1. Clinical Research Laboratory in STD and AIDS, Evandro Chagas National Institute of Infectious Diseases, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
2. Department of Clinica Medicine, School of Medicine, University of São Paulo, São Paulo, Brazil.
3. Department of Epidemiology, National School of Public Health, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
4. Scientific Computing Program, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.