1. Laboratory of Viral Hepatitis, National Center for Microbiology, Institute of Health Carlos III, Majadahonda, Madrid, Spain;
2. Department of Preventive Medicine & Public Health, Rey Juan Carlos University, Madrid, Spain;
3. Department of Infectious Diseases, Infanta Leonor Hospital, Madrid, Spain;
4. Facultad de Medicina, Universidad Complutense de Madrid (UCM), Spain;
5. Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain;
6. Unit of HIV Surveillance and Behavioral Monitoring. National Center of Epidemiology, Institute of Health Carlos III, Madrid, Spain