 The risks are not apparent until, for example, they are admitted to hospital, when they can become "self infected" with their own resistant organisms following a surgical procedure.As persistent nasal, skin or bowel carriage in the healthy population spreads "silently" across the world, the risks from resistant strains in both hospitals and the community increases.In particular the data indicates that clothing and household linens are a risk factor for spread of S. aureus (including MRSA and PVL-producing MRSA strains), and that effectiveness of laundry processes may be an important factor in defining the rate of community spread of these strains.