[1] UNIV CENT HOSP TAMPERE, DEPT PATHOL, SF-33520 TAMPERE, FINLAND
[2] UNIV CENT HOSP, DEPT OBSTET & GYNAECOL, SF-33520 TAMPERE, FINLAND
[3] UNIV CENT HOSP, DEPT MED MICROBIOL, SF-33520 TAMPERE, FINLAND
[4] UNIV TAMPERE, DEPT CLIN SCI, SF-33101 TAMPERE 10, FINLAND
[5] UNIV TAMPERE, DEPT BIOMED SCI, SF-33101 TAMPERE 10, FINLAND