1 Unit of Epidemiology and Surveillance, RIVM/Centre for Infectious Disease Control Netherlands, Bilthoven, The Netherlands ingrid.van.den.broek@rivm.nl.
2 European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden.
3 Unit of Epidemiology and Surveillance, RIVM/Centre for Infectious Disease Control Netherlands, Bilthoven, The Netherlands Julius Centre, UMC Utrecht, Utrecht, The Netherlands.
4 Department of Public Health, Randers Hospital, Skovlyvej, Randers, Denmark.
5 Section of Clinical Bacteriology, Department of Medical Sciences, Uppsala University, Uppsala, Sweden.
6 Infectious Diseases Epidemiology, School of Public Health, Imperial College London, St Mary's Campus, Norfolk Place, London, UK.
7 Department of Infectious Disease Control, Municipal Public Health Service Rotterdam-Rijnmond, Rotterdam, The Netherlands.
8 Department of Public Health, University of Tartu, Tartu, Estonia.
9 HIV & STI Department, National Centre for Infectious Disease Surveillance and Control, Public Health England, London, UK.
10 Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland.
11 Unit of Epidemiology and Surveillance, RIVM/Centre for Infectious Disease Control Netherlands, Bilthoven, The Netherlands Department of General Practice, University of Amsterdam, Amsterdam, The Netherlands STI AIDS Netherlands, Amsterdam, The Netherlands.