Prevalence of GB virus C (hepatitis G virus) and risk factors for infection in São Paulo, Brazil - Santos, G. Ribeiro dos; Nishiya, A. S.; Nascimento, C. M. R.; Bassit, L.; Chamone, Dalton de Alencar Fischer; Focaccia, R.; Eluf Neto, Jose; Sabino, Ester Cerdeira (European Journal of Clinical Microbiology & Infections Diseases, 2002)