[1] Karolinska Univ Hosp, Clin Infect Dis, S-14186 Huddinge, Sweden
[2] Karolinska Univ Hosp, Inst Med, Karolinska Inst, Infect Dis Unit, S-17177 Solna, Sweden
[3] Statens Serum Inst, DK-2300 Copenhagen S, Denmark
[4] Swedish Inst Infect Dis Control, S-17182 Stockholm, Sweden
[5] Soder Sjukhuset, Karolinska Inst, Dept Clin Sci & Educ, S-11883 Stockholm, Sweden
[6] Karolinska Inst, Microbiol & Tumor Biol Ctr, S-17177 Stockholm, Sweden