Table 1.
Cohort characteristics and serology subsets at the beginning of each follow up year.
| 2004 | 2005 | 2006 | 2007 | 2008 | 2009 | |
|---|---|---|---|---|---|---|
| N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | |
| Number of enrollees | 2190 | 1645 | 722 | 652 | — | — |
| Size of the cohort in Jan. | 2190 | 3239 | 3146 | 3081 | 2350 | 1775 |
| Sex | ||||||
| Male | 1103 (50.4) | 1593 (49.2) | 1559 (49.6) | 1551 (50.3) | 1207 (51.4) | 908 (51.2) |
| Female | 1087 (49.6) | 1646 (50.8) | 1587 (50.4) | 1530 (49.7) | 1143 (48.6) | 867 (48.8) |
| Age (years) | ||||||
| Mean +/− SD | 6.89 +/− 2.11 | 8.45 +/− 278 | 8.53 +/− 2.87 | 8.55 +/− 2.91 | 9.13 +/− 2.59 | 9.66 +/− 2.24 |
| Min; Max | 3; 10 | 3; 14 | 2; 15 | 3; 15 | 4; 15 | 5; 15 |
| Median | 7 | 9 | 9 | 9 | 9 | 9 |
| Serology | ||||||
| Number of PRNT50 measurements from sera collected in the annual surveys | 259 | 270 | 92 | 296 | 148 | 138 |
| Clinical cases in the year following those PRNT50 measurements |
53 (0.205) |
39 (0.144) |
78 (0.848) |
113 (0.382) |
9 (0.061) |
28 (0.203) |