The last government decided to get tough on NHS performance. Waiting lists were driven down by a regime that carpeted chief executives who allowed any patient to wait more than 18 months for an operation. Then attention turned to hospital acquired infection - MRSA and Clostridium difficile.
Hospitals were given, well, not exactly a quota, but a permissible number of MRSA or C Diff infections before the carpet beckoned. And this is taken seriously - every surgeon in the hospital knows what the number is, gel dispensers spouted on all wards and entrances, performance is reported monthly at the Board meetings, and so on.
All of this is jolly good but it's a bit unfair if the number of infections is nothing to do with the hospital. The target is based on an assumption that C diff is transmitted within the hospital by poor infection control practices. But this article challenges that assumption. It's published in the mighty New England Journal of Medicine but based in old England - the Oxford hospitals group. Whole genome sequencing showed how varied the sources of the cases were.
There are some careful definitions of what was regarded as close enough contact in place or time to justify an assumption that one patient had transmitted it to another - epidemiology is rooted in careful definitions. An interesting paragraph deals with evolution of the microbial genome - the estimate is that you could expect up to two mutations (single nucleotide variants SNV) to occur over a 124 day period.
That said, a third of the cases do seem to have been transmitted within the hospital, and ramping up the pressure on hospitals to do the basics of hand washing, isolation and general infection control has undoubtedly improved (or do I mean coincided with?) the national position. So perhaps the carpet is fair after all.