Table 2. Within-season variation of Sindbis virus antibody prevalence in birds in the River Dalälven floodplains, Sweden.
| Age | 2002 | 2003 | 2004 | 2009 | Total | |
|---|---|---|---|---|---|---|
| Early summer | All birds | 0/13 | 4/81 (5)A | 17/107 (16) | 37/161 (23) | 58/362 (16) |
| Hatchlings | 0/3 | 0/0 | 0/6 | 0/1 | 0/10 | |
| Mid summer | All birds | 1/89 (1) | 6/63 (10) | 13/108 (12) | 22/58 (38) | 42/318 (13) |
| Hatchlings | 0/44 | 0/28 | 3/40 (8) | 1/10 (10) | 4/122 (3) | |
| Late summer | All birds | 2/38 (5) | 6/62 (10) | 2/19 (11) | 83/164 (51) | 93/283 (33) |
| Hatchlings | 2/22 (9) | 4/47 (9) | 1/13 (8) | 56/120 (47) | 63/202 (31) | |
| Total | All birds | 3/140 (2) | 16/206 (7) | 32/234 (14) | 142/383 (37) | 193/963 (20) |
| Hatchlings | 2/69 (3) | 4/75 (5) | 4/59 (7) | 57/131 (44) | 67/334 (20) |
Sindbis virus (SINV) prevalence in early summer (May 13 –June 19), mid summer (June 20—August 10) and late summer (August 11- September 16) shown over four years and for all birds tested or hatchlings only.
A Number of PRNT positive individuals/number of tested individuals (percentage positive)