[1] HOP CANTONAL,SERV MED,FRIBOURG,SWITZERLAND
[2] UNIV ZURICH,KANTONSSPITAL,CHIRURG KLIN A,CH-8091 ZURICH,SWITZERLAND
[3] UNIV ZURICH,INST MED MIKROBIOL,CH-8006 ZURICH,SWITZERLAND
[4] UNIV ZURICH,KANTONSSPITAL,MED POLIKLIN,CH-8091 ZURICH,SWITZERLAND
[5] KANTONSSPITAL,MED KLIN,LIESTAL,SWITZERLAND
[6] HOP CANTONAL,DIV MALAD INFECT,GENEVE,SWITZERLAND