[1] Univ Hosp Tubingen, Dept Trop Med, Wilhelmstr 27, D-72074 Tubingen, Germany
[2] Univ Ulm, Inst Transfus Med, D-89081 Ulm, Germany
[3] Inst Clin Transfus Med & Immunogenet Ulm, D-89081 Ulm, Germany
[4] Berit Klin, Gastrointestinal Ctr, Florastr 1, CH-9403 Goldach, Switzerland
[5] Univ Hosp Tubingen, Dept Ophthalmol, Elfriede Alhorn Str 7, D-72076 Tubingen, Germany