Table 3. Serological evaluation: comparison of Microscopic Agglutination Test (MAT) positive results (retrospective and in 2011).
| Year of infection | Participant ID | MAT – Retrospective serological evaluation | MAT – Results in 2011 (unique samples) | ||
| Presumptive serogroup | MAT titre | Presumptive serogroup | MAT titre | ||
| 1994 | 13 | Icterohaemorrhagiae | 1∶1280 | Icterohaemorrhagiae | 1∶320 |
| 1994 | 52 | Icterohaemorrhagiae | 1∶160 | Co-agglutination (Icterohaemorrhagiae; Australis; Ballum) | ≤1∶320 |
| 1995 | 17 | Icterohaemorrhagiae | 1∶10240 | Co-agglutination (Icterohaemorrhagiae; Tarassovi) | 1∶160 |
| 1997 | 43 | Icterohaemorrhagiae | 1∶640 | Icterohaemorrhagiae | 1∶160 |
| 1997 | 48 | Icterohaemorrhagiae | 1∶1280 | Icterohaemorrhagiae | 1∶320 |
| 1997 | 81 | Co-agglutination (Icterohaemorrhagiae; Canicola) | ≤1∶2560 | Icterohaemorrhagiae | 1∶320 |
| 1998 | 14 | Icterohaemorrhagiae | 1∶1280 | Co-agglutination (Icterohaemorrhagiae; Ballum) | 1∶160 |
| 1998 | 16 | ND | NA | Icterohaemorrhagiae | 1∶160 |
| 1998 | 20 | ND | NA | Icterohaemorrhagiae | 1∶1280 |
| 2000 | 97 | Canicola | 1∶320 | Icterohaemorrhagiae | 1∶320 |
| 2000 | 103 | Co-agglutination (Australis; Pomona) | ≤1∶640 | Icterohaemorrhagiae | 1∶160 |
| 2000 | 104 | Co-agglutination (Icterohaemorrhagiae; Canicola) | 1∶320 | Icterohaemorrhagiae | 1∶320 |
| 2001 | 11 | Co-agglutination (Icterohaemorrhagiae; Ballum) | ≤1∶5120 | Icterohaemorrhagiae | 1∶320 |
| 2001 | 32 | Co-agglutination (Icterohaemorrhagiae; Tarassovi) | ≤1∶1280 | Icterohaemorrhagiae | 1∶160 |
| 2002 | 63 | Co-agglutination (Icterohaemorrhagiae; Canicola; Cynopteri) | 1∶1280 | Co-agglutination (Icterohaemorrhagiae; Cynopteri) | ≤1∶640 |
| 2002 | 50 | Icterohaemorrhagiae | 1∶1280 | Icterohaemorrhagiae | 1∶1280 |
| 2003 | 55 | Icterohaemorrhagiae | 1∶1280 | Icterohaemorrhagiae | 1∶640 |
| 2003 | 67 | Icterohaemorrhagiae | 1∶640 | Icterohaemorrhagiae | 1∶160 |
| 2003 | 35 | Co-agglutination (Icterohaemorrhagiae; Javanica) | ≤1∶1280 | Icterohaemorrhagiae | 1∶160 |
| 2003 | 56 | Co-agglutination (Icterohaemorrhagiae; Autumnalis) | ≤1∶1280 | Icterohaemorrhagiae | 1∶160 |
| 2003 | 58 | Icterohaemorrhagiae | 1∶1280 | Icterohaemorrhagiae | 1∶320 |
| 2004 | 95 | Icterohaemorrhagiae | 1∶5160 | Co-agglutination (Icterohaemorrhagiae; Ballum) | ≤1∶320 |
| 2004 | 22 | Co-agglutination (Icterohaemorrhagiae; Autumnalis) | ≤1∶1280 | Icterohaemorrhagiae | 1∶1280 |
| 2004 | 7 | Icterohaemorrhagiae | 1∶1280 | Icterohaemorrhagiae | 1∶320 |
| 2004 | 19 | Icterohaemorrhagiae | 1∶1280 | Icterohaemorrhagiae | 1∶1280 |
| 2005 | 5 | Icterohaemorrhagiae | 1∶2560 | Icterohaemorrhagiae | 1∶160 |
| 2005 | 25 | Icterohaemorrhagiae | 1∶1280 | Icterohaemorrhagiae | 1∶320 |
| 2005 | 100 | Icterohaemorrhagiae | 1∶5120 | Icterohaemorrhagiae | 1∶1280 |
| 2005 | 6 | ND | NA | Ballum | 1∶320 |
| 2006 | 82 | Icterohaemorrhagiae | 1∶640 | Icterohaemorrhagiae | 1∶160 |
| 2006 | 83 | Icterohaemorrhagiae | 1∶2560 | Icterohaemorrhagiae | 1∶160 |
| 2006 | 12 | Ballum | 1∶2560 | Icterohaemorrhagiae | 1∶320 |
| 2007 | 28 | Co-agglutination (Icterohaemorrhagiae; Ballum) | ≤1∶320 | Icterohaemorrhagiae | 1∶640 |
| 2008 | 26 | Icterohaemorrhagiae | 1∶1280 | Icterohaemorrhagiae | 1∶160 |
| 2008 | 99 | Icterohaemorrhagiae | 1∶2560 | Co-agglutination (Icterohaemorrhagiae; Autumnalis) | ≤1∶1280 |
| 2008 | 54 | Co-agglutination (Icterohaemorrhagiae; Ballum) | ≤1∶2560 | Icterohaemorrhagiae | 1∶640 |
| 2008 | 65 | Co-agglutination (Icterohaemorrhagiae; Pomona; Ballum) | ≤1∶1280 | Icterohaemorrhagiae | 1∶640 |
| 2009 | 8 | Ballum | 1∶1280 | Ballum | 1∶640 |
| 2009 | 41 | ND | NA | Co-agglutination (Icterohaemorrhagiae; Ballum) | ≤1∶2560 |
| 2010 | 73 | Icterohaemorrhagiae | 1∶640 | Icterohaemorrhagiae | 1∶640 |
| 2010 | 1 | Ballum | 1∶1280 | Co-agglutination (Icterohaemorrhagiae; Ballum) | ≤1∶1280 |
| 2010 | 71 | ND | NA | Icterohaemorrhagiae | 1∶320 |
| 2011 | 68 | Co-agglutination (Icterohaemorrhagiae; Javanica) | ≤1∶2560 | Co-agglutination (Icterohaemorrhagiae; Australis; Ballum) | ≤1∶2560 |
| 2011 | 69 | Co-agglutination (Icterohaemorrhagiae; Ballum) | ≤1∶640 | Ballum | 1∶160 |
| 2011 | 70 | Co-agglutination (Icterohaemorrhagiae; Tarassovi) | ≤1∶640 | Icterohaemorrhagiae | 1∶640 |
ND: not determined (borderline reactivity). A unique sample was collected from these individuals; the observed titles were below the cut-off (1∶160), value taken by the reference laboratory (IHMT) to endemic areas.
NA: not applicable.