1. Infectious Diseases Clinic, Department of Preventive Medicine, Hospital Universitário Clementino Fraga Filho, Federal University of Rio de Janeiro, Rio de Janeiro, CEP 21941-590, Brazil
2. Infectious Diseases Epidemiology Research Unit, University of Pittsburgh School of Medicine and Graduate School of Public Health, Pittsburgh, Pennsylvania 15261
3. Department of Internal Medicine, Universidade do Rio de Janeiro, Rio de Janeiro, 20270-049, Brazil.