Ten years ago, outbreaks of methicillin-resistant staphylococcus aureus (MRSA) and Clostridium difficile (C. diff) infections in NHS hospitals killed patients, made headline news and had everybody worried about the rise of so- called superbugs.But the most common are respiratory infections such as pneumonia (22.8% of cases), urinary tract infections (17.2%) and surgical site infections, which account for 15.7% (NHS England, 2011).MRSA and C. diff were linked to as many as 9000 deaths in healthcare settings in England in 2007 (NAO, 2007) and infection control was stepped up and the number of cases has since fallen significantly (NHS England, 2011).The more common communicable infections, such as norovirus and influenza (see box overleaf), pose the biggest danger, though cases of E. coli are becoming more widespread.Schools and care homes in particular are at risk from microbes because so many vulnerable people interact in a confined space, and good hygiene habits can be hard to enforce.The threat of healthcare-associated infections (HCAI) is ever-present.