[1] Univ Amsterdam, Acad Med Ctr, Dept Human Retrovirol, NL-1105 AZ Amsterdam, Netherlands
[2] Univ Amsterdam, Acad Med Ctr, Dept Clin Epidemiol & Biostat, NL-1105 AZ Amsterdam, Netherlands
[3] Univ Limburg, Acad Hosp Maastricht, Dept Med Microbiol, Maastricht, Netherlands
[4] Univ Amsterdam, Acad Med Ctr, Dept Neurol, NL-1105 AZ Amsterdam, Netherlands
[5] Hannover Med Sch, Dept Virol, Hannover, Germany