[1] Inst Salud Carlos III, Infect Dis Serv, Madrid, Spain
[2] Spedali Civil Brescia, Clin Malattie Infett & Trop, I-25125 Brescia, Italy
[3] Johns Hopkins Univ, Sch Med, Div Infect Dis, Baltimore, MD 21205 USA
[4] Ctr HIV & Hepatogastroenterol, Dusseldorf, Germany
[5] Hop La Pitie Salpetriere, Serv Med Interne, Paris, France
[6] Osped L Sacco, Div Malattie Infett, Milan, Italy
[7] Mt Sinai Med Ctr, Dept Med, New York, NY 10029 USA
[8] Univ Athens, Sch Med, Dept Hyg & Epidemiol, GR-11527 Athens, Greece
[9] Univ Bonn, Dept Med, D-5300 Bonn, Germany