1 Centre of Defence Pathology, Royal Centre for Defence Medicine, Queen Elizabeth Hospital Birmingham, Birmingham B15 2WB, UK; Chelsea and Westminster Hospital NHS Foundation Trust, London, UK. Electronic address: scott.pallett@nhs.net.
2 Chelsea and Westminster Hospital NHS Foundation Trust, London, UK.
3 NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Imperial College London, London, UK.
4 Chelsea and Westminster Hospital NHS Foundation Trust, London, UK; North West London Pathology, London, UK.
5 Chelsea and Westminster Hospital NHS Foundation Trust, London, UK; NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Imperial College London, London, UK; North West London Pathology, London, UK.