1. Communicable Disease Surveillance Centre, Public Health Wales, Cardiff, United Kingdom
2. Institute of Psychological Medicine and Clinical Neurosciences, Cardiff University School of Medicine, Cardiff, United Kingdom
3. Department of Neurology, University Hospital of Wales, Cardiff, United Kingdom
4. Health Protection Division, Public Health Wales, Cardiff, United Kingdom
5. Public Health Wales Microbiology Cardiff, University hospital of Wales, Heath Park, Cardiff, United Kingdom