- Correspondence to Dr Casper D J den Heijer, Department of Sexual Health, Infectious Diseases and Environmental Health, Public Health Service South Limburg, Geleenbeeklaan 2, Geleen 6166 GR, The Netherlands;
- Received February 26, 2015
- Revised June 19, 2015
- Accepted July 20, 2015
- First published August 11, 2015.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.