[1] Univ Tubingen, Ctr Ophthalmol, Univ Eye Hosp, D-72076 Tubingen, Germany
[2] Univ Tubingen, Inst Med Virol & Epidemiol Viral Dis, D-72076 Tubingen, Germany
[3] Univ Tubingen, Inst Med Microbiol & Hyg, D-72076 Tubingen, Germany
[4] Univ Tubingen, Inst Pathol & Neuropathol, D-72076 Tubingen, Germany
[5] Univ Tubingen, Dept Clin Epidemiol & Biostat, D-72076 Tubingen, Germany
[6] Knappschaftskrankenhaus Sulzbach, Sulzbach, Germany