infections, preserve existing antibiotics and promote the development of new therapies and interventions.
“This study sheds light on MRSA transmission within and between hospitals and the community, which could help strengthen infection prevention and control measures.”
The researchers said the study, published in Science Translational Medicine, showed that catching outbreaks quickly could prevent further spread and reduce the number of people involved.