A new study used whole-genome sequencing to track how Staphylococcus aureus spreads in hospitals. Researchers analyzed nearly 4,800 S. aureus samples from patients in two interconnected hospitals. They compared what the sequencing revealed with what standard surveillance methods would have detected.
The results showed that standard surveillance missed 361 transmission events. In fact, 90% of these hidden transmissions were only spotted when patients were readmitted to the hospital. The study also found that transmission was more common with methicillin-resistant strains and when patients had more healthcare exposure.
This was a review of observational data, so it cannot prove cause and effect. The researchers note that it is unclear how practical it would be to use whole-genome sequencing in real time, and that such an approach is unlikely to be used for all patients.
For now, the findings suggest that hospitals may need to use more targeted surveillance, including screening patients when they are discharged or readmitted, to better understand and prevent the spread of S. aureus.