[1] Med Lab Dr Berg, Berlin, Germany
[2] Ctr Hosp Lisboa Ocidental, Mol Biol Lab, Lisbon, Portugal
[3] Grp Hosp Bichat Claude Bernard, Lab Virol, Paris, France
[4] Grp Hosp Bichat Claude Bernard, Paris, France
[5] Univ Munich, Max Von Pettenkofer Inst, Munich, Germany
[6] Catholic Univ Louvain, AIDS Reference Lab, Brusselles, Belgium
[7] Max Planck Inst Informat, Dept Computat Biol, D-66123 Saarbrucken, Germany
[8] Univ Clin, Inst Med Virol, Frankfurt, Germany
[9] Univ Cologne, Inst Virol, D-50931 Cologne, Germany