[1] Akershus Univ Hosp, Div Med, Lorenskog, Norway
[2] Oslo Univ Hosp, Div Med, Oslo, Norway
[3] Oslo Univ Hosp, Expt Med Res Inst, Oslo, Norway
[4] Univ Oslo, Dept Mol Biosci, Oslo, Norway
[5] Univ Oslo, Rikshosp, Oslo Univ Hosp, Div Med, N-0027 Oslo, Norway
[6] Akershus Univ Hosp, Div Diagnost & Technol, Lorenskog, Norway
[7] Univ Oslo, Rikshosp, Oslo Univ Hosp, Dept Microbiol, N-0027 Oslo, Norway
[8] Uppsala Univ, Dept Med Sci, Uppsala, Sweden