Methicillin-resistant Staphylococcus aureus (MRSA) bacteria tends to spread from larger hospitals in urban settings to small, regional facilities by way of patients, according to a new study in the Proceedings of the National Academy of Sciences.
Researchers at the University of Edinburgh’s Roslin Institute in Scotland analyzed the genetic makeup of more than 80 variants of a major clone of MRSA bacteria found in hospitals—and found that large hospitals act as a hub for transmission between patients.
"Our findings suggest that the referral of patients to different hospitals is a major cause of MRSA transmission," according to study author Paul McAdam.
The study says the MRSA strain that was tracked evolved from antibiotic-sensitive bacteria that existed more than 100 years ago. MRSA first appeared about 50 years ago, HealthDay notes, after the introduction of antibiotics.
Health experts say that poor hand washing by health care workers and lack of good infection-control practices can add to MRSA's spread (Novick, Proceedings of the National Academy of Sciences, 5/14; Roberts, BBC News, 5/14; HealthDay, 5/16).